磁共振技术在丝素蛋白结构与功能研究中的应用

丝素蛋白纤维因其优异的力学性能和良好的生物相容性而得到广泛关注. 人们通过对丝素蛋白二级结构的构象转变及其诱导因素的研究，试图阐明蚕吐丝机理、相关蛋白结构与功能的关系，为人工合成性能优良的丝纤维材料以及认识生命过程提供有益指导和帮助. 磁共振技术是研究丝素蛋白结构最有效的方法之一. 我们课题组多年来运用核磁共振（NMR）的方法研究了桑蚕丝素蛋白的构象及环境对其的影响因素，如pH、金属离子（K⁺、Na⁺、Ca²⁺、Cu²⁺、Zn²⁺）等，并运用电子自旋顺磁共振（EPR）方法研究了金属Cu²⁺离子与丝素蛋白的相互作用，试图揭示蛋白质构象转变与金属离子影响的内在联系. 另外，我们还发展了一种广义二维核磁共振相关技术，有效缩短了传统二维核磁共振的实验时间. 本文将综述这些年来我们所做的相关工作.

Application of Magnetic Resonance Methods in the Structural and Functional Characterization of Silk Fibroin

Silk fibers are widely used because of their strong mechanical performance and good biocompatibility. People have tried to understand the natural spinning mechanism of silkworm, the relationship between the structure and the function of silk fibroin, and the factors affecting the secondary structure transition of silk fibroin. Among the methods being used to study silk fibroin, the most effective one is magnetic resonance spectroscopy, including both nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR). We have used NMR techniques to study the conformation of silk fibroin and how it is affected by environmental factors such as pH and metal ions (K⁺, Na⁺, Ca²⁺, Cu²⁺ and Zn²⁺) etc. We have also applied EPR spectroscopy to investigate the interaction between Cu(Ⅱ) and silk fibroin in order to discover the intrinsic relationship between conformational transition of silk fibroin and its interaction with Cu(Ⅱ). Besides, a generalized two-dimensional NMR correlation spectroscopy method has been developed for efficiently reducing the traditional 2D NMR experimental time. In this paper, the related work in our group during the past few years is reviewed.