- 作者: 張德州
- 作者服務機構: Department of Polymer Technology, Tokyo Institute of Technology, Ookayama, Meguro-Ku, Tokyo Japan
- 中文摘要: To study the role of glycine residues in stabilizing the collagen triple helix, the glycine residues in the polytripeptide (Pro-Ala-Gly)/sub n/ were partially replaced by alanine. The proline content was kept constant. The stability of the helical conformation of these polypeptides was studied by IR- and X-ray measurements in the solid state and by ORD, CD and viscometry in solution. The renaturation was followed as a function of time. All the polytripeptides studied, with the exception of (-Pro-Ala-Ala-)/sub n/, attained the polyproline II conformation. However the stability decreased with increasing alanine content. Obviously the molecules of (Pro-Ala-Gly) are highly associated by intermolecular hydrogen bonds and one may therefore suppose that a triple-standarded helix aggregation occurs. The results of the refolding process show that the stability of the helices seems to also affect the refolding rate in terms of the optical rotation. Two transitions appeared: the first one is responsible for a rapid reversible change in conformation and the second one for a further slow and irreversible change in the hydrodynamic shape. The latter seems to be due to the partial helical nature, leading to higher chain mobility.
- 英文摘要: --
- 中文關鍵字: Collagen; polytripeptide; glycine; fibrous protein; conformation; refolding process; helical structure; triple helices.
- 英文關鍵字: Collagen; polytripeptide; glycine; fibrous protein; conformation; refolding process; helical structure; triple helices.