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Pramanik, Bapan, i Sahnawaz Ahmed. "Peptide-Based Low Molecular Weight Photosensitive Supramolecular Gelators". Gels 8, nr 9 (25.08.2022): 533. http://dx.doi.org/10.3390/gels8090533.
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Over the last couple of decades, stimuli-responsive supramolecular gels comprising synthetic short peptides as building blocks have been explored for various biological and material applications. Though a wide range of stimuli has been tested depending on the structure of the peptides, light as a stimulus has attracted extensive attention due to its non-invasive, non-contaminant, and remotely controllable nature, precise spatial and temporal resolution, and wavelength tunability. The integration of molecular photo-switch and low-molecular-weight synthetic peptides may thus provide access to supramolecular self-assembled systems, notably supramolecular gels, which may be used to create dynamic, light-responsive “smart” materials with a variety of structures and functions. This short review summarizes the recent advancement in the area of light-sensitive peptide gelation. At first, a glimpse of commonly used molecular photo-switches is given, followed by a detailed description of their incorporation into peptide sequences to design light-responsive peptide gels and the mechanism of their action. Finally, the challenges and future perspectives for developing next-generation photo-responsive gels and materials are outlined.
2
Carter, Jennifer M., Yun Qian, Jeffrey C. Foster i John B. Matson. "Peptide-based hydrogen sulphide-releasing gels". Chemical Communications 51, nr 66 (2015): 13131–34. http://dx.doi.org/10.1039/c5cc04883d.
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Gomes, Valéria, Sérgio R. S. Veloso, Miguel A. Correa-Duarte, Paula M. T. Ferreira i Elisabete M. S. Castanheira. "Tuning Peptide-Based Hydrogels: Co-Assembly with Composites Driving the Highway to Technological Applications". International Journal of Molecular Sciences 24, nr 1 (22.12.2022): 186. http://dx.doi.org/10.3390/ijms24010186.
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Self-assembled peptide-based gels provide several advantages for technological applications. Recently, the co-assembly of gelators has been a strategy to modulate and tune gel properties and even implement stimuli-responsiveness. However, it still comprises limitations regarding the required library of compounds and outcoming properties. Hence, efforts have been made to combine peptide-based gels and (in)organic composites (e.g., magnetic nanoparticles, metal nanoparticles, liposomes, graphene, silica, clay, titanium dioxide, cadmium sulfide) to endow stimuli-responsive materials and achieve suitable properties in several fields ranging from optoelectronics to biomedical. Herein, we discuss the recent developments with composite peptide-based gels including the fabrication, tunability of gels’ properties, and challenges on (bio)technological applications.
4
Wang, Shuo, Youguo Zhang, Qiang Li, Rongqin Sun, Lin Ma i Liangchun Li. "Self-Assembly of an Amphiphilic OEG-Linked Glutamide Lipid". Australian Journal of Chemistry 70, nr 1 (2017): 52. http://dx.doi.org/10.1071/ch16127.
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Amphiphilic peptides with or without oligoethylene glycol (OEG) chains based on 3,4-bis(benzyloxy)benzoic-linked glutamide were designed and their self-assembly was investigated. It was found that the amphiphilic peptide 3 with OEG chains could not only form stable gels in a wide range of solvents, but also showed better solubility in solvents than those without OEG chains. Fibrillar and nanotube structures were found in the gels formed and the width of the fibres could be tuned with added water content. The UV-vis and XRD results suggested that the driving forces for the peptide self-assembly were mainly intermolecular π–π and hydrogen-bonding interactions. These results provide a deeper understanding of the self-assembly mechanism and size control of nanofibrils formed by an OEG-based amphiphilic peptide.
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Kurbasic, Marina, Evelina Parisi, Ana M. Garcia i Silvia Marchesan. "Self-Assembling, Ultrashort Peptide Gels as Antimicrobial Biomaterials". Current Topics in Medicinal Chemistry 20, nr 14 (11.06.2020): 1300–1309. http://dx.doi.org/10.2174/1568026620666200316150221.
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Supramolecular antimicrobial hydrogels based on peptides are attractive soft materials for the treatment of infections, considering their ease of preparation and benign fate in biological settings and in the environment. In particular, stimuli-responsive systems that can be assembled/disassembled ad hoc could offer the opportunity to switch on/off their bioactivity as needed. Besides, the shorter is the peptide, the lower its cost of production. However, a structure-to-function relationship is yet to be defined and reported activities are generally not yet competitive relative to traditional antibiotics. Inspiration for their design can be found in host defense peptides (HDPs), which can self-assemble to exert their function. This article reviews research developments in this emerging area, and it examines features, differences and similarities between antimicrobial and amyloid peptides to open the avenue towards the next generation of supramolecular antimicrobial peptides as innovative therapeutic materials.
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Zanna, Nicola, i Claudia Tomasini. "Peptide-Based Physical Gels Endowed with Thixotropic Behaviour". Gels 3, nr 4 (21.10.2017): 39. http://dx.doi.org/10.3390/gels3040039.
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Galzitskaya, Oxana V., Olga M. Selivanova, Elena Y. Gorbunova, Leila G. Mustaeva, Viacheslav N. Azev i Alexey K. Surin. "Mechanism of Amyloid Gel Formation by Several Short Amyloidogenic Peptides". Nanomaterials 11, nr 11 (20.11.2021): 3129. http://dx.doi.org/10.3390/nano11113129.
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Under certain conditions, many proteins/peptides are capable of self-assembly into various supramolecular formations: fibrils, films, amyloid gels. Such formations can be associated with pathological phenomena, for example, with various neurodegenerative diseases in humans (Alzheimer’s, Parkinson’s and others), or perform various functions in the body, both in humans and in representatives of other domains of life. Recently, more and more data have appeared confirming the ability of many known and, probably, not yet studied proteins/peptides, to self-assemble into quaternary structures. Fibrils, biofilms and amyloid gels are promising objects for the developing field of research of nanobiotechnology. To develop methods for obtaining nanobiomaterials with desired properties, it is necessary to study the mechanism of such structure formation, as well as the influence of various factors on this process. In this work, we present the results of a study of the structure of biogels formed by four 10-membered amyloidogenic peptides: the VDSWNVLVAG peptide (AspNB) and its analogue VESWNVLVAG (GluNB), which are amyloidogenic fragments of the glucantransferase Bgl2p protein from a yeast cell wall, and amyloidogenic peptides Aβ(31–40), Aβ(33–42) from the Aβ(1–42) peptide. Based on the analysis of the data, we propose a possible mechanism for the formation of amyloid gels with these peptides.
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Dudukovic, Nikola A., i Charles F. Zukoski. "Nanoscale dynamics and aging of fibrous peptide-based gels". Journal of Chemical Physics 141, nr 16 (28.10.2014): 164905. http://dx.doi.org/10.1063/1.4899905.
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Vilaça, Helena, André Carvalho, Tarsila Castro, Elisabete M. S. Castanheira, Loic Hilliou, Ian Hamley, Manuel Melle-Franco, Paula M. T. Ferreira i José A. Martins. "Unveiling the Role of Capping Groups in Naphthalene N-Capped Dehydrodipeptide Hydrogels". Gels 9, nr 6 (6.06.2023): 464. http://dx.doi.org/10.3390/gels9060464.
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Self-assembled peptide-based hydrogels are archetypical nanostructured materials with a plethora of foreseeable applications in nanomedicine and as biomaterials. N-protected di- and tri-peptides are effective minimalist (molecular) hydrogelators. Independent variation of the capping group, peptide sequence and side chain modifications allows a wide chemical space to be explored and hydrogel properties to be tuned. In this work, we report the synthesis of a focused library of dehydrodipeptides N-protected with 1-naphthoyl and 2-naphthylacetyl groups. The 2-naphthylacetyl group was extensively reported for preparation of peptide-based self-assembled hydrogels, whereas the 1-naphthaloyl group was largely overlooked, owing presumably to the lack of a methylene linker between the naphthalene aromatic ring and the peptide backbone. Interestingly, dehydrodipeptides N-capped with the 1-naphthyl moiety afford stronger gels, at lower concentrations, than the 2-naphthylacetyl-capped dehydrodipeptides. Fluorescence and circular dichroism spectroscopy showed that the self-assembly of the dehydrodipeptides is driven by intermolecular aromatic π–π stacking interactions. Molecular dynamics simulations revealed that the 1-naphthoyl group allows higher order aromatic π–π stacking of the peptide molecules than the 2-naphthylacetyl group, together with hydrogen bonding of the peptide scaffold. The nanostructure of the gel networks was studied by TEM and STEM microscopy and was found to correlate well with the elasticity of the gels. This study contributes to understanding the interplay between peptide and capping group structure on the formation of self-assembled low-molecular-weight peptide hydrogels. Moreover, the results presented here add the 1-naphthoyl group to the palette of capping groups available for the preparation of efficacious low-molecular-weight peptide-based hydrogels.
