Evidence for histidine residues in the immunoglobulin-binding site of human C1q
- 1 February 1983
- journal article
- research article
- Published by Portland Press Ltd. in Bioscience Reports
- Vol. 3 (2) , 135-140
- https://doi.org/10.1007/bf01121944
Abstract
The immunoglobulin-binding activity of subcomponent Clq of human complement is lost following treatment with diethylpyrocarbonate; the inactivation showed first-order kinetics with respect to time and modifier concentration. Soluble IgG oligomers protected Clq against diethylpyrocarbonate modification. Treatment of modified Clq with hydroxylamine resulted in an 85% recovery of its ability to bind to aggregated immuno-globulin. The inactivation process was associated with modification of 12.1±0.7 histidine residues per Clq molecule. These data are consistent with the presence of histidine residues in the immunoglobulin-binding sites of Clq; these residues may participate in ionic interactions with the carboxyl groups known to be in the Clq binding site of IgG.This publication has 22 references indexed in Scilit:
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