Biomaterial Database

Enzyme-catalyzed detoxication reactions: mechanisms and stereochemistry. 1987

R N Armstrong

Department of Chemistry and Biochemistry, University of Maryland, College Park.

Enzyme catalyzed detoxication reactions are one of the primary defenses organisms have against chemical insult. This article reviews current chemical approaches to understanding the cooperative role of enzymes in the metabolism of foreign compounds. Emphasis is placed on chemical and stereochemical studies which help elucidate the mechanism of action and active-site topologies of the detoxication enzymes. The stereoselectivity of the cytochromes P-450 and flavin containing monooxygenases as well as the role of hemoglobin and lipid peroxidation in the primary metabolism of xenobiotics is discussed. Current knowledge of the mechanism and stereoselectivity of epoxide hydrolase is also presented. Three enzymes involved in secondary metabolism of xenobiotics, UDP-glucuronosyltransferase, sulfotransferase and glutathione S-transferase are discussed with particular emphasis on active site topology and cooperative participation with the enzymes of primary metabolism.

UI	MeSH Term	Description	Entries
D008658	Inactivation, Metabolic	Reduction of pharmacologic activity or toxicity of a drug or other foreign substance by a living system, usually by enzymatic action. It includes those metabolic transformations that make the substance more soluble for faster renal excretion.	Detoxication, Drug, Metabolic,Drug Detoxication, Metabolic,Metabolic Detoxication, Drug,Detoxification, Drug, Metabolic,Metabolic Detoxification, Drug,Metabolic Drug Inactivation,Detoxication, Drug Metabolic,Detoxication, Metabolic Drug,Detoxification, Drug Metabolic,Drug Inactivation, Metabolic,Drug Metabolic Detoxication,Drug Metabolic Detoxification,Inactivation, Metabolic Drug,Metabolic Drug Detoxication,Metabolic Inactivation
D008968	Molecular Conformation	The characteristic three-dimensional shape of a molecule.	Molecular Configuration,3D Molecular Structure,Configuration, Molecular,Molecular Structure, Three Dimensional,Three Dimensional Molecular Structure,3D Molecular Structures,Configurations, Molecular,Conformation, Molecular,Conformations, Molecular,Molecular Configurations,Molecular Conformations,Molecular Structure, 3D,Molecular Structures, 3D,Structure, 3D Molecular,Structures, 3D Molecular
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
D003577	Cytochrome P-450 Enzyme System	A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.	Cytochrome P-450,Cytochrome P-450 Enzyme,Cytochrome P-450-Dependent Monooxygenase,P-450 Enzyme,P450 Enzyme,CYP450 Family,CYP450 Superfamily,Cytochrome P-450 Enzymes,Cytochrome P-450 Families,Cytochrome P-450 Monooxygenase,Cytochrome P-450 Oxygenase,Cytochrome P-450 Superfamily,Cytochrome P450,Cytochrome P450 Superfamily,Cytochrome p450 Families,P-450 Enzymes,P450 Enzymes,Cytochrome P 450,Cytochrome P 450 Dependent Monooxygenase,Cytochrome P 450 Enzyme,Cytochrome P 450 Enzyme System,Cytochrome P 450 Enzymes,Cytochrome P 450 Families,Cytochrome P 450 Monooxygenase,Cytochrome P 450 Oxygenase,Cytochrome P 450 Superfamily,Enzyme, Cytochrome P-450,Enzyme, P-450,Enzyme, P450,Enzymes, Cytochrome P-450,Enzymes, P-450,Enzymes, P450,Monooxygenase, Cytochrome P-450,Monooxygenase, Cytochrome P-450-Dependent,P 450 Enzyme,P 450 Enzymes,P-450 Enzyme, Cytochrome,P-450 Enzymes, Cytochrome,Superfamily, CYP450,Superfamily, Cytochrome P-450,Superfamily, Cytochrome P450
D004798	Enzymes	Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.	Biocatalyst,Enzyme,Biocatalysts
D004851	Epoxide Hydrolases	Enzymes that catalyze reversibly the formation of an epoxide or arene oxide from a glycol or aromatic diol, respectively.	Epoxide Hydrase,Epoxide Hydrases,Epoxide Hydratase,Epoxide Hydratases,Epoxide Hydrolase,9,10-Epoxypalmitic Acid Hydrase,Microsomal Epoxide Hydrolase,Styrene Epoxide Hydrolase,9,10 Epoxypalmitic Acid Hydrase,Acid Hydrase, 9,10-Epoxypalmitic,Epoxide Hydrolase, Microsomal,Epoxide Hydrolase, Styrene,Hydrase, 9,10-Epoxypalmitic Acid,Hydrase, Epoxide,Hydrases, Epoxide,Hydratase, Epoxide,Hydratases, Epoxide,Hydrolase, Epoxide,Hydrolase, Microsomal Epoxide,Hydrolase, Styrene Epoxide,Hydrolases, Epoxide
D005982	Glutathione Transferase	A transferase that catalyzes the addition of aliphatic, aromatic, or heterocyclic FREE RADICALS as well as EPOXIDES and arene oxides to GLUTATHIONE. Addition takes place at the SULFUR. It also catalyzes the reduction of polyol nitrate by glutathione to polyol and nitrite.	Glutathione S-Alkyltransferase,Glutathione S-Aryltransferase,Glutathione S-Epoxidetransferase,Ligandins,S-Hydroxyalkyl Glutathione Lyase,Glutathione Organic Nitrate Ester Reductase,Glutathione S-Transferase,Glutathione S-Transferase 3,Glutathione S-Transferase A,Glutathione S-Transferase B,Glutathione S-Transferase C,Glutathione S-Transferase III,Glutathione S-Transferase P,Glutathione Transferase E,Glutathione Transferase mu,Glutathione Transferases,Heme Transfer Protein,Ligandin,Yb-Glutathione-S-Transferase,Glutathione Lyase, S-Hydroxyalkyl,Glutathione S Alkyltransferase,Glutathione S Aryltransferase,Glutathione S Epoxidetransferase,Glutathione S Transferase,Glutathione S Transferase 3,Glutathione S Transferase A,Glutathione S Transferase B,Glutathione S Transferase C,Glutathione S Transferase III,Glutathione S Transferase P,Lyase, S-Hydroxyalkyl Glutathione,P, Glutathione S-Transferase,Protein, Heme Transfer,S Hydroxyalkyl Glutathione Lyase,S-Alkyltransferase, Glutathione,S-Aryltransferase, Glutathione,S-Epoxidetransferase, Glutathione,S-Transferase 3, Glutathione,S-Transferase A, Glutathione,S-Transferase B, Glutathione,S-Transferase C, Glutathione,S-Transferase III, Glutathione,S-Transferase P, Glutathione,S-Transferase, Glutathione,Transfer Protein, Heme,Transferase E, Glutathione,Transferase mu, Glutathione,Transferase, Glutathione,Transferases, Glutathione
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities