Enzymes classifications

Enzymes have been classified into six major groups based on their action/function as oxidoreductase, transferase, hydrolase, lyase, isomerase, and ligase. Industrial enzymes have been grouped under above classes and are enlisted in Table 13.1. 

1 Existing Commerciai Process versus Enzymatic Processes 

The use of enzymes in chemical processes saves vast amount of water for example, in the textile industry, about 70,000-90,000 L of water is used for 1 ton of knitwears, which can be saved by employing the enzymes. Considering that approximately 9 million tons of knitwear is produced annually worldwide, about 630 billion liters of water could be saved if produced using enzymes. Enzymes can replace many chemicals in the industrial processes giving the process more environmental friendly touch. For example, enzymes can reduce the use of sulfides in tanneries, which are serious source of pollution. Acids 

3 Hydrolase Amylases, cellulases, lipases, marmanases, pectinases, phytases, proteases, pullulanases, xylanases 

5 Isomerase Glucose isomerases, epimerases, mutases, lyases, topoisomerases 

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Enzyme Enzyme classification number Substrate Wavelength of detection, nm... 

Six DA, Dennis EA (2000) The expanding superfamily of phospholipase A2 enzymes classification and characterization. Biochim Biophys Acta 1488 1—19... 

In all three examples, / -elimination was monitored by measuring the absorbance at 235 nm (with high-molecular substrates). Voragen186 pointed out that use of these substrates, which, at higher concentrations, can form viscous, optically dense solutions, could prevent the measurement of absorbance at 235 nm and thus cause an error in enzyme classification. The existence of polymethylgalacturonase is not definite, and revision of some of the results may be necessary. 

Merops (http //merops.sanger.ac.uk), database of peptidases and their proteinaceous inhibitors. Includes enzyme classification and nomenclature, external links to literature, and the structure of proteins of interest (if known). Enables one to find the gene coding for a given peptidase or to find the best enzyme to digest a chosen substrate. 

Arylsulfatase [EC 3.1.6.1 ], also known simply as sulfatase, catalyzes the hydrolysis of a phenol sulfate, thereby producing a phenol and sulfate. This enzyme classification represents a collection of enzymes with rather similar specificities. (1) Steryl-sulfatase [EC3.1.6.2],also referred to as arylsulfatase C and steroid sulfatase, catalyzes the hydrolysis of 3-j8-hydroxyandrost-5-en-17-one 3-sulfate to 3-j8-hydroxyandrost-5-en-17-one and sulfate. The enzyme utilizes other steryl sulfates as substrates. (2) Cere-broside-sulfatase [EC 3.1.6.8], or arylsulfatase A, catalyzes the hydrolysis of a cerebroside 3-sulfate to yield a cerebroside and sulfate. The enzyme will also hydrolyze the galactose 3-sulfate bond present in a number of lipids. In addition, the enzyme will also hydrolyze ascorbate 2-sulfate and other phenol sulfates. 

The use of enzymes and whole cells as catalysts in organic chemistry is described. Emphasis is put on the chemical reactions and the importance of providing enantiopure synthons. In particular kinetics of resolution is in focus. Among the topics covered are enzyme classification, structure and mechanism of action of enzymes. Examples are given on the use of hydrolytic enzymes such as esterases, proteases, lipases, epoxide hydrolases, acylases and amidases both in aqueous and low-water media. Reductions and oxidations are treated both using whole cells and pure enzymes. Moreover, use of enzymes in sngar chemistiy and to prodnce amino acids and peptides are discnssed. 

Amino acids, zwitterions, cysteine Peptides, protein structures Enzyme classification Enzyme activity Third hour exam Chemical messengers... 

Usually the enzymes are given an Enzyme Classification (EC) number, consisting of three or four figures separated by dots, to indicate subgroup and subsubgroup (e.g., bovine superoxide dismutase [SOD], EC 1.15.1.1). The enzymes discussed in the present monograph are given with their EC numbers in the Abbreviations section. 

Enzymes have been given various trivial names as they were discovered. Some of these names were informative, and some were not. To establish an unambiguous system for enzyme classification and nomenclature, the International Union of Biochemists proposed a system in which enzymes are grouped into six major classes. 

The complex nature and interconnectivity of plant cell wall polymers preclude straightforward enzymatic digestion. There are dozens of enzyme families involved in plant cell wall hydrolysis, including cellulases, hemicellu-lases, pectinases, and lignin-modifying enzymes. The Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (IUBMB) has classified cellulases and hemicellulases, like all enzymes, into different classes based on activity. Table 33.2 and Table 33.3, compiled from the IUBMB enzyme nomenclature database (http //www.chem.qmul.ac.uk/iubmb/ enzyme/), list the IUBMB enzyme classifications for cellulases and hemicellulases.153... 

The names of the examples of textile-relevant enzymes follow the nomenclature of Duclaux from 1898, characterising an enzyme by the end-syllable ase , added to the name of the snbstrate that is split, synthesised or otherwise catalysed. As with all catalysts, enzymes reduce the activation energy of a specific reaction. The discovery of large qnantities of new enzyme systems afforded a more differentiated nomenclatnre, realised in 1964 by the International Union of Pure and Applied Chemistry (lUPAC) and the International Union for Biochemistry (lUB). In the new enzyme classification (EC) the first nnmber refers to one of the six main gronps and the following numbers to subgroups, for example EC 3.4.S.6, where 3 stands for hydrolases. ... 

Garcia, R., Rivera, J., and Rolz, C. 1974. Rheological properties of tropical products and their enzymic classification. Proc. IV. Int. cong. Fd. Sci. Technol. 2 18-26. 

Substrate, benzylpenicillin with 5 min pre-incubation substrate, cephaloridine with 5 min pre-incubation enzyme classification based upon Richmond-Sykes. 

Concentration required to give 50% protection of 250 fig/mX nitrocefin substrate after a 5 min reaction time Enzyme classification based upon Richmond-Sykes. For abbreviations, see footnote to Table 6.1. 

Enzyme classification based on Richmond-Sykes CDjo of amoxycillin in the presence of inhibitor relative to that of amoxycillin in the presence of BRL 42715 (31) in an E. coli (TEM-1) infection in mice compounds were administered subcutaneously at 2 mg/kg with varying doses of amoxycillin at 1 and 5 hours post-infection (figures less than 1 indicative of inferior potency relative to BRL 42715). For abbreviations, see footnote to Table 6.1... 

Q-24 The following enzyme is classified as EC -2.7.I.I., What does this mean A-24 The name of the enzyme catalyzing following reaction is ATPrglucose phospo transferase. Its enzyme classification number (E.C.number) is 2.7.1.1... 

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