Artículos de revistas: "Macromolecular"

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Li, Yue, Jinlian Duan, Heng Xia, Bin Shu y Weigang Duan. "Macromolecular substances as a dangerous factor in traditional Chinese medicine injections were determined by size-exclusive chromatography". Toxicology Research 9, n.º 3 (21 de mayo de 2020): 323–30. http://dx.doi.org/10.1093/toxres/tfaa024.

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Abstract Macromolecular substances in traditional Chinese medicine injections (TCMIs) are expected to be a main dangerous factor causing anaphylactic or anaphylactoid reaction. The main aim of the study was to verify the macromolecular substances’ anaphylactic or anaphylactoid reaction in guinea pigs and establish a size-exclusive chromatographic method to detect them. The macromolecular substances from six TCMIs (Danshen injection, Dengzhanxixin injection, Honghua injection, Qingkailing injection, Shuanghuanglian injection and Shuxuening injection) were prepared by removing substances with molecular weight less than 10 kDa with an ultra-filter. The anaphylactic and anaphylactoid reactions caused by original TCMIs, injections rich in or free of macromolecules were assayed in guinea pigs. The relationship between the amount of the macromolecular substances and peak area of chromatogram was established by size-exclusive chromatography. Injections free of macromolecules were not likely to cause anaphylactic and anaphylactoid reactions, but injections rich in macromolecular substances were more likely to do so. If the macromolecular substances with molecular weight bigger than 10 kDa were removed, the signal of macromolecular substances in TCMIs was quantitatively reduced. All the results suggested that macromolecular substances in TCMIs are a dangerous factor causing safety problems, and the macromolecular substances can be quantitatively detected with size-exclusive chromatography.

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Henneberg, Fabian y Ashwin Chari. "Chromatography-Free Purification Strategies for Large Biological Macromolecular Complexes Involving Fractionated PEG Precipitation and Density Gradients". Life 11, n.º 12 (24 de noviembre de 2021): 1289. http://dx.doi.org/10.3390/life11121289.

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A complex interplay between several biological macromolecules maintains cellular homeostasis. Generally, the demanding chemical reactions which sustain life are not performed by individual macromolecules, but rather by several proteins that together form a macromolecular complex. Understanding the functional interactions amongst subunits of these macromolecular machines is fundamental to elucidate mechanisms by which they maintain homeostasis. As the faithful function of macromolecular complexes is essential for cell survival, their mis-function leads to the development of human diseases. Furthermore, detailed mechanistic interrogation of the function of macromolecular machines can be exploited to develop and optimize biotechnological processes. The purification of intact macromolecular complexes is an essential prerequisite for this; however, chromatographic purification schemes can induce the dissociation of subunits or the disintegration of the whole complex. Here, we discuss the development and application of chromatography-free purification strategies based on fractionated PEG precipitation and orthogonal density gradient centrifugation that overcomes existing limitations of established chromatographic purification protocols. The presented case studies illustrate the capabilities of these procedures for the purification of macromolecular complexes.

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3

Juliano, R. "Challenges to macromolecular drug delivery". Biochemical Society Transactions 35, n.º 1 (22 de enero de 2007): 41–43. http://dx.doi.org/10.1042/bst0350041.

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The use of macromolecules, particularly monoclonal antibodies, as therapeutic agents has come to the forefront in recent years. The biodistribution and delivery issues for protein drugs are shared to a substantial degree with other emerging therapeutic approaches including pharmacologically active nucleic acids and nanoparticles. A generalized approach to these issues involves consideration of the multiple biological barriers that stand between the macromolecular drug or nanoparticle at its site of administration and its ultimate biological target. Considerations of size, stability, non-specific versus specific associations and potency versus toxicity all play a role. The creation of delivery approaches that combine high specificity for the target cell or tissue, high therapeutic payload and modest toxicity remains a challenge, although some very promising examples have emerged recently. A variety of sophisticated targeting strategies, based primarily on combinatorial library methods, when used in combination with new technologies to identify cell-surface receptor ‘signatures’ of specific tissues, will facilitate advances in targeted delivery of macromolecules and nanoparticles. The challenges to contemporary macromolecule drug delivery are complex, thus new research paradigms are emerging that combine the talents of physical and biological scientists to address this key issue for modern pharmacology and therapeutics.

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Hudder, Alice, Lubov Nathanson y Murray P. Deutscher. "Organization of Mammalian Cytoplasm". Molecular and Cellular Biology 23, n.º 24 (15 de diciembre de 2003): 9318–26. http://dx.doi.org/10.1128/mcb.23.24.9318-9326.2003.

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ABSTRACT Although the role of macromolecular interactions in cell function has attracted considerable attention, important questions about the organization of cells remain. To help clarify this situation, we used a simple protocol that measures macromolecule release after gentle permeabilization for the examination of the status of endogenous macromolecules. Treatment of Chinese hamster ovary cells with saponin under carefully controlled conditions allowed entry of molecules of at least 800 kDa; however, there were minimal effects on internal cellular architecture and protein synthesis remained at levels comparable to those seen with intact cells. Most importantly, total cellular protein and RNA were released from these cells extremely slowly. The release of actin-binding proteins and a variety of individual cytoplasmic proteins mirrored that of total protein, while marker proteins from subcellular compartments were not released. In contrast, glycolytic enzymes leaked rapidly, indicating that cells contain at least two distinct populations of cytoplasmic proteins. Addition of microfilament-disrupting agents led to rapid and extensive release of cytoplasmic macromolecules and a dramatic reduction in protein synthesis. These observations support the conclusion that mammalian cells behave as highly organized, macromolecular assemblies (dependent on the actin cytoskeleton) in which endogenous macromolecules normally are not free to diffuse over large distances.

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Blakeley, Matthew. "Macromolecular crystallography using neutrons". Biochemist 36, n.º 3 (1 de junio de 2014): 40–42. http://dx.doi.org/10.1042/bio03603040.

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When you think about macromolecular crystallography, the technique that most often comes to mind is X-ray diffraction and it's no wonder. Over 88000 structures of biological macromolecules – from proteins and nucleic acids to viruses and macromolecular assemblies – have been determined using X-rays, and these have contributed significantly to our understanding of a vast array of biological systems and processes.

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Mittal, Shruti, Rimpy Kaur Chowhan y Laishram Rajendrakumar Singh. "Macromolecular crowding: Macromolecules friend or foe". Biochimica et Biophysica Acta (BBA) - General Subjects 1850, n.º 9 (septiembre de 2015): 1822–31. http://dx.doi.org/10.1016/j.bbagen.2015.05.002.

