Thomas W H, Weser U, Hempel K
Hoppe Seylers Z Physiol Chem. 1977 Oct;358(10):1345-52. doi: 10.1515/bchm2.1977.358.2.1345.
The structures of two biologically different myelin proteins, A1 from the central nervous system and P2 from the peripheral nervous system, were investigated. Both proteins were isolated from nerve tissues. Conformational changes in the homogeneous proteins were examined in aqueous solutions by means of circular dichroism measurements. The secondary structures of both proteins proved to be very stable between pH 2.5 and pH 11.7. Unlike the P2 protein, the A1 protein is stable up to pH 13 without detectable conformational changes. The stereochemistry of the polypeptide chains of both proteins is markedly different in the presence of urea. While the value of theta222 for the A1 protein changes linearly with increasing urea concentration, a sigmoidal curve was obtained for the P2 protein. The observed differences in the dichroic properties of the basic myelin proteins A1 and P2 indicate the possibility of further structure - function correlations.
对两种生物学特性不同的髓磷脂蛋白进行了研究，一种是来自中枢神经系统的A1蛋白，另一种是来自外周神经系统的P2蛋白。两种蛋白均从神经组织中分离得到。通过圆二色性测量在水溶液中检测了均一蛋白的构象变化。两种蛋白的二级结构在pH 2.5至pH 11.7之间被证明非常稳定。与P2蛋白不同，A1蛋白在pH 13时仍保持稳定，未检测到构象变化。在尿素存在的情况下，两种蛋白的多肽链立体化学明显不同。A1蛋白的θ222值随尿素浓度增加呈线性变化，而P2蛋白则得到一条S形曲线。碱性髓磷脂蛋白A1和P2在二色性特性上观察到的差异表明了进一步进行结构 - 功能相关性研究的可能性。
