Primary structure of bovine plasma high-molecular-weight kininogen. The amino acid sequence of a glycopeptide portion (fragment 1) following the C-terminus ot the bradykinin moiety.

On incubation of bovine plasma high-molecular-weight (HMW) kininogen with purified plasma kallikrein [EC 3.4.21.8], a large glycopeptide fragment and the vasoactive peptide, bradykinin, were initially liberated; the former, named fragment 1-2, was subsequently cleaved into fragment 1 (glycopeptide) and the previously established fragment 2 (histidine-rich peptide). The isolated fragment 1-2 contained a total of 108 to 110 amino acid residues and carbohydrates, and the amino-terminal sequence Ser-Val-Gln was established. The other fragment, fragment 1, consisted of a total of 69 amino acid residues with serine and arginine (and lysine) at the amino and carboxyl termini, respectively. It contained eleven residues each of histidine and glycine, together with an oligosaccharide chain consisting of galactosamine, hexose and sialic acid. The complete amino acid sequence of fragment 1 was determined by Edman degradation and standard enzymatic and chemical techniques. These results established the following sequence: H-Ser-Val-Gln-Val-Met-Lys-Thr-Glu-Gly-Ser-Thr-Pro/Thr-Val-Ser(CHO)-Val/Leu-Pro-His-Ser-Ala-Met-Ser-Pro-Val-Gln-Asp-Glu-Glu-Arg-Asp-Ser-Gly-Lys-Glu-Gln-Gly-Pro-Thr-His-Gly-His-Gly-Trp-Asp-His-Gly-Lys-Gln-Ile-Lys-Leu-His-Gly-Leu-Gly-Leu-Gly-His-Lys-His-Lys-His-Asp-Gln-Gly-His-Gly-His-His-Lys/ArgOH.