Identification of two functional forms of immunoglobulin G3-binding protein expressed by group A streptococci.
Analysis of group A streptococcal immunoglobulin G (IgG)-binding protein reactivity with different human IgG3-myeloma proteins provided evidence for at least two functional forms of these molecules. Representative IgG3-binding molecules were isolated, biotinylated, and used as tracers in competitive binding assays. Cross-inhibition studies demonstrated the existence of two distinct patterns of IgG3-binding activity. Proteins of one form could be inhibited from binding to an IgG3-myeloma protein by streptococcal protein G while binding of the second form was not inhibited. These studies further underscore the extent of heterogeneity among immunoglobulin-binding proteins expressed by group A streptococci.
Pack
T D
TD
Department of Microbiology, Medical College of Ohio, Toledo 43699.
Otten
R A
RA
Raeder
R H
RH
Boyle
M D
MD
D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis* / Q000502:physiology; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D009194:Myeloma Proteins / Q000378:metabolism; D017452:Receptors, IgG / Q000032:analysis*; D013297:Streptococcus pyogenes / Q000737:chemistry*
D001426:Bacterial Proteins; C034284:IgG Fc-binding protein, Streptococcus; D007074:Immunoglobulin G; D009194:Myeloma Proteins; D017452:Receptors, IgG