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Zhu, Ying, Liying Wang, Yiping Li, Zhewei Huang, Shiyao Luo, Yue He, Han Han, Faisal Raza, Jun Wu i Liang Ge. "Injectable pH and redox dual responsive hydrogels based on self-assembled peptides for anti-tumor drug delivery". Biomaterials Science 8, nr 19 (2020): 5415–26. http://dx.doi.org/10.1039/d0bm01004a.
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Fichman, Galit, i Joel P. Schneider. "Dopamine Self-Polymerization as a Simple and Powerful Tool to Modulate the Viscoelastic Mechanical Properties of Peptide-Based Gels". Molecules 26, nr 5 (4.03.2021): 1363. http://dx.doi.org/10.3390/molecules26051363.
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Dopamine is a small versatile molecule used for various biotechnological and biomedical applications. This neurotransmitter, in addition to its biological role, can undergo oxidative self-polymerization to yield polydopamine, a robust universal coating material. Herein, we harness dopamine self-polymerization to modulate the viscoelastic mechanical properties of peptide-based gels, expanding their ever-growing application potential. By combining rapid peptide assembly with slower dopamine auto-polymerization, a double network gel is formed, where the fibrillar peptide gel network serves as a scaffold for polydopamine deposition, allowing polydopamine to interpenetrate the gel network as well as establishing crosslinks within the matrix. We have shown that triggering the assembly of a lysine-rich peptide gelator in the presence of dopamine can increase the mechanical rigidity of the resultant gel by a factor of 90 in some cases, while retaining the gel’s shear thin-recovery behavior. We further investigate how factors such as polymerization time, dopamine concentration and peptide concentration alter the mechanical properties of the resultant gel. The hybrid peptide–dopamine gel systems were characterized using rheological measurements, circular dichroism spectroscopy and transmission electron microscopy. Overall, triggering peptide gelation in the presence of dopamine represents a simple yet powerful approach to modulate the viscoelastic mechanical properties of peptide-based gels.
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Jain, Rashmi, i Sangita Roy. "Designing a bioactive scaffold from coassembled collagen–laminin short peptide hydrogels for controlling cell behaviour". RSC Advances 9, nr 66 (2019): 38745–59. http://dx.doi.org/10.1039/c9ra07454f.
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Baixe, Sébastien, Vincent Ball, Loïc Jierry, Sarah Cianférani, Jean-Marc Strub, Youssef Haikel, Marie-Hélène Metz-Boutigue i Olivier Etienne. "Strongly Adhesive and Antimicrobial Peptide-Loaded, Alginate–Catechol-Based Gels for Application against Periimplantitis". Applied Sciences 11, nr 21 (27.10.2021): 10050. http://dx.doi.org/10.3390/app112110050.
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Background: Periimplantitis is a disease linked to oral virulent bacteria such as P. gingivalis that grow in dental implants surrounding tissues and between implants and abutments. Antimicrobial gels previously described to fill these sites lose their effectiveness and resorb over time. Objective: Characterization of biophysical and antimicrobial properties of an original hydrogel, Alginate–Catechol (Alg–Cat), combined to D-Cateslytin (D-CTL). Methods: Gelation kinetics, frequency and strain sweep measurements were performed by rheology. Antibacterial activity of the gels was tested against P. gingivalis, and the MIC was determined. Peptides released from the gels were purified by HPLC and characterized by MALDI–TOF mass spectrometry. The behavior of bacteria in contact with the gel was observed using optical and electronic microscopy (SEM and TEM). Results: Gelation was fast and was achieved in 2 min with a storage modulus between 25 and 30 Pa. The gels were stable under strain and showed an adhesive potential reinforced with aging at 18 h (5.4 kPa) under a slow retraction speed (4 J·m−2 at 10 µm/s) with a mixed rupture profile (adhesive/cohesive). The MIC of D-CTL inside the Alg–Cat gel against P. gingivalis was equal to 470 µg·mL−1 after 24 h. Peptides recovered in the supernatant and inside the gel were fragmented, most of them conserving the ⍺-helix active site. No bacteria were visualized at the surface and inside the gel after 24 h. This gel is promising for clinical application for the prevention of periimplantitis.
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Gradinaru, Luiza Madalina, Maria Bercea, Alexandra Lupu i Vasile Robert Gradinaru. "Development of Polyurethane/Peptide-Based Carriers with Self-Healing Properties". Polymers 15, nr 7 (29.03.2023): 1697. http://dx.doi.org/10.3390/polym15071697.
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In situ-forming gels with self-assembling and self-healing properties are materials of high interest for various biomedical applications, especially for drug delivery systems and tissue regeneration. The main goal of this research was the development of an innovative gel carrier based on dynamic inter- and intramolecular interactions between amphiphilic polyurethane and peptide structures. The polyurethane architecture was adapted to achieve the desired amphiphilicity for self-assembly into an aqueous solution and to facilitate an array of connections with peptides through physical interactions, such as hydrophobic interactions, dipole-dipole, electrostatic, π–π stacking, or hydrogen bonds. The mechanism of the gelation process and the macromolecular conformation in water were evaluated with DLS, ATR-FTIR, and rheological measurements at room and body temperatures. The DLS measurements revealed a bimodal distribution of small (~30–40 nm) and large (~300–400 nm) hydrodynamic diameters of micelles/aggregates at 25 °C for all samples. The increase in the peptide content led to a monomodal distribution of the peaks at 37 °C (~25 nm for the sample with the highest content of peptide). The sol–gel transition occurs very quickly for all samples (within 20–30 s), but the equilibrium state of the gel structure is reached after 1 h in absence of peptide and required more time as the content of peptide increases. Moreover, this system presented self-healing properties, as was revealed by rheological measurements. In the presence of peptide, the structure recovery after each cycle of deformation is a time-dependent process, the recovery is complete after about 300 s. Thus, the addition of the peptide enhanced the polymer chain entanglement through intermolecular interactions, leading to the preparation of a well-defined gel carrier. Undoubtedly, this type of polyurethane/peptide-based carrier, displaying a sol–gel transition at a biologically relevant temperature and enhanced viscoelastic properties, is of great interest in the development of medical devices for minimally invasive procedures or precision medicine.
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Veloso, Sérgio R. S., Ecem Tiryaki, Carlos Spuch, Loic Hilliou, C. O. Amorim, V. S. Amaral, Paulo J. G. Coutinho i in. "Tuning the drug multimodal release through a co-assembly strategy based on magnetic gels". Nanoscale 14, nr 14 (2022): 5488–500. http://dx.doi.org/10.1039/d1nr08158f.
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Co-assembly of (di)phenylalanine-functionalized magnetic nanoparticles and liposomes with supramolecular peptide-based hydrogels for tunability of gel's properties, and modulation of both passive and active doxorubicin release.
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Gupta, Jyoti K., Dave J. Adams i Neil G. Berry. "Will it gel? Successful computational prediction of peptide gelators using physicochemical properties and molecular fingerprints". Chemical Science 7, nr 7 (2016): 4713–19. http://dx.doi.org/10.1039/c6sc00722h.
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Meier, U. T., i G. Blobel. "A nuclear localization signal binding protein in the nucleolus." Journal of Cell Biology 111, nr 6 (1.12.1990): 2235–45. http://dx.doi.org/10.1083/jcb.111.6.2235.
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We used functional wild-type and mutant synthetic nuclear localization signal peptides of SV-40 T antigen cross-linked to human serum albumin (peptide conjugates) to assay their binding to proteins of rat liver nuclei on Western blots. Proteins of 140 and 55 kD (p140 and p55) were exclusively recognized by wild-type peptide conjugates. Free wild-type peptides competed for the wild-type peptide conjugate binding to p140 and p55 whereas free mutant peptides, which differed by a single amino acid from the wild type, competed less efficiently. The two proteins were extractable from nuclei by either low or high ionic strength buffers. We purified p140 and raised polyclonal antibodies in chicken against the protein excised from polyacrylamide gels. The anti-p140 antibodies were monospecific as judged by their reactivity with a single nuclear protein band of 140 kD on Western blots of subcellular fractions of whole cells. Indirect immunofluorescence microscopy on fixed and permeabilized Buffalo rat liver (BRL) cells with anti-p140 antibodies exhibited a distinct punctate nucleolar staining. Rhodamine-labeled wild-type peptide conjugates also bound to nucleoli in a similar pattern on fixed and permeabilized BRL cells. Based on biochemical characterization, p140 is a novel nucleolar protein. It is possible that p140 shuttles between the nucleolus and the cytoplasm and functions as a nuclear import carrier.
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Basu, Kingshuk, Nibedita Nandi, Biplab Mondal, Ashkan Dehsorkhi, Ian W. Hamley i Arindam Banerjee. "Peptide-based ambidextrous bifunctional gelator: applications in oil spill recovery and removal of toxic organic dyes for waste water management". Interface Focus 7, nr 6 (20.10.2017): 20160128. http://dx.doi.org/10.1098/rsfs.2016.0128.
