Protein A--a new ligand for human C-reactive protein.
Phosphorylcholine (PC) is a classical ligand of C-reactive protein (CRP), a clinically important acute phase protein. In search of new ligands, CRPs were affinity-purified from several pathological samples, which exhibited distinct molecular variants induced in different diseases. Both glycosylated and non-glycosylated CRPs showed calcium-independent differential-binding to Staphylococcus aureus cell-surface Protein A. CRP possesses separate binding sites for Protein A and PC with different binding constants. We have demonstrated that Protein A is another ligand in addition to PC establishing an extended definition of CRP. Protein A binding may impart immunomodulatory roles of CRP in combating microorganisms or other foreign materials.
Immunobiology Division, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India.
Tanusree
T
Das
Chhabinath
C
Mandal
Chitra
C
Mandal
D001665:Binding Sites; D015153:Blotting, Western; D002097:C-Reactive Protein / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006031:Glycosylation; D006801:Humans; D008024:Ligands; D010767:Phosphorylcholine / Q000378:metabolism; D011485:Protein Binding; D013205:Staphylococcal Protein A / Q000302:isolation & purification / Q000378:metabolism*
D005456:Fluorescent Dyes; D008024:Ligands; D013205:Staphylococcal Protein A; D010767:Phosphorylcholine; D002097:C-Reactive Protein; D016650:Fluorescein-5-isothiocyanate