Gross Peter C, Possart Wulff, Zeppezauer Michael
Fraunhofer-Institute for Manufacturing and Applied Materials Research (IFAM), Wiener Strasse 12, D-28359 Bremen, Germany.
Z Naturforsch C J Biosci. 2003 Nov-Dec;58(11-12):873-8. doi: 10.1515/znc-2003-11-1223.
Polypentapeptides (GVGVP)n which are designed in analogy to the connective tissue protein elastin are reported to transform various kinds of energy into mechanical work by the so-called deltaT(t)-mechanism in cross-linked macroscopic polypentapeptide (PPP) films. In the literature, the responsible element of conformation in such polypeptides is described as a beta-spiral and the deltaT(t) effect is explained as a sudden change of macroconformation of single polypeptide molecules from an extended but not regular state below a transition temperature T(t) to the beta-spiral above T(t). We examined the secondary structure of the linear PPP C(GVGVP)6 in solution with DSC, CD, UV absorption, FTIR and NMR spectroscopy. The results suggest that the beta-spiral is not present in the conformational structure of the PPP molecules. The antiparallel beta-sheet is proposed to be the basic regular part of conformation because it agrees with all spectroscopic data. As a consequence, the elasticity of natural elastin must be considered from a new perspective.
据报道，类似于结缔组织蛋白弹性蛋白设计的聚五肽（GVGVP）n，通过交联宏观聚五肽（PPP）薄膜中的所谓deltaT(t)机制，将各种能量转化为机械功。在文献中，此类多肽中负责构象的元素被描述为β-螺旋，并且deltaT(t)效应被解释为单个多肽分子的宏观构象在转变温度T(t)以下从伸展但不规则的状态突然转变为T(t)以上的β-螺旋。我们用差示扫描量热法（DSC）、圆二色光谱法（CD）、紫外吸收光谱法、傅里叶变换红外光谱法（FTIR）和核磁共振光谱法（NMR）研究了溶液中线性PPP C(GVGVP)6的二级结构。结果表明，β-螺旋不存在于PPP分子的构象结构中。反平行β-折叠被认为是构象的基本规则部分，因为它与所有光谱数据相符。因此，必须从新的角度考虑天然弹性蛋白的弹性。