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A low molecular weight peptide-based ambidextrous gelator molecule has been discovered for efficient control of water pollution. The gelator molecules can gel various organic solvents with diverse polarity, e.g. n -hexane, n -octane, petroleum ether, petrol, diesel, aromatic solvents like chlorobenzene, toluene, benzene, o -xylene and even aqueous phosphate buffer of pH 7.5. These gels have been thoroughly characterized using various techniques including field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction analysis, small angle X-ray scattering and rheological experiments. Interestingly, hydrogel obtained from the gelator molecule has been found to absorb toxic organic dyes (both cationic and anionic dyes) from dye-contaminated water. The gelator molecule can be reused for several cycles, indicating its possible future use in waste water management. Moreover, this gelator can selectively gel petrol, diesel, pump oil from an oil–water mixture in the presence of a carrier solvent, ethyl acetate, suggesting its efficient application for oil spill recovery. These results indicate that the peptide-based ambidextrous gelator produces soft materials (gels) with dual function: (i) removal of toxic organic dyes in waste water treatment and (ii) oil spill recovery.
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Gungormus, Mustafa. "Biocatalytic synthesis and ordered self-assembly of silica nanoparticles via a silica-binding peptide". Beilstein Journal of Nanotechnology 14 (28.02.2023): 280–90. http://dx.doi.org/10.3762/bjnano.14.25.
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Achieving scalable and economic methods for manufacturing ordered structures of nanoparticles is an ongoing challenge. Ordered structures of SiO2 nanoparticles have gained increased attention due to the great potential they offer in filtering, separation, drug delivery, optics, electronics, and catalysis. Biomolecules, such as peptides and proteins, have been demonstrated to be useful in the synthesis and self-assembly of inorganic nanostructures. Herein, we describe a simple Stöber-based method wherein both the synthesis and the self-assembly of SiO2 nanoparticles can be facilitated by a silica-binding peptide (SiBP). We demonstrate that the SiBP acts as a multirole agent when used alone or in combination with a strong base catalyst (NH3). When used alone, SiBP catalyzes the hydrolysis of precursor molecules in a dose-dependent manner and produces 17–20 nm SiO2 particles organized in colloidal gels. When used in combination with NH3, the SiBP produces smaller and more uniformly distributed submicrometer particles. The SiBP also improves the long-range self-assembly of the as-grown particles into an opal-like structure by changing the surface charge, without any need for further modification or processing of the particles. The results presented here provide a biomimetic route to the single-step synthesis and assembly of SiO2 nanoparticles into colloidal gels or opal-like structures.
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Camana, Giulia, Mirko Tavano, Min Li, Franca Castiglione, Filippo Rossi i Francesco Cellesi. "Design of Functional Pluronic-Based Precursors for Tailoring Hydrogel Thermoresponsiveness and Cell-Adhesive Properties". Materials 16, nr 7 (29.03.2023): 2749. http://dx.doi.org/10.3390/ma16072749.
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In this study, functional Pluronic F127 precursors were designed and synthesized for the preparation of thermosensitive hydrogels. Using linear Pluronic thioacetate and Pluronic multi-acrylate precursors, F127-based hydrogels were prepared through thioacetate deprotection-mediated Michael-type addition. The properties of these gels were compared to those obtained through free radical crosslinking of F127 diacrylate. Temperature was found to have a clear influence on gel swelling as a result of F127 thermoresponsiveness. The macromolecular architecture and functionality of the precursors were also optimized and characterized in terms of gelation kinetics and drug diffusion. In vitro tests were conducted on fibroblasts and endothelial cells to assess their response to cellular adhesion with Pluronic gels that were functionalized with an RGD peptide or pretreated with serum proteins to promote cell adhesion. This study provides a method for creating tailored hydrogels suitable for various biomedical applications, such as soft-tissue engineering, cell encapsulation, wound healing, and sustained delivery of therapeutic molecules.
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Andrews, Robert K., Katsue Suzuki-Inoue, Yang Shen, David Tulasne, Stephen P. Watson i Michael C. Berndt. "Interaction of calmodulin with the cytoplasmic domain of platelet glycoprotein VI". Blood 99, nr 11 (1.06.2002): 4219–21. http://dx.doi.org/10.1182/blood-2001-11-0008.
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The platelet collagen receptor, glycoprotein VI (GPVI), and GPIb-IX-V, which binds von Willebrand factor, initiate platelet aggregation at low or high shear stress, respectively. We recently reported that positively charged, membrane-proximal sequences within cytoplasmic domains of GPIbβ and GPV of GPIb-IX-V bind calmodulin. We now show that GPVI also binds calmodulin as follows—(1) calmodulin coimmunoprecipitated with GPVI from resting platelet lysates using an anti-GPVI IgG, but partially dissociated in platelets activated by collagen or collagen-related peptide; (2) calmodulin coprecipitated from platelet lysates with maltose-binding protein (MBP)–GPVI cytoplasmic domain fusion protein, but not MBP alone; (3) GPVI-related synthetic peptide based on the membrane-proximal sequence, His269-Pro287, induced a shift in calmodulin migration on nondenaturing gels, an assay that identifies calmodulin-binding peptides. His269-Pro287 is analogous to the calmodulin-binding sequence in GPIbβ. The novel interaction of GPVI and calmodulin may regulate aspects of GPVI function.
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Nelson, C. A., N. J. Viner, S. P. Young, S. J. Petzold i E. R. Unanue. "A negatively charged anchor residue promotes high affinity binding to the MHC class II molecule I-Ak." Journal of Immunology 157, nr 2 (15.07.1996): 755–62. http://dx.doi.org/10.4049/jimmunol.157.2.755.
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Abstract An allele-specific peptide-binding motif for the murine MHC class II molecule I-Ak has proven elusive. Here we demonstrate that the I-Ak molecule preferentially binds peptides that contain negatively charged amino acids at the primary anchor position (Asp or Glu at P1), and that I-Ak can also bind peptides with polar residues at P1 (Cys, Ser, Asn, Gin, or Thr), although with lower affinity. This preference for a negatively charged anchor residue is so pronounced that polyalanine peptides containing a single Asp can bind to I-Ak. Eight naturally processed peptides were found to use an Asp, as demonstrated by a drop in the I-Ak binding affinity of these peptides after Ala substitution. The chemical identity of the amino acid in the anchor position was also important in determining the ability of peptide-I-Ak complexes to resist denaturation on SDS-polyacrylamide gels. The P1 binding pockets of HLA-DR and H-2E molecules are reported to be large and hydrophobic, and these class II molecules prefer to bind peptides with large aliphatic or aromatic side chains at P1. Our results suggest that the structure of the I-Ak P1 binding pocket is different. Based on sequence comparisons, we suggest that the P1 binding pockets of H-2A molecules may prove more polymorphic than the P1 binding pockets of H-2E molecules, and that this additional polymorphism will cause H-2A molecules to display larger intra-allelic differences in peptide binding specificities.
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Criado-Gonzalez, Miryam, Breyinn Loftin, Jennifer Rodon Fores, Dominique Vautier, Leyla Kocgozlu, Loïc Jierry, Pierre Schaaf, Fouzia Boulmedais i Eva Harth. "Enzyme assisted peptide self-assemblies trigger cell adhesion in high density oxime based host gels". Journal of Materials Chemistry B 8, nr 20 (2020): 4419–27. http://dx.doi.org/10.1039/d0tb00456a.
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Wu, Junchen, Qiwei Tian, He Hu, Qian Xia, Ying Zou, Fuyou Li, Tao Yi i Chunhui Huang. "Self-assembly of peptide-based multi-colour gels triggered by up-conversion rare earth nanoparticles". Chemical Communications, nr 27 (2009): 4100. http://dx.doi.org/10.1039/b907517h.
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Havryliuk, Serhiy P., Ievhenia M. Krasnobryzha, Olena S. Havryliuk i Heorgii L. Volkov*. "High Affinity Peptides in Processes of IgG Purification, Chromatographic Column Virus Inactivation/Elimination and Titer of Anti-Rubella IgG Enrichment". Journal of Biomedical Research & Environmental Sciences 3, nr 1 (styczeń 2022): 044–59. http://dx.doi.org/10.37871/jbres1399.
