Introduction to bacterial immunoglobulin-binding proteins

Streptococcal IgA-binding Proteins Bind in the Cα2-Cα3 Interdomain Region and Inhibit Binding of IgA to Human CD89

“…Surface proteins that bind to the Fc part of human IgA or IgG are expressed by many pathogenic bacteria, in particular by Gram-positive pathogens (38). While IgA-binding proteins have been less extensively studied than those binding IgG, more is known about their biological properties.…”

Crystal structure of aStaphylococcus aureusprotein A domain complexed with the Fab fragment of a human IgM antibody: Structural basis for recognition of B-cell receptors and superantigen activity

“…T he common bacterial pathogen, Staphylococcus aureus, produces a 42-kDa factor, protein A (SpA), that contains five highly homologous extracellular Ig-binding domains in tandem, designated domains E, D, A, B, and C. Protein A, which exists in both secreted and membrane-associated forms, possesses two distinct Ig-binding activities: each domain can bind Fc␥ (the constant region of IgG involved in effector functions) and Fab (the Ig fragment responsible for antigen recognition) (1). The Fc␥ binding site has been localized to the elbow region at the CH2 and CH3 interface of most IgG subclasses, and this binding property has been extensively used for the labeling and purification of antibodies (2,3).…”

A comparative evaluation of random and site‐specific immobilization techniques for the preparation of antibody‐based chiral stationary phases

“…Since then, a number of such "bacterial Fc receptors" have been described [41]. Besides protein A, the streptococcal protein G has been most widely used for purification or immobilization of antibodies [42,43].…”