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Collagen Model Peptide (collagen + model_peptide)
Selected AbstractsThermosensitive gel formation of novel polypeptides containing a collagen-derived Pro-Hyp-Gly sequence and an elastin-derived Val-Pro-Gly-Val-Gly sequenceJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 23 2005Yasushi Morihara Abstract A triple-helix-forming collagen model peptide, (prolyl- trans -4-hydroxyprolyl-glycyl)10 [(Pro-Hyp-Gly)10], and a thermosensitive elastin-derived pentapeptide, valyl-prolyl-glycyl-valyl-glycyl (Val-Pro-Gly-Val-Gly), were copolymerized in various mole ratios using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride and 1-hydroxybenzotriazole in dimethyl sulfoxide at 20 °C. All of the obtained polypeptides have molecular weight higher than 103 and contain a triple-helical structure, and showed an inverse phase transition from transparent solution to turbid suspension in response to a rise in temperature. The lower critical solution temperature of the polypeptide solution decreased upon increasing the content of Val-Pro-Gly-Val-Gly. Furthermore, polypeptides containing 82,86 mol % of Val-Pro-Gly-Val-Gly in composition showed reversible gel formation, suggesting that (Pro-Hyp-Gly)10 acts as a hydrated unit and Val-Pro-Gly-Val-Gly acts as a thermosensitive crosslinking point. These biodegradable thermosensitive polypeptides may be useful for biomedical applications, including, as a scaffold for tissue regeneration. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6048,6056, 2005 [source] Two crystal modifications of (Pro-Pro-Gly)4 -Hyp-Hyp-Gly-(Pro-Pro-Gly)4 reveal the puckering preference of Hyp(X) in the Hyp(X):Hyp(Y) and Hyp(X):Pro(Y) stacking pairs in collagen helicesACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2010Kenji Okuyama Two crystal modifications of a collagen model peptide, (Pro-Pro-Gly)4 -Hyp-Hyp-Gly-(Pro-Pro-Gly)4 [where Hyp is (4R,2S)- l -hydroxyproline], showed very similar unit-cell parameters and belonged to the same space group P21. Both crystals exhibited pseudo-merohedral twinning. The main difference was in their molecular-packing arrangements. One modification showed pseudo-hexagonal packing, while the other showed pseudo-tetragonal packing. Despite their different packing arrangements, no significant differences were observed in the hydration states of these modifications. The peptide in the pseudo-tetragonal crystal showed a cyclic fluctuation of helical twists with a period of 20,Å, while that in the pseudo-hexagonal crystal did not. In these modifications, the puckering conformations of four of the 12 Hyp residues at the X position of the Hyp(X)-Hyp(Y)-Gly sequence were in the opposite conformations to the previous hypothesis that Hyp(X) residues involved in Hyp(X):Hyp(Y) and Hyp(X):Pro(Y) stacking pairs prefer up-puckering and down-puckering conformations, respectively. Detailed investigation of the molecular interactions between Hyp(X) and adjacent molecules revealed that these opposite conformations appeared because the puckering conformation, which follows the hypothesis, is subject to steric hindrance from the adjacent molecule. [source] Collagen-like triple helix formation of synthetic (Pro-Pro-Gly)10 analogues: (4(S)-hydroxyprolyl-4(R)-hydroxyprolyl-Gly)10, (4(R)-hydroxyprolyl-4(R)-hydroxyprolyl-Gly)10 and (4(S)-fluoroprolyl-4(R)-fluoroprolyl-Gly)10JOURNAL OF PEPTIDE SCIENCE, Issue 10 2005Masamitsu Doi Abstract For the rational design of a stable collagen triple helix according to the conventional rule that the pyrrolidine puckerings of Pro, 4-hydroxyproline (Hyp) and 4-fluoroproline (fPro) should be down at the X-position and up at the Y-position in the X-Y-Gly repeated sequence for enhancing the triple helix propensities of collagen model peptides, a series of peptides were prepared in which X- and Y-positions were altogether occupied by HypR, HypS, fProR or fProS. Contrary to our presumption that inducing the X-Y residues to adopt a down-up conformation would result in an increase in the thermal stability of peptides, the triple helices of (HypS -HypR -Gly)10 and (fProS -fProR -Gly)10 were less stable than those of (Pro-HypR -Gly)10 and (Pro-fProR -Gly)10, respectively. As reported by Bächinger's and Zagari's groups, (HypR -HypR -Gly)10 which could have an up-up conformation unfavorable for the triple helix, formed a triple helix that has a high thermal stability close to that of (Pro-HypR -Gly)10. These results clearly show that the empirical rule based on the conformational preference of pyrrolidine ring at each of X and Y residues should not be regarded as still valid, at least for predicting the stability of collagen models in which both X and Y residues have electronegative groups at the 4-position. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd. [source] Conformation-dependent side reactions in interstrand-disulfide bridging of trimeric collagenous peptides by regioselective cysteine chemistryJOURNAL OF PEPTIDE SCIENCE, Issue 5 2002Barbara Saccá Abstract Conversion of single-chain or disulfide-bridged dimeric collagenous peptides into Cys(Npys) derivatives as activated species for subsequent regioselective thiol/disulfide exchange reactions leads to side products whose origin and nature was determined by HPLC and ESI-MS. In both cases the high tendency of the educts to self-associate into triple-helical homotrimers, as assessed by their dichroic properties in the reaction media, is responsible for the failure of this well established cysteine chemistry. Only by optimizing the synthetic strategy or by exploiting a kinetic control of the reaction, could these conformation-dependent limitations be more or less efficiently bypassed for the regioselective assembly of heterotrimeric collagen model peptides crosslinked with artificial cystine knots. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd. [source] | ||||||||||