Isolation and characterization of bovine haptoglobin from acute phase sera.
A macromolecular hemoglobin-binding protein, which was not detectable in normal bovine sera but appeared during acute phase inflammation, was purified, characterized, and designated as bovine haptoglobin (Hp). The purified protein had a molecular mass of 1,000-2,000 kDa, and was composed of two kinds of peptides, a 20-kDa peptide (alpha chain) and a 35-kDa glycopeptide (beta chain) linked by disulfide bonds. Amino acid composition and N-terminal sequence analyses revealed that both peptides were homologous to each counterpart of human Hp. Studies using some reducing reagents proved that highly polymerized Hp in serum was composed of 2-20 polymerized forms of alpha 2 beta 2 tetramer. Hp could bind one molecule of hemoglobin/alpha 2 beta 2 unit. Hp with smaller sizes obtained from native Hp by partial reduction with cysteine showed almost the same Hb-binding capacity.
Morimatsu
M
M
Department of Biochemistry, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Syuto
B
B
Shimada
N
N
Fujinaga
T
T
Yamamoto
S
S
Saito
M
M
Naiki
M
M
D000210:Acute-Phase Reaction / Q000097:blood*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006242:Haptoglobins / Q000737:chemistry / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D008970:Molecular Weight
D000596:Amino Acids; D006242:Haptoglobins