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According to "The Proteome Code" concept introduced by J. Biro and our early development of affinity peptide calculation method it was studied the possibility of high affinity peptide chromatographic gels development for IgG1-4 separation from the donor plasma. Given the next step of virus inactivation of IgG directly in the chromatographic column, the affinity gel had bind IgG at several spatially spaced points in order to limit the degree of freedom of the protein for retention IgG at high buffer flow rate or elevated buffer temperatures without denaturation. In addition, the possibility of creating highly specific affinity sense-antisense peptides against Rubella virus in order to increase the titer of aRIgG in plasma or even its isolation in highly purified form was studied. Based on previous experiments, an affinity multi-peptide chromatographic gel with the following properties was developed: the DBC with enough residence time 10 min was around 50-54 mg × mL-1 of total 98.0% purity of IgG with natural proportion of the 1-4 subclasses, any other immunoglobulins were not found. The virus inactivation/elimination on this gel directly in chromatographic column shown a highly effective virus elimination (log10>9) for both nonenveloped and lipid enveloped viruses. Using RV sequence from UniProt_KB and dates from more than 20 literature sources on the virus proteins interaction, affinity peptides were calculated against virus proteins C and E1,2. Then these peptides were modified to reach more affinity enhancement and affinity-peptide chromatographic gel was synthetized. By this gel from total mass IgG1-4 contained 6644 IU anti-Rubella IgG with specificity 6.64 IU × mg-1 were isolated 5382 IU aRIgG (> 80%) with a specificity of 791 IU × mg-1.
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Valentini, Luca, Lorenzo Pacini, Fosca Errante, Cecilia Morchio, Beatrice Sanna, Paolo Rovero i Antonino Morabito. "Peptide-Functionalized Silk Fibers as a Platform to Stabilize Gelatin for Use in Ingestible Devices". Molecules 27, nr 14 (19.07.2022): 4605. http://dx.doi.org/10.3390/molecules27144605.
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The combination of pharmacologic and endoscopic therapies is the gold standard for treating intestinal failures. The possibility of chemical solubility in water is mandatory for intelligent capsules. Functionalised silk fibroin with peptides and covalently linking different molecular entities to its structure make this protein a platform for preparing gels dissolving in the small and large intestine for drug delivery. In the present study, we linked a peptide containing the cell-adhesive motif Arginine–Glycine–Aspartic acid (RGD) to degummed silk fibres (DSF). Regenerated silk fibroin (RS) films obtained by dissolving functionalised DSF in formic acid were used to prepare composite gelatin. We show that such composite gelatin remains stable and elastic in the simulated gastric fluid (SGF) but can dissolve in the small and large intestines’ neutral-pH simulated intestine fluid (SIF). These findings open up the possibility of designing microfabricated and physically programmable scaffolds that locally promote tissue regeneration, thanks to bio-enabled materials based on functionalised regenerated silk.
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Schussler, Olivier, Pierre E. Falcoz, Juan C. Chachques, Marco Alifano i Yves Lecarpentier. "Possible Treatment of Myocardial Infarct Based on Tissue Engineering Using a Cellularized Solid Collagen Scaffold Functionalized with Arg-Glyc-Asp (RGD) Peptide". International Journal of Molecular Sciences 22, nr 22 (22.11.2021): 12563. http://dx.doi.org/10.3390/ijms222212563.
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Currently, the clinical impact of cell therapy after a myocardial infarction (MI) is limited by low cell engraftment due to low cell retention, cell death in inflammatory and poor angiogenic infarcted areas, secondary migration. Cells interact with their microenvironment through integrin mechanoreceptors that control their survival/apoptosis/differentiation/migration and proliferation. The association of cells with a three-dimensional material may be a way to improve interactions with their integrins, and thus outcomes, especially if preparations are epicardially applied. In this review, we will focus on the rationale for using collagen as a polymer backbone for tissue engineering of a contractile tissue. Contractilities are reported for natural but not synthetic polymers and for naturals only for: collagen/gelatin/decellularized-tissue/fibrin/Matrigel™ and for different material states: hydrogels/gels/solids. To achieve a thick/long-term contractile tissue and for cell transfer, solid porous compliant scaffolds are superior to hydrogels or gels. Classical methods to produce solid scaffolds: electrospinning/freeze-drying/3D-printing/solvent-casting and methods to reinforce and/or maintain scaffold properties by reticulations are reported. We also highlight the possibility of improving integrin interaction between cells and their associated collagen by its functionalizing with the RGD-peptide. Using a contractile patch that can be applied epicardially may be a way of improving ventricular remodeling and limiting secondary cell migration.
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Bellotti, Denise, Maria D’Accolti, Walter Pula, Nicolas Huang, Fanny Simeliere, Elisabetta Caselli, Elisabetta Esposito i Maurizio Remelli. "Calcitermin-Loaded Smart Gels Activity against Candida albicans: A Preliminary In Vitro Study". Gels 9, nr 2 (18.02.2023): 165. http://dx.doi.org/10.3390/gels9020165.
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Calcitermin is an antimicrobial peptide of 15 amino acids found in human nasal fluid characterized by antifungal and antibacterial properties. Candida albicans is the most common human fungal pathogen affecting many tissues, such as vaginal mucosa. In this study a formulation suitable for calcitermin administration on vaginal mucosa was developed for the treatment of fungal infections. To favor topical application, mucosal adhesion, and permanence, gels based on poloxamer 407 and xanthan gum were designed and compared with regard to their rheological behavior, erosion, and leakage. The selected gel was loaded with calcitermin, whose release kinetic was evaluated in vitro by Franz cells. An antifungal activity assay was conducted to assess the calcitermin anticandidal potential and the effect of its inclusion in the selected gel. The rheological study revealed the elastic and viscous moduli behavior as a function of poloxamer 407 and xanthan gum concentration. Xanthan gum presence decreased the transition temperature of the gel, while prolonging its erosion and leakage. Particularly, poloxamer 407, 18% and xanthan gum 0.4% were chosen. The calcitermin loading in the selected gel resulted in a transparent and homogeneous formulation and in a 4-fold decrease of the release rate with respect to the calcitermin solution, as evidenced by Franz cell study. The anticandidal activity tests demonstrated that calcitermin-loaded gel was more active against Candida albicans with respect to the peptide solution.
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Andrews, Robert K., Adam D. Munday, Christina A. Mitchell i Michael C. Berndt. "Interaction of calmodulin with the cytoplasmic domain of the platelet membrane glycoprotein Ib-IX-V complex". Blood 98, nr 3 (1.08.2001): 681–87. http://dx.doi.org/10.1182/blood.v98.3.681.
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Abstract Engagement of platelet membrane glycoprotein (GP) Ib-IX-V by von Willebrand factor triggers Ca++-dependent activation of αIIbβ3, resulting in (patho)physiological thrombus formation. It is demonstrated here that the cytoplasmic domain of GPIb-IX-V associates with cytosolic calmodulin. First, an anti-GPIbα antibody coimmunoprecipitated GPIb-IX and calmodulin from platelet lysates. Following platelet stimulation, calmodulin dissociated from GPIb-IX and, like the GPIb-IX–associated proteins 14-3-3ζ and p85, redistributed to the activated cytoskeleton. Second, a synthetic peptide based on the cytoplasmic sequence of GPIbβ, R149–L167 (single-letter amino acid codes), affinity-isolated calmodulin from platelet cytosol in the presence of Ca++ as confirmed by comigration with bovine calmodulin on sodium dodecyl sulfate–polyacrylamide gels, by sequence analysis, and by immunoreactivity with the use of an anticalmodulin antibody. The membrane-proximal GPIbβ sequence was analogous to a previously reported calmodulin-binding sequence in the leukocyte adhesion receptor, L-selectin. In addition, the cytoplasmic sequence of GPV, K529–G544, was analogous to a calmodulin-binding IQ motif within the α1c subunit of L-type Ca++ channels. Calmodulin coimmunoprecipitated with GPV from resting platelet lysates, but was dissociated in stimulated platelets. A GPV-related synthetic peptide also bound calmodulin and induced a Ca++-dependent shift on nondenaturing gels. Together, these results suggest separate regions of GPIb-IX-V can directly bind calmodulin, and this novel interaction potentially regulates aspects of GPIb-IX-V–dependent platelet activation.
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Jayawarna, V., A. Smith, J. E. Gough i R. V. Ulijn. "Three-dimensional cell culture of chondrocytes on modified di-phenylalanine scaffolds". Biochemical Society Transactions 35, nr 3 (22.05.2007): 535–37. http://dx.doi.org/10.1042/bst0350535.
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The design of self-assembled peptide-based structures for three-dimensional cell culture and tissue repair has been a key objective in biomaterials science for decades. In search of the simplest possible peptide system that can self-assemble, we discovered that combinations of di-peptides that are modified with aromatic stacking ligands could form nanometre-sized fibres when exposed to physiological conditions. For example, we demonstrated that a number of Fmoc (fluoren-9-ylmethyloxycarbonyl) modified di- and tri-peptides form highly ordered hydrogels via hydrogen-bonding and π–π interactions from the fluorenyl rings. These highly hydrated gels allowed for cell proliferation of chondrocytes in three dimensions [Jayawarna, Ali, Jowitt, Miller, Saiani, Gough and Ulijn (2006) Adv. Mater. 18, 611–614]. We demonstrated that fibrous architecture and physical properties of the resulting materials were dictated by the nature of the amino acid building blocks. Here, we report the self-assembly process of three di-phenylalanine analogues, Fmoc-Phe-Phe-OH, Nap (naphthalene)-Phe-Phe-OH and Cbz (benzyloxycarbonyl)-Phe-Phe-OH, to compare and contrast the self-assembly properties and cell culture conditions attributable to their protecting group difference. Fibre morphology analysis of the three structures using cryo-SEM (scanning electron microscopy) and TEM (transmission electron microscopy) suggested fibrous structures with dramatically varying fibril dimensions, depending on the aromatic ligand used. CD and FTIR (Fourier-transform IR) data confirmed β-sheet arrangements in all three samples in the gel state. The ability of these three new hydrogels to support cell proliferation of chondrocytes was confirmed for all three materials.
