Journal articles on the topic '14-helix'

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1

Hart, Scott A., Adilah B. F. Bahadoor, Erin E. Matthews, Xiaoyan J. Qiu, and Alanna Schepartz. "Helix Macrodipole Control of β3-Peptide 14-Helix Stability in Water." Journal of the American Chemical Society 125, no. 14 (April 2003): 4022–23. http://dx.doi.org/10.1021/ja029868a.

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2

Seta, Yuji, Shinobu Takeda, Takashi Toyono, Hidemitsu Harada, and Kuniaki Toyoshima. "14. Expression of basic helix-loop-helix transcription factors in rat taste buds." Journal of the Kyushu Dental Society 53, no. 6 (1999): 729–30. http://dx.doi.org/10.2504/kds.53.729.

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3

Wang, Ting, Deguo Du, and Feng Gai. "Helix–coil kinetics of two 14-residue peptides." Chemical Physics Letters 370, no. 5-6 (March 2003): 842–48. http://dx.doi.org/10.1016/s0009-2614(03)00223-9.

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4

Choi, Soo Hyuk, Ilia A. Guzei, and Samuel H. Gellman. "Crystallographic Characterization of the α/β-Peptide 14/15-Helix." Journal of the American Chemical Society 129, no. 45 (November 2007): 13780–81. http://dx.doi.org/10.1021/ja0753344.

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5

Wu, Yun-Dong, and De-Ping Wang. "Theoretical Study on Side-Chain Control of the 14-Helix and the 10/12-Helix of β-Peptides." Journal of the American Chemical Society 121, no. 40 (October 1999): 9352–62. http://dx.doi.org/10.1021/ja990955l.

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6

Lee, Jaeyeon, Geunhyeok Jang, Philjae Kang, Moon-Gun Choi, and Soo Hyuk Choi. "Helical α/β-depsipeptides with alternating residue types: conformational change from the 11-helix to the 14/15-helix." Organic & Biomolecular Chemistry 14, no. 36 (2016): 8438–42. http://dx.doi.org/10.1039/c6ob01602b.

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7

Son, Hyosuk, Seong-Cheol Park, Young-Min Kim, Jong-Kook Lee, Soyoung Park, Taeuk Guk, A.-Mi Yoon, Hye Song Lim, Mi-Kyeong Jang, and Jung Ro Lee. "Potent Anti-Inflammatory Effects of a Helix-to-Helix Peptide against Pseudomonas aeruginosa Endotoxin-Mediated Sepsis." Antibiotics 11, no. 11 (November 21, 2022): 1675. http://dx.doi.org/10.3390/antibiotics11111675.

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Although considerable scientific research data is available for sepsis and cytokine storm syndrome, there is a need to develop new treatments or drugs for sepsis management. Antimicrobial peptides (AMPs) possess anti-bacterial and anti-inflammatory activity, neutralizing toxins such as lipopolysaccharides (LPS, endotoxin). Most AMPs have been designed as a substitute for conventional antibiotics, which kill drug-resistant pathogens. The present study aimed to determine the anti-inflammatory potential of 10 designed XIW (X: lysine, arginine, or glutamic acid) α-helical peptides in macrophages and a mouse model in the presence of LPS. Among them, WIKE-14, a peptide with a helix-to-helix structure, having the 12th amino acid substituted with glutamic acid, suppressed pro-inflammatory cytokines in RAW 264.7 macrophages. This reaction was mediated by the inhibition of the binding between LPS and macrophages. In addition, the WIKE-14 peptide exhibited a potent anti-inflammatory activity in mice ears and lungs inflamed using LPS. Thus, our results may provide useful insights for the development of anti-sepsis agents via the sequence and structure information of the WIKE-14 peptide.
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8

BROOK, FRED J., and JONATHAN D. ABLETT. "Type material of land snails (Mollusca: Gastropoda) described from New Zealand by taxonomists in Europe and North America between 1830 and 1934, and the history of research on the New Zealand land snail fauna from 1824 to 1917." Zootaxa 4697, no. 1 (November 14, 2019): 1–117. http://dx.doi.org/10.11646/zootaxa.4697.1.1.

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Details are provided on 124 land snail species and varieties from New Zealand, and a further 14 species putatively from New Zealand, all of which were described by European and North American taxonomists between 1830 and 1934, based on specimens collected between 1824 and 1924. Primary type material of 95 of these taxa was located in Northern Hemisphere museums during the present study. Lectotypes are designated for: Helix chimmoi Pfeiffer, 1857, Helix glabriuscula Reeve, 1852, Helix (Paryphanta) gilliesi Smith, 1880, Nanina ? celinde Gray, 1850, Zonites chiron Gray, 1850 and Zonites coma Gray, 1843. Neotypes are designated for Helix conella Pfeiffer, 1861 and Helix tau Pfeiffer, 1861. Primary type material of the following taxa is figured herein for the first time: Bulimus? (Laoma) leimonias Gray, 1850, Cyclophorus cytora Gray, 1850, Cyclostoma (Cyclophorus?) lignarium Pfeiffer, 1857, Helix chimmoi Pfeiffer, 1857, Helix egesta Gray, 1850, Helix fatua Pfeiffer, 1857, Helix greenwoodi Gray, 1850, Helix guttula Pfeiffer, 1853, Helix kermandeci Pfeiffer, 1857, Helix portia Gray, 1850, Helix sciadium Pfeiffer, 1857, Helix venulata Pfeiffer, 1857, Helix (Paryphanta) gilliesi Smith, 1880, Hydrocena (Omphalotropis) vestita Pfeiffer, 1855, Nanina ? celinde Gray, 1850, Nanina erigone Gray, 1850, Nanina mariae Gray, 1843, Patula modicella var. vicinalis Mousson, 1873, Realia egea Gray, 1850, Vitrina kermadecensis Smith, 1873 and Zonites chiron Gray, 1850. New taxonomic combinations introduced herein include: Allodiscus nematophora (Reeve, 1854), Cavellia biconcava (Reeve, 1852), Charopa chimmoi (Pfeiffer, 1857), Coneuplecta regularis (Reeve, 1854), Delos jeffreysiana (Reeve, 1852), Fectola tau (Pfeiffer, 1861), Fectola varicosa (Reeve, 1852), Flammulina crebriflammea (Reeve, 1852), Lyrotropis vestita (Pfeiffer, 1855), ?Neophenacohelix ziczac (Gould, 1846), Parabalea peregrina (Gould, 1847), Phacussa hypopolea (Reeve, 1852), Phenacharopa novoseelandica (Küster, 1852), Phrixgnathus glabriusculus (Reeve, 1852), Phrixgnathus poecilostictus (Reeve, 1852), Thalassohelix obnubila (Reeve, 1852), Tornatellinops novoseelandica (Küster, 1852) and Wainuia urnula (Reeve, 1854). Helix collyrula Reeve, 1852 and Nanina tullia Gray, 1850 are treated as junior synonyms of Phenacohelix (Neophenacohelix) giveni Cumber 1961 nomen protectum and Helix (Huttonella) pseudoleioda Suter, 1890 nomen protectum, respectively. A brief account is given of the history of research on the New Zealand land snail fauna from 1824 to 1917.
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9

Wang, Yunjun, Jan Sejbal, George Kotovych, and Paul G. Scott. "Evidence for the role of the α-helix in the xylosylation reactions involving the glycosaminoglycan-bearing serine of decorin/DS-PGII as shown by 1H NMR, CD, and molecular modeling studies." Canadian Journal of Chemistry 74, no. 3 (March 1, 1996): 389–401. http://dx.doi.org/10.1139/v96-044.

