Isolation of fibrinogen A alpha-chain by affinity chromatography on concanavalin A-sepharose

A method was developed for isolation of the A alpha-chain from S-carboxamidomethylated fibrinogen. A mixture of the three constituent polypeptide chains of human fibrinogen was applied onto a column of concanavalin A-Sepharose. While the carbohydrate-free A alpha-chain was not delayed on the affinity chromatography column, both glycosylated subunit chains, B beta- and gamma-chain, were adsorbed to the insolubilized lectin and were quantitatively eluted from the column with 0.2 M methyl-alpha-D-mannoside. SDS-electrophoresis on polyacrylamide gel was employed for analysis of chromatographic fractions. Complete recovery of the A alpha-chain was observed. The described procedure is very simple and permits isolation of large amounts of pure A alpha-chain from S-carboxyamidomethylated fibrinogen.