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Marquardt, Laura M., Vanessa M. Doulames, Alice T. Wang, Karen Dubbin, Riley A. Suhar, Michael J. Kratochvil, Zachary A. Medress, Giles W. Plant i Sarah C. Heilshorn. "Designer, injectable gels to prevent transplanted Schwann cell loss during spinal cord injury therapy". Science Advances 6, nr 14 (kwiecień 2020): eaaz1039. http://dx.doi.org/10.1126/sciadv.aaz1039.
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Transplantation of patient-derived Schwann cells is a promising regenerative medicine therapy for spinal cord injuries; however, therapeutic efficacy is compromised by inefficient cell delivery. We present a materials-based strategy that addresses three common causes of transplanted cell death: (i) membrane damage during injection, (ii) cell leakage from the injection site, and (iii) apoptosis due to loss of endogenous matrix. Using protein engineering and peptide-based assembly, we designed injectable hydrogels with modular cell-adhesive and mechanical properties. In a cervical contusion model, our hydrogel matrix resulted in a greater than 700% improvement in successful Schwann cell transplantation. The combination therapy of cells and gel significantly improved the spatial distribution of transplanted cells within the endogenous tissue. A reduction in cystic cavitation and neuronal loss were also observed with substantial increases in forelimb strength and coordination. Using an injectable hydrogel matrix, therefore, can markedly improve the outcomes of cellular transplantation therapies.
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Chang, Chia Lin, Zheqing Cai i Sheau Yu Teddy Hsu. "Sustained Activation of CLR/RAMP Receptors by Gel-Forming Agonists". International Journal of Molecular Sciences 23, nr 21 (2.11.2022): 13408. http://dx.doi.org/10.3390/ijms232113408.
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Adrenomedullin (ADM), adrenomedullin 2 (ADM2), and CGRP family peptides are important regulators of vascular vasotone and integrity, neurotransmission, and fetoplacental development. These peptides signal through CLR/RAMP1, 2, and 3 receptors, and protect against endothelial dysfunction in disease models. As such, CLR/RAMP receptor agonists are considered important therapeutic candidates for various diseases. Methods and Results: Based on the screening of a series of palmitoylated chimeric ADM/ADM2 analogs, we demonstrated a combination of lipidation and accommodating motifs at the hinge region of select peptides is important for gaining an enhanced receptor-activation activity and improved stimulatory effects on the proliferation and survival of human lymphatic endothelial cells when compared to wild-type peptides. In addition, by serendipity, we found that select palmitoylated analogs self-assemble to form liquid gels, and subcutaneous administration of an analog gel led to the sustained presence of the peptide in the circulation for >2 days. Consistently, subcutaneous injection of the analog gel significantly reduced the blood pressure in SHR rats and increased vasodilation in the hindlimbs of adult rats for days. Conclusions: Together, these data suggest gel-forming adrenomedullin analogs may represent promising candidates for the treatment of various life-threatening endothelial dysfunction-associated diseases such as treatment-resistant hypertension and preeclampsia, which are in urgent need of an effective drug.
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Sidorskii, Egor V., Mikhail S. Krasnov, Viktoria P. Yamskova i Vladimir I. Lozinsky. "Cryostructuring of Polymeric Systems. 57. Spongy Wide-Porous Cryogels Based on the Proteins of Blood Serum: Preparation, Properties and Application as the Carriers of Peptide Bioregulators". Gels 6, nr 4 (14.12.2020): 50. http://dx.doi.org/10.3390/gels6040050.
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Wide-pore proteinaceous freeze–thaw spongy gels were synthesized via the cryotropic gelation technique using the bovine blood serum or its diluted solutions as the protein-containing precursors. The feed systems also included the denaturant (urea) and the thiol-reductant (cysteine). The gel-fraction yield decreased and the swelling degree of the walls of macropores in such heterophase matrices increased with decreasing the initial protein concentration. The optimum freezing temperature was found to be within a rather narrow range from −15 to −20 °C. In this case, the average size of the macropores in the resultant cryogels was 90–110 μm. The suitability of such soft wide-pore gel materials for the application as the carriers of peptide bioregulators was demonstrated in the in vitro experiments, when the posterior segments of the Pleurodeles waltl adult newts’ eyes were used as a model biological target. It was shown that a statistically reliable protective effect on the state of the sclera, vascular membrane and retinal pigment epithelium, as well as on the viability of fibroblasts, was inherent in the proteinaceous cryogels loaded with the peptide bioregulator (Viophtan-5™) isolated from the bovine eye sclera.
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James, Peter. "Protein Expression Analysis: From ‘Tip of the Iceberg’ to a Global Method". Disease Markers 17, nr 4 (2001): 235–46. http://dx.doi.org/10.1155/2001/385075.
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In this review I will describe the advances that have recently been made in ‘traditional’ two-dimensional gel based protein expression analysis. A major jump has been made toward the automation of gel image analysis and comparison, one of the major bottlenecks in the analysis chain as well as the automation of spot excision and preparation for mass spectrometric analysis. Currently the gel-based ‘proteome mapping’ approach is highly effective and 300 gels and over 10,000 spots a week can be analysed. Very recently, viable alternatives to the use of two-dimensional gel electrophoresis have emerged and these approaches are discussed here. In combination with the recently developed stable isotopic tagging methods for peptide quantitation and new mass spectrometers, this emerging technology will be a rapid and highly effective alternative to gel-based methods with few of the latter's shortcomings.
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Niwa, K., A. Yaginuma, M. Nakanishi, Y. Wada, T. Sugo, S. Asakura, N. Watanabe i M. Matsuda. "Fibrinogen Mitaka II: a hereditary dysfibrinogen with defective thrombin binding caused by an A alpha Glu-11 to Gly substitution". Blood 82, nr 12 (15.12.1993): 3658–63. http://dx.doi.org/10.1182/blood.v82.12.3658.3658.
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Abstract A new type of A alpha Glu-11 to Gly substitution has been identified in a congenitally abnormal fibrinogen, fibrinogen Mitaka II, derived from a 14-year-old female suffering from easy bruising since childhood. Plasma of the patient and fibrinogen purified therefrom were found to clot slowly by thrombin but in a normal fashion by ancrod, a thrombin- like snake venom enzyme. The ancrod-clotted fibrin gels were normally solid and turbid, whereas the thrombin-clotted gels were initially fragile and transparent but became gradually normalized during further incubation. On reverse-phase high-performance liquid chromatography, there was an additional peptide group eluted distinctly later than the corresponding normal fibrinopeptide A in the clot-liquor of the patient's samples. Sequence analysis of these aberrant peptides and isolated A alpha chains of the patient's fibrinogen showed that Glu at position 11 of the abnormal A alpha chain had been replaced by Gly. Studies using 125I-labeled thrombin showed that the binding with thrombin was evidently reduced for her fibrinogen and the aberrant fibrinopeptide A as compared with that for the normal controls, indicating that A alpha Glu-11 may be critical for the fibrinogen- thrombin interaction. Indeed, A alpha Glu-11 of fibrinogen has recently been proposed to stabilize the local conformation, including the beta- turn, and to form a salt bridge between its side-chain carboxyl group and the guanidino group of Arg-173 of thrombin based on crystallographic analyses using analogs of fibrinopeptide A complexed with thrombin (Stubb et al, Eur J Biochem 206:187, 1992 and Martin et al, J Biol Chem 267:7911, 1992).
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Niwa, K., A. Yaginuma, M. Nakanishi, Y. Wada, T. Sugo, S. Asakura, N. Watanabe i M. Matsuda. "Fibrinogen Mitaka II: a hereditary dysfibrinogen with defective thrombin binding caused by an A alpha Glu-11 to Gly substitution". Blood 82, nr 12 (15.12.1993): 3658–63. http://dx.doi.org/10.1182/blood.v82.12.3658.bloodjournal82123658.
