双亲嵌段共聚物P103对牛血清白蛋白构象的影响

Effect of Amphiphilic Block Copolymer Pluronic P103 on the Conformation of Bovine Serum Albumin

利用傅立叶变换红外光谱和傅立叶变换拉曼光谱研究了牛血清白蛋白(BSA)与双亲嵌段共聚物P103作用过程中蛋白质构象的变化规律。研究表明,当P103浓度较低时,BSA二级结构变化不大,当P103浓度为16 g/L或以上时,α-螺旋结构由45.9%降至40%以下,β-折叠结构升高,由6.1%增至17%左右,同时无规结构略微下降。P103的加入主要改变BSA分子内部氢键的结合方式,使α-螺旋结构转变为β-折叠结构;P103的加入还影响BSA中氨基酸侧链的微环境变化和蛋白质二硫键的构象变化。

Fourier transform infrared and Fournier transform -Raman spectroscopy were applied to investigate the interaction between Poly （ ethylene oxide） -poly （ propylene oxide） -poly （ ethylene oxide） （PEO-PPO-PEO） block copolymer （ Pluronic P103 ） and bovine serum albumin （BSA）. Microenvironment of some amino acids and the conformation of S--S bond in BSA were influenced by Pluronic P103, when Pluronic P103 was added. Pluronic P103 also could change some a-helixes into β-sheets. The secondary structure of BSA showed little change at lower P103 concentration when the concentration of P103 is not lower than 16 g/L. a-helixes decreased from 45.9% to 40% , and β-sheets increased from 6.1% to 17%, in the meantime the random structure showed a little decrease.