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Vohlídal, Jiří, Edward S. Wilks, Andrey Yerin, Alain Fradet, Karl-Heinz Hellwich, Philip Hodge, Jaroslav Kahovec, Werner Mormann y Robert F. T. Stepto. "Terminology and nomenclature for macromolecular rotaxanes and pseudorotaxanes (IUPAC Recommendations 2012)". Pure and Applied Chemistry 84, n.º 10 (21 de septiembre de 2012): 2135–65. http://dx.doi.org/10.1351/pac-rec-11-10-15.

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This document provides (i) definitions of terms related to macromolecular rotaxanes and macromolecular pseudorotaxanes and (ii) recommendations for naming these macromolecular assemblies. The nomenclature recommendations presented here have been developed by combining the nomenclature rules for the low-molar-mass (low-M) rotaxanes and those for macromolecules (both established in published IUPAC recommendations) in such a way that the developed nomenclature system provides unambiguous names for macromolecular rotaxanes (and pseudorotaxanes), including differentiation among various isomers of these supramolecular assemblies. Application of the nomenclature recommendations is illustrated using examples covering a wide range of structure types of macromolecular rotaxanes and pseudorotaxanes. An Alphabetical Index of Terms and a List of Abbreviations and Prefixes are included.

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8

Bazunova, Marina, Valentina Chernova, Roman Lazdin, Angela Shurshina, Anna Bazunova, Mariya Elinson y Elena Kulish. "Cosolvents Impact on some Properties of the Solutions and the Films of Succinamide Chitosan". Chemistry & Chemical Technology 14, n.º 4 (15 de diciembre de 2020): 481–86. http://dx.doi.org/10.23939/chcht14.04.481.

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The article deals with the method of the medical purpose materials creation with the controlled physico-chemical and mechanical deformation properties on the basis of water-soluble derivative of amino polysaccharide chitosan – succinamide chitosan. The essence of the method is the macromolecules aggregation processes regulation in the initial solutions by the injection of organic cosolvents – acetone and ethanol. It has been stated that in a mixed solvent succinamide chitosan molecules are not in the form of the isolated macromolecular balls but as the macromolecules interacting (aggregated) systems. It has been proved that the presence of cosolvents decreases the polymer macromolecule links capability to interact with an enzyme and increases physico-mechanical characteristics of the film materials.

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Confer, David R. y Bruce E. Logan. "A conceptual model describing macromolecule degradation by suspended cultures and biofilms". Water Science and Technology 37, n.º 4-5 (1 de febrero de 1998): 231–34. http://dx.doi.org/10.2166/wst.1998.0631.

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Macromolecular (> 1,000 daltons) compounds such as proteins and polysaccharides can constitute a significant portion of dissolved organic carbon (DOC) in wastewater, but limited information is available on how these compounds are degraded in suspended and fixed-film biological wastewater treatment systems. Bacteria cannot assimilate intact macromolecules but must first hydrolyze them to monomers or small oligomers. Here, we summarize experiments performed in our laboratory which indicate that the enzymes responsible for hydrolysis are primarily those that remain attached to the cell. In biofilm cultures fed macromolecular substrates, for example, no more than 8% of total hydrolytic activity was found to be located in the cell-free bulk solution. These and other experiments support a generalized mechanism for macromolecule degradation by biofilms that features cell-associated hydrolysis, followed by the release of hydrolytic fragments back into bulk solution. The extent of fragment release is larger for proteins (bovine serum albumin) than for carbohydrates (dextrans).

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10

Sharp, Kim A. "Analysis of the size dependence of macromolecular crowding shows that smaller is better". Proceedings of the National Academy of Sciences 112, n.º 26 (15 de junio de 2015): 7990–95. http://dx.doi.org/10.1073/pnas.1505396112.

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The aqueous milieu inside cells contains as much as 30–40% dissolved protein and RNA by volume. This large concentration of macromolecules is expected to cause significant deviations from solution ideality. In vivo biochemical reaction rates and equilibria might differ significantly from those measured in the majority of in vitro experiments that are performed at much lower macromolecule concentrations. Consequently crowding, a nonspecific phenomenon believed to arise from the large excluded volume of these macromolecules, has been studied extensively by experimental and theoretical methods. However, the relevant theory has not been applied consistently. When the steric effects of macromolecular crowders and small molecules like water and ions are treated on an equal footing, the effect of the macromolecules is opposite to that commonly believed. Large molecules are less effective at crowding than water and ions. There is also a surprisingly weak dependence on crowder size. Molecules of medium size, ∼5 Å radius, have the same effect as much larger macromolecules like proteins and RNA. These results require a reassessment of observed high-concentration effects and of strategies to mimic in vivo conditions with in vitro experiments.

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11

Yashchuk, V. M., I. V. Lebedyeva y O. M. Navozenko. "Manifestations of triplet electronic excitations migration in π-electron containing polymers". Bulletin of Taras Shevchenko National University of Kyiv. Series: Physics and Mathematics, n.º 1 (2019): 242–45. http://dx.doi.org/10.17721/1812-5409.2019/1.55.

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The results of spectral studies of polymers with aromatic side groups are considered and analyzed. In particular, the phosphorescence spectra of polyvinylcarbazole (PVCa) polyvinyl-7-benzocarbazole (PV7BK) polypropylcarbazole (PEPC) are presented and analyzed. The phosphorescence of these polymers has been shown to be related to the migration of triplet excitons in macromolecules. The phosphorescence of PVC is determined at 77by deep traps (oxides), at 4.2 -shallow traps (monomer units of PVCa). The spreading length of triplet excitons in PVCa macromolecules is 600 A – that corresponds to the average distances between adjacent traps in the macromolecule. There are no such traps in PV7BK macromolecules. The boundary conditions for triplet excitons in macromolecules of PV7BCa were used for evaluation the excitons spreading length. With this aim the dependence of phosphorescence spectra on molecular weihgt were studied The effect of changing of spectral positions of phosphorescence bands when exciton rich the end macromolecular cell was used. The average trip length of triplet excitons is approximately 1000 A. This distance is in fact limited by the probability of the meeting of triplet excitons in the macromolecule and their annihilation at a given excitation intensity.

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Summers, J. C., L. Trais, R. Lajvardi, D. Hergan, R. Buechler, H. Chang, C. Pena-Rasgado y H. Rasgado-Flores. "Role of concentration and size of intracellular macromolecules in cell volume regulation". American Journal of Physiology-Cell Physiology 273, n.º 2 (1 de agosto de 1997): C360—C370. http://dx.doi.org/10.1152/ajpcell.1997.273.2.c360.

