ENZYMOLOGY

From Big Medical Encyclopedia

ENZYMOLOGY (enzyme[s] + Greek logos the doctrine) — the section of biochemistry devoted to studying of a structure, the mechanism of catalytic action and molecular structure of enzymes. AA. is engaged in a solution of the problem of cleaning and preparative release of enzymes (see), their classification, studying of kinetics of an enzyme catalysis (see Kinetics of biological processes), specificity, inhibition and activation of enzymes, a research of their cofactors (see Coenzymes), and also process of biosynthesis of enzymes, their biology, practical application, including for an enzimodiagnostika (see Enzymes) and enzymotherapies (see). The enzymology is closely connected with chemistry (see), physical chemistry (see), bioorganic chemistry, biophysical chemistry (see), molecular biology (see), microbiology (see), genetics (see), pharmacology (see), toxicology (see), physiology (see), biophysics (see), biotechnology (see t. 29, additional materials) and chemical technology.

Stages of development of enzyme of l about and and. Beginning scientific E. it is possible to consider researches E. Bukhner and M. M. Manasseina, to-rye experimentally proved the chemical nature of enzymes. Important milestone of formation E. development at the beginning of 20 century of fundamentals of enzymatic kinetics was. By V. Henri, L. Michaelis and Menthene (M. of L. Menten) it was suggested that at an initial stage of enzymatic reaction between enzyme and substrate intermediate enzyme-substrate-ny a complex is formed and the mathematical model of this process is created. Following stage of development E. it is connected with promotion E. Fischer of a hypothesis

of the structural compliance of enzyme to a molecule of substrate which is the cornerstone of substrate specificity of enzymes. According to E. Fischer, enzyme approaches the substrate as a key to the lock. These representations were added in the 60th 20 century with D. E. Kosh-land's hypothesis of influence of the substrate which is occluded in an active center of enzyme on structure of the enzyme (the so-called induced compliance).

Turning point in the history E. came in the late twenties 20 century when for the first time it was succeeded to receive in crystalline state enzymes urease (see) and pepsin (see) and to prove that enzymes are proteins (see). Further it was established that molecules of many enzymes consist of two components — protein and nonprotein prosthetic troupe, a role a cut in some cases is played by derivatives of these or those vitamins (see). Since 50 — - the 60th 20 century spatial structure of molecules of a large number of enzymes was deciphered, and in 1969 it is for the first time carried out chemical - synthesis of enzyme of ribonuclease (see).

The first attempt of systematization of names of enzymes was Dyuklo's proposal (E. Duclaux, 1898) to add the termination «-an aza» to the word or a part of the word designating substrate on to-ry this enzyme works, except for traditionally developed names of the digestive enzymes terminating on «-in» — trypsin (see), pepsin (see) and some other. In 60 — the 70th 20 century the new nomenclature and classification of enzymes (more than 2 thousand names) was developed. All enzymes according to this classification were divided into 6 main classes in the following sequence: oksi-

doreduktaza (see), transferase (see), hydrolases (see), lyase, isomerase (see) and ligases (sintetaza).

Enzyme logiya and medicine and. Insufficiency of these or those enzymes causes in an organism of a deviation from fiziol. the norms which received the name of an enzymopathy <(see). Enzymopathies according to

A. A. Pokrovsky's proposal divide on: 1) hereditary, at to-rykh synthesis of any enzyme does not occur in general or proceeds with insufficient intensity or enzyme is synthesized inactive because formation of active enzyme from its proferment or a choloenzyme from fermental protein (apoenzyme) and prosthetic group (coenzyme) it is broken.; 2) toksshchchesky, arising at selective inhibition of separate enzymes, at specific exogenous selective braking of biosynthesis of separate enzymes or the general oppression of biosynthesis of proteins; 3) alimentary, developing at a vitamin deficiency (see), shortage of protein, microelements or at unbalanced food (see Food); 4) the enzymopathies caused by disturbance of neurohumoral regulation; 5) the enzymopathies connected with disturbance of the intracellular organization of enzymatic processes.

The size of activity of a number of enzymes (apprx. 40) in blood, urine, fibroblasts, erythrocytes, etc. is important diagnostic test. Change of activity of enzymes at patol. states can be either a cause of illness (enzymopathy), or its investigation. Besides, many enzymes are used as chemical reactants for definition of components of fabrics and liquids of an organism, e.g., urease apply at quantitative definition of urea (see), glucose oxydas — to definition of glucose in urine and blood (see Gorodetsky methods), cholinesterase (see) use for determination of residual number of organophosphorous connections (see), including willows biological substrates.

Enzymes apply as pharmaceuticals more and more widely. AA. studies them pharmakol. properties, develops methods of enzyme immobilization on neutral carriers, etc. (See) the role of fermental drugs on the basis of the immobilized enzymes (Streptokinasa, Streptodecasum, etc.), and also the enzymes entered into an organism by means of liposomes increases in pharmacotherapy. Fermental drugs (see) use for compensation of deficit of enzymes at replacement therapy; e.g., at nek-ry forms of gastritis (see) appoint digestive enzymes of a stomach and pancreas. Proteolytic enzymes (see Peptide-hydrolase) apply at treatment of pyoinflammatory diseases or thromboses. However at treatment of hereditary enzymopathies (see. Hereditary diseases) fermental drugs are still inefficient.

In our country and abroad courses on E. read in high fur boots and medical in-ta at departments of biochemistry, physiological chemistry and physiology. Works on problems E. publish in all periodicals on biochemistry, molecular biology, physics, physical chemistry, biophysics, etc.

Bibliogrvvedeniye in applied enzymology, under the editorship of. I. V. Berezina and K. Martinek, M., 1982; Vilkin

dream of. The principles and methods of diagnostic enzymology, the lane with English, M., 1981; Dickson M. and Webb E. Enzymes, the lane with English, M., 1982; Kretovichv.L. Introduction to enzymology, M., 1974;

Moss D. U. and Battervortp. J. Enzyme a logiya and medicine, the lane with English, M., 1978; The Nomenclature of enzymes, the lane with English, under the editorship of A. E. Braunstein, M., 1979; Rozengart V. I. Enzymes — engines of life, JI., 1983.

E. V. Rozengart.

Яндекс.Метрика