Liang Li, Yao Ping, Jiang Ming
The Key Laboratory of Molecular Engineering of Polymer and Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
Biomacromolecules. 2006 Jun;7(6):1829-35. doi: 10.1021/bm060150n.
The interaction of cytochrome c (cyt c) with poly(isobutylene-alt-maleic acid) (PIMA) and poly(1-tetradecene-alt-maleic acid) (PTMA) was studied using circular dichroism, absorption spectroscopy, and atomic force microscopy to investigate the electrostatic and hydrophobic influence of the copolymers on the structure of cyt c. At pH 7.4, the interaction of PIMA with cyt c can only partly disturb the integrity of the heme pocket, while PTMA has very intensive influence on the structure of cyt c. After adding 0.15 M NaCl, PIMA-cyt c complexes dissociate, and the released cyt c recovers its native structure, whereas NaCl has no significant influence on PTMA-cyt c complexes. GuHCl (0.5 M) destroys PTMA-cyt c complexes, forming GuHCl-PTMA precipitates; the cyt c released from the complexes regenerates its native structure. In comparison with electrostatic interaction, hydrophobic interaction leads to more stable polymer-cyt c complexes and more intensive influence on cyt c structure, but cyt c can recover its native state after release.
利用圆二色性、吸收光谱和原子力显微镜研究了细胞色素c（cyt c）与聚（异丁烯-alt-马来酸）（PIMA）和聚（1-十四碳烯-alt-马来酸）（PTMA）的相互作用，以研究共聚物对cyt c结构的静电和疏水影响。在pH 7.4时，PIMA与cyt c的相互作用只能部分扰乱血红素口袋的完整性，而PTMA对cyt c的结构有非常强烈的影响。加入0.15 M NaCl后，PIMA-cyt c复合物解离，释放出的cyt c恢复其天然结构，而NaCl对PTMA-cyt c复合物没有显著影响。盐酸胍（0.5 M）破坏PTMA-cyt c复合物，形成盐酸胍-PTMA沉淀；从复合物中释放出的cyt c恢复其天然结构。与静电相互作用相比，疏水相互作用导致聚合物-cyt c复合物更稳定，对cyt c结构的影响更强烈，但cyt c释放后可恢复其天然状态。