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To gain insight into the mechanism(s) by which cells sense volume changes, specific predictions of the macromolecular crowding theory (A. P. Minton. In: Cellular and Molecular Physiology of Cell Volume Regulation, edited by K. Strange. Boca Raton, FL: CRC, 1994, p. 181-190. A. P. Minton, C. C. Colclasure, and J. C. Parker. Proc. Natl. Acad. Sci. USA 89: 10504-10506, 1992) were tested on the volume of internally perfused barnacle muscle cells. This preparation was chosen because it allows assessment of the effect on cell volume of changes in the intracellular macromolecular concentration and size while maintaining constant the ionic strength, membrane stretch, and osmolality. The predictions tested were that isotonic replacement of large macromolecules by smaller ones should induce volume decreases proportional to the initial macromolecular concentration and size as well as to the magnitude of the concentration reduction. The experimental results were consistent with these predictions: isotonic replacement of proteins or polymers with sucrose induced volume reductions, but this effect was only observed when the replacement was > or = 25% and the particular macromolecule had an average molecular mass of < or = 20 kDa and a concentration of at least 18 mg/ml. Volume reduction was effected by a mechanism identical with that of hypotonicity-induced regulatory volume decrease, namely, activation of verapamil-sensitive Ca2+ channels.

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Kanso, Mona A., A. Jeffrey Giacomin, Chaimongkol Saengow y Jourdain H. Piette. "Diblock copolymer architecture and complex viscosity". International Journal of Modern Physics B 34, n.º 14n16 (3 de junio de 2020): 2040110. http://dx.doi.org/10.1142/s0217979220401104.

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General rigid bead-rod theory [O. Hassager, J. Chem. Phys. 60, 4001 (1974)] explains polymer viscoelasticity from macromolecular orientation. By means of general rigid bead-rod theory, we relate the complex viscosity of polymeric liquids to the architecture of axisymmetric macromolecules. In this paper, we explore the complex viscosities of different axisymmetric diblock copolymer configurations. When nondimensionalized with the zero-shear viscosity, the diblock copolymer complex viscosity depends on the dimensionless frequency and the sole dimensionless architectural parameter, the macromolecular lopsidedness. In this paper, through this way, we thus compare the dimensionless relaxation time of different diblock macromolecular chains. We explore the effects of linear density, macromolecular length, and bead number ratio.

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Stepto, Robert, Taihyun Chang, Pavel Kratochvíl, Michael Hess, Kazuyuki Horie, Takahiro Sato y Jiří Vohlídal. "Definitions of terms relating to individual macromolecules, macromolecular assemblies, polymer solutions, and amorphous bulk polymers (IUPAC Recommendations 2014)". Pure and Applied Chemistry 87, n.º 1 (1 de enero de 2015): 71–120. http://dx.doi.org/10.1515/pac-2013-0201.

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AbstractThis document defines terms relating to the properties of individual macromolecules, macromolecular assemblies, polymer solutions, and amorphous bulk polymers. In the section on polymer solutions and amorphous bulk polymers, general and thermodynamic terms, dilute solutions, phase behaviour, transport properties, scattering methods, and separation methods are considered. The recommendations are a revision and expansion of the IUPAC terminology published in 1989 dealing with individual macromolecules, macromolecular assemblies, and dilute polymer solutions. New terms covering the principal theoretical and experimental developments that have occurred over the intervening years have been introduced. Polyelectrolytes are not included.

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Emancipator, S. N., C. S. Rao, A. Amore, R. Coppo y J. G. Nedrud. "Macromolecular properties that promote mesangial binding and mesangiopathic nephritis." Journal of the American Society of Nephrology 2, n.º 10 (abril de 1992): S149. http://dx.doi.org/10.1681/asn.v210s149.

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The hydrodynamic size, electrostatic charge, and specificity are established determinants of the site of glomerular localization of macromolecules. Larger macromolecules or aggregates and anionic charge are associated with mesangial deposits, despite the fact that the mesangial matrix bears a negative charge similar to that of the capillary wall. Antigens such as Sendai virus, a model infectious pathogen, gliadin, a model dietary/environmental agent and fibronectin, a model endogenous macromolecule, bind to mesangial cells in vitro on the basis of cell surface glycoconjugates. Nonantibody immunoglobulin A, which does not bind to cells directly, binds to these elements via different carbohydrate specificities (simple sugar inhibition). Such binding promotes or augments macromolecular deposition in the mesangium. More significantly, mesangial deposits per se are not pathogenic, because normal renal function can be observed with florid deposits. Pathogenic deposits must have properties that alter mesangial cell metabolism or interaction with the matrix. Although complement activation is well recognized, complement-independent mechanisms related to cell surface modulation are being recognized. In vitro, antigen/immunoglobulin A aggregates alter mesangial cell eicosanoid synthesis. In vivo, large-lattice cross-linking by particulate antigen promotes hematuria. We conclude that the binding of macromolecules to cells and the cross-linking of cell surface molecules cause alterations in the mesangial cells and therefore in glomerular function. The mesangial cell, rather than a passive respondent, is an active participant in the genesis of glomerulonephritis.

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KIKUCHI, Yasuo. "Macromolecular complexes consisting of sodium tetrapolyphosphate with either fnctional organic macromolecule or inorganic macromolecules." NIPPON KAGAKU KAISHI, n.º 6 (1987): 1086–88. http://dx.doi.org/10.1246/nikkashi.1987.1086.

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Weik, Martin y Jacques-Philippe Colletier. "Temperature-dependent macromolecular X-ray crystallography". Acta Crystallographica Section D Biological Crystallography 66, n.º 4 (24 de marzo de 2010): 437–46. http://dx.doi.org/10.1107/s0907444910002702.

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X-ray crystallography provides structural details of biological macromolecules. Whereas routine data are collected close to 100 K in order to mitigate radiation damage, more exotic temperature-controlled experiments in a broader temperature range from 15 K to room temperature can provide both dynamical and structural insights. Here, the dynamical behaviour of crystalline macromolecules and their surrounding solvent as a function of cryo-temperature is reviewed. Experimental strategies of kinetic crystallography are discussed that have allowed the generation and trapping of macromolecular intermediate states by combining reaction initiation in the crystalline state with appropriate temperature profiles. A particular focus is on recruiting X-ray-induced changes for reaction initiation, thus unveiling useful aspects of radiation damage, which otherwise has to be minimized in macromolecular crystallography.

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Li, Chao, Xiangxiang Zhang, Mingdong Dong y Xiaojun Han. "Progress on Crowding Effect in Cell-like Structures". Membranes 12, n.º 6 (3 de junio de 2022): 593. http://dx.doi.org/10.3390/membranes12060593.