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The conformation of four peptides (N-terminal acetylated and unacetylated 14-mers DEASGIGPEEHFPENH2 and 24-mers AcQKGLFDFMLEDEASGIGPEEHFPENH2 with a normal and an oxidized methionine residue) containing the sequence Asp-Glu-Ala-Ser-Gly-Ile-Gly (DEASGIG), which is known to play an important role in the xylosylation reactions involving the glycosaminoglycan-bearing serine of decorin/DS-PGII, were studied by two-dimensional proton NMR techniques, circular dichroism spectroscopy, and molecular dynamics in a methanol–water mixture. The 14-residue peptide comprises the first (i.e., N-terminal) 14 amino acids of the mature decorin protein and the 24-residue peptide incorporates an additional (N-terminal) sequence of 10 amino acids derived from the procore of decorin. The resonance heterogeneity induced by the isomerization of the two prolines (Pro8, Pro13 in the 14-mer, and Pro18, Pro23 in the 24-mer) in the peptides studied was evaluated from TOCSY and NOESY NMR spectra. The trans-trans, trans-cis, and cis-trans isomers exist in approximate 68:25:7 proportions in the methanol–water mixture. The NOE distance constraints were used as input parameters for molecular dynamics and restrained energy minimization calculations. It was demonstrated that the conformation of the DEASGIG fragment was affected by the presence of the 10 amino acids at the N-terminal end of the 24-mer, and that the serine is part of an α-helix. The results indicate that an α-helix is present in the 24-mer beginning at the N-terminal end with Lys2 and ending at Gly15, and suggest that this could be the signal for the xylosylation of serine Ser14. A type VIb β turn was observed, involving the C-terminal cis-proline in the sequence His-Phe-Pro-Glu. Key words: xylosylation, nascent helix, α-helix, csi-proline, type VIb β-turn, molecular dynamics.
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10

Pomerantz, William C., Tami L. R. Grygiel, Jonathan R. Lai, and Samuel H. Gellman. "Distinctive Circular Dichroism Signature for 14-Helix-Bundle Formation by β-Peptides." Organic Letters 10, no. 9 (May 2008): 1799–802. http://dx.doi.org/10.1021/ol800622e.

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11

Sarma, Ramaswamy H. "New Nomenclature for Nucleic Acid Helix Parameters Cambridge, UK, September 14, 1988." Journal of Biomolecular Structure and Dynamics 6, no. 3 (December 1988): 391–95. http://dx.doi.org/10.1080/07391102.1988.10506496.

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12

Kaur, Kamaljit, Tara Sprules, Wael Soliman, Reem Beleid, and Sahar Ahmed. "Right-handed 14-Helix in β3-Peptides from L-Aspartic Acid Monomers." Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 1784, no. 4 (April 2008): 658–65. http://dx.doi.org/10.1016/j.bbapap.2008.01.009.

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13

Legrand, Baptiste, Christophe André, Laure Moulat, Claude Didierjean, Patrick Hermet, Jean-Louis Bantignies, Jean Martinez, Muriel Amblard, and Monique Calmès. "12/14/14-Helix Formation in 2:1 α/β-Hybrid Peptides Containing Bicyclo[2.2.2]octane Ring Constraints." Chemistry - A European Journal 22, no. 34 (July 14, 2016): 11986–90. http://dx.doi.org/10.1002/chem.201602746.

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14

Bao, Zhongli, Ya-Chi Cheng, Justin Jun Wei, Mary Ziping Luo, and Jack Yongfeng Zhang. "Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance Spectroscopy." Molecules 27, no. 22 (November 12, 2022): 7805. http://dx.doi.org/10.3390/molecules27227805.

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Glucagon, a 29-amino acid polypeptide hormone, is an essential therapeutic agent used in the emergency treatment of hypoglycemia. However, glucagon is inherently unstable in aqueous solution. While glucagon equilibrates between unordered and the secondary α-helix state in solution, it can quickly transform into a different secondary β-sheet-rich amyloid-like fibril/oligomer structure under various conditions. Since changes in the secondary structure of glucagon can cause significant impacts, structure analysis is necessary and essential to assess the safety of the product. This study analyzed the secondary structure of glucagon products at the release and at the expiry using circular dichroism spectroscopy (CD) and 2D Nuclear Overhauser effect spectroscopy (2D NOESY). In order to also determine if structural differences exist between glucagon produced through different manufacturing processes, synthetic and recombinant glucagon products were used and compared. The CD results indicated that for all release and expired glucagon products, the structure compositions were 14 to 16% α-helix, 17 to 19% β-strand, 14 to 15% Turn, and 53 to 54% Unordered. This was consistent with the 2D NOESY analysis which showed that both products had an approximate α-helix composition of 14 to 17%. Overall, there were no significant differences in terms of the secondary structure between synthetic and recombinant glucagon products both at the release and at the expiry.
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15

Jagadeesh, Bharatam, Marelli Udaya Kiran, Ambadi Sudhakar, and Srivari Chandrasekhar. "Backbone Regulation Mimicry by β-Peptidic Foldamers: Formation of a 10-Helix in a Mixed 6-Strand/14-Helix Conformational Pool." Chemistry - A European Journal 15, no. 46 (November 23, 2009): 12592–95. http://dx.doi.org/10.1002/chem.200902332.

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16

Guo, Li, Weicheng Zhang, Andrew G. Reidenbach, Michael W. Giuliano, Ilia A. Guzei, Lara C. Spencer, and Samuel H. Gellman. "Characteristic Structural Parameters for the γ-Peptide 14-Helix: Importance of Subunit Preorganization." Angewandte Chemie International Edition 50, no. 26 (May 12, 2011): 5843–46. http://dx.doi.org/10.1002/anie.201101301.