Pełny tekst źródłaStreszczenie:
A new type of A alpha Glu-11 to Gly substitution has been identified in a congenitally abnormal fibrinogen, fibrinogen Mitaka II, derived from a 14-year-old female suffering from easy bruising since childhood. Plasma of the patient and fibrinogen purified therefrom were found to clot slowly by thrombin but in a normal fashion by ancrod, a thrombin- like snake venom enzyme. The ancrod-clotted fibrin gels were normally solid and turbid, whereas the thrombin-clotted gels were initially fragile and transparent but became gradually normalized during further incubation. On reverse-phase high-performance liquid chromatography, there was an additional peptide group eluted distinctly later than the corresponding normal fibrinopeptide A in the clot-liquor of the patient's samples. Sequence analysis of these aberrant peptides and isolated A alpha chains of the patient's fibrinogen showed that Glu at position 11 of the abnormal A alpha chain had been replaced by Gly. Studies using 125I-labeled thrombin showed that the binding with thrombin was evidently reduced for her fibrinogen and the aberrant fibrinopeptide A as compared with that for the normal controls, indicating that A alpha Glu-11 may be critical for the fibrinogen- thrombin interaction. Indeed, A alpha Glu-11 of fibrinogen has recently been proposed to stabilize the local conformation, including the beta- turn, and to form a salt bridge between its side-chain carboxyl group and the guanidino group of Arg-173 of thrombin based on crystallographic analyses using analogs of fibrinopeptide A complexed with thrombin (Stubb et al, Eur J Biochem 206:187, 1992 and Martin et al, J Biol Chem 267:7911, 1992).
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Kalemba, Ewa Marzena, Benoît Valot, Dominique Job, Christophe Bailly i Patrice Meimoun. "Are Methionine Sulfoxide-Containing Proteins Related to Seed Longevity? A Case Study of Arabidopsis thaliana Dry Mature Seeds Using Cyanogen Bromide Attack and Two-Dimensional-Diagonal Electrophoresis". Plants 11, nr 4 (21.02.2022): 569. http://dx.doi.org/10.3390/plants11040569.
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In recent years, several reports pointed out the role of protein oxidation in seed longevity, notably regarding the oxidation of methionine (Met) residues to methionine sulfoxide (MetO) in proteins. To further consider this question, we present a handy proteomic method based on the use of two-dimensional diagonal electrophoresis (2Dd) and cyanogen bromide (CNBr) cleavage, which we refer to as 2Dd-CNBr. CNBr treatment of proteins causes the non-enzymatic hydrolysis of peptide bonds on the carboxyl side of reduced Met residues. However, Met oxidation causes a lack of cleavage, thus modifying the electrophoretic mobility of CNBr-induced peptides. This approach was first validated using bovine serum albumin as a model protein, which confirmed the possibility of distinguishing between oxidized and non-oxidized forms of Met-containing peptides in gels. Then, the 2Dd-CNBr method was applied to the Arabidopsis thaliana seed protein extract in a control (non-oxidized) condition and in an oxidized one (as obtained following hypochlorous acid treatment). Twenty-four oxidized Met residues in 19 proteins identified by mass spectrometry were found to be surface exposed in these proteins. In the three-dimensional environment of the oxidized Met, we detected amino acid residues that could be converted by oxidation (carbonylation) or by phosphorylation, suggesting a possible interplay between Met oxidation and the other protein modifications. The identification of the proteins oxidatively modified in Met residues revealed the finding that MetO-containing proteins are related to seed longevity. Based on these results, we suggest that the method presently described also has the potential for wider applications.
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Hook, Sarah, Sharan Bobbala i Ashim Mitra. "One-shot sustained release nanoparticle vaccines (VAC13P.1133)". Journal of Immunology 194, nr 1_Supplement (1.05.2015): 214.13. http://dx.doi.org/10.4049/jimmunol.194.supp.214.13.
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Abstract Sustained release of vaccines over an extended period of time may reduce or negate the need for multiple vaccinations (boosters) and also effectively enhance the immunogenicity of subunit vaccines. We have investigated the physcial, chemical and immunological properties of polymeric thermogelling formulations loaded with nanoparticulate protein and peptide based vaccines. The formulations were developed to be free-flowing liquids at room temperature and to form stable gels at body temperature. The vaccine components were loaded into nanoparticles before incorporation into the polymers in order to achieve synchronous release of antigen and adjuvant. The ability of the vaccines to stimulate long lived cellular and humoral responses after a single dose of antigen was investigated in mice. A single dose of formulations could induce detectable responses 50 days post immunisation and could protect mice in a tumor challenge model.
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Brunel, Dominique, Nicole Froger i Georges Pelletier. "Development of amplified consensus genetic markers (ACGM) in Brassica napus from Arabidopsis thaliana sequences of known biological function". Genome 42, nr 3 (1.06.1999): 387–402. http://dx.doi.org/10.1139/g98-141.
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A method for the development of consensus genetic markers between species of the same taxonomic family is described in this paper. It is based on the conservation of the peptide sequences and on the potential polymorphism within non-coding sequences. Six loci sequenced from Arabidopsis thaliana, AG, LFY3, AP3, FAD7, FAD3, and ADH, were analysed for one ecotype of A. thaliana, four lines of Brassica napus, and one line for each parental species, Brassica oleracea and Brassica rapa. Positive amplifications with the degenerate primers showed one band for A. thaliana, two to four bands in rapeseed, and one to two bands in the parental species. Direct sequencing of the PCR products confirms their peptide similarity with the "mother" sequence. By comparison of intron sequences, the correspondence between each rapeseed gene and its homologue in one of the parental species can be determined without ambiguity. Another important result is the presence of a polymorphism inside these fragments between the rapeseed lines. This variability could generally be detected by differences of electrophoretic migration on long non-denaturing polyacrylamide gels. This method enables a quick and easy shuttle between A. thaliana and Brassica species without cloning.Key words: consensus genetics markers, PCR specific, Brassica, Arabidopsis, targeted markers, DSCP.
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Kraemer, Markus, Magali Bellion, Ann-Kathrin Kissmann, Tilmann Herberger, Christopher V. Synatschke, Anil Bozdogan, Jakob Andersson i in. "Aptamers as Novel Binding Molecules on an Antimicrobial Peptide-Armored Composite Hydrogel Wound Dressing for Specific Removal and Efficient Eradication of Pseudomonas aeruginosa". International Journal of Molecular Sciences 24, nr 5 (2.03.2023): 4800. http://dx.doi.org/10.3390/ijms24054800.
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Here we present for the first time a potential wound dressing material implementing aptamers as binding entities to remove pathogenic cells from newly contaminated surfaces of wound matrix-mimicking collagen gels. The model pathogen in this study was the Gram-negative opportunistic bacterium Pseudomonas aeruginosa, which represents a considerable health threat in hospital environments as a cause of severe infections of burn or post-surgery wounds. A two-layered hydrogel composite material was constructed based on an established eight-membered focused anti-P. aeruginosa polyclonal aptamer library, which was chemically crosslinked to the material surface to form a trapping zone for efficient binding of the pathogen. A drug-loaded zone of the composite released the C14R antimicrobial peptide to deliver it directly to the bound pathogenic cells. We demonstrate that this material combining aptamer-mediated affinity and peptide-dependent pathogen eradication can quantitatively remove bacterial cells from the “wound” surface, and we show that the surface-trapped bacteria are completely killed. The drug delivery function of the composite thus represents an extra safeguarding property and thus probably one of the most important additional advances of a next-generation or smart wound dressing ensuring the complete removal and/or eradication of the pathogen of a freshly infected wound.
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Green, M. R. "Identification of human milk kappa-casein on polyacrylamide gels by differential staining with Ethyl-Stains-all and chymosin sensitivity." Journal of Histochemistry & Cytochemistry 34, nr 2 (luty 1986): 147–50. http://dx.doi.org/10.1177/34.2.2418097.
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Ethyl-Stains-all (ESA), a cationic carbocyanine dye that stains phosphorylated, sialylated, and unmodified proteins differentially, was used to stain a human casein fraction enriched for its kappa-casein-like characteristics. The staining properties and chymosin sensitivity of this fraction were compared with those of human milk and bovine casein proteins. Phosphorylated human and bovine beta caseins stained blue with ESA. The sialic acid-containing bovine kappa-casein stained blue-green. The human kappa-like fraction was enriched for a protein that stained blue-green with ESA. Both bovine kappa-casein and the human blue-green-staining protein were susceptible to chymosin digestion at lower concentrations of chymosin than that required for digestion of beta-caseins. In each case, following chymosin digestion, a green-staining peptide of lower molecular weight replaced the original protein and para-kappa-casein was formed. Identification of human kappa-casein on SDS-polyacrylamide gels was based on its differential staining with ESA and chymosin sensitivity with respect to beta-casein.
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Makarević, Janja, Milan Jokić, Leo Frkanec, Vesna Čaplar, Nataša Šijaković Vujičić i Mladen Žinić. "Oxalyl retro-peptide gelators. Synthesis, gelation properties and stereochemical effects". Beilstein Journal of Organic Chemistry 6 (4.10.2010): 945–59. http://dx.doi.org/10.3762/bjoc.6.106.
