From Big Medical Encyclopedia

LEUKOCIDIN — the bacterial toxin having ability to kill polymorphonuclear leukocytes and macrophages. Distinctive property L. the fact that it does not affect erythrocytes and other cells is. The L is most studied. golden staphylococcus. It actively cosecretes in culture medium and consists of two components: F (bystry) and S (slow) differing on mobility in a column with CM cellulose. Both components are separately not active, but in a combination work sinergidno, killing leukocytes. Components are proteins about a pier. (F) weighing 32 000 and 38 000 (S) and an identical isoelectric point of pI — 9,0. In an electrophoresis at pH 5,0 S-component possesses higher charge.

Mechanism of action of L. it is connected with its activation of kaliyzavisimy acylphosphatase of a leukocytic membrane that leads to increase in permeability of the last, leak from a cell of potassium ions and her death. Effect of L. specifically is suppressed with one of phosphatides — trifosfoinozitidy and ions tetraethyl of ammonium. About a role of L. in pathology of a consensus is not present, however, considering its action on leukocytes, it is possible to assume that it interferes with effective phagocytosis of in vivo. L. has antigenic and immunogene properties. The detoxication of the formalin purified by H.p. the help of 0,2% leads to formation of rather harmless toxoid keeping the immunogenicity.

In recent years rather thermostable L is found in streptococci and a pyocyanic stick (Pseudomonas aeruginosa)., maintaining 30 — 60-minute warming up at t ° 56 — 70 °. Aeruginosa leukocidin P. is closely connected with its membrane structures and is emitted in culture medium at an autolysis. It is protein about a pier. weighing 27 000 also consists of two active fractions with pH 5,0 and 5,2.

Bibliography: Gladstone G. P. An improved leucocidin toxoid, Brit. J. exp. Path., v. 54, p. 255, 1973; W o o d i n A. M of Staphylococcal leucocidin, in book: Staphylococci, ed. by J. O. Cohen, p. 281, N. Y. a.o., 1972, bibliogr.

A. K. Akatov.