ENGINEERING OF NOVEL SUBSTRATE OXIDATION IN HEME ENZYMES

该项目的目标是利用酶的工程形式 细胞色素c过氧化物酶证明合理的可行性 蛋白质设计，以实现氧化催化， 特定的有机反应。发现活性位点Trp- 在CCP的氧化“ES”状态下，191被可逆地氧化成 稳定的阳离子自由基引起了人们对利用 该位点可能结合的固有化学和/或 有机分子的氧化。为此， W191 G突变体，其中活性位点色氨酸被替换为 甘氨酸，最近报道，和小分子的可行性， 与该位点的结合被清楚地证明。本届第一期 建议涉及系统确定的因素， 控制底物特异性和腔内结合。第二部分 这项建议涉及的氧化化学的调查 有机底物，如氨基噻唑类抗甲状腺药物， 能与血红素酶发生反应第三部分建议 研究利用了本报告第一部分和第二部分收集的信息， 建议，并侧重于利用W191 G的可行性 空腔突变体，用于催化 有机基质从空腔内。

The goal of this project is to utilize engineered forms of the enzyme cytochrome c peroxidase to demonstrate the feasibility of rational protein design towards the accomplishment of oxidative catalysis of specific organic reactions. The discovery that the active site Trp- 191 in the oxidized "ES" state of CCP is reversibly oxidized to a stable cation free radical has prompted an interest in exploiting the chemistry inherent at this site for the possible binding and/or oxidation of organic molecules. To this end, construction of the W191G mutant, in which the active site tryptophan was replaced with glycine, was recently reported, and the feasibility of small molecule binding to this site was clearly demonstrated. Part I of this proposal involves the systematic determination of the factors that control substrate specificity and binding within the cavity. Part II of this proposal involves an investigation of the oxidative chemistry of organic substrates, such as the aminothiazole anti-thyroid drugs, that are known to react with heme enzymes. Part III of this proposed study utilizes the information gleaned from Parts I and II of this proposal, and focuses on the feasibility of utilizing the W191G cavity mutant for the purposes of catalyzing general oxidation of organic substrates from within the cavity.