Primary structure of human alpha 2-macroglobulin. IV. Primary structure of two large CNBr fragments, located in the COOH-terminal part and accounting for 337 residues.

The amino acid sequences have been determined for two CNBr fragments of human alpha 2-macroglobulin which, due to the presence of an uncleaved Hse-Thr bond, form an Mr = 40,000 fragment. These fragments are located in the COOH-terminal part of alpha 2-macroglobulin (CB21, residues 955-1185 and CB22, residues 1186-1291). CB21 contains one glucosamine-based carbohydrate group attached to Asn-14 and one internal disulfide bridge (Cys-102 bound to Cys-150). CB21 and CB22 account for 337 of the 1451 residues of the subunit of alpha 2-macroglobulin.