MOLECULAR INTERPRETATION OF ELASTICITY OF RESILIN, A RUBBER-LIKE PROTEIN
MOLECULAR INTERPRETATION OF ELASTICITY OF RESILIN, A RUBBER-LIKE PROTEIN
复制标题
DOI：
10.1016/s0022-2836(61)80028-4
复制
发表时间：
1961-01-01
影响因子：
5.6
通讯作者：
WEISFOGH, T
中科院分区：
文献类型：
--
作者：
WEISFOGH, T
对蜻蜓(蜻蜓)弹性肌腱中的Resilin进行了力学和光学分析，包括压缩和伸展的大范围应变和膨胀，以及从pH 1.8到12.3的氢离子浓度。在所有条件下，该蛋白质表现为典型的橡胶。将所得结果与短链橡胶网络的动力学理论进行了详细的比较，结果表明，无论是在力学性能还是光弹性性能方面，实验结果与理论结果几乎完全一致。在室温和中性pH条件下，平均模数G为6.4 kg cm-2(经溶胀校正)，断裂强度为30~40 kg/cm2，断裂点长度约为无张力长度的3倍。未应变的Resilin是各向同性的，但在变形时变得双折射，在伸展方向上为正。双折射随应力呈非线性增加，应力-光学比C‘’与溶胀度和pH无关，与绝对温度成反比。室温下，C‘’为1.3×10~(-4)cm~2·kg~(-1)。结果表明，Resilin是由长的多肽链组成的三维网络，这些多肽链在所有条件下都是随机盘绕的，当蛋白质膨胀时，这些多肽链会进行热搅拌。在两个连接点之间有大约60个氨基酸残基，至少有一半的连接点由稳定的化学交联键组成，即每60到120个残基就有一个链间交联键。Resilin的一级结构必须是这样的：二级结构非常不稳定，以至于实际上不存在。另一方面，化学交联物代表三维延伸的三级结构。在细胞学和肌肉热力学方面简要讨论了这种网络的可能重要性。
Resilin from the elastic tendon of dragonflies (Odonata) was analysed mechanically and optically over a large range of strain and swelling, both in compression and in extension and at hydrogen-ion concentrations from pH 1.8 to 12.3. Under all conditions, the protein behaved as a typical rubber. A detailed comparison between the results and the kinetic theories for short-chain rubber networks showed that the agreement between experiment and theory was almost perfect, with respect to both mechanical and photo-elastic properties. At room temperature and neutral pH, the average modulus G is 6.4 kg cm-2 (corrected for swelling), the breaking strength 30 to 40 kg per cm2 unstrained swollen area, and the length at breaking point about 3 times the unstrained length. Unstrained resilin is isotropic but becomes birefringent on deformation, positive in the direction of extension. The birefringence increases in a non-linear manner with the stress, the stress-optical ratio C'' being independent of the degree of swelling and of pH, while it is inversely proportional to the absolute temperature. At room temperature, C'' was 1.3 x 10-4 cm2 kg-1. It is concluded that resilin consists of a three-dimensional network of long polypeptide chains which are randomly coiled under all conditions and thermally agitated when the protein is swollen. There are about 60 amino-acid residues between two junction points and at least half of the junction points consist of stable chemical cross-linkages, i.e. one inter-chain cross-link per 60 to 120 residues. The primary structure of resilin must be such that the secondary structure is so unstable as to be practically absent. On the other hand, the chemical cross-links represent a tertiary structure which extends in three dimensions. The possible importance of such networks is briefly discussed in relation to cytology and muscle thermodynamics.