Purification of the First Component of Human Complement by Affinity Chromatography on Human γ Globulin Linked to Sepharose

摘要

The first component of human complement, C1?, has been purified by affinity chromatography on a resin consisting of Sepharose covalently linked to human IgG. This resin selectively adsorbs at least 90% of the C1? detectable in a precipitate of human serum prepared at a final ionic strength of 0.03 and pH of 6.4. The C1? is eluted from the resin with 0.2 M 1, 4-diaminobutane. Virtually all the protein is recovered and the C1? has a high specific activity whether assayed with N-carbobenzoxy-L-Tyrosine-para-nitrophenyl ester or with EAC4, C2 and C-EDTA. Evidence that the protein obtained by this procedure is indeed C1? is based on the ability of C1? inhibitor to inhibit the enzymatic activity, of anti-C1s? antiserum to inhibit EAC4?,2? formation and of the eluted protein to form the EAC1?,4 intermediate. The procedure appears to be a simple reliable technique for preparing large quantities of human C1?.