The Clq receptor site on immunoglobulin G.
We propose that, the binding site for the complement subcomponent Clq on immunoglobulin G involves the last two (C-terminal) beta-strands of the C gamma 2 domain. This region contains a large number of accessible and highly conserved charged residues and charge is postulated as an important component of the Clq-IgG interaction. The conclusions are reached on the basis of accessibility and sequence conservation analyses of C gamma 2 amino acid residues, the use of specific inhibitors and chemical modification studies.
D000595:Amino Acid Sequence; D000818:Animals; D000936:Antigen-Antibody Complex; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003172:Complement C1 / Q000378:metabolism*; D007127:Immunoglobulin Constant Regions / Q000378:metabolism; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G / Q000378:metabolism*; D007142:Immunoglobulin gamma-Chains; D011487:Protein Conformation; D011951:Receptors, Complement / Q000378:metabolism*; D013329:Structure-Activity Relationship
D000936:Antigen-Antibody Complex; D003172:Complement C1; D007127:Immunoglobulin Constant Regions; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D007142:Immunoglobulin gamma-Chains; D011951:Receptors, Complement