RAPID KINETICS & OTHER STUDIES OF BIOLOGICAL OXYGENASES

这个项目是一项酶学研究，目的是确定化学物质 氧气被称为加氧酶的酶激活的机制。 加氧酶存在于所有需氧生物体中，并且在 类固醇、核酸的生物合成、转化和降解， 儿茶酚胺、胶原蛋白、药物、前列腺素、木质素和各种 外国化合物。这些酶对大多数生命形式至关重要。 我们的目标是继续调查三种不同类型的 我们以均一形式分离的加氧酶：1)邻苯二酚 双加氧酶，包括儿茶酚和原儿茶酸双加氧酶，它们 非亚铁血红素含铁酶是否在降解 土壤细菌产生的芳香族化合物。2)黄素蛋白羟基酶 包括细菌和酵母酶，如对羟基苯甲酸酯 羟基酶。3)邻苯二甲酸酯加氧酶，一种多组分的双加氧酶系统 它将未活化的芳香族化合物转化为二氢二醇。这 加氧酶的类型在芳香族化合物的环境控制中非常重要 化合物，目前还知之甚少。 拟议的研究将使用快速动力学分光光度法、化学 淬火等酶学方法。X射线结晶学和 基因技术，包括克隆、基因测序和突变， 将被广泛使用，以更好地理解这些 有趣的酵素。 我们希望这些研究的结果将有助于更好地理解 分子氧如何被激活以进行受控的代谢过程。 这反过来可能导致预测各种化合物将如何变化的能力 在环境中代谢。

This project is an enzymological study aimed at determining the chemical mechanism whereby oxygen is activated by enzymes called oxygenases. Oxygenases are found in all aerobic organisms and are important in the biosynthesis, transformation, and degradation of steroids, nucleic acids, catecholamines, collagen, drugs, prostaglandins, lignin, and various foreign compounds. These enzymes are crucial to a majority of life forms. Our aims are to continue the investigation of three different types of oxygenases which we have isolated in homogeneous form: 1) Catechol dioxygenases, including catechol and protocatechuate dioxygenases, which are nonheme iron-containing enzymes important in the degradation of aromatic compounds by soil bacteria. 2) Flavoprotein hydroxylases which include bacterial and yeast enzymes such as para-hydroxybenzoate hydroxylase. 3) Phthalate oxygenase, a multicomponent dioxygenase system which converts an unactivated aromatic compound to a dihydrodiol. This type of oxygenase is very important in environmental control of aromatic compounds, and is poorly understood at present. The proposed study will employ rapid kinetics spectrophotometry, chemical quenching, and other enzymological methods. X-ray crystallography and genetic techniques, including cloning, gene sequencing and mutagenesis, will be used extensively to develop a better understanding of these interesting enzymes. We hope that results from these studies will lead to a better understanding of how molecular oxygen is activated for controlled metabolic processes. This in turn may lead to the ability to predict how various compounds will be metabolized in the environment.