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Several biological macromolecules, such as proteins, nucleic acids, and polysaccharides, occupy about 30% of the space in cells, resulting in a crowded macromolecule environment. The crowding effect within cells exerts an impact on the functions of biological components, the assembly behavior of biomacromolecules, and the thermodynamics and kinetics of metabolic reactions. Cell-like structures provide confined and independent compartments for studying the working mechanisms of cells, which can be used to study the physiological functions arising from the crowding effect of macromolecules in cells. This article mainly summarizes the progress of research on the macromolecular crowding effects in cell-like structures. It includes the effects of this crowding on actin assembly behavior, tubulin aggregation behavior, and gene expression. The challenges and future trends in this field are presented at the end of the paper.

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Prasetyanti, Intan Kris, Sukardiman Sukardiman y Suharjono Suharjono. "Molecular Docking of Mangostin and Sinensetin Derivatives on SUR1-Pancreatic KATP Channel Target as Antidiabetic". JURNAL FARMASI DAN ILMU KEFARMASIAN INDONESIA 8, n.º 3 (30 de noviembre de 2021): 271. http://dx.doi.org/10.20473/jfiki.v8i32021.271-276.

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Background: Diabetes Mellitus (DM) is a complex chronic disease characterized by increased blood glucose. The incidence of this disease is rising, especially type 2 diabetes which is caused by insulin resistance in the body. SUR1-Pancreatic KATP Channel is a receptor as an antidiabetic target because its inhibition process can increase insulin production so that it can reduce blood glucose in people with type 2 diabetes. Objective: This study aims to identify the in-silico activity of the SUR1-Pancreatic KATP Channel macromolecules. Methods: Identification of macromolecular binding sites using Protein Plus software, then carried out molecular docking using AutoDock software, where the formed molecular interactions are further identified using the BIOVIA Discovery Studio software. Results: After determining the macromolecular binding site, the RMSD value was 1.253, allowing for further molecular docking. Molecular docking showed that the Ligands of mangostin (α, β, γ-mangostin) and sinensetin derivatives had a good affinity, namely α-mangostin -6,31 kcal/mol; β-mangostin -5.78 kcal/mol; γ-mangostin -6.17 kcal/mol and sinensetin -4.75 kcal/mol. Conclusion: The affinity sequence in the docking process for the SUR1 KATP channel macromolecules is α-mangostin > γ-mangostin > β-mangostin > sinensetin. The highest affinity for the docking process on the macromolecule SUR1 KATP channel was α-mangostin with a value of ΔG -6.31 kcal/mol Ki 23.65 μM.

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Garner, M. M. y M. B. Burg. "Macromolecular crowding and confinement in cells exposed to hypertonicity". American Journal of Physiology-Cell Physiology 266, n.º 4 (1 de abril de 1994): C877—C892. http://dx.doi.org/10.1152/ajpcell.1994.266.4.c877.

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The nonideal properties of solutions containing high concentrations of macromolecules can result in enormous increases in the activity of the individual macromolecules. It has been proposed that molecular crowding and confinement occur in cells and are major determinants of the activity of the proteins and other intracellular macromolecules. This concept has important implications for cell volume regulation because, under crowded conditions, relatively small changes in concentration, consequent to alterations of water content, lead to large changes in macromolecular activity. This review considers several aspects of macromolecular crowding and confinement, including: 1) the physical chemical principles involved; 2) in vitro demonstrations of the effects; 3) relation to water activity; 4) estimates of the actual intracellular activity of water and macromolecules; 5) relation to osmotic regulation in various types of cells, including bacteria, red blood cells, and complex nucleated cells; and 6) the relation to inorganic ions and organic osmolytes in cells stressed by hypertonicity. We conclude that, while there is compelling evidence for important effects of molecular crowding in vitro and in red blood cells, the role of macromolecular crowding and confinement in osmotic regulation of more complex cells is an open question that deserves the extensive attention it is currently receiving.

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Hasan, Mahadi, Anowara Khatun y Kentaro Kogure. "Iontophoresis of Biological Macromolecular Drugs". Pharmaceutics 14, n.º 3 (26 de febrero de 2022): 525. http://dx.doi.org/10.3390/pharmaceutics14030525.

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Over the last few decades, biological macromolecular drugs (e.g., peptides, proteins, and nucleic acids) have become a significant therapeutic modality for the treatment of various diseases. These drugs are considered superior to small-molecule drugs because of their high specificity and favorable safety profiles. However, such drugs are limited by their low oral bioavailability and short half-lives. Biological macromolecular drugs are typically administrated via invasive methods, e.g., intravenous or subcutaneous injections, which can be painful and induce needle phobia. Noninvasive transdermal delivery is an alternative administration route for the local and systemic delivery of biological macromolecular drugs. However, a challenge with the noninvasive transdermal delivery of biological macromolecular drugs is the outermost layer of the skin, known as the stratum corneum, which is a physical barrier that restricts the entry of extraneous macromolecules. Iontophoresis (IP) relies on the application of a low level of electricity for transdermal drug delivery, in order to facilitate the skin permeation of hydrophilic and charged molecules. The IP of several biological macromolecular drugs has recently been investigated. Herein, we review the IP-mediated noninvasive transdermal delivery of biological macromolecular drugs, their routes of skin permeation, their underlying mechanisms, and their advance applications.

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Grube, Mandy, Gizem Cinar, Ulrich S. Schubert y Ivo Nischang. "Incentives of Using the Hydrodynamic Invariant and Sedimentation Parameter for the Study of Naturally- and Synthetically-Based Macromolecules in Solution". Polymers 12, n.º 2 (31 de enero de 2020): 277. http://dx.doi.org/10.3390/polym12020277.

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The interrelation of experimental rotational and translational hydrodynamic friction data as a basis for the study of macromolecules in solution represents a useful attempt for the verification of hydrodynamic information. Such interrelation originates from the basic development of colloid and macromolecular science and has proven to be a powerful tool for the study of naturally- and synthetically-based, i.e., artificial, macromolecules. In this tutorial review, we introduce this very basic concept with a brief historical background, the governing physical principles, and guidelines for anyone making use of it. This is because very often data to determine such an interrelation are available and it only takes a set of simple equations for it to be established. We exemplify this with data collected over recent years, focused primarily on water-based macromolecular systems and with relevance for pharmaceutical applications. We conclude with future incentives and opportunities for verifying an advanced design and tailored properties of natural/synthetic macromolecular materials in a dispersed or dissolved manner, i.e., in solution. Particular importance for the here outlined concept emanates from the situation that the classical scaling relationships of Kuhn–Mark–Houwink–Sakurada, most frequently applied in macromolecular science, are fulfilled, once the hydrodynamic invariant and/or sedimentation parameter are established. However, the hydrodynamic invariant and sedimentation parameter concept do not require a series of molar masses for their establishment and can help in the verification of a sound estimation of molar mass values of macromolecules.

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Oliver, Susan, Orazio Vittorio, Giuseppe Cirillo y Cyrille Boyer. "Enhancing the therapeutic effects of polyphenols with macromolecules". Polymer Chemistry 7, n.º 8 (2016): 1529–44. http://dx.doi.org/10.1039/c5py01912e.