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17

Guo, Li, Weicheng Zhang, Andrew G. Reidenbach, Michael W. Giuliano, Ilia A. Guzei, Lara C. Spencer, and Samuel H. Gellman. "Characteristic Structural Parameters for the γ-Peptide 14-Helix: Importance of Subunit Preorganization." Angewandte Chemie 123, no. 26 (May 12, 2011): 5965–68. http://dx.doi.org/10.1002/ange.201101301.

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18

Kang, Young Kee, and Joo Yun Lee. "Helix foldamers of γ-peptides based on 2-aminocyclopentylacetic acid." New Journal of Chemistry 39, no. 5 (2015): 3241–49. http://dx.doi.org/10.1039/c4nj01202j.

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Oligo-γ-peptides based on 2-aminocyclopentylacetic acid (γAc5a) with a cyclopentyl constraint on the Cβ–Cγ bond and homochiral (1S,2S) configurations preferentially adopt the right-handed 14-helix foldamers in the gas phase and in solution.
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19

Milbeo, Pierre, Matthieu Simon, Claude Didierjean, Emmanuel Wenger, Emmanuel Aubert, Jean Martinez, Muriel Amblard, Monique Calmès, and Baptiste Legrand. "A bicyclic unit reversal to stabilize the 12/14-helix in mixed homochiral oligoureas." Chemical Communications 56, no. 57 (2020): 7921–24. http://dx.doi.org/10.1039/d0cc02902e.

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20

Kritzer, Joshua A., Julian Tirado-Rives, Scott A. Hart, James D. Lear, William L. Jorgensen, and Alanna Schepartz. "Relationship between Side Chain Structure and 14-Helix Stability of β3-Peptides in Water." Journal of the American Chemical Society 127, no. 1 (January 2005): 167–78. http://dx.doi.org/10.1021/ja0459375.

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21

Lee, Myung-ryul, Tami L. Raguse, Marina Schinnerl, William C. Pomerantz, Xiaodong Wang, Peter Wipf, and Samuel H. Gellman. "Origins of the High 14-Helix Propensity of Cyclohexyl-Rigidified Residues in β-Peptides." Organic Letters 9, no. 9 (April 2007): 1801–4. http://dx.doi.org/10.1021/ol070511r.

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22

Vaz, Esther, William C. Pomerantz, Matthias Geyer, Samuel H. Gellman, and Luc Brunsveld. "Comparison of Design Strategies for Promotion of β-Peptide 14-Helix Stability in Water." ChemBioChem 9, no. 14 (September 22, 2008): 2254–59. http://dx.doi.org/10.1002/cbic.200800355.

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23

Stabach, Paul R., Ivana Simonović, Miranda A. Ranieri, Michael S. Aboodi, Thomas A. Steitz, Miljan Simonović, and Jon S. Morrow. "The structure of the ankyrin-binding site of β-spectrin reveals how tandem spectrin-repeats generate unique ligand-binding properties." Blood 113, no. 22 (May 28, 2009): 5377–84. http://dx.doi.org/10.1182/blood-2008-10-184291.

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Spectrin and ankyrin participate in membrane organization, stability, signal transduction, and protein targeting; their interaction is critical for erythrocyte stability. Repeats 14 and 15 of βI-spectrin are crucial for ankyrin recognition, yet the way spectrin binds ankyrin while preserving its repeat structure is unknown. We have solved the crystal structure of the βI-spectrin 14,15 di-repeat unit to 2.1 Å resolution and found 14 residues critical for ankyrin binding that map to the end of the helix C of repeat 14, the linker region, and the B-C loop of repeat 15. The tilt (64°) across the 14,15 linker is greater than in any published di-repeat structure, suggesting that the relative positioning of the two repeats is important for ankyrin binding. We propose that a lack of structural constraints on linker and inter-helix loops allows proteins containing spectrin-like di-repeats to evolve diverse but specific ligand-recognition sites without compromising the structure of the repeat unit. The linker regions between repeats are thus critical determinants of both spectrin's flexibility and polyfunctionality. The putative coupling of flexibility and ligand binding suggests a mechanism by which spectrin might participate in mechanosensory regulation.
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24

Teterina, Natalya L., Eric Levenson, Mario S. Rinaudo, Denise Egger, Kurt Bienz, Alexander E. Gorbalenya, and Ellie Ehrenfeld. "Evidence for Functional Protein Interactions Required for Poliovirus RNA Replication." Journal of Virology 80, no. 11 (June 1, 2006): 5327–37. http://dx.doi.org/10.1128/jvi.02684-05.

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ABSTRACT Poliovirus protein 2C contains a predicted N-terminal amphipathic helix that mediates association of the protein with the membranes of the viral RNA replication complex. A chimeric virus that contains sequences encoding the 18-residue core from the orthologous amphipathic helix from human rhinovirus type 14 (HRV14) was constructed. The chimeric virus exhibited defects in viral RNA replication and produced minute plaques on HeLa cell monolayers. Large plaque variants that contained mutations within the 2C-encoding region were generated upon subsequent passage. However, the majority of viruses that emerged with improved growth properties contained no changes in the region encoding 2C. Sequence analysis and reconstruction of genomes with individual mutations revealed changes in 3A or 2B sequences that compensated for the HRV14 amphipathic helix in the polio 2C-containing proteins, implying functional interactions among these proteins during the replication process. Direct binding between these viral proteins was confirmed by mammalian cell two-hybrid analysis.
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25

Griffin, Vernetta, Tracee McMiller, Erika Jones, and Casonya M. Johnson. "Identifying Novel Helix–Loop–Helix Genes in Caenorhabditis elegans through a Classroom Demonstration of Functional Genomics." Cell Biology Education 2, no. 1 (March 2003): 51–62. http://dx.doi.org/10.1187/cbe.02-09-0040.

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A 14-week, undergraduate-level Genetics and Population Biology course at Morgan State University was modified to include a demonstration of functional genomics in the research laboratory. Students performed a rudimentary sequence analysis of the Caenorhabditis elegans genome and further characterized three sequences that were predicted to encode helix–loop–helix proteins. Students then used reverse transcription–polymerase chain reaction to determine which of the three genes is normally expressed in C. elegans. At the end of this laboratory activity, students were 1) to demonstrate a rudimentary knowledge of bioinformatics, including the ability to differentiate between“ having” a gene and “expressing” a gene, and 2) to understand basic approaches to functional genomics, including one specific technique for assaying for gene expression. It was also anticipated that students would increase their skills at effectively communicating their research activities through written and/or oral presentation. This article describes the laboratory activity and the assessment of the effectiveness of the activity.
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26

Chandrasekhar, Srivari, Marepally Srinivasa Reddy, Bharatam Jagadeesh, Anabathula Prabhakar, Mallem H. V. Ramana Rao, and Bulusu Jagannadh. "Formation of a Stable 14-Helix in Short Oligomers of Furanoidcis-β-Sugar-Amino Acid‖." Journal of the American Chemical Society 126, no. 42 (October 2004): 13586–87. http://dx.doi.org/10.1021/ja0467667.