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In this work we report on gelation properties, self-assembly motifs, chirality effects and morphological characteristics of gels formed by chiral retro-dipeptidic gelators in the form of terminal diacids (1a–5a) and their dimethyl ester (1b–5b) and dicarboxamide (1c–5c) derivatives. Terminal free acid retro-dipeptides (S,S)-bis(LeuLeu) 1a, (S,S)-bis(PhgPhg) 3a and (S,S)-bis(PhePhe) 5a showed moderate to excellent gelation of highly polar water/DMSO and water/DMF solvent mixtures. Retro-peptides incorporating different amino acids (S,S)-(LeuPhg) 2a and (S,S)-(PhgLeu) 4a showed no or very weak gelation. Different gelation effectiveness was found for racemic and single enantiomer gelators. The heterochiral (S,R)-1c diastereoisomer is capable of immobilizing up to 10 and 4 times larger volumes of dichloromethane/DMSO and toluene/DMSO solvent mixtures compared to homochiral (S,S)-1c. Based on the results of 1H NMR, FTIR, CD investigations, molecular modeling and XRPD studies of diasteroisomeric diesters (S,S)-1b/(S,R)-1b and diacids (S,S)-1b/(S,R)-1a, a basic packing model in their gel aggregates is proposed. The intermolecular hydrogen bonding between extended gelator molecules utilizing both, the oxalamide and peptidic units and layered organization were identified as the most likely motifs appearing in the gel aggregates. Molecular modeling studies of (S,S)- 1a/(S,R)-1a and (S,S)-1b/(S,R)- 1b diasteroisomeric pairs revealed a decisive stereochemical influence yielding distinctly different low energy conformations: those of (S,R)-diastereoisomers with lipophilic i-Bu groups and polar carboxylic acid or ester groups located on the opposite sides of the oxalamide plane resembling bola amphiphilic structures and those of (S,S)-diasteroisomers possessing the same groups located at both sides of the oxalamide plane. Such conformational characteristics were found to strongly influence both, gelator effectiveness and morphological characteristics of gel aggregates.
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Abdul Sisak, Muhammad Asri, Fiona Louis, Sun Hyeok Lee, Young-Tae Chang i Michiya Matsusaki. "Fabrication of Blood Capillary Models for Live Imaging Microarray Analysis". Micromachines 11, nr 8 (27.07.2020): 727. http://dx.doi.org/10.3390/mi11080727.
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Conventional microarray analysis usually deals with the monolayer or two-dimensional (2D) assays for the high-throughput screening applications. Even though these cell-based assays are effective for preliminary screening at least to have information on cytotoxicity, they do not adequately re-create the in vivo complexity of three-dimensional (3D) tissues. In this study, 3D-blood capillary models were constructed by using physiological collagen microfibers (CMF), which provide the extracellular matrix in the complex tissue. Micro-droplets of fibrin gels containing CMF, endothelial cells, and fibroblasts were cultured for five days in 48-wells plate to provide a medium-throughput system for screening applications. Blood capillaries networks were formed by optimizing the concentration of CMF used and the number of cells. Finally, this screening method was a powerful assay for the application on the selection of not only a specific chemical probe for blood capillary live-imaging, but also a drug, aptamer, and peptide with potential blood vessel targeting property.
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Fu, Xiaoyun, Mallory N. Pahl, Yi Wang, Barbara A. Konkle, Junmei Chen i Jose A. Lopez. "A Quantitative Assay of In Vivo Cleavage of Von Willebrand Factor By ADAMTS13 Reveals Excessive Cleavage in Type 2B Von Willebrand Disease and Diminished Cleavage in Thrombotic Thrombocytopenic Purpura". Blood 128, nr 22 (2.12.2016): 2532. http://dx.doi.org/10.1182/blood.v128.22.2532.2532.
Pełny tekst źródłaStreszczenie:
Abstract Von Willebrand Factor (VWF) is a large glycoprotein that plays a crucial role in hemostasis by enabling platelets to adhere to sites of vascular injury, particularly under conditions of high shear stress. The multimeric structure of VWF is central to its activity; VWF is most active in its ultra-large multimer form (ULVWF). The size of plasma VWF is regulated by the plasma metalloprotease ADAMTS13, which cleaves VWF at the Tyr1605-Met1606 peptide bond within the A2 domain. Abnormal VWF cleavage has been implicated in a wide range of thrombotic and bleeding disorders, including thrombotic thrombocytopenic purpura (TTP) and Type 2 von Willebrand disease (VWD). These two diseases represent extreme phenotypes of VWF proteolysis-the former with too little cleavage and the latter with too much cleavage. ADAMTS13 proteolysis of VWF is currently assessed by either multimer gel analysis or ADAMTS13 activity assays. High-resolution agarose gels give an estimate of the extent to which a particular band represents cleaved vs native VWF. This method, however, is not quantitative and cannot distinguish whether a particular cleavage product is produced by ADAMTS13 or by another protease. Alternatively, ADAMTS13 activity assays are indirect measures of VWF cleavage, used especially to diagnose TTP. These assays measure the extent to which a subject's ADAMTS13 can cleave an exogenous substrate, usually a small peptide, and do not determine the extent of endogenous VWF cleavage. Therefore, we developed a mass spectrometry-based method to directly quantify cleavage of the Tyr1605-Met1606 peptide bond in plasma VWF. Here, we report quantification of VWF cleavage in plasma from normal donors, and TTP and VWD patients. Methods: VWF was isolated from plasma by immunoprecipitation using polyclonal VWF antibody and then digested with trypsin. Tryptic peptides, including the ADAMTS13-cleaved peptide and a control peptide, were quantified by nano ultra-performance liquid chromatography tandem mass spectrometry (nanoLC-MS/MS) using heavy isotope-labelled peptides as internal standards. The extent of VWF cleavage by ADAMTS13 was determined as the concentration ratio of ADAMTS13-cleaved peptide to a control peptide representative of total VWF, and expressed as percent cleavage. Results: Given that the plasma concentration of VWF is relatively low, we first optimized conditions for sample preparation and analysis. Using NanoLC-MS/MS with isotopic dilution, we quantified ADAMTS13 cleavage of VWF in plasma samples (10-100 µl) containing 100-500 ng of VWF. We tested the reproducibility of the measurement using pooled normal plasma. The quantification was highly reproducible, with a wide linear range. VWF cleavage in pooled normal plasma was 4.9% ± 0.3% (mean ± SD, n=6), indicating that one VWF monomer in 20 is cleaved, on average. Cleavage was much higher in plasma from type 2B VWD patients (n=5), ranging from 15-30% depending on mutations. In contrast, we observed only 2.1-3.2% (n=6) cleavage in plasma VWF from TTP patients. Summary: This is the first report of quantification of ADAMTS13-mediated VWF cleavage in plasma. In normal plasma, approximately 5% of VWF A2 domains are cleaved, whereas cleavage was reduced to approximately 60% of normal on average in 6 TTP patients, and increased up to 6 times normal in patients with Type 2B VWD. In TTP, this level of proteolysis would be expected to result in accumulation of ULVWF multimers, as only between 1 in 50 to 1 in 30 monomers were cleaved. In type 2B VWD, by contrast, proteolysis may play a much larger role in the lack of larger multimers than previously appreciated, as up to 1 in 3 monomers were cleaved. This method should also prove useful in conditions such as severe malaria, in which it has been suggested that VWF cleavage is impaired, but this is not necessarily accompanied by low ADAMTS13 activity as measured with a small peptide substrate. Disclosures No relevant conflicts of interest to declare.
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Ghilan, Alina, Alexandra Croitoriu, Aurica P. Chiriac, Loredana Elena Nita, Maria Bercea i Alina Gabriela Rusu. "Injectable Networks Based on a Hybrid Synthetic/Natural Polymer Gel and Self-Assembling Peptides Functioning as Reinforcing Fillers". Polymers 15, nr 3 (26.01.2023): 636. http://dx.doi.org/10.3390/polym15030636.
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Double network (DN) hydrogels composed of self-assembling low-molecular-weight gelators and a hybrid polymer network are of particular interest for many emerging biomedical applications, such as tissue regeneration and drug delivery. The major benefits of these structures are their distinct mechanical properties as well as their ability to mimic the hierarchical features of the extracellular matrix. Herein, we describe a hybrid synthetic/natural polymer gel that acts as the initial network based on sodium alginate and a copolymer, namely poly(itaconic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro (5,5) undecane). The addition of amino acids and peptide-derived hydrogelators, such as Fmoc-Lys-Fmoc-OH and Fmoc-Gly-Gly-Gly-OH, to the already-made network gives rise to DNs crosslinked via non-covalent interactions. Fourier transform infrared spectroscopy (FTIR) and thermal analysis confirmed the formation of the DN and highlighted the interactions between the two component networks. Swelling studies revealed that the materials have an excellent water absorption capacity and can be classified as superabsorbent gels. The rheological properties were systematically investigated in response to different variables and showed that the prepared materials present injectability and a self-healing ability. SEM analysis revealed a morphology consisting of a highly porous and interconnected fibrous network. Finally, the biocompatibility was evaluated using the MTT assay on dermal fibroblasts, and the results indicated that the new structures are non-toxic and potentially useful for biomedical applications.
