Complex Fluids and Polymer Engineering Group, Polymer Science and Engineering Division, National Chemical Laboratory, India-411 008.
Phys Chem Chem Phys. 2010 Apr 21;12(15):3834-44. doi: 10.1039/b916319k. Epub 2010 Feb 24.
Silk fibroin was regenerated from cocoons produced by the silkworm Bombyx Mori. Light scattering showed that an aqueous solution of the regenerated silk fibroin (RSF) was made of individual proteins with a weight average molar mass of about 4 x 10(5) g mol(-1) and a hydrodynamic radius of about 10 nm. Gel formation of RSF in acidic solutions was investigated as a function of the pH (2-4), concentration (0.5-10 g L(-1)) and temperature (5-70 degrees C). The structure of the gels was studied using light scattering and confocal laser scanning microscopy. The structure was found to be self-similar from length scales of less than 15 nm up to length scales of about 1 microm, and characterized by a correlation length of a few microns. Gel formation was tracked using turbidity, rheology, light scattering and circular dichroism. Gelation involves the formation of self-similar aggregates with a growth rate that increases exponentially. The protein aggregation is correlated to, and perhaps caused by, the formation of beta-sheets, the fraction of which also increases exponentially with time.
丝素蛋白是由家蚕（Bombyx Mori）生产的茧中再生的。光散射表明，再生丝素蛋白（RSF）的水溶液由单个蛋白质组成，重均摩尔质量约为 4×10（5）g/mol，流体力学半径约为 10nm。研究了酸性溶液中 RSF 的凝胶形成作为 pH（2-4）、浓度（0.5-10g/L）和温度（5-70℃）的函数。使用光散射和共焦激光扫描显微镜研究了凝胶的结构。发现结构从小于 15nm 到约 1μm 的长度尺度具有自相似性，其特征在于几个微米的相关长度。使用浊度、流变学、光散射和圆二色性跟踪凝胶形成。凝胶形成涉及具有指数增长的增长率的自相似聚集体的形成。蛋白质聚集与β-折叠的形成相关，并且可能是由β-折叠的形成引起的，β-折叠的分数也随时间呈指数增长。
