DETERMINATION OF THE DISULFIDE BRIDGE ARRANGEMENT OF BOVINE HISTIDINE-RICH GLYCOPROTEIN

Histidine-rich glycoprotein (HRG) was purified from bovine plasma and the disulphide bridge arrangement established. Disulphide-bridged pept ides were obtained from peptic and tryptic degradation of native bovin e HRG. Twelve half-cystine residues were found in bovine HRG (compared to sixteen cysteines in human HRG), all involved in the formation of six disulphide bridges connecting Cys-1 to Cys-12, Cys-2 to Cys-3, Cys -4 to Cys-5, Cys-6 to Cys-11, Cys-7 to Cys-8, and Cys-9 to Cys-10. Add itional sequence analysis of C-14-carboxymethylated chymotryptic and S taphylococcus aureus V8 protease generated peptides and CNBr-fragments of bovine HRG yielded a partial amino acid sequence of bovine HRG con stituting 78% of the sequence when compared to the human cDNA sequence .