Enzymes recommended names

Hydrolases. Enzymes catalysing the hydrolytic cleavage ofC —O, C —N and C —C bonds. The systematic name always includes hydrolase but the recommended name is often formed by the addition of ase to the substrate. Examples are esterases, glucosidases, peptidases, proteinases, phospholipases. Other bonds may be cleaved besides those cited, e.g. during the action of sulphatases and phosphatases. 

Each enzyme is assigned two names. The first is its short, recommended name, convenient for everyday use. The second is the more complete systematic name, which is used when an enzyme must be identified without ambiguity. 

The International Union of Biochemistry has recommended that enzymes have three names, namely a systematic name, which shows the reaction being catalysed and the type of reaction based on the classification in Table A7.1, a recommended trivial name and a four figure Enzyme Commission code (EC code). Nearly all systematic and trivial enzyme names have the suffix -ase. Systematic names show, often in semi-chemical equation form, the conversion the enzyme promotes and the class of the enzyme. Trivial names are usually based on the function of the enzyme but may also include or be based on the name of the substrate. However, some trivial names in current use are historical and bear no relationship to the action of the enzyme or its substrate, for example, pepsin and trypsin are the names commonly used for two enzymes that catalyse the breakdown of proteins during digestion. The Enzyme Commission s code is unique for each enzyme. It is based on the classification in Table A7.1 but further subdivides each class of enzyme according to how it functions. The full code is... 

The enzymes referred to in the chapters of this review are listed in alphabetical order generally under their recommended names as in ENZYME NOMENCLATURE... 

Dehydrogenases (or oxidoreductases) constitute the first of six main divisions in the Enzyme Commission classification [ 1 ]. About 300 dehydrogenases that utilize nicotinamide coenzymes are known, and this chapter deals with some of them. The recommended name and EC number designate not a single enzyme protein, but a group of proteins with the same catalytic property [1]. 

Again each class is divided into subclasses according to the type of reaction catalysed. Each enzyme is assigned a recommended name usually a short one for everyday use, a systematic name which identify the reaction it catalyses and a classification number which is used where accurate and unambiguous identification of an enzyme is required (Table 6.1). 

Requires that high doses of proteases be delivered to the duodenum for relief of pain non-enteric-coated pancreatic enzymes are recommended and should betaken with each meal and at night if needed recommend name brands with proven efficacy and safety, as generic products have been associated with treatment failure add H2-receptor antagonist or proton pump... 

A much more ambitious database that builds on the IUBMB classification is BRENDA, maintained by the Institute of Biochemistry at the University of Cologne. In addition to the data provided by the ENZYME database, the BRENDA curators have extracted a large body of information from the enzyme literature and incorporated it into the database. The database format strives to be readable by both humans and machines. The categories of data stored in BRENDA comprise the EC-number, systematic and recommended names, synonyms, CAS-registry numbers, the reaction catalyzed, a list of known substrates and products, the natural substrates, specific activities, KM values, pH and temperature optima, cofactor and ion requirements, inhibitors, sources, localization, purification schemes, molecular weight, subunit structure, posttranslational modifications, enzyme stability, database links, and last but not least an extensive bibliography. Currently, BRENDA holds entries for approximately 3500 different enzymes. 

A large number of different enzymes has been described. Their nomenclature has been rather haphazard, although many enzymes are named by placing -ase after their substrate others are called product synthetase. Enzymes that transfer phosphate from ATP to a substrate are called substrate kinase. An international enzyme commission (EC) has developed a classification number, a systematic name, and a recommended name. Recommended names are widely used, but the EC numbers and systematic names are increasingly used to avoid confusion, often in a footnote. 

Protein (arginine) Methyltransferase. The enzyme(s) which methylates arginine residues of proteins was named protein methylase I by Paik and Kim (202). The recommended name is protein (arginine) methyltransferase (S-adenosyl-L-methionine protein N-methylttransferase, EC 2.1.1.23). The enzyme(s) catalyzes the reaction... 

