title: Donkey and horse alpha 1 B-glycoprotein: partial characterization and new alleles.
abstract: 1. The donkey postalbumin protein has been shown to be the equivalent of human alpha 1 B-glycoprotein by protein immunoblotting and N-terminal amino acid sequence. 2. The horse A1B system (already identified as the homologue of human alpha 1 B-glycoprotein) and the donkey alpha 1 B-glycoprotein were characterized further for terminal sialic acid content, isoelectric point, amino acid composition and affinity for the dye-ligand, Cibacron Blue F3GA (known to bind human alpha 1 B-glycoprotein). 3. Two new alleles in the horse A1B system were found, bringing the total number of alleles to five. No polymorphism was found in the donkey alpha 1 B system. 4. As expected the first 20 N-terminal residues of the donkey and horse proteins are highly conserved with only two differences being found. 5. The polymorphism of the horse alpha 1 B-glycoproteins may be due in part to differing numbers of terminal sialic acid residues and the higher electrophoretic mobility of the donkey alpha 1 B-glycoprotein may be due in part to increased sialylation. 6. The horse and donkey alpha 1 B-glycoproteins exhibited differences in affinity for the dye-ligand, Cibacron Blue F3GA, with the donkey alpha 1 B-glycoprotein not being bound.
authors.affiliation: Department of Physiology and Pharmacology, University of Queensland, Australia.
authors.forename: S D
authors.initials: SD
authors.lastname: Patterson
authors.forename: K
authors.initials: K
authors.lastname: Bell
authors.forename: D C
authors.initials: DC
authors.lastname: Shaw
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry* / Q000235:genetics; D004586:Electrophoresis; D006023:Glycoproteