Acetyl-Terminated and Template-Assembled Collagen-Based Polypeptides Composed of Gly-Pro-Hyp Sequences. 2. Synthesis and Conformational Analysis by Circular Dichroism, Ultraviolet Absorbance, and Opti
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- 作者：Yangbo Feng ; Giuseppe Melacini ; Joseph P. Taulane ; and Murray Goodman
- 刊名：Journal of the American Chemical Society
- 出版年：1996
- 出版时间：October 30, 1996
- 年：1996
- 卷：118
- 期：43
- 页码：10351 - 10358
- 全文大小：405K
- 年卷期：v.118,no.43(October 30, 1996)
- ISSN：1520-5126
文摘
Template-assembled collagen-based polypeptidesKTA-[Gly-(Gly-Pro-Hyp)n-NH2]3(n = 1, 3, 5, 6; KTAiscis,cis-1,3,5-trimethylcyclohexane-1,3,5-tricarboxylicacid, also known as the Kemp triacid) andacetyl-terminatedsingle-chain collagen-based analogsAc-(Gly-Pro-Hyp)n-NH2 (n= 1, 3, 5, 6, 9) were synthesized by solid phasesegment condensation methods. The triple-helical propensities ofthese collagen analogs were investigated usingcircular dichroism, ultraviolet absorbance, optical rotation, andnuclear magnetic resonance measurements. The acetylanalogs, Ac-(Gly-Pro-Hyp)n-NH2(n = 6, 9), assume a stable triple-helical conformation inH2O (0.2 mg/mL) atroom temperature. By contrast,Ac-(Gly-Pro-Hyp)5-NH2 adopts a triple-helicalconformation in H2O only below 18
C at a concentration of 0.2 mg/mL. For the template-assembledcollagen analogs, results show that KTA-[Gly-(Gly-Pro-Hyp)n-NH2]3(n = 5, 6) peptides form triple-helical structures whichhave melting temperatures above 70C in H2O. These melting temperatures are muchhigher than those of the corresponding acetyl analogs,demonstratingthe significant triple-helix-stabilizing effects of the KTA template.In addition, the KTA template facilitates triple-helical structures by dramatically accelerating triple-helixformation.
C at a concentration of 0.2 mg/mL. For the template-assembledcollagen analogs, results show that KTA-[Gly-(Gly-Pro-Hyp)n-NH2]3(n = 5, 6) peptides form triple-helical structures whichhave melting temperatures above 70C in H2O. These melting temperatures are muchhigher than those of the corresponding acetyl analogs,demonstratingthe significant triple-helix-stabilizing effects of the KTA template.In addition, the KTA template facilitates triple-helical structures by dramatically accelerating triple-helixformation.