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27

Raguse, Tami L., Jonathan R. Lai, Paul R. LePlae, and Samuel H. Gellman. "Toward β-Peptide Tertiary Structure: Self-Association of an Amphiphilic 14-Helix in Aqueous Solution." Organic Letters 3, no. 24 (November 2001): 3963–66. http://dx.doi.org/10.1021/ol016868r.

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28

Guarracino, Danielle A., HyoJin R. Chiang, Tereece N. Banks, James D. Lear, Michael E. Hodsdon, and Alanna Schepartz. "Relationship between Salt-Bridge Identity and 14-Helix Stability of β3-Peptides in Aqueous Buffer." Organic Letters 8, no. 5 (March 2006): 807–10. http://dx.doi.org/10.1021/ol0527532.

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29

Kumar, Ajay. "Conformational Studies ofε- CBz-L- Lysine andL- Valine Block Copolypeptides." E-Journal of Chemistry 7, no. 3 (2010): 1013–17. http://dx.doi.org/10.1155/2010/478089.

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Conformational studies ofε-CBz-L-lysine andL-valine block copoylpeptides using x- ray diffraction and CD spectra are described. The block copolypeptides contain valine block in the center and on both side of the valine areε-CBz-L-lysine blocks. The conformation of the copolypeptides changes with increases in the chain length ofε- CBz-L- lysine blocks. When length ofε- CBZ-L- lysine blocks is 9, the block copolypeptide has exclusive beta sheet structure. With the increase in chain length ofε-CBz-L-lysine blocks from 9 to 14, the block copolypeptide shows presence of both alpha helix and beta sheet components. With further increase in chain length ofε- CBz-L- lysine blocks, the beta sheet component disappears and block copolypeptides exhibits exclusive α -helix conformation.
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30

Steger, Lena M. E., Annika Kohlmeyer, Parvesh Wadhwani, Jochen Bürck, Erik Strandberg, Johannes Reichert, Stephan L. Grage, et al. "Structural and functional characterization of the pore-forming domain of pinholin S2168." Proceedings of the National Academy of Sciences 117, no. 47 (November 5, 2020): 29637–46. http://dx.doi.org/10.1073/pnas.2007979117.

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Pinholin S2168 triggers the lytic cycle of bacteriophage φ21 in infectedEscherichia coli. Activated transmembrane dimers oligomerize into small holes and uncouple the proton gradient. Transmembrane domain 1 (TMD1) regulates this activity, while TMD2 is postulated to form the actual “pinholes.” Focusing on the TMD2 fragment, we used synchrotron radiation-based circular dichroism to confirm its α-helical conformation and transmembrane alignment. Solid-state15N-NMR in oriented DMPC bilayers yielded a helix tilt angle of τ = 14°, a high order parameter (Smol= 0.9), and revealed the azimuthal angle. The resulting rotational orientation places an extended glycine zipper motif (G40xxxS44xxxG48) together with a patch of H-bonding residues (T51, T54, N55) sideways along TMD2, available for helix–helix interactions. Using fluorescence vesicle leakage assays, we demonstrate that TMD2 forms stable holes with an estimated diameter of 2 nm, as long as the glycine zipper motif remains intact. Based on our experimental data, we suggest structural models for the oligomeric pinhole (right-handed heptameric TMD2 bundle), for the active dimer (right-handed Gly-zipped TMD2/TMD2 dimer), and for the full-length pinholin protein before being triggered (Gly-zipped TMD2/TMD1-TMD1/TMD2 dimer in a line).
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31

Sahoo, Bikash Ranjan, Madhubanti Basu, Banikalyan Swain, Manas Ranjan Dikhit, Pallipuram Jayasankar, and Mrinal Samanta. "Elucidation of Novel Structural Scaffold in Rohu TLR2 and Its Binding Site Analysis with Peptidoglycan, Lipoteichoic Acid and Zymosan Ligands, and Downstream MyD88 Adaptor Protein." BioMed Research International 2013 (2013): 1–15. http://dx.doi.org/10.1155/2013/185282.

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Toll-like receptors (TLRs) play key roles in sensing wide array of microbial signatures and induction of innate immunity. TLR2 in fish resembles higher eukaryotes by sensing peptidoglycan (PGN) and lipoteichoic acid (LTA) of bacterial cell wall and zymosan of yeasts. However, in fish TLR2, no study yet describes the ligand binding motifs in the leucine rich repeat regions (LRRs) of the extracellular domain (ECD) and important amino acids in TLR2-TIR (toll/interleukin-1 receptor) domain that could be engaged in transmitting downstream signaling. We predicted these in a commercially important freshwater fish species rohu (Labeo rohita) by constructing 3D models of TLR2-ECD, TLR2-TIR, and MyD88-TIR by comparative modeling followed by 40 ns (nanosecond) molecular dynamics simulation (MDS) for TLR2-ECD and 20 ns MDS for TLR2-TIR and MyD88-TIR. Protein (TLR2-ECD)–ligands (PGN, LTA, and zymosan) docking in rohu by AutoDock4.0, FlexX2.1, and GOLD4.1 anticipated LRR16–19, LRR12–14, and LRR20-CT as the most important ligand binding motifs. Protein (TLR2-TIR)—protein (MyD88-TIR) interaction by HADDOCK and ZDOCK predicted BB loop,αB-helix,αC-helix, and CD loop in TLR2-TIR and BB loop,αB-helix, and CD loop in MyD88-TIR as the critical binding domains. This study provides ligands recognition and downstream signaling.
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32

Mandelkow, E. M., R. Schultheiss, R. Rapp, M. Müller, and E. Mandelkow. "On the surface lattice of microtubules: helix starts, protofilament number, seam, and handedness." Journal of Cell Biology 102, no. 3 (March 1, 1986): 1067–73. http://dx.doi.org/10.1083/jcb.102.3.1067.

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The tubulin monomers of brain microtubules reassembled in vitro are arranged on a 3-start helix, irrespective of whether the number of protofilaments is 13 or 14. The dimer packing is that of the B-lattice described for flagellar microtubules. This implies that the tubulin core of microtubules contains at least one helical discontinuity. Neither 5-start nor 8-start helices have a physical significance and thus cannot be implicated in models of microtubule elongation, but the structure is compatible with elongation of protofilaments by dimers or protofilamentous oligomers. The inner and outer surfaces of the microtubule wall can be visualized by propane jet freezing, freeze fracturing, and metal replication, at a resolution of at least 4 nm. The 3-start helix is left-handed, in contrast to a previous study based on negative staining and shadowing. The reasons for this discrepancy are discussed.
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33

Brunet, Anne, Fumihiko Kanai, Justine Stehn, Jian Xu, Dilara Sarbassova, John V. Frangioni, Sorab N. Dalal, James A. DeCaprio, Michael E. Greenberg, and Michael B. Yaffe. "14-3-3 transits to the nucleus and participates in dynamic nucleocytoplasmic transport." Journal of Cell Biology 156, no. 5 (February 25, 2002): 817–28. http://dx.doi.org/10.1083/jcb.200112059.

