From Big Medical Encyclopedia

GLOBULINS (Latin globulus a ball) — the group name of the natural proteins making nearly a half of serum proteins of blood of the person; rastvorima in weak saline solutions, not rastvorima in a distilled water also drop out in a deposit at 50% and more saturation of solutions ammonium sulfate.

The concept «globulins» as well as the concept "albumine", arose as result of the first attempts to understand complex proteinaceous structure of animal and vegetable organisms. With development of methods of allocation and fractionation of proteins the term «globulins» most often began to designate a number of protein fractions of blood serum of the person and animals. Are a part of any fabrics of plants and animals. In an organism of animals and the person they are found in blood serum, milk, saliva, cerebrospinal liquid, in extracts of various bodies and fabrics. Simple belong to G. proteins (see), glycoproteins (see), lipoproteids (see), metalloproteins (see). Among them the proteins which are carrying out transport of lipoid (alipoproteida, beta lipoproteids), hormones (transcortinum, Retinolum - and thyroxine - the connecting proteins, alfa2-macroglobulin), gland (transferrin, hemopexin, gaptoglobin), copper are found (ceruloplasmin). In fraction G. activity of some enzymes, napr, serumal cholinesterase, ceruloplasmin, and some inhibitors of enzymes, napr, inhibitors of trypsin, chymotrypsin, thrombin, acetylcholinesterase is found. Some blood-coagulation factors (a prothrombin, plasminogen, fibrinogen, a fibrinstabiliziruyushchy factor) also belong to G. It is especially important to emphasize that treat G. antibodies (see) and complement (see), creating humoral immunity. G. of a blood plasma are fullestly characterized. G.'s concentration in a blood plasma of the person makes 2 — 3%. Serumal G. together with albumine and low-molecular substances of blood serum carry out the major biol, function, participating in maintenance constant osmotic pressure of blood. This function G. becomes especially essential at decrease in content in blood serum of albumine (as a result of some diseases, at long immunization). Definition absolute and abundance of serumal G. and their fraction is additional diagnostic test at a large number of diseases of the person, G. of plants form considerable group of proteins in extracts of leaves, seeds, fruits, etc. The lectins interacting with carbohydrates belong to vegetable G. (see), to the Crimea the phytohemagglutinin which gained fame as an immunological reactant belongs. Studying of structure of soya beans showed that their reserve proteins having great nutritional value belong to the class. Since the end of 19 century globulins began to subdivide on eu-and pseudoglobulins. Euglobulina (evglobulina) of a rastvorima only in weak salt solutions, and at dialysis against a dist, waters or at 33% saturation of solution ammonium sulfate they drop out in a deposit. Pseudoglobulins of a rastvorima in water are also besieged at 50% saturation of solution by ammonium sulfate. If to classify proteins by electrophoretic mobility, then all proteins, moving more slowly, albumine in the field of direct electric current treat G. at pH 8,2 — 8,6.

The isoelectric point of G. is at pH ~ 7,3. Are steady in the range of pH values of 5,0 — 9,5; maintain heating at 50 ° within several hours, especially in the presence of sugar, napr, lactoses, or amino acids, napr, glycine.

In the analysis of serum proteins by method of zone electrophoresis (see) at pH 8,6 globulins are divided into several fractions, called (as reduction of their electrophoretic mobility) alfa1, alfa2, beta1, beta2 and gamma-globulins. These fractions also also may contain geterogenna as eu-, and pseudoglobulins. At the person the amount of protein in fraction of alfa1-globulins makes 4,6% of all serum protein, alfa2-globulins — 7,2%, beta1-globulins — 12,1%, beta2-globulins — 5,1%, gamma-globulins — 11,0%. From globulinovy fraction of a blood plasma of the person more than 40 individual proteins are emitted in a homogeneous or high cleaning state; many their physical. - chemical properties are studied. Besides, in fraction G. some more biologically active proteins are found. Half-life of mix r-and 7 globulins of blood serum makes 9 — 12 days, and one gamma-globulins of 18 — 19 days.

G.'s allocation is carried out most often by sedimentation by ammonium sulfate, sodium sulfate or magnesium and phosphate of ammonia; serumal G.' fractionation by alcohol by Kohn's method; by electrophoretic, hromatografichesky and other methods. The main industrial way of receiving fractions G. is Kohn's method.

The quantitative change of electrophoretic fractions of G. (not immunoglobulins) and separate proteins, entering into these fractions, is considered in a wedge, practice as additional diagnostic tests at many diseases.

Emergence in blood serum of the adult of embryonal protein of a-fetoprotein (AFP) in trace amounts (0,05 — 0,5% of its concentration in blood serum of a fruit) can be observed at patients with a viral hepatitis. More substantial increase of concentration of AFP is found at hepatocellular cancer, germinogenny teratoblastomas, in 10 — 15% of cases of metastasises in a liver of tumors of a stomach and intestines, at a hereditary tirozinemiya, an ataxy, a teleangiectasia. AFP is used as a specific marker of a gepatoma, and dynamics of changes of its concentration in blood demonstrates growth or regression of a tumor.

