A monoclonal antibody to C1q which appears to interact with C½C½s2‐binding site

FEBS Letters

Dodds, Alister W.¹  Mason, Donald W.²  Reid, Kenneth B.M.¹  Hsiung, Li-min¹ 

[1] MRC Immunochemistry Unit, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, England;MRC Cellular Immunology Unit, William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, England

关键词: C1q;    Monoclonal antibody;    C½r2-C½s2 complex;    Antigenic site;    Binding site;    Complement;   

DOI  :  10.1016/0014-5793(88)80789-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A monoclonal antibody (SB-4) to human C1q was prepared. The equilibrium constant of the antibody for C1q was found to be greater than 10¹⁰ M⁻¹. It has been shown that the antibody binds to the A-B chain dimer, probably via the B chain of C1q. Pepsin digestion of C1q at pH 4.5, which fragments the globular regions but leaves the collagenous region intact, allowed the demonstration that the antigenic site is located in the collagenous region of the molecule. The effect of the antibody on haemolytic activity has shown that it is capable of inhibiting the formation of EAC1 cells from EAC1q cells plus C1r and C1s but is incapable of inhibiting the C1 activity of preformed EAC1 cells. This indicates that the binding of the antibody to the collagenous portion of the B chain of C1q probably prevents interaction between C1q and the C1r₂-C1s₂ complex.

【 授权许可】

Unknown