[Rule of antibody structure. the primary structure of a monoclonal IgG1 immunoglobulin (myeloma protein Nie), I: Purification and characterization of the protein, the L- and H-chains, the cyanogenbromide cleavage products, and the disulfide bridges (author's transl)].

Myeloma protein Nie has been isolated from the serum of a myeloma patient by free flow continuous high voltage electrophoresis or by Pevicon-block electrophoresis. It was further purified by ion-exchange chromatography and gel filtration, and characterized by amino acid analysis and end group determination. Serologically, the protein belongs to the IgG1 subclass. It has been typed as Gm1+, 2-,4- and 17+. The L-chain is of the k-type. The L- and H-chains have been separated by gel-filtration after partial reduction and alkylation and characterized by amino acid analysis and end group determination. The F(ab)- and Fc-fragments, prepared by limited tryptic digestion, have been separated and characterized. Cyanogen bromide splitting products have been prepared both from the intact IgG and from the Fc-and the partially reduced and alkylated F(ab)-fragment. These splitting products have been purified and characterized by amino acid analysis and end group determination. By means of these cyanogen bromide splitting products and by partial reduction and alkylation, the disulfide bridges in the protein could be localized: one L-H-bridge, two inter-H-bridges and four loop forming intra-H-bridges.