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14-3-3 proteins regulate the cell cycle and prevent apoptosis by controlling the nuclear and cytoplasmic distribution of signaling molecules with which they interact. Although the majority of 14-3-3 molecules are present in the cytoplasm, we show here that in the absence of bound ligands 14-3-3 homes to the nucleus. We demonstrate that phosphorylation of one important 14-3-3 binding molecule, the transcription factor FKHRL1, at the 14-3-3 binding site occurs within the nucleus immediately before FKHRL1 relocalization to the cytoplasm. We show that the leucine-rich region within the COOH-terminal α-helix of 14-3-3, which had been proposed to function as a nuclear export signal (NES), instead functions globally in ligand binding and does not directly mediate nuclear transport. Efficient nuclear export of FKHRL1 requires both intrinsic NES sequences within FKHRL1 and phosphorylation/14-3-3 binding. Finally, we present evidence that phosphorylation/14-3-3 binding may also prevent FKHRL1 nuclear reimport. These results indicate that 14-3-3 can mediate the relocalization of nuclear ligands by several mechanisms that ensure complete sequestration of the bound 14-3-3 complex in the cytoplasm.
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Cortés, Fanny M., Ledia A. Troncoso, Angélica R. Alliende, and Bianca L. Curotto. "Barber-Say syndrome: further delineation of the clinical spectrum." Genetics and Molecular Biology 23, no. 2 (June 2000): 265–67. http://dx.doi.org/10.1590/s1415-47572000000200003.

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We report on a 14-year-old girl who presented a multiple congenital anomaly pattern: ablepharon, hypertelorism, telecanthus, macrostomia, helix agenesis of both ears, redundant thick skin and severe hirsutism, the 5th reported case of Barber-Say syndrome. Our patient had almost the same phenotype as that of the patient cited by Martínez Santana et al. (Am. J. Med. Genet. 47: 20-23, 1993) including the same until then undescribed dermatoglyphic pattern.
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Kinuhata, Toshiki, Keita Sato, Tetsuya Bando, Taro Mito, Satoru Miyaishi, Tsutomu Nohno, and Hideyo Ohuchi. "Involvement of a Basic Helix-Loop-Helix Gene BHLHE40 in Specification of Chicken Retinal Pigment Epithelium." Journal of Developmental Biology 10, no. 4 (October 29, 2022): 45. http://dx.doi.org/10.3390/jdb10040045.

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The first event of differentiation and morphogenesis in the optic vesicle (OV) is specification of the neural retina (NR) and retinal pigment epithelium (RPE), separating the inner and outer layers of the optic cup, respectively. Here, we focus on a basic helix-loop-helix gene, BHLHE40, which has been shown to be expressed by the developing RPE in mice and zebrafish. Firstly, we examined the expression pattern of BHLHE40 in the developing chicken eye primordia by in situ hybridization. Secondly, BHLHE40 overexpression was performed with in ovo electroporation and its effects on optic cup morphology and expression of NR and RPE marker genes were examined. Thirdly, we examined the expression pattern of BHLHE40 in LHX1-overexpressed optic cup. BHLHE40 expression emerged in a subset of cells of the OV at Hamburger and Hamilton stage 14 and became confined to the outer layer of the OV and the ciliary marginal zone of the retina by stage 17. BHLHE40 overexpression in the prospective NR resulted in ectopic induction of OTX2 and repression of VSX2. Conversely, BHLHE40 was repressed in the second NR after LHX1 overexpression. These results suggest that emergence of BHLHE40 expression in the OV is involved in initial RPE specification and that BHLHE40 plays a role in separation of the early OV domains by maintaining OTX2 expression and antagonizing an NR developmental program.
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Alway, Stephen E., Julie K. Martyn, Jun Ouyang, Archana Chaudhrai, and Zsolt S. Murlasits. "Id2 expression during apoptosis and satellite cell activation in unloaded and loaded quail skeletal muscles." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 284, no. 2 (February 1, 2003): R540—R549. http://dx.doi.org/10.1152/ajpregu.00550.2002.

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Inhibitor of differentiation-2 (Id2) is a basic helix-loop-helix protein that acts as a negative regulator of the myogenic regulatory transcription factor family, but Id2 has also been implicated in apoptosis in several cell lines. In this study, we tested the hypothesis that Id2 has a role in both apoptosis-associated muscle atrophy and muscle hypertrophy. A weight corresponding to 12% of the body weight was attached to one wing of Japanese quail to induce hypertrophy in the patagialis (PAT) muscle. Birds in group 1 were killed after 5 ( n = 8), 7 ( n = 10), or 14 days ( n = 10) of loading. The left wing was loaded for 14 days in group 2 birds, and then the weight was removed and the PAT was examined after 7 ( n = 10), 14 ( n = 10), or 21 ( n = 5) days of unloading. A time-released bromodeoxyuridine (BrdU) pellet was implanted subcutaneously with wing weighting to identify activated satellite cells during loading. The left wing was loaded for 14 days, unloaded for 14 days, and then the weight was reattached for a subsequent 7 ( n = 10) or 14 days ( n = 10) in group 3 birds. BrdU was implanted on the second loading phase in this group. Id2 mRNA as measured by kinetic PCR increased by 3.9-, 2.7-, and 1.6-fold, relative to control levels after 7, 14, and 21 days of unloading ( group 2). Id2 protein as estimated by Western blots increased by 1.5-, 1.4-, and 0.75-fold after 7, 14, and 21 days of unloading ( group 2). Muscle unloading induced apoptosis, because poly(ADP-ribose) polymerase-(PARP)-positive nuclei increased and caspase 8 levels increased by 2.6- and 1.7-fold after 7 or 14 days of unloading, respectively ( group 2). Although BrdU-positive nuclei increased during loading ( groups 1 and 3), 50% failed to survive during unloading ( group 2). Id2 mRNA increased by 2.2- and 1.8-fold after 5 and 7 days of loading, respectively, but decreased to control levels by 14 days of loading in group 1. Id2 protein levels increased 2.1-fold after 5 days of loading ( group 1). In contrast, Id2 did not increase in reloaded muscles of group 3 birds. These data suggest that Id2 may have a role in apoptosis-associated atrophy of skeletal muscles, but its role in muscle hypertrophy is less clear.
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Cummins, Rebecca E., Sandra Klingberg, Julie Wesley, Maureen Rogers, Yali Zhao, and Dedee F. Murrell. "Keratin 14 Point Mutations at Codon 119 of Helix 1A Resulting in Different Epidermolysis Bullosa Simplex Phenotypes." Journal of Investigative Dermatology 117, no. 5 (November 2001): 1103–7. http://dx.doi.org/10.1046/j.0022-202x.2001.01508.x.