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Wang, Yang, Yan Dai, Qiang Luo, Xiaoli Wei, Xueyang Xiao, Haonan Li, Jiani Hu, Qiyong Gong, Jianlin Wu y Kui Luo. "Tumor Environment-Responsive Degradable Branched Glycopolymer Magnetic Resonance Imaging Contrast Agent and Its Tumor-Targeted Imaging". Journal of Biomedical Nanotechnology 15, n.º 7 (1 de julio de 2019): 1384–400. http://dx.doi.org/10.1166/jbn.2019.2759.

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Branched macromolecules have been used as carriers for imaging probes and drug delivery systems because of their tunable molecular structures, as well as their regular nanoscale structures and dimensions. We designed and synthesized two tumor environment-responsive branched and gadolinium (Gd)-based glycopolymer conjugates and investigated their potency as highly effective and safe magnetic resonance imaging (MRI) contrast agents. These branched macromolecules were prepared by one-pot reversible addition fragmentation chain transfer (RAFT) polymerization and conjugating chemistry. A biodegradable GFLG oligopeptide was used to successfully link the branch-chains of the branched macromolecules, finally a conjugate of this branched macromolecule and DOTA-Gd (HB-pGAEMA-Gd) with a molecular weight (MW) of 124 kDa was produced. Meanwhile, to improve the ability of tumor-targeting, we conjugated a tumor-targeting cRGDyK cyclic peptide to the branched molecule to prepare a tumor-targeted branched macromoleculeDOTA-Gd conjugate (HB-pGAEMA-RGD-Gd) with a MW of 136 kDa. The prepared branched macromolecules had a nanoscale hydrodynamic particle size and could be degraded into lower MW fragments with the cathepsin B. The aqueous phase relaxation efficiency of HB-pGAEMA-RGD-Gd (12.3 mM–1s–1 and HB-pGAEMA-Gd (13.2 mM–1s–1 was four times higher than that of DTPA-Gd (2.9 mM–1s–1), a clinically used contrast agent. In comparison with DTPA-Gd, the branched macromolecular contrast agents significantly enhanced the MRI signal intensity at the tumor site in vivo, and the enhancement of MRI signal intensity was up to 6 times that of the DTPA-Gd owing to their high relaxation efficiencies and accumulation at the tumor site. In addition, in vitro and in vivo toxicity studies indicated that the degradable macromolecular contrast agents had no significant toxicity.

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Zhang, Jie Bing, An Ning Zhou y Xiao Li Zhang. "The Coal Oxidized by HNO₃ on the Conductivity Effect of Coal-Based Polyaniline". Advanced Materials Research 152-153 (octubre de 2010): 1138–41. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.1138.

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The interation between aniline and shenfu-coal(SFC) was studied by the changes about acidic functional groups and the absence of coal macromolecules. The results showed that the acid content in coal is increased by HNO3, the conductivity of OCPANI, HNO3-OCEX-PANI, as well as SFCEX-PANI is lower than SFC-PANI. The macromolecular structure of the SFC play an important role,the macromolecular acid in coal only play the weak doping role.

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Sheriff, Falana Aziza y Styliani Consta. "Charge-induced instabilities of droplets containing macromolecular complexes". Canadian Journal of Chemistry 93, n.º 2 (febrero de 2015): 173–80. http://dx.doi.org/10.1139/cjc-2014-0299.

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Solvated macromolecular complexes are ubiquitous in nature, notably in biological systems containing proteins and nucleic acids. Studies of the interactions within a macromolecular complex and between the complex and the solvent in droplet environments are critical for understanding the stability of macromolecular complexes in electrospray ionization (ESI) and nanofluidic experiments. In this study, two distinct cases of macromolecular complexes in aqueous nanodrops are examined by using molecular dynamics simulations: (i) a pair of sodiated poly(ethylene) glycol (PEG) macroions and (ii) a double-stranded DNA (dsDNA). PEG represents a case in which the surface energy of the aqueous droplet is larger than the solvent–macromolecule energy. Conversely, in a droplet solvating dsDNA, the solvent–macromolecule interaction energy overcomes the solvent interaction energy. We report that charge-induced instabilities previously identified for single macroions also appear in the case of complexes, but with a higher level of complexity. In the case of a pair of PEG macroions, we found that their conformations on the surface of a droplet “sense” each other. The charged PEGs are each released from a droplet at different times through contiguous extrusion or drying-out mechanisms. In the case of the DNA, the charge-induced instability manifests as a spine droplet morphology. Narrow regions of the spines promote break down of the hydrogen bonds that hold the dsDNA together. The dsDNA separates into two single strands as it is increasingly exposed to vacuum. These findings elucidate charge-induced instabilities of macromolecular complexes in droplets, which are critical intermediates in ESI and nanofluidic experiments.

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27

C.M.D. "Macromolecular structures 1991: Atomic structures of biological macromolecules". Trends in Biochemical Sciences 17, n.º 7 (julio de 1992): 272. http://dx.doi.org/10.1016/0968-0004(92)90412-3.

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28

Holloway, Joshua O., Filip Van Lijsebetten, Nezha Badi, Hannes A. Houck y Filip E. Du Prez. "From Sequence‐Defined Macromolecules to Macromolecular Pin Codes". Advanced Science 7, n.º 8 (3 de marzo de 2020): 1903698. http://dx.doi.org/10.1002/advs.201903698.

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29

Painter, Jay y Ethan A. Merritt. "mmLibPython toolkit for manipulating annotated structural models of biological macromolecules". Journal of Applied Crystallography 37, n.º 1 (17 de enero de 2004): 174–78. http://dx.doi.org/10.1107/s0021889803025639.

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ThePython Macromolecular Library(mmLib) is a software toolkit and library of routines for the analysis and manipulation of macromolecular structural models, implemented in the Python programming language. It is accessedviaa layered object-oriented application programming interface, and provides a range of useful software components for parsing mmCIF, PDB and MTZ files, a library of atomic elements and monomers, an object-oriented data structure describing biological macromolecules, and an OpenGL molecular viewer. The mmLib data model is designed to provide easy access to the various levels of detail needed to implement high-level application programs for macromolecular crystallography, NMR, modeling and visualization. We describe here the establishment ofmmLibas a collaborative open-source code base, and the use of mmLib to implement several simple illustrative application programs.

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30

Nam, Ki Hyun. "Serial X-ray Crystallography II". Crystals 13, n.º 2 (25 de enero de 2023): 222. http://dx.doi.org/10.3390/cryst13020222.

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Traditional macromolecular crystallography (MX) and recently spotlighted cryogenic electron microscopy (Cryo-EM) techniques have contributed greatly to the development of macromolecule structures and the related fields [...]

