Biochemical and biological properties of the binding of human fibrinogen to M protein in group A streptococci

Journal Article · Tue Oct 01 00:00:00 EDT 1985 · J. Bacteriol.; (United States)

OSTI ID:6235637

Whitnack, E; Beachey, E H

Fibrinogen is known to bind to group A streptococci and precipitate with extracts containing streptococcal M protein. The authors have previously shown that the binding of fibrinogen to M-positive streptococci prevents opsonization by complement and protects that organism from phagocytosis in nonimmune blood. In the present study, they used TH-labeled fibrinogen, a highly purified peptide fragment of type 24 M protein (pep M24), and anti-pep M sera to show that fibrinogen binds to M-positive streptococci with high affinity; occupation of the high-affinity binding sites suffices to protect the organism from phagocytosis; proteolytic treatments that remove M protein from streptococcal cells abolish binding; binding is competitively inhibited by anti-pep M sera; pep M24 precipitates fibrinogen; and binding to type 24 cells is inhibited by pep M24. They conclude that M protein is the cell surface structure principally responsible for binding fibrinogen on the surface of M-positive streptococci and that this binding contributes to the known antiopsonic property of M proteins.

• Research Organization: Veterans Administration Medical Center, Memphis, TN
• OSTI ID: 6235637
• Journal Information: J. Bacteriol.; (United States), Vol. 1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
FIBRINOGEN
CONFIGURATION INTERACTION
PROTEINS
BIOCHEMISTRY
STREPTOCOCCUS
TRITIUM COMPOUNDS
COMPLEMENT
IMMUNE SERUMS
PEPTIDE HYDROLASES
PHAGOCYTOSIS
PRECIPITATION
BACTERIA
BLOOD COAGULATION FACTORS
CHEMISTRY
COAGULANTS
DRUGS
ENZYMES
GLOBULINS
HEMATOLOGIC AGENTS
HEMOSTATICS
HYDROLASES
LABELLED COMPOUNDS
MICROORGANISMS
ORGANIC COMPOUNDS
SEPARATION PROCESSES
550201* - Biochemistry- Tracer Techniques