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SLIVA, Daniel, Minyi GU, Yuan Xiao ZHU, Jun CHEN, Schickwann TSAI, Xiaoping DU, and Yu-Chung YANG. "14-3-3ζ interacts with the α-chain of human interleukin 9 receptor." Biochemical Journal 345, no. 3 (January 25, 2000): 741–47. http://dx.doi.org/10.1042/bj3450741.

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Interleukin 9 (IL-9) exerts its pleiotropic effects through the IL-9 receptor (IL-9R) complex, which consists of the IL-9R α-chain, which determines the cytokine specificity, and the IL-2 receptor γ-chain. In the present study we used a modified yeast two-hybrid system to isolate cDNA species encoding proteins that interacted with the intracellular domain of the human IL-9R α-chain (hIL-9Rα). We have identified 14-3-3ζ as an hIL-9Rα-interacting protein. We also mapped residues 518-522 (Arg-Ser519-Trp-Thr521-Phe) in hIL-9Rα and helix I of 14-3-3ζ as being important for interaction. Moreover, peptide competition experi-ments suggested that interaction between hIL-9Rα and 14-3-3ζ requires the phosphorylation of Ser519 or Thr521. This is the first demonstration that 14-3-3 can interact with a non-tyrosine kinase receptor. The interaction between 14-3-3 and IL-9Rα but not IL-4Rα also suggests a potential role for 14-3-3 in determining cytokine specificity.
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Matsuoka, Rei, Roman Fudim, Sukkyeong Jung, Chenou Zhang, Andre Bazzone, Yurie Chatzikyriakidou, Carol V. Robinson, et al. "Structure, mechanism and lipid-mediated remodeling of the mammalian Na+/H+ exchanger NHA2." Nature Structural & Molecular Biology 29, no. 2 (February 2022): 108–20. http://dx.doi.org/10.1038/s41594-022-00738-2.

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AbstractThe Na+/H+ exchanger SLC9B2, also known as NHA2, correlates with the long-sought-after Na+/Li+ exchanger linked to the pathogenesis of diabetes mellitus and essential hypertension in humans. Despite the functional importance of NHA2, structural information and the molecular basis for its ion-exchange mechanism have been lacking. Here we report the cryo-EM structures of bison NHA2 in detergent and in nanodiscs, at 3.0 and 3.5 Å resolution, respectively. The bison NHA2 structure, together with solid-state membrane-based electrophysiology, establishes the molecular basis for electroneutral ion exchange. NHA2 consists of 14 transmembrane (TM) segments, rather than the 13 TMs previously observed in mammalian Na+/H+ exchangers (NHEs) and related bacterial antiporters. The additional N-terminal helix in NHA2 forms a unique homodimer interface with a large intracellular gap between the protomers, which closes in the presence of phosphoinositol lipids. We propose that the additional N-terminal helix has evolved as a lipid-mediated remodeling switch for the regulation of NHA2 activity.
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Denis, Antonia, Mario Alberto Martínez-Núñez, Silvia Tenorio-Salgado, and Ernesto Perez-Rueda. "Dissecting the Repertoire of DNA-Binding Transcription Factors of the Archaeon Pyrococcus furiosus DSM 3638." Life 8, no. 4 (September 21, 2018): 40. http://dx.doi.org/10.3390/life8040040.

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In recent years, there has been a large increase in the amount of experimental evidence for diverse archaeal organisms, and these findings allow for a comprehensive analysis of archaeal genetic organization. However, studies about regulatory mechanisms in this cellular domain are still limited. In this context, we identified a repertoire of 86 DNA-binding transcription factors (TFs) in the archaeon Pyrococcus furiosus DSM 3638, that are clustered into 32 evolutionary families. In structural terms, 45% of these proteins are composed of one structural domain, 41% have two domains, and 14% have three structural domains. The most abundant DNA-binding domain corresponds to the winged helix-turn-helix domain; with few alternative DNA-binding domains. We also identified seven regulons, which represent 13.5% (279 genes) of the total genes in this archaeon. These analyses increase our knowledge about gene regulation in P. furiosus DSM 3638 and provide additional clues for comprehensive modeling of transcriptional regulatory networks in the Archaea cellular domain.
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Håversen, L., N. Kondori, L. Baltzer, L. Å Hanson, G. T. Dolphin, K. Dunér, and I. Mattsby-Baltzer. "Structure-Microbicidal Activity Relationship of Synthetic Fragments Derived from the Antibacterial α-Helix of Human Lactoferrin." Antimicrobial Agents and Chemotherapy 54, no. 1 (November 16, 2009): 418–25. http://dx.doi.org/10.1128/aac.00908-09.

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ABSTRACT There is a need for new microbicidal agents with therapeutic potential due to antibiotic resistance in bacteria and fungi. In this study, the structure-microbicidal activity relationship of amino acid residues 14 to 31 (sequence 14-31) from the N-terminal end, corresponding to the antibacterial α-helix of human lactoferrin (LF), was investigated by downsizing, alanine scanning, and substitution of amino acids. Microbicidal analysis (99% killing) was performed by a microplate assay using Escherichia coli, Staphylococcus aureus, and Candida albicans as test organisms. Starting from the N-terminal end, downsizing of peptide sequence 14-31 showed that the peptide sequence 19-31 (KCFQWQRNMRKVR, HL9) was the optimal length for antimicrobial activity. Furthermore, HL9 bound to lipid A/lipopolysaccharide, as shown by neutralizing endotoxic activity in a Limulus assay. Alanine scanning of peptide sequence 20-31 showed that Cys20, Trp23, Arg28, Lys29, or Arg31 was important for expressing full killing activity, particularly against C. albicans. Substituting the neutral hydrophilic amino acids Gln24 and Asn26 for Lys and Ala (HLopt2), respectively, enhanced microbicidal activity significantly against all test organisms compared to the amino acids natural counterpart, also, in comparison with HL9, HLopt2 had more than 10-fold-stronger fungicidal activity. Furthermore, HLopt2 was less affected by metallic salts than HL9. The microbicidal activity of HLopt2 was slightly reduced only at pH 7.0, as tested in the pH range of 4.5 to 7.5. The results showed that the microbicidal activity of synthetic peptide sequences, based on the antimicrobial α-helix region of LF, can be significantly enhanced by optimizing the length and substitution of neutral amino acids at specific positions, thus suggesting a sequence lead with therapeutic potential.
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Safo, Martin K., Qixun Zhao, Tzu-Ping Ko, Faik N. Musayev, Howard Robinson, Neel Scarsdale, Andrew H. J. Wang, and Gordon L. Archer. "Crystal Structures of the BlaI Repressor from Staphylococcus aureus and Its Complex with DNA: Insights into Transcriptional Regulation of the bla and mec Operons." Journal of Bacteriology 187, no. 5 (March 1, 2005): 1833–44. http://dx.doi.org/10.1128/jb.187.5.1833-1844.2005.