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31

Gjuroski, Ilche, Julien Furrer y Martina Vermathen. "Probing the Interactions of Porphyrins with Macromolecules Using NMR Spectroscopy Techniques". Molecules 26, n.º 7 (30 de marzo de 2021): 1942. http://dx.doi.org/10.3390/molecules26071942.

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Porphyrinic compounds are widespread in nature and play key roles in biological processes such as oxygen transport in blood, enzymatic redox reactions or photosynthesis. In addition, both naturally derived as well as synthetic porphyrinic compounds are extensively explored for biomedical and technical applications such as photodynamic therapy (PDT) or photovoltaic systems, respectively. Their unique electronic structures and photophysical properties make this class of compounds so interesting for the multiple functions encountered. It is therefore not surprising that optical methods are typically the prevalent analytical tool applied in characterization and processes involving porphyrinic compounds. However, a wealth of complementary information can be obtained from NMR spectroscopic techniques. Based on the advantage of providing structural and dynamic information with atomic resolution simultaneously, NMR spectroscopy is a powerful method for studying molecular interactions between porphyrinic compounds and macromolecules. Such interactions are of special interest in medical applications of porphyrinic photosensitizers that are mostly combined with macromolecular carrier systems. The macromolecular surrounding typically stabilizes the encapsulated drug and may also modify its physical properties. Moreover, the interaction with macromolecular physiological components needs to be explored to understand and control mechanisms of action and therapeutic efficacy. This review focuses on such non-covalent interactions of porphyrinic drugs with synthetic polymers as well as with biomolecules such as phospholipids or proteins. A brief introduction into various NMR spectroscopic techniques is given including chemical shift perturbation methods, NOE enhancement spectroscopy, relaxation time measurements and diffusion-ordered spectroscopy. How these NMR tools are used to address porphyrin–macromolecule interactions with respect to their function in biomedical applications is the central point of the current review.

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32

Staudinger-Woit, Magda. "Macromolecule and polymer". Terminology 3, n.º 2 (1 de enero de 1996): 343–47. http://dx.doi.org/10.1075/term.3.2.07sta.

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33

Afonine, Pavel V., Alexandre Urzhumtsev y Paul D. Adams. "Macromolecular crystallographic estructure refinement". Arbor 191, n.º 772 (30 de abril de 2015): a219. http://dx.doi.org/10.3989/arbor.2015.772n2005.

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34

Bohl, Katrin, Sabine Hummert, Sarah Werner, David Basanta, Andreas Deutsch, Stefan Schuster, Günter Theißen y Anja Schroeter. "Evolutionary game theory: molecules as players". Mol. BioSyst. 10, n.º 12 (2014): 3066–74. http://dx.doi.org/10.1039/c3mb70601j.

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In many situations macromolecules, such as proteins, DNA and RNA, can be considered as players in the sense of game theory. In this review we discuss the usefulness of game theory in describing macromolecular processes.

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35

Kratochvíl, P. y U. W. Suter. "Macromolecular division commission on macromolecular nomenclature". Polymer Science U.S.S.R. 32, n.º 8 (enero de 1990): 1683–704. http://dx.doi.org/10.1016/0032-3950(90)90092-k.

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36

Petrova, Maria V., Тatiana А. Аgeeva, Sofia S. Rodina y Oscar I. Koifman. "STUDY OF DILUTED SOLUTIONS OF PORPHYRIN-CONTAINING POLYMERIC SYSTEMS BASED ON POLY-4-VINYLPYRIDINE". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, n.º 8 (19 de agosto de 2019): 87–94. http://dx.doi.org/10.6060/ivkkt.20196208.6058.

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The dynamic light scattering method was used to determine the diffusion coefficients and hydrodynamic radius of particles in diluted dimethylformamide solutions of poly-4-vinylpyridine, polystyrene, styrene and 4-vinylpyridine copolymers with different comonomer compositions and poly-4-vinylpyridine modified by zinc meso-tetraphenilporphrine. The temperature range was from 20 °C to 25 °C. The copolymers were obtained in different conditions - by thermal and microwave heating. In order to determine the optimal conditions for the behavior of macromolecular reactions involving these polymers, diluted solutions of all samples were studied by the viscometric method. For these systems, a solvent of appropriate quality was selected, the structure of the solution was studied, the interaction of the solvent with the polymer was evaluated, the parameters of the macromolecular ravel were calculated: characteristic viscosities, Huggin’s constants, root-mean-square distances between the ends of the chains and the specific indicator of the system taking into account the molecular weight of the polymers was presented. It is shown, that the values of characteristic viscosity fall with increasing temperature, the Huggin’s constant, on the contrary increases. These data indicate that the "quality" of the solvent for the systems under study is deteriorating, that is, the tangle of macromolecules in dimethylformamide shrinks with increasing temperature. This behavior is typical for systems with a lower critical temperature of dissolution. The introduction of the porphyrin fragment into the polymer macromolecule loosens the macromolecular coil, but does not change the behavior of the system in the solution as a whole. The results obtained by the quasi-elastic light scattering method are consistent with the data obtained by the viscometric method. The surface morphology and elemental composition of poly-4-vinylpyridine and coordination-related porphyrin polymers on its basis were studied by scanning electron microscopy.

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37

Wei, Zheng, Shuzhe Zhu y Hanying Zhao. "Brush macromolecules with thermo-sensitive coil backbones and pendant polypeptide side chains: synthesis, self-assembly and functionalization". Polymer Chemistry 6, n.º 8 (2015): 1316–24. http://dx.doi.org/10.1039/c4py01268b.

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Macromolecular brushes with thermo-sensitive coil backbones and pendant poly(γ-benzyl-l-glutamate) side chains were synthesized by reversible addition–fragmentation chain transfer and ring-opening polymerization. Functionalization and self-assembly of the macromolecules were investigated.

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38

Mohapatra, Somesh, Joyce An y Rafael Gómez-Bombarelli. "Chemistry-informed macromolecule graph representation for similarity computation, unsupervised and supervised learning". Machine Learning: Science and Technology 3, n.º 1 (21 de febrero de 2022): 015028. http://dx.doi.org/10.1088/2632-2153/ac545e.

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Abstract The near-infinite chemical diversity of natural and artificial macromolecules arises from the vast range of possible component monomers, linkages, and polymers topologies. This enormous variety contributes to the ubiquity and indispensability of macromolecules but hinders the development of general machine learning methods with macromolecules as input. To address this, we developed a chemistry-informed graph representation of macromolecules that enables quantifying structural similarity, and interpretable supervised learning for macromolecules. Our work enables quantitative chemistry-informed decision-making and iterative design in the macromolecular chemical space.

