ENZYMATIC ACTIVATION MECHANISMS

本论文的工作涉及酶的化学表征 氧活化和酶促卤化反应中的中间体， 它们与过氧化物酶和细胞色素P-450化学的关系。 一个主要重点 本文主要研究过氧化物酶化合物的化学性质 I和化合物X。 我们还计划继续在三个方面开展工作， 氯过氧化物酶的三维结构，特别是在血红素活性 这个酶的位置。 以前的工作建立了密切的关系 在氯过氧化物酶、P-450细胞色素和含有 血红素铁的硫醇配体。 我们计划继续开展工作， 丙酮酸的脂质和蛋白酶活化形式的表征 氧化酶。 这种外周膜酶的催化活性是 通过将两亲分子结合到独特的 酶上的高亲和力脂质结合位点。 一种共价亲和标记， 为了鉴定这种高亲和性结合位点，已经开发了一种新的方法。 丙酮酸氧化酶的天然60 K单体的蛋白水解切口产生 具有脂质活化的催化活性的58 K物质 酶。 58 k物质不需要脂质两亲物来增强 活性，事实上已经失去了与60 K单体。

The proposed work involves the chemical characterization of enzyme intermediates in oxygen activation and enzymatic halogenation reactions and their relation to peroxidase and cytochrome P-450 chemistry. A major focus of the work centers on the chemical characterization of peroxidase Compound I and Compound X. We also plan to continue our work on the three dimensional structure of chloroperoxidase, especially at the heme active site of this enzyme. Previous work has established a close relation between chloroperoxidase, P-450 cytochromes and model compounds containing a thiolate ligand to heme iron. We plan to continue our work on the characterization of the lipid and proteaseactiviated forms of pyruvate oxidase. The catalytic activity of this peripheral membrane enzyme is dramatically increased by the binding of amphiphilic molecules to a unique high affinity lipid binding site on the enzyme. A covalent affinity label has been developed in order to identify this high affinity binding site. Proteolytic nicking of the native 60 K monomer of pyruvate oxidase produces a 58 K species having the catalytic activity of the lipid activated anzyme. The 58 k species does not require lipid amphiphiles for enhanced activity and in fact has lost the lipid binding site associated with the 60 K monomer.