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ABSTRACT The 14-kDa BlaI protein represses the transcription of blaZ, the gene encoding β-lactamase. It is homologous to MecI, which regulates the expression of mecA, the gene encoding the penicillin binding protein PBP2a. These genes mediate resistance to β-lactam antibiotics in staphylococci. Both repressors can bind either bla or mec DNA promoter-operator sequences. Regulated resistance genes are activated via receptor-mediated cleavage of the repressors. Cleavage is induced when β-lactam antibiotics bind the extramembrane sensor of the sensor-transducer signaling molecules, BlaR1 or MecR1. The crystal structures of BlaI from Staphylococcus aureus, both in free form and in complex with 32 bp of DNA of the mec operator, have been determined to 2.0- and 2.7-Å resolutions, respectively. The structure of MecI, also in free form and in complex with the bla operator, has been previously reported. Both repressors form homodimers, with each monomer composed of an N-terminal DNA binding domain of winged helix-turn-helix topology and a C-terminal dimerization domain. The structure of BlaI in complex with the mec operator shows a protein-DNA interface that is conserved between both mec and bla targets. The recognition helix α3 interacts specifically with the conserved TACA/TGTA DNA binding motif. BlaI and, probably, MecI dimers bind to opposite faces of the mec DNA double helix in an up-and-down arrangement, whereas MecI and, probably, BlaI dimers bind to the same DNA face of bla promoter-operator DNA. This is due to the different spacing of mec and bla DNA binding sites. Furthermore, the flexibility of the dimeric proteins may make the C-terminal proteolytic cleavage site more accessible when the repressors are bound to DNA than when they are in solution, suggesting that the induction cascade involves bound rather than free repressor.
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Anamofa, Jusuf Nikolas. "Pertumbuhan Publikasi Ilmiah Dosen di Maluku Pada Portal SINTA Tahun 2017 dan 2019." JAS-PT (Jurnal Analisis Sistem Pendidikan Tinggi Indonesia) 3, no. 2 (December 22, 2019): 71. http://dx.doi.org/10.36339/jaspt.v3i2.258.

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Penelitian ini bertujuan untuk mengetahui pertumbuhan publikasi ilmiah para dosen di Maluku pada perguruan tinggi di bawah naungan Kementerian Pendidikan dan Kebudayaan. Metode yang digunakan adalah time series comparative terhadap data penelitian tahun 2017 yang dibandingkan dengan data penelitian tahun 2019. Variabel yang dibandingkan adalah jumlah dosen yang terdata dalam Pangkalan Data Pendidikan Tinggi, jumlah dosen yang terdaftar sebagai penulis terverifikasi pada portal SINTA, jumlah publikasi yang terindeks scopus, web of science, dan google scholar, jumlah sitasi, dan jumlah jurnal dari perguruan tinggi di Maluku yang terdaftar pada portal SINTA. Hasil penelitian menunjukkan peningkatan signifikan pada variabel-variabel tersebut meskipun beberapa PT mengalami stagnasi. REFERENSI Ayu, N.A.K. 2018. Peluang Social Innovation dalam Revolusi Industri 4.0: Bagaimana Perkembangannya di Indonesia. Yogyakarta: Forbil Institute Disas, E. P. Link and Match sebagai Kebijakan Pendidikan Kejuruan. Jurnal Penelitian Pendidikan, 18(2), 231-242. Etzkowitz, H., & Leydesdorff, L. 1995. The Triple Helix – University Industry Government Relations: A Laboratory for Knowledge Based Economic Development. EASST Review 14, 14-19. Etzkowitz, H., & Leydesdorff, L. 2000. The Dynamics of Innovation: From National Systems and '‘Mode 2'’ to a Triple Helix of University -Industry - Government relations. Research Policy, 29(2), 109-123. Izzati, MF & Wilopo. 2018. Implementasi Triple Helix Dalam Mendorong Pertumbuhan Industri Kreatif Di Kota Malang Sebagai Upaya Peningkatan Daya Saing Untuk Menghadapi Masyarakat Ekonomi Asean. Jurnal Administrasi Bisnis (JAB)Vol. 55 No. 1 Februari 2018 hal 59-68. McKinsey. 2015. Industry 4.0 How to navigate digitization of the manufacturing sector. England: Stamford Senarath, S. A. C. L., & Patabendige, S. S. J. (2014). Job-education mismatch among the graduates: A Sri Lankan Perspective. Ruhuna Journal of Management and Finance, 1(2), 1-16. UNIDO. Industry 4.0: Opportunities and Challenges of the New Industrial Revolution for Developing Countries and Economies in Transition. Panel Discussion USDA. 2008. SWOT analysis a tool for making better business decisions. United States Department of Agriculture Risk Management Agency.
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Datta, Saumen, Ramesh Kaul, R. Balaji Rao, N. Shamala, and P. Balaram. "Stereochemistry of linking segments in the design of helix–helix motifs in peptides. Crystallographic comparison of a glycyl–dipropylglycyl–glycyl segment in a tripeptide and a 14-residue peptide." Journal of the Chemical Society, Perkin Transactions 2, no. 9 (1997): 1659–64. http://dx.doi.org/10.1039/a702109g.

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45

Chandrasekhar, Srivari, Marepally Srinivasa Reddy, Bathini Nagendra Babu, Bharatam Jagadeesh, Anabathula Prabhakar, and Bulusu Jagannadh. "Expanding the Conformational Pool ofcis-β-Sugar Amino Acid: Accommodation of β-hGly Motif in Robust 14-Helix‖." Journal of the American Chemical Society 127, no. 27 (July 2005): 9664–65. http://dx.doi.org/10.1021/ja051014d.

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46

Chen, Marisa A., Jeannette M. Bonlfas, Kule Matsumura, Anat Blumenfeld, and Ervin H. Epstein. "A novel three-nucleotide deletion in the helix 2B region of keratin 14 in epidermolysis bullosa simples: δE375." Human Molecular Genetics 2, no. 11 (1993): 1971–72. http://dx.doi.org/10.1093/hmg/2.11.1971.

