Characterization of the CNBr peptides generated from the factor B cleavage fragments, Ba and Bb, by molecular exclusion high performance liquid chromatography.

Highly purified human factor B of the alternative complement pathway was treated with factor D in the presence of cobra venom factor to generate its Ba and Bb cleavage fragments. These cleavage fragments were isolated by preparative polyacrylamide gradient gel electrophoresis followed by electrodialysis elution and treatment with CNBr. The resultant CNBr cleavage peptides were isolated by molecular exclusion high performance liquid chromatography and characterized by SDS polyacrylamide gel electrophoresis. Results of these experiments indicate that the Ba fragment essentially consisted of a 28,000 CNBr peptide, whereas 34,700 (28,000 + 3,500 when characterized under reducing polyacrylamide gel electrophoresis conditions); 14,500 (=20,000); and 8,300 CNBr peptides were derived from the Bb fragment.