The ENZYME database (http //www.expasy.ch/enzyme/) provides basic information about specific enzymes. It is based on the recommendations of the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology. In this database, you can obtain the EC number of any enzyme, its recommended name, alternative names, cofactors, and human diseases associated with the enzyme. You can trace the enzyme from its name to the reaction it catalyses—to the metabolic pathway(s) in which it participates—to the large and intricate Boehringer Mannheim Biochemical Pathways Wallchart. You also can search the database by metabolites or pathways. 

NOTE 1 Enzyme names and enzyme numbers are taken from Enzyme Nomenclature, Recommendations (1978) of the Nomenclature Committee of the International Union of Biochemistry Academic Press, New York. With few exceptions, the recommended names are listed first in Section 34, followed by Other Names or synonyms in a set of brackets, and/or finally followed by the official enzyme numbers in a set of parentheses.]... 

Enzymes are classified in terms of the reactions which they catalyse and were formerly named by adding the suffix ase to the substrate or to the process of the reaction. In order to clarify the confusing nomenclature a system has been developed by the International Union of Biochemistry and the International Union of Pure and Applied Chemistry (see Enzyme Nomenclature , Elsevier, 1973). The enzymes are classified into divisions based on the type of reaction catalysed and the particular substrate. The suffix ase is retained and recommended trivial names and systematic names for classification are usually given when quoting a particular enzyme. Any one particular enzyme has a specific code number based upon the new classification. 

The lUBMB Commission on Nomenclature has issued a number of recommendations dealing with areas of a more biochemical nature (72), such as peptide hormones (86), conformation of polypeptide chains (87), abbreviations for nucleic acids and polynucleotides (88), iron—sulfur proteins (89), enzyme units (90), etc. The Commission has also produced rules and recommendations for naming enzymes (91,92). 

A system based partly on historical names, partly on the substrate, and partly on the type of reaction catalyzed is far from satisfactory. In 1956, the International Union of Biochemistry set up a Commission on Enzymes to consider the classification and nomenclature of enzymes. The Commission presented a report in 1961 whose recommendations for naming and classifying enzymes were subsequently adopted (12). Enzymes are classified on the basis of the reactions they catalyze. Despite its apparent complexities, the system is precise and very descriptive, accommodating existing enzymes and serving as a systematic basis for the naming of new enzymes. AH enzymes are placed in one of the six principal classes. 

Note. The cyclic oligosaccharides arising from enzymic transglycosylation of starch have been referred to as Schardinger dextrins. These names (and those of the cyclohexaamylose type) are not recommended, but the abbreviation CD is tolerated. 

First, the true physiological substrates of most esterases are unknown. It is, therefore, hardly practicable to systematically name esterases according to the recommendations of the Enzyme Nomenclature Committee [1], i.e., based on the definite (physiological) role of the enzyme. The difficulty is that the use of nonphysiological substrates during purification and in characterization assays does not contribute to discovering the physiological role of an enzyme. 

This enzyme [EC 6.3.4.3], whose recommended EC name is formate-tetrahydrofolate ligase, catalyzes the ATP-dependent conversion of formate and tetrahydrofolate to yield ADP, phosphate, and 10-formyltetrahy-drofolate. 

This pyridoxal-phosphate-dependent enzyme [EC 2.1.2.1], which has a recommended EC name of glycine hydroxymethyltransferase, catalyzes the reversible reaction of 5,10-methylenetetrahydrofolate with glycine and water to produce tetrahydrofolate and L-serine. The enzyme will also catalyze the reaction of glycine with acetaldehyde to form L-threonine as well as with 4-tri-methylammoniobutanal to form 3-hydioxy-N, N, N -trimethyl-L-lysine. 

We have tried throughout this book to use the enzyme name most commonly used by working biochemists and to point out cases in which an enzyme has more than one widely used name. For current information on enzyme nomenclature, refer to the recommendations of the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (www.chem.qmw.ac.uk/iubmb/nomenclature/). 

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