Increase in maintenance of alpha fraction of glycoproteins in blood serum is observed at tuberculosis, an active phase of rheumatism, exudative pleurisy, pneumonia, a glomerulonephritis, at necroses, tumors, a diabetes mellitus, in certain cases the macroglobulinemia

Increase in content in blood serum of a-lipoproteids (LP) is observed sometimes at hron, hepatitises, and its reduction — at acute hepatitises, cirrhoses of a liver, congestive jaundices. Contents beta LP in blood serum is increased at a diabetes mellitus, a hypothyroidism, an infectious mononucleosis, Hend's disease — Schueller — Krischena, a xanthomatosis, the expressed hypoproteinemias, in certain cases a multiple myeloma. Increase in contents alfa2-LP is observed at lipoid nefroza at children. The fraction of lipids revealed in a zone of gamma-globulins (the lipidic rest) is increased at alimentary and essential a hyperlipemia cases of an inborn abetalipoproteinemiya and an analfalipoproteinemiya Meet. At Wilson's disease (a hepatolenticular degeneration) considerable decrease in content of ceruloplasmin is observed; it is less expressed at nephrotic syndromes and anemias of babies.

Erythropoetins , (see), belonging to group G., take part in fiziol, regulation of a hemogenesis, influencing stem cells and providing a differentiation in cells of an erythroidal row. Content of erythropoetin (E) increases at hypoxemic states, at hypo - or aplastic anemias in a stage of an aggravation, in a stage of progressing of an acute leukosis. At an erythremia contents E in a blood plasma increases not at all patients; at secondary hyperglobulias this increase is observed always. At Addison's disease — Birmer and agastralny anemia E in a blood plasma is not found at all. At an acute renal failure noted anemia is explained by disturbance of education E (the main place of synthesis E are kidneys) and accumulation in blood of inhibitors of an erythrogenesis.

Serumal complementary system (page to. the page), consisting more than of 9 proteins (the first nine designate from C1 to C9), participates in immune processes. Classical signs of an inflammation are caused by local activation of page to. page. The congenital anomaly of inhibitor of protein C1 leading to activation of the corresponding protein promotes emergence of Quincke's diseases with localization on skin and in a throat. Hypersensitivity to infections is noted at persons with the reduced maintenance of S3-and C5 proteins of page to. by page in the absence of reduction of concentration of immunoglobulins and normal hypersensitivity it is slowed down * a leg of type (see the Allergy). The acquired defects of C3 protein are observed at a proliferative and post-streptococcal glomerulonephritis. Decrease in maintenance of all components of a complement can be observed at a system lupus erythematosus. In certain cases agammaglobulinemias the inhibition of protein C1 is noted. The acquired defects of page to. pages do not cause hypersensitivity to infections.

Decrease in concentration of a gaptoglobulin and hemopexin (GP) in blood serum is observed at hemolitic states. At a sickemia and a big thalassemia concentration of C3 - and C5 proteins are lowered. At patients with a paroxysmal night haemoglobinuria and autoimmune hemolitic anemia the maintenance of GP is not changed, and contents of is considerably reduced. Contents of and GP is reduced at patients with acute and hron, diseases of a liver and at nephrotic syndromes. The increased maintenance of GP in blood serum is found at malignant new growths, a diabetes mellitus, active tuberculosis, a pseudorheumatism, idiopathic hemochromatosis, schizophrenia. Definition of concentration of GP in an amniotic fluid is used for diagnosis of a hemolitic syndrome at a fruit.

General iron-binding ability of serum (lake. the village of the village) depends on concentration of transferrin (siderophilin). Decrease in the lake. the village of the village is observed at nephrotic syndromes, acute and hron, infections, uraemia. Cases of an inborn asiderofiliya are described. Increase in the lake. the village of the village can be observed at iron deficiency and hemolitic anemias.

Strengthening lysozyme (see), belonging to G., in blood serum it is characteristic for acute and hron, monocytic leukoses. At leukemoid monocytic tests of a lizotsimemiya it is not observed. The long lizotsimuriya makes an adverse effect on kidneys, up to disturbance of their function.

Genetically caused insufficiency of blood-coagulation factors (see. Coagulant system of blood ) leads to development of a hemorrhagic syndrome at an inborn hereditary prothrombinopenia, an afibrinogenemiya, a fibrinogenopenia. Insufficiency of a prothrombin is observed at hypovitaminoses (insufficiency of function of a liver) and at newborns (a melena of newborns, an inborn atresia of bilious ways). Increase in content of plasmin meets at a nephrotic syndrome, diseases of a liver, a diabetes mellitus. The fibrinogenopenia can be observed at diseases of a liver, a hyper fibrinolysis. Insufficiency of a factor of the XIII system of a blood coagulation can be inborn and is observed at acute leukoses.

See also Albumine , Proteins , Immunoglobulins .

Bibliography Proteins, under the editorship of G. Neyrat and K. Bailey, lane with English, t. 3, p.1, M., 1958; Introduction to clinical biochemistry, under the editorship of I. I. Ivanov, L., 1969; Glycoproteins, under the editorship of A. Gottschalk, the lane with English, t. 2, p. 4, page 58, M., 1969; SchultzeH. E. a. Heremans J.F. Molecular biology of human proteins, Amsterdam, 1966; T u r-ner M. W. a. H u 1 m e B. The plasma proteins, an introduction, L., 1971; Werner M., Brooks S. H. a. Cohnen G. Diagnostic effectiveness of electrophoresis and specific protein assays evaluated of discriminate analysis, Clin. Chem., v. 18, p. 116, 1972.

I. D. Grozdova, A. K. Golenkov.