生物小分子与铜锌超氧化物歧化酶相互作用的波谱学研究及其应用

本工作以ESR和NMR为主要手段,并结合其它生化方法,考察了氨基酸、核酸碱基、糖等生命基本物质,和抗坏血酸等生命必需物质与钢锌超氧化物歧化酶的相互作用,实验观测到氨基酸、核酸碱基和抗坏血酸在水溶液中可以与酶中的Cu²⁺作用而使其脱离活性部位,以小分子络合物形式游离在溶液中,同时使酶失活,脱离活性部位的Cu²⁺的比例和酶的失活程度取决于小分子配体的加入量及其与Cu²⁺的络合能力。此外,首次尝试使用ESR方法,并借助氨基酸与酶的作用,考察了铜锌超氧化物歧化酶在盐酸胍变性和热变性过程中的构象变化行为,结果表明这一方法是直观而有效的。

SPECTROSCOPIC STUDIES AND APPLICATION OF THE INTERACTION BETWEEN COPPER ZINC SUPEROXIDE DISMUTASE AND SMALL BIOLOGICAL MOLECULES

The interaction between copper zinc superoxide dismutasc and some small biological molecules were studied by ESR, NMR and other biochemical methods. These biological molecules consists of amino acids, nucleic acid bases, ascorbic acid and others. It's found that the Cu²⁺ in the active site of the enzyme can be extracted out by amino acids, bases and ascorbic aied, distributed in solution as copper complexes, with the inactivation of the enzyme. The amount of the Cu²⁺ extracted out and the extent of inactivation are dependent of the amount of this biological ligand and its interaction ability. Besides, by the way of the interaction of amino acid and the enzyme, the conformational changes of the enzyme molecule resulted by guanidine hydrochloride denaturation and thermal denaturation can be studied effectively and visually by ESR method.