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Campbell, M. J., W. Carroll, S. Kon, K. Thielemans, J. B. Rothbard, S. Levy i R. Levy. "Idiotype vaccination against murine B cell lymphoma. Humoral and cellular responses elicited by tumor-derived immunoglobulin M and its molecular subunits." Journal of Immunology 139, nr 8 (15.10.1987): 2825–33. http://dx.doi.org/10.4049/jimmunol.139.8.2825.
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Abstract C3H/HeN mice were immunized with idiotypic immunoglobulin M (IgM) and its molecular subunits from the syngeneic 38C13 lymphoma. Immunization with idiotypic IgM (38C-Id) resulted in idiotype-specific humoral and cellular immunity and protection against a lethal tumor cell challenge. Heavy (H38C) and light (L38C) chains were isolated by electroelution from preparative polyacrylamide gels. Both of these immunogens induced significant resistance to a subsequent tumor challenge. Variable region immunogens, in the form of trpE-fusion proteins, were obtained by cloning heavy and light chain variable region genes into the expression plasmid pATH-11. Of these, only the trpE-VH38C immunogen yielded immune resistance to tumor challenge. Finally, the nucleic acid sequence of 38C-Id light chain was determined and, based on the corresponding amino acid sequence and an analysis of predicted secondary structure, a region of potential antigenicity in complementarity-determining region 3 was chosen for the production of a synthetic peptide. Vaccination with this synthetic peptide resulted in significant suppression of tumor growth. Analysis of the humoral and cellular immunity generated by these vaccines revealed the presence of antibodies reactive with native idiotypic IgM only in 38C-Id, H38C, and trpE-VH38C immune sera, although the latter two were not idiotype-specific. Idiotype-specific lymphocytes, which proliferated in response to native 38C-Id, were observed in all immune animals. With the exception of the fusion protein immunogens, conjugation to an immunogenic carrier protein (keyhole limpet hemocyanin or thyroglobulin) was required for optimal humoral and cellular responses.
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Schibler, Matthew J., i Fernando R. Cabral. "Maytansine-resistant mutants of Chinese hamster ovary cells with an alteration in α-tubulin". Canadian Journal of Biochemistry and Cell Biology 63, nr 6 (1.06.1985): 503–10. http://dx.doi.org/10.1139/o85-069.
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Mutant clones of Chinese hamster ovary cells resistant to killing by the Vinca alkaloid maytansine have been isolated using a single-step procedure. These mutants are threefold more resistant to killing by the drug than the wild-type parent. The majority of the clones (30 of 34) probably contain alterations in membrane permeability based on their cross-resistance to an unrelated drug, puromycin. Two of the four puromycin-sensitive clones were found to contain "extra" spots which migrated close to α-tubulin on two-dimensional gels. The "extra" spots were shown to be electrophoretic variants of α-tubulin with an identical two-dimensional tryptic peptide map to that of the wild-type α-tubulin. The α-tubulin mutants were cross-resistant to other microtubule disrupting drugs such as griseofulvin, vinblastine, and colcemid, but were more sensitive to the microtubule-stabilizing agent taxol than the wild-type parental cells. Mutant – wild-type hybrids were found to be resistant to levels of maytansine intermediate between the lethal doses for mutant and wild-type cells. A possible explanation for the drug resistance of these mutants is discussed.
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Boggs, B., i F. Cabral. "Mutations affecting assembly and stability of tubulin: evidence for a nonessential beta-tubulin in CHO cells". Molecular and Cellular Biology 7, nr 8 (sierpień 1987): 2700–2707. http://dx.doi.org/10.1128/mcb.7.8.2700-2707.1987.
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Eight strains of Chinese hamster ovary (CHO) cells having an assembly-defective beta-tubulin were found among revertants of strain Cmd 4, a mutant with a conditional lethal mutation in a beta-tubulin gene (F. Cabral, M. E. Sobel, and M. M. Gottesman, Cell 20:29-36, 1980). The altered beta-tubulins in these strains have electrophoretically silent alterations or, in some cases, an increase or a decrease in apparent molecular weight based on their migration in two-dimensional gels. The identity of these variant proteins as beta-tubulin was confirmed by peptide mapping, which also revealed the loss of distinct methionine-containing peptides in the assembly-defective beta-tubulins of lower apparent molecular weight. The altered mobility of these beta-tubulin polypeptides was not the result of a posttranslational modification, since the altered species could be labeled in very short incubations with [35S]methionine and were found among in vitro-translated polypeptides by using purified mRNA. In at least one strain, an altered DNA restriction fragment could be demonstrated, suggesting that an alteration occurred in one of the structural genes for beta-tubulin. Assembly-defective beta-tubulin was unstable and turned over with a half-life of only 1 to 2 h in exponentially growing cells. This rapid degradation of a tubulin gene product resulted in approximately 30% lower steady-state levels of both alpha- and beta-tubulin yet did not affect the growth rate of the cells or the distribution of the microtubules as judged by immunofluorescence microscopy. These results argue that CHO cells possess a beta-tubulin gene product that is not essential for survival.
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Boggs, B., i F. Cabral. "Mutations affecting assembly and stability of tubulin: evidence for a nonessential beta-tubulin in CHO cells." Molecular and Cellular Biology 7, nr 8 (sierpień 1987): 2700–2707. http://dx.doi.org/10.1128/mcb.7.8.2700.
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Eight strains of Chinese hamster ovary (CHO) cells having an assembly-defective beta-tubulin were found among revertants of strain Cmd 4, a mutant with a conditional lethal mutation in a beta-tubulin gene (F. Cabral, M. E. Sobel, and M. M. Gottesman, Cell 20:29-36, 1980). The altered beta-tubulins in these strains have electrophoretically silent alterations or, in some cases, an increase or a decrease in apparent molecular weight based on their migration in two-dimensional gels. The identity of these variant proteins as beta-tubulin was confirmed by peptide mapping, which also revealed the loss of distinct methionine-containing peptides in the assembly-defective beta-tubulins of lower apparent molecular weight. The altered mobility of these beta-tubulin polypeptides was not the result of a posttranslational modification, since the altered species could be labeled in very short incubations with [35S]methionine and were found among in vitro-translated polypeptides by using purified mRNA. In at least one strain, an altered DNA restriction fragment could be demonstrated, suggesting that an alteration occurred in one of the structural genes for beta-tubulin. Assembly-defective beta-tubulin was unstable and turned over with a half-life of only 1 to 2 h in exponentially growing cells. This rapid degradation of a tubulin gene product resulted in approximately 30% lower steady-state levels of both alpha- and beta-tubulin yet did not affect the growth rate of the cells or the distribution of the microtubules as judged by immunofluorescence microscopy. These results argue that CHO cells possess a beta-tubulin gene product that is not essential for survival.
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Hallan, Supandeep Singh, Jhaleh Amirian, Agnese Brangule i Dace Bandere. "Lipid-Based Nano-Sized Cargos as a Promising Strategy in Bone Complications: A Review". Nanomaterials 12, nr 7 (30.03.2022): 1146. http://dx.doi.org/10.3390/nano12071146.
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Bone metastasis has been considered the fatal phase of cancers, which remains incurable and to be a challenge due to the non-availability of the ideal treatment strategy. Unlike bone cancer, bone metastasis involves the spreading of the tumor cells to the bones from different origins. Bone metastasis generally originates from breast and prostate cancers. The possibility of bone metastasis is highly attributable to its physiological milieu susceptible to tumor growth. The treatment of bone-related diseases has multiple complications, including bone breakage, reduced quality of life, spinal cord or nerve compression, and pain. However, anticancer active agents have failed to maintain desired therapeutic concentrations at the target site; hence, uptake of the drug takes place at a non-target site responsible for the toxicity at the cellular level. Interestingly, lipid-based drug delivery systems have become the center of interest for researchers, thanks to their biocompatible and bio-mimetic nature. These systems possess a great potential to improve precise bone targeting without affecting healthy tissues. The lipid nano-sized systems are not only limited to delivering active agents but also genes/peptide sequences/siRNA, bisphosphonates, etc. Additionally, lipid coating of inorganic nanomaterials such as calcium phosphate is an effective approach against uncontrollable rapid precipitation resulting in reduced colloidal stability and dispersity. This review summarizes the numerous aspects, including development, design, possible applications, challenges, and future perspective of lipid nano-transporters, namely liposomes, exosomes, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and lipid nanoparticulate gels to treat bone metastasis and induce bone regeneration. Additionally, the economic suitability of these systems has been discussed and different alternatives have been discussed. All in all, through this review we will try to understand how far nanomedicine is from clinical and industrial applications in bone metastasis.