The Study for the Solution Properties and the Thermal Dependence of Semi-flexible Polymers in a Wide Range of Concentration

从线虫（Nereis Japonica）中提取的角质层胶原蛋白是一种半柔性聚合物，在0.1 m乙酸中，其分子量约为1.6 × 10^6，轮廓长度为18000 a，其轮廓长度约为分子量为30 × 10^4的原胶原蛋白的6倍。本研究的目的是更详细地研究从稀到半稀的宽浓度范围内的溶液性质，以及热变性过程中分子形状的变化。从1986年到1988年进行的这项研究中获得的有价值的结果总结如下：1)角质层胶原的水动力特性特征变化的浓度与对原胶原的水动力特性特征变化的浓度基本一致，该值0.12g/dl与两种样品的热力学特性得到的浓度0.16g/dl相对应。还得出了水动力性质的变化不像热力学性质的变化那么剧烈的结论。2)两种胶原蛋白的热变性都是从三股到单螺旋链的转变。角质层胶原蛋白的分子形态变化不像原胶原蛋白那样剧烈，而且是循序渐进的。3)本研究中观察到的两种胶原样品的浓度转变表明从半稀范围到浓范围的可能性。

Cuticle collagen extracted from lugworm, Nereis Japonica, is a semi-flexible polymer with a molecular weight of about 1.6 x 10^6, a contour length of 18,000A, in 0,1M acetic acid, of which contour length was about six times as large as that of tropocollagen with a molecular weight of 30 x 10^4.The purpose of this research is to investigate the solution properties in a wide concentration range from dilute to semi-dilute and also the change of molecular shape during the thermal denaturation in more detail.The worthwhile results obtained from this research carried out from 1986 to 1988 are summarized as follows. 1) The concentration relating to the characteristic change of hydrodynamic properties for cuticle collagen almost coincide with those for tropocollagen and this value, 0.12g/dl, corresponds to the concentration, 0.16g/dl, obtained from the thermodynamic properties for both samples. It is also concluded that the change in hydrodynamic properties is not so drastic as compared with those in thermodynamic properties. 2) The thermal denaturation for both collagens is the transition from triple strand to single coil chain. The molecular shape change for cuticle collagen is not so sharp as compared with that for tropocollagen and also is step wise. 3) The concentration transitions for bothcollagen samples observed in this investigation indicate the possibility from semi-dilute range to concentrated range.