THE BIOCHEMISTRY OF OPSONIZATION - CENTRAL ROLE OF THE REACTIVE THIOLESTER OF THE 3RD COMPONENT OF COMPLEMENT
THE BIOCHEMISTRY OF OPSONIZATION - CENTRAL ROLE OF THE REACTIVE THIOLESTER OF THE 3RD COMPONENT OF COMPLEMENT
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DOI：
10.1093/infdis/150.5.653
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发表时间：
1984-01-01
影响因子：
6.4
通讯作者：
SCHMELING, DJ
中科院分区：
文献类型：
--
作者：
HOSTETTER, MK;KRUEGER, RA;SCHMELING, DJ
The mechanism by which the opsonic fragment of the 3rd component of complement (C3) binds to pathogenic bacteria is defined. Using purified human C3 to reconstitute the alternative pathway in human serum in which both C3 and C4 had been chemically inactivated, opsonization of pathogenic serotypes of Streptococcus pneumoniae (serotypes 3, 4, 6A, 14, and 18C) is shown to require the reactive thiolester of native C3. When purified human C3 (thiolester intact) is added to serum deficient in C3 and C4, phagocytic uptake of 3H-labeled pneumococci by polymorphonuclear leukocytes from normal adults is fully reconstituted. Hydrolysis of the thiolester or reaction of the thiolester with the inhibitor methylamine abolishes opsonization and phagocytosis. By characterizing those C3 fragments released from pneumococcal surfaces after treatment with 1.0 M hydroxylamine, a role for covalent bond formation in the opsonic interaction was defined. Therefore, the presence of the reactive thiolester of C3 is an absolute requirement for the opsonic and covalent binding of the C3b molecule to pathogenic bacteria.