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47

Raguse, Tami L., Jonathan R. Lai, and Samuel H. Gellman. "Environment-Independent 14-Helix Formation in Short β-Peptides: Striking a Balance between Shape Control and Functional Diversity." Journal of the American Chemical Society 125, no. 19 (May 2003): 5592–93. http://dx.doi.org/10.1021/ja0341485.

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48

Vázquez, María-Isabel, German Rivas, David Cregut, Luis Serrano, and Mariano Esteban. "The Vaccinia Virus 14-Kilodalton (A27L) Fusion Protein Forms a Triple Coiled-Coil Structure and Interacts with the 21-Kilodalton (A17L) Virus Membrane Protein through a C-Terminal α-Helix." Journal of Virology 72, no. 12 (December 1, 1998): 10126–37. http://dx.doi.org/10.1128/jvi.72.12.10126-10137.1998.

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ABSTRACT The vaccinia virus 14-kDa protein (encoded by the A27L gene) plays an important role in the biology of the virus, acting in virus-to-cell and cell-to-cell fusions. The protein is located on the surface of the intracellular mature virus form and is essential for both the release of extracellular enveloped virus from the cells and virus spread. Sequence analysis predicts the existence of four regions in this protein: a structureless region from amino acids 1 to 28, a helical region from residues 29 to 37, a triple coiled-coil helical region from residues 44 to 72, and a Leu zipper motif at the C terminus. Circular dichroism spectroscopy, analytical ultracentrifugation, and chemical cross-linking studies of the purified wild-type protein and several mutant forms, lacking one or more of the above regions or with point mutations, support the above-described structural division of the 14-kDa protein. The two contiguous cysteine residues at positions 71 and 72 are not responsible for the formation of 14-kDa protein trimers. The location of hydrophobic residues at the a and d positions on a helical wheel and of charged amino acids in adjacent positions, e and g, suggests that the hydrophobic and ionic interactions in the triple coiled-coil helical region are involved in oligomer formation. This conjecture was supported by the construction of a three-helix bundle model and molecular dynamics. Binding assays with purified proteins expressed in Escherichia coli and cytoplasmic extracts from cells infected with a virus that does not produce the 14-kDa protein during infection (VVindA27L) show that the 21-kDa protein (encoded by the A17L gene) is the specific viral binding partner and identify the putative Leu zipper, the predicted third α-helix on the C terminus of the 14-kDa protein, as the region involved in protein binding. These findings were confirmed in vivo, following transfection of animal cells with plasmid vectors expressing mutant forms of the 14-kDa protein and infected with VVindA27L. We find the structural organization of 14kDa to be similar to that of other fusion proteins, such as hemagglutinin of influenza virus and gp41 of human immunodeficiency virus, except for the presence of a protein-anchoring domain instead of a transmembrane domain. Based on our observations, we have established a structural model of the 14-kDa protein.
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Kawai, Takayuki, Norio Takagi, Keiko Miyake-Takagi, Noriko Okuyama, Nobuyuki Mochizuki, and Satoshi Takeo. "Characterization of BrdU-Positive Neurons Induced by Transient Global Ischemia in Adult Hippocampus." Journal of Cerebral Blood Flow & Metabolism 24, no. 5 (May 2004): 548–55. http://dx.doi.org/10.1097/00004647-200405000-00009.

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Neurogenesis in the brain continues throughout life and is promoted by brain insults including ischemia. There is no critical conclusion, however, about whether proliferated cells acquire neuronal function after ischemia. Transient global ischemia was produced by a four-vessel occlusion procedure in rats (n = 54). To label proliferative cells, rats were administrated with a single dose of 5-bromo-2’-deoxyuridine (BrdU) at 4, 6, 8, 10, 13, or 15 days after ischemia. Increases in BrdU-positive cells were detected in the hippocampal dentate gyrus at 5, 7, and 9 days after ischemia. To determine the phenotype of BrdU-positive cells, BrdU was administrated twice daily for 3 consecutive days during 6 to 8 days after ischemia. A basic helix–loop–helix transcription factor NeuroD at 7 and 14 days and an immature migrating neuronal marker doublecortin at 14 days after ischemia were expressed transiently in proliferative cells. These proliferative cells after ischemia differentiated to the phenotype of neuron at 28 days after ischemia. Furthermore, BrdU-positive neurons showed phosphorylation of extracellular signal-regulated kinase (ERK) by intracerebroventricular injection of N-methyl-D-aspartate (NMDA) at 28 and 56 days after ischemia as seen in surrounding mature neurons. The number of BrdU-positive neurons, which responded to NMDA stimulation, increased with time after ischemia and was greater than that of sham-operated animals. The present study provides evidence for in vivo ERK phosphorylation in response to NMDA stimulation of BrdU-positive neurons in the adult hippocampus after transient forebrain ischemia.
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50

Kamali, Roya, Eugene Kwan, Misha Regouski, T. Jared Bunch, Derek J. Dosdall, Ed Hsu, Rob S. Macleod, Irina Polejaeva, and Ravi Ranjan. "Contribution of atrial myofiber architecture to atrial fibrillation." PLOS ONE 18, no. 1 (January 31, 2023): e0279974. http://dx.doi.org/10.1371/journal.pone.0279974.

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Background The role of fiber orientation on a global chamber level in sustaining atrial fibrillation (AF) is unknown. The goal of this study was to correlate the fiber direction derived from Diffusion Tensor Imaging (DTI) with AF inducibility. Methods Transgenic goats with cardiac-specific overexpression of constitutively active TGF-β1 (n = 14) underwent AF inducibility testing by rapid pacing in the left atrium. We chose a minimum of 10 minutes of sustained AF as a cut-off for AF inducibility. Explanted hearts underwent DTI to determine the fiber direction. Using tractography data, we clustered, visualized, and quantified the fiber helix angles in 8 different regions of the left atrial wall using two reference vectors defined based on anatomical landmarks. Results Sustained AF was induced in 7 out of 14 goats. The mean helix fiber angles in 7 out of 8 selected regions were statistically different (P-Value < 0.05) in the AF inducible group. The average fractional anisotropy (FA) and the mean diffusivity (MD) were similar in the two groups with FA of 0.32±0.08 and MD of 8.54±1.72 mm2/s in the non-inducible group and FA of 0.31±0.05 (P-value = 0.90) and MD of 8.68±1.60 mm2/s (P-value = 0.88) in the inducible group. Conclusions DTI based fiber direction shows significant variability across subjects with a significant difference between animals that are AF inducible versus animals that are not inducible. Fiber direction might be contributing to the initiation and sustaining of AF, and its role needs to be investigated further.
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