English Lectures / Functional chemistry 2 eng

Fraction 3: α-Globulins

Vitamin D binding protein (0.4 g/L):

•Structure: 70kDa

•Synthesis: in the liver.

•Functions: provides transport of vitamin A in plasma and prevents its excretion in the urine.

Let’s write! Fraction 3: α-Globulins

Ceruloplasmin (0.35 g/L):

•Structure: the main copper-containing plasma protein (contains 95% copper in plasma) with a mass of 150kDa. The half-life is 6 days.

•Synthesis: in the liver, regulated by vitamin K, formed by the intestinal flora.

•Functions:

•possesses pronounced oxidase activity;

•limits the release of iron,

•activates the oxidation of ascorbic acid, norepinephrine, serotonin and sulfhydryl compounds,

•inactivates reactive oxygen species

•acute phase protein (group 3) - it increases in patients with infectious diseases, liver cirrhosis, hepatitis, myocardial infarction, systemic diseases, lymphogranulomatosis, and malignant neoplasms of various localization.

Fraction 3: α-Globulins

Antithrombin III (0.3 g/L):

Functions: plasma protease inhibitor.

Fraction 3: α-Globulins

Retin Binding Protein (0.04 g/L):

•Synthesis: in the liver.

•Functions: binds retinol, provides its transport and prevents decomposition. It functions in combination with transthyretin. Retinol-binding protein captures excess vitamin A, which prevents the membrane-acting effect of high doses of vitamin A.

Dysproteinemia due to the β-globulin fraction can occur with:

•some dyslipoproteinemia;

•inflammation, because this fraction contains proteins of the acute phase;

•with a violation of the coagulation system of blood.

Fraction 4: β-Globulins

organs to the liver.

Transferrin (3 g/L):

•Structure: glycoprotein, half-life - 8 days.

•Synthesis: in the liver, regulated by vitamin K, formed by the intestinal flora.

•Functions: the main plasma transporter of iron, 1 transferrin molecule binds 2 Fe3 +, and 1 g of transferrin, respectively, about 1.25 mg of iron. Protein of the acute phase (group 5).

•With a decrease in iron concentration, transferrin synthesis increases. Decreases in liver failure.

Fraction 4: β-Globulins

Let’s write!

Fibrinogen (3 g/L):

•Structure: glycoprotein, half-life - 100 hours. The molecular weight of 340kDa.

•Synthesis: in the liver, regulated by vitamin K, formed by the intestinal flora.

•Functions: coagulation factor I, capable of turning into fibrin under the action of thrombin. It is a source of fibrinopeptides with anti-inflammatory activity. Protein of the acute phase (group 2).

•The fibrinogen content increases with inflammatory processes and tissue necrosis. It decreases with DIC, liver failure. Fibrinogen is the main plasma protein that affects the value of ESR.

C-reactive protein (<0.01 g/L):

•Synthesis: in the liver, initiated by antigens, immune complexes, bacteria, fungi, with trauma (4-6 hours after damage).

•Functions: Protein of the acute phase (1 group). It is able to bind microorganisms, toxins, particles of damaged tissues, thereby preventing their spread. These complexes activate complement along the classical pathway, stimulating the processes of phagocytosis and elimination of harmful products. C-reactive protein can interact with T-lymphocytes, phagocytes and platelets, regulating their functions in conditions of inflammation. It has antiheparin activity, with an increase in concentration inhibits platelet aggregation. CRP is a marker of the rate of progression of atherosclerosis.

•Determined for the diagnosis of myocarditis, inflammatory diseases of the heart valves, inflammatory diseases of various organs.

•Structure: glycoproteins, consist of 2 heavy (440 AA) and 2 light (220 AA) polypeptide chains of various configurations, which are interconnected by disulfide bridges. Antibodies are heterogeneous, the individual constituent parts of polypeptides are encoded by different genes, with different mutability.

•Synthesis: functionally active B-lymphocytes (plasmocytes).

Dysproteinemia due to the β-globulin fraction can occur with:

•immunodeficiency condition;

•infectious processes;

•nephrotic syndrome.