ENZYMES IN MEDICINE

Enzymes are used as therapeutic agents:

- in their absence or deficiency (inherited or acquired);

- for the specific destruction of some metabolic products.

Enzymes are used in the clinic as analytical reagents.

Immobilized enzymes are often used for the analysis, which are artificially connected with the water-insoluble carrier, which increases the stability of protein catalysts.

Analysis of the kinetics of appearance and disappearance of enzymes in the serum is used in the diagnosis.

The composition of enzymes and their tissue distribution in an adult is mainly constant and can change in diseases. Almost all of the enzymes of the organism are functioning intracellularly. When tissue is damaged intracellular enzymes appear in the serum. Such enzymes are called indicator enzymes.

By the appearance of several tissue enzymes in plasma or serum in high amounts one can conclude on the functional status and lesions of various organs.

Enzimopathy (synonym fermentopathy) is the common name of diseases, developing as a result of the absence or decreased activity of certain enzymes. As a result of the interdependence of metabolic pathways defect of a single enzyme often leads to a number of disorders in the metabolism.

We distinguish hereditary and acquired enzymopathy.

1. Hereditary enzimopathysare associated with genetically determined deficiency of one or more enzymes. There are more than 150 hereditary enzymopathies, which are based on gene mutations.

2. Acquired enzimopathy.

Toxic enzymopathy is a consequence of toxic effects of xenobiotics and environmental mutagens. Lead, which is contained in the transport exhaust fumes, causes a inhibition of the enzyme aminolevulinatdehydrase involved in the synthesis of heme, which manifests the development of anemia of children in the city.

Nutritional enzymopathy may be due to prolonged lack of protein in the diet, vitamin deficiency, unbalanced nutrition.

Test Questions

1. Describe the chemical nature and structure of enzymes.

2. What is the structure of the active center of enzyme? What is the allosteric center?

3. Give examples of isozymes; multimolecular enzyme systems.

4. On what basis enzymes are classified?

5. Describe the mechanism of enzyme action.

6. What is the difference between the theories of Fisher and Koshland?

7. How do changes in pH and temperature influence on the rate of enzymatic reactions?

8. What is meant by the specificity of enzyme action?

9. How is the regulation of enzyme activity done?

10. What types of enzymes inhibition do you know?

11. How can be carried out in practice the determination of the enzymes activity?

12. Give examples of the enzymes usage in medicine.

VITAMINS

Vitamins (from Lat. vita - life) are organic compounds required in the diet in small amounts. They ensure the normal development of human and animal, and an adequate rate of occurrence of biochemical and physiological processes.

Vitamins are the assembly group of organic compounds in the chemical and physical point of view. The physiological effects of vitamins are also very different.

100 years ago it was believed that for the normal life of the human organism flux of proteins, fats, carbohydrates, minerals and water is enough. Practice and experience have shown that there are specific diseases which development is directly related to malnutrition (scurvy, beriberi).

The need for vitamins is negligible: approximately a person should consume daily 0.1 - 0.2 g. of vitamins. In many cases, vitamins are components of enzymes.

Avitaminosis (vitamin deficiency) is a disease that occurs in the absence of food vitamins or in total violation of assimilation of any vitamin.

Hypovitaminosis is insufficient intake of vitamins with food or their incomplete assimilation.

Hypervitaminosis is pathological state associated with large quantities of vitamins in the organism.

The causes of hypo- and avitaminosis in humans and animals are usually divided into exogenous and endogenous. An exogenous factoris insufficient intake of vitamins or their complete absence in the diet. Endogenous factors are: a) increased requirement for vitamins in certain physiological and pathological conditions (pregnancy, hyperthyroidism); b) violation of the process of absorption of vitamins in the digestive tract diseases; c) enhanced disruption of vitamins in the intestine due to the development of its flora; d) liver, pancreas diseases, accompanied by malabsorption of fat and therefore fat-soluble vitamins.

The classification is currently used based on the solubility of the vitamins.