Oxidoreductase nomenclature

NAD(P)+ as Anode Mediator. A majority of redox enzymes require the cation nicotinamide adenine dinucleotide, possibly phosphorylated (NAD(P)+) as a cofactor. Of the oxidoreductases listed in Enzyme Nomenclature, over 60% have NAD(P)+ as a reactant or product.For example, methanol can be oxidized to form formaldehyde by methanol dehydrogenase (MDH, EC 1.1.1.244) according to... 

PHYSICAL ORGANIC CHEMISTRY NOMENCLATURE ALDEHYDE DEHYDROGENASE ALDEHYDE HYDRATION ALDEHYDE OXIDASE ALDEHYDE OXIDOREDUCTASE ALDOSE REDUCTASE Aldehyde reduction to alcohols, BOROHYDRIDE REDUCTION ALDOLASE Aldolase reduction,... 

The trivial name oxidoreductase is often used for enzymes that catalyze this reaction, but the systematic Enzyme Nomenclature includes them in the hydrolyase group (E.C. 4.2.1) and not in the oxidoreductase one. 

The cytochrome P450 system is the principal enzyme system for the metabolism of lipophilic xenobiotics. It is a heme-containing, membrane-bound, multi-enzyme system which is present in many tissues in vivo but is present at the highest level in liver. A coenzyme, cytochrome P450 NADPH oxidoreductase (OR), is essential for P450 catalytic function and cytochrome bs may stimulate catalytic activities of some enzymes. In human liver, it is estimated that there are 15-20 different xenobiotic-metabolizing cytochrome P450 forms. A standard nomenclature, based on relatedness of the amino acid sequences, has been developed (Nelson et al., 1993). The most recent... 

The International Union of Biochemistry and Molecular Biology (IUBMB) developed a system of nomenclature in which enzymes are divided into six major classes (Figure 5.1), each with numerous subgroups. The suffix -ase is attached to a fairly complete description of the chemical reaction catalyzed, for example D-glyceraldehyde 3-phosphate NAD oxidoreductase. The IUBMB names are unambiguous and informative, but are sometimes too cumbersome to be of general use. 

An alternative mechanism for the oxidation of phenolic compounds is enzyme-catalyzed oxidation. Several classes of enzymes can catalyze this reaction. According to the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB), these enzymes are part of the E C. 1 class of oxidoreductases (see the Internet web site http //www.chem.qmul.ac.uk/iubmb/enzyme/ECl). The three main classes of enzymes that catalyze the oxidation of phenolic compounds are the oxidoreductases that use oxygen as electron acceptor (E.C. 1.10.3), the peroxidases (E.C. 1.11.1), and monophenol monooxygenase (E.C. 

Aldehyde dehydrogenases [AEDHs alde-hyde NAD(P) oxidoreductases EC 1.2.1.3 and EC 1.2.1.51 exist in multiple forms in the cytosol, mitochondria, and microsomes of various mammalian tissues. It has been proposed that AEDHs form a superfamily of related enzymes consisting of class 1 AEDHs (cytosolic), class 2 AEDHs (mitochondrial), and class 3 AEDHs (tumor-associated and other isozymes). In all three major classes, constitutive and inducible isozymes exist. In a proposed nomenclature system, the human AEDHs are designated as lAl, 1A6, IBl, 2, 3A1, 3A2, 3B1, 3B2, 4A1, 5A1, 6A1, 7A1, 8A1, and 9A1 (33-35). 

Note There is a systematic nomenclature for classifying the enzymes by function, as follows oxidoreductases involve oxidation-reduction reactions transferases involve the transfer of functional groups hydrolases involve hydrolysis reactions with water lyases involve the elimination of a group to form double bonds isomerases involve isomerization to a different structure but with the same chemical composition ligases involve the formation of a chemical bond simultaneously with ATP hydrolysis. There are in turn subclasses and sub-subclasses, and a subclass that... 

Enzymes are most frequently named by using the common system of nomenclature. The names are useful because they are often derived from the name of the substrate and/or the reaction of the substrate that is catalyzed by the enzyme. Enzymes are classified according to fimction. The six general classes are oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. 

Each enzyme category (e.g., EC 1) is divided into subclasses (e.g., EC 1.2) and its subclass is subdivided into sub-subclasses (e.g., EC 1.2.2). The last (fourth) number of the lUBMB nomenclature refers to the particular enzyme (e.g., EC 1.2.2.3). For example, the enzyme EC 1.10.3.2 (laccase) represents an oxidoreductase enzyme (EC 1) that acts on diphenols and related substances as donors (EC 1.10), with oxygen as the acceptor (EC 1.10.3). Table 4.2 shows the six EC enzyme classes with their functionalities. 

Enzyme commission of the International Union of Biochemistry and Molecular Biology (lUBMB) established two enzyme nomenclatures systematic and trivial. According the systematic nomenclature all enzymes are divided upon 6 classes l.Oxidoreductases 2. Transferases 3. Hydrolyses 4. Lyases cleaving C-C C-O, C-N bonds 5. Isomerases, and 6. indication ofbond formed. 

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