Binding of complement component C1q by rat adipocyte membranes.

Human C1q was found to bind to rat adipocyte membranes with an affinity comparable to that for aggregated immunoglobulin. The binding was ionic strength dependent, and modification of arginyl and histidyl residues in C1q abrogated its binding activity. Treatment of the adipocyte membranes with either high ionic strength buffers, EDTA or trypsin had little effect on their C1q-binding activity.