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39

KIKUCHI, Yasuo. "Macromolecular Complexes of Potassium Metaphosphate with Cationic Organic Macromolecules". NIPPON KAGAKU KAISHI, n.º 9 (1988): 1636–38. http://dx.doi.org/10.1246/nikkashi.1988.1636.

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40

Graham, John. "OptiPrep? Density Gradient Solutions for Macromolecules and Macromolecular Complexes". Scientific World JOURNAL 2 (2002): 1547–50. http://dx.doi.org/10.1100/tsw.2002.844.

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Any density gradient for the isolation of mammalian cells should ideally only expose the sedimenting particles to an increasing concentration of the gradient solute. Thus they will experience only an increasing density and viscosity, other parameters such as osmolality, pH, ionic strength and the concentration of important additives (such as EDTA or divalent cations) should remain as close to constant as possible. This Protocol Article describes the strategies for the dilution of OptiPrep™ in order to prepare such solutions for mammalian cells.

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41

Zheng, Heping, David R. Cooper, Przemyslaw J. Porebski, Ivan G. Shabalin, Katarzyna B. Handing y Wladek Minor. "CheckMyMetal: a macromolecular metal-binding validation tool". Acta Crystallographica Section D Structural Biology 73, n.º 3 (22 de febrero de 2017): 223–33. http://dx.doi.org/10.1107/s2059798317001061.

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Metals are essential in many biological processes, and metal ions are modeled in roughly 40% of the macromolecular structures in the Protein Data Bank (PDB). However, a significant fraction of these structures contain poorly modeled metal-binding sites.CheckMyMetal(CMM) is an easy-to-use metal-binding site validation server for macromolecules that is freely available at http://csgid.org/csgid/metal_sites. TheCMMserver can detect incorrect metal assignments as well as geometrical and other irregularities in the metal-binding sites. Guidelines for metal-site modeling and validation in macromolecules are illustrated by several practical examples grouped by the type of metal. These examples showCMMusers (and crystallographers in general) problems they may encounter during the modeling of a specific metal ion.

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42

Rapisarda, Chiara, Matteo Tassinari, Francesca Gubellini y Rémi Fronzes. "Using Cryo-EM to Investigate Bacterial Secretion Systems". Annual Review of Microbiology 72, n.º 1 (8 de septiembre de 2018): 231–54. http://dx.doi.org/10.1146/annurev-micro-090817-062702.

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Bacterial secretion systems are responsible for releasing macromolecules to the extracellular milieu or directly into other cells. These membrane complexes are associated with pathogenicity and bacterial fitness. Understanding of these large assemblies has exponentially increased in the last few years thanks to electron microscopy. In fact, a revolution in this field has led to breakthroughs in characterizing the structures of secretion systems and other macromolecular machineries so as to obtain high-resolution images of complexes that could not be crystallized. In this review, we give a brief overview of structural advancements in the understanding of secretion systems, focusing in particular on cryo–electron microscopy, whether tomography or single-particle analysis. We describe how such techniques have contributed to knowledge of the mechanism of macromolecule secretion in bacteria and the impact they will have in the future.

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43

Choudhuri, Supratim. "Toxicological Implications of Biological Heterogeneity". International Journal of Toxicology 41, n.º 2 (marzo de 2022): 132–42. http://dx.doi.org/10.1177/10915818211066492.

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From a micro to macro scale of biological organization, macromolecular diversity and biological heterogeneity are fundamental properties of biological systems. Heterogeneity may result from genetic, epigenetic, and non-genetic characteristics (e.g., tissue microenvironment). Macromolecular diversity and biological heterogeneity are tolerated as long as the sustenance and propagation of life are not disrupted. They also provide the raw materials for microevolutionary changes that may help organisms adapt to new selection pressures arising from the environment. Sequence evolution, functional divergence, and positive selection of gene and promoter dosage play a major role in the evolution of life’s diversity including complex metabolic networks, which is ultimately reflected in changes in the allele frequency over time. Robustness in evolvable biological systems is conferred by functional redundancy that is often created by macromolecular diversity and biological heterogeneity. The ability to investigate biological macromolecules at an increasingly finer level has uncovered a wealth of information in this regard. Therefore, the dynamics of biological complexity should be taken into consideration in biomedical research.

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44

Girard, Eric, Anne-Claire Dhaussy, Bernard Couzinet, Jean-Claude Chervin, Mohamed Mezouar, Richard Kahn, Isabella Ascone y Roger Fourme. "Toward fully fledged high-pressure macromolecular crystallography". Journal of Applied Crystallography 40, n.º 5 (5 de septiembre de 2007): 912–18. http://dx.doi.org/10.1107/s0021889807033833.

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Pressure allows one to explore the energy landscape and the various conformations of macromolecules. This might be one of the most interesting prospects of combining macromolecular crystallography (MX) with pressure perturbation. This paper presents innovations in high-pressure macromolecular crystallography (HPMX). A new-generation diamond anvil cell extends the technical feasibility of HPMX experiments up to about 2.5 GPa (depending on the sample). Thanks to the large useful aperture (82°) provided by this cell and special loading techniques (use of splinter and/or multiple samples), HPMX can now be more readily applied to crystals with very anisotropic habits and/or low-symmetry space groups, as demonstrated by analysis of diffraction data collected at 140 MPa from orthorhombic urate oxidase crystals. The behaviour of hexagonal crystals of an octanucleotide was investigated up to 2 GPa.

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45

Putnam, Christopher D., Michal Hammel, Greg L. Hura y John A. Tainer. "X-ray solution scattering (SAXS) combined with crystallography and computation: defining accurate macromolecular structures, conformations and assemblies in solution". Quarterly Reviews of Biophysics 40, n.º 3 (agosto de 2007): 191–285. http://dx.doi.org/10.1017/s0033583507004635.

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AbstractCrystallography supplies unparalleled detail on structural information critical for mechanistic analyses; however, it is restricted to describing low energy conformations of macromolecules within crystal lattices. Small angle X-ray scattering (SAXS) offers complementary information about macromolecular folding, unfolding, aggregation, extended conformations, flexibly linked domains, shape, conformation, and assembly state in solution, albeit at the lower resolution range of about 50 Å to 10 Å resolution, but without the size limitations inherent in NMR and electron microscopy studies. Together these techniques can allow multi-scale modeling to create complete and accurate images of macromolecules for modeling allosteric mechanisms, supramolecular complexes, and dynamic molecular machines acting in diverse processes ranging from eukaryotic DNA replication, recombination and repair to microbial membrane secretion and assembly systems. This review addresses both theoretical and practical concepts, concerns and considerations for using these techniques in conjunction with computational methods to productively combine solution scattering data with high-resolution structures. Detailed aspects of SAXS experimental results are considered with a focus on data interpretation tools suitable to model protein and nucleic acid macromolecular structures, including membrane protein, RNA, DNA, and protein–nucleic acid complexes. The methods discussed provide the basis to examine molecular interactions in solution and to study macromolecular flexibility and conformational changes that have become increasingly relevant for accurate understanding, simulation, and prediction of mechanisms in structural cell biology and nanotechnology.

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46

Boublik, M., V. Mandiyan, S. Tumminia, J. F. Hainfeld y J. S. Wall. "Structural analysis of ribosomal particles from Escherichia coli by STEM". Proceedings, annual meeting, Electron Microscopy Society of America 48, n.º 3 (12 de agosto de 1990): 134–35. http://dx.doi.org/10.1017/s0424820100158212.

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Presently, dedicated scanning transmission electron microscopy (STEM) is the most direct, most versatile and least destructive electron microscopic technique for high resolution studies of biological specimens. Apart from the morphology (shape, characteristic dimensions) of biological macromolecules, STEM can provide quantitative information on their molecular mass, the mass distribution within individual particles (for calculation of the radius of gyration), and the topography of their individual macromolecular components and functional sites. Deposition of nucleic acid molecules under non-denaturing conditions opened the EM field for studies of their conformation under various ionic conditions, their interactions with other macromolecules, proteins in particular, and ultimately to the visualization of the total reconstitution process of macromolecular complexes from their constituents.The potential of high resolution STEM at Brookhaven National Laboratory (BNL) was applied to the study of structure-function relationships of ribosomal particles of Escherichia coli, minute but complex cellular organelles playing a fundamental role in protein synthesis.

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47

Berwick, Richard, David J. Vaux y Létitia Jean. "Multiphasic effect of vinyl pyrrolidone polymers on amyloidogenesis, from macromolecular crowding to inhibition". Biochemical Journal 475, n.º 21 (9 de noviembre de 2018): 3417–36. http://dx.doi.org/10.1042/bcj20180715.

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Deposition of misfolded amyloid polypeptides, associated with cell death, is the hallmark of many degenerative diseases (e.g. type II diabetes mellitus and Alzheimer's disease). In vivo, cellular and extracellular spaces are occupied by a high volume fraction of macromolecules. The resulting macromolecular crowding energetically affects reactions. Amyloidogenesis can either be promoted by macromolecular crowding through the excluded volume effect or inhibited due to a viscosity increase reducing kinetics. Macromolecular crowding can be mimicked in vitro by the addition of non-specific polymers, e.g. Ficoll, dextran and polyvinyl pyrrolidone (PVP), the latter being rarely used to study amyloid systems. We investigated the effect of PVP on amyloidogenesis of full-length human islet amyloid polypeptide (involved in type II diabetes) using fibrillisation and surface activity assays, ELISA, immunoblot and microscale thermophoresis. We demonstrate that high molecular mass PVP360 promotes amyloidogenesis due to volume exclusion and increase in effective amyloidogenic monomer concentration, like other crowders, but without the confounding effects of viscosity and surface activity. Interestingly, we also show that low molecular mass PVP10 has unique inhibitory properties as inhibition of fibril elongation occurs mainly in the bulk solution and is due to PVP10 directly and strongly interacting with amyloid species rather than the increase in viscosity typically associated with macromolecular crowding. In vivo, amyloidogenesis might be affected by the properties and proximity of endogenous macromolecular crowders, which could contribute to changes in associated pathogenesis. More generally, the PVP10 molecular backbone could be used to design small compounds as potential inhibitors of toxic species formation.

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48

Ordanini, Stefania, Wanda Celentano, Anna Bernardi y Francesco Cellesi. "Mannosylated brush copolymers based on poly(ethylene glycol) and poly(ε-caprolactone) as multivalent lectin-binding nanomaterials". Beilstein Journal of Nanotechnology 10 (7 de noviembre de 2019): 2192–206. http://dx.doi.org/10.3762/bjnano.10.212.

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A class of linear and four-arm mannosylated brush copolymers based on poly(ethylene glycol) and poly(ε-caprolactone) is presented here. The synthesis through ring-opening and atom transfer radical polymerizations provided high control over molecular weight and functionality. A post-polymerization azide–alkyne cycloaddition allowed for the formation of glycopolymers with different mannose valencies (1, 2, 4, and 8). In aqueous media, these macromolecules formed nanoparticles that were able to bind lectins, as investigated by concanavalin A binding assay. The results indicate that carbohydrate–lectin interactions can be tuned by the macromolecular architecture and functionality, hence the importance of these macromolecular properties in the design of targeted anti-pathogenic nanomaterials.

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49

Kato, Takashi, Takeshi Sakamoto y Tatsuya Nishimura. "Macromolecular Templating for the Formation of Inorganic-Organic Hybrid Structures". MRS Bulletin 35, n.º 2 (febrero de 2010): 127–32. http://dx.doi.org/10.1557/mrs2010.632.

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AbstractBiominerals such as the nacre of shells, spicules of sea urchins, teeth, and bones are inorganic-organic hybrids that have highly controlled hierarchical and complex structures. These structures are formed in mild conditions, and the processes are controlled by macromolecular templates of proteins, peptides, and polysaccharides. Materials scientists can obtain ideas from the structures, properties, and formation processes of biominerals for use in creating synthetic, biomimetic materials. This article highlights bioinspired synthetic approaches to the development of organic/CaCO3 hybrids using macromolecular templates. These hybrids have oriented, patterned, and 3D complex structures, as well as thin films with smooth surfaces. The structures are formed by templating synthetic and semisynthetic macromolecules. These materials have great potential for new functional materials.

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50

Golden, Emily A. y Alice Vrielink. "Looking for Hydrogen Atoms: Neutron Crystallography Provides Novel Insights Into Protein Structure and Function". Australian Journal of Chemistry 67, n.º 12 (2014): 1751. http://dx.doi.org/10.1071/ch14337.

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Neutron crystallography allows direct localization of hydrogen positions in biological macromolecules. Within enzymes, hydrogen atoms play a pivotal role in catalysis. Recent advances in instrumentation and sample preparation have helped to overcome the difficulties of performing neutron diffraction experiments on protein crystals. The application of neutron macromolecular crystallography to a growing number of proteins has yielded novel structural insights. The ability to accurately position water molecules, hydronium ions, and hydrogen atoms within protein structures has helped in the study of low-barrier hydrogen bonds and hydrogen-bonding networks. The determination of protonation states of protein side chains, substrates, and inhibitors in the context of the macromolecule has provided important insights into enzyme chemistry and ligand binding affinities, which can assist in the design of potent therapeutic agents. In this review, we give an overview of the method and highlight advances in knowledge attained through the application of neutron protein crystallography.

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