Immunological Cross Reaction Between Chains of Human Fibrinogen

Abstract

Employing the crossed immunoelectrophoresis technique (CIE) the antigenic composition of fibrinogen chains and heterogeneity in their electrophoretic mobility was investigated.Highly purified chains of fibrinogen were prepared by chromatography on CM-cellulose (1). Antisera against chains were prepared by immunizing rabbits with Aα, Bβ and γ chains respectively. The CIE was performed on 10 × 10 glass plates with an 1 mm thick layer of 1% agarose in 0.04 M barbital buffer pH 8.6. The electrophoresis was run for 1 h with 12 V/cm. Four fifth of the gel was cut off and replaced with the same agarose solution containing antibodies. The second dimension electrophoresis was run for about 20 h with 2 V/cm.Using anti Bβ chain serum a partial immunological identity was revealed between the Bβ chain and the γ chain. The Bβ chain has except for the antigenic sites in common with the γ chain additional sites that are unique for the B β chain. The results were confirmed with the anti γ chain serum which gave a strong reaction with both the γ chain and the B β chain preparations. The Aα chain did not react with γ antiserum, nor did the γ chain react with anti Aα chain serum. The immunological relation between the Aα chain and the B β chain is under investigation.These experiments also concluded that the γ chain preparation is contaminated with a B β chain variant that has an electrophoretic mobility similar to that of the γ chain. Also the Bβ chain seemed to be impure due to contamination by an Aα chain derivative with higher electrophoretic mobility.(1) Murano, G., Wiman, B., Blomböck, B. and Blomböck, M. : Preparation and isolation of the S-carboxymethyl derivative chains of human fibrinogen. F.E.B.S. Letters: 14, 37, 1971.