Title : Amino acid sequence of the N-terminal region of human hemopexin
Abstract :
Cyanogen bromide digestion of hemopexin at its 6 methionine residues results in 7 fragments ( CB1-CB7 ) partially connected by disulfide bridges
By sequence studies of fragments CB1-CB4 and peptides prepared by their enzyme cleavage, a continuous amino acid sequence of the N-terminal region of human hemopexin , comprising 220 amino acid residues , was determined
The presence of intramolecular disulfide bonds, connecting half-cystine residues 126/130 and 165/170, was proved in fragments CB2 and CB3
Fragments CB1-CB4 include 5 sites, where hexosamine oligosaccharides are attached ( positions 1,41,164,217 and probably 223)
In the sequenced region two sites sensitive to acid hydrolysis--bonds ... Asp--Pro ... in positions 20 /21 and 187/188 were found
In spite of the fact that pooled material of many donors was studied, no sequence heterogeneity was discovered