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.
Das
Tanusree
T
Immunobiology Division, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India.
Mandal
Chhabinath
C
Mandal
Chitra
C
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