Non-competitive inhibition

This inhibition is observed when there isn’t structural resemblance between inhibitor and substrate. Complex inhibitor-substrate-enzyme is formed due to binding of inhibitor to catalytic part of active site. For example, enzyme cytochrome oxydase. Its substrate is oxygen and non-competitive inhibitor is cyanic acid or its salts (cyanides).

Allosteric regulation of enzymic activity

Some of enzymes with quaternary structure have allosteric center beside of active one. Allosteric center usually occurs near active site of enzyme. Modification of allosteric center is transmitted to active center and activity of enzyme is activated or inhibited in depend of action of allosteric activator or inhibitor. For example, adenylyl cyclase (or guanylyl cyclase) are enzymes with allosteric types of regulation.

Classification of enzymes

In 1961 the commission of Enzymes of the International Union of Biochemistry divided all enzymes into six main classes, each one of which is further subdivided into subclasses and sub-subclasses. The main classes are the following – I. Oxireductases, II. Transferases, III. Hydrolases, IV. Lyases, V. Isomerases, VI. Lygases (or synthetases). The numbers of classes, subclass, sub-subclass and one’s number of enzyme are the code of each enzyme. In many cases the old terminology is used: pepsin, trypsin, chymotrypsin, papain. We begin to study a different classes from more simple – third class – hydrolyses.

<== попередня сторінка	\|	наступна сторінка ==>
The effect of substrate concentration	\|	III. Hydrolases

Не знайшли потрібну інформацію? Скористайтесь пошуком google:

Генерація сторінки за: 0.004 сек.