Enzymes Commission

Hydrolases represent a significant class of therapeutic enzymes [Enzyme Commission (EC) 3.1—3.11] (14) (Table 1). Another group of enzymes with pharmacological uses has budt-ia cofactors, eg, in the form of pyridoxal phosphate, flavin nucleotides, or zinc (15). The synthases, and other multisubstrate enzymes that require high energy phosphates, are seldom available for use as dmgs because the required co-substrates are either absent from the extracellular space or are present ia prohibitively low coaceatratioas. 

Enzyme CAS Registry Number Enzyme commission number Catalysis Use... 

Systematic Classification of Enzymes According to the Enzyme Commission ... 

The first Enzyme Commission, in its 1961 report, devised a system for classification of enzymes that also serves as a basis for assigning code numbers to them. Every enzyme has got a 4-digit number EC A.B.C.D. where EC stands for Enzyme Commission with the following properties encoded ... 

All enzymes already mentioned, except oligo-D-galactosiduronate hydrolase, are included in the Enzyme Nomenclature of the IUPAC-IUB Enzyme Commission,11 and their code numbers and suitably modified, systematic names are used herein. 

This corresponds to the recommendations given in 1959 by a joint committee of the Clinical Chemistry Commission of IUPAC (International Union of Pure and Applied Chemistry) and the Enzyme Commission of IUB (International Union of Biochemistry). Thus, one unit of enzyme activity should be defined as that amount of enzyme which catalyzes the conversion of one micromole of substrate per minute under defined conditions (W9). 

Each enzyme has been given a four-digit number by the Enzyme Commission of the International Union of Biochemistry. The first three digits relate to the reaction catalysed by the enzyme and the final one is required if several enzymes with different protein structures catalyse the same reaction. 

EC - Enzyme Commission number system W - indicates the reaction catalysed (1—6)... 

The criteria for gene displacement in this study were strict. The reactions catalyzed were required to have the same EC (Enzyme Commission) number, which implies that the same cofactors had to be involved. In the example of reactions involved in the citric acid cycle given previously, when only the carbohydrate substrate and product of the reaction were the same, we could identify gene displacements at 6 of the 11 steps included in the analysis. Only two of those (malate dehydrogenase and fumarase) met the criteria in Galperin et al. (1998). 

Table 3.1 Major classes in the Enzyme Commission system for enzyme nomenclature...

EC book is an index server that provides access to enzymes and EC numbers. EC numbers are assigned by the Enzyme Commission on the basis of enzyme functionality [37]. Each EC number consists of four levels of function. There are six main classes of enzymes. The EC book database is usually updated once a year (but more frequently in recent years). 

More than 2000 different enzymes are currently known. A system of classification has been developed that takes into account both their reaction specificity and their substrate specificity. Each enzyme is entered in the Enzyme Catalogue with a four-digit Enzyme Commission number (EC number). The first digit indicates membership of one of the six major classes. The next two indicate subclasses and subsubclasses. The last digit indicates where the enzyme belongs in the subsubclass. For example, lactate dehydrogenase (see pp. 98-101) has the EC number 1.1.1.27 (class 1, oxidoreductases subclass 1.1, CH-OH group as electron donor sub-subclass 1.1.1, NAD(P) " as electron acceptor). 

Proteins that catalyze the exchange of protein-bound nucleotide with nucleotide free in solution. These exchange factors represent an unclassified type of iso-merase, but there has been no Enzyme Commission of this class. 

ENZYME COMMISSION NOMENCLATURE ENZYME CONCENTRATION EFFECTS... 

ENZYME COMMISSION NOMENCLATURE ISOMERIZATION Isomerization mechanisms,... 

ENZYME COMMISSION NOMENCLATURE LYATE ION LYONIUM ION LEVELING EFFECT Lysine,... 

In the literature of PVA biodegradation, the orientation with respect to the enzymatic activities that are described is not clear-cut and sometimes even perplexing. This originates in the historical development of the field that gave rise to the nomenclature used today. Table 2 aims to give a clear denomination of the enzymes that are directly involved in the biodegradation of PVA, and that are cited in the literature so far. As an unambiguous denomination for enzyme activity, the Enzyme Commission number (EC number) is used. Every EC number is... 

---