ENZYMATIC ACTIVATION MECHANISMS

拟议的工作涉及酶的化学特性。 氧活化和酶促卤化反应的中间体和 它们与过氧化物酶和细胞色素P-450化学的关系。一个主要的焦点 的工作集中在过氧化物酶化合物的化学表征上 I和化合物X。我们还计划继续我们在这三个方面的工作 氯过氧化物酶的空间结构，尤其是在血红素活跃时 这种酶的位置。以前的工作已经建立了密切的关系 氯过氧化物酶、P-450细胞色素与含有 亚铁血红素铁的硫酸盐配体。我们计划继续我们在 丙酮酸的脂类和蛋白酶活性形式的表征 氧化物酶。该外周膜酶的催化活性为 通过将两亲性分子与独特的 酶上的高亲和力脂质结合部位。一种共价亲和标记 已被开发用于鉴定该高亲和力结合部位。 天然60K丙酮酸氧化酶单体的蛋白水解性划痕 具有脂类催化活性的58K物种 安吉米。58k物种不需要脂类两亲性来增强 活性，实际上已经失去了与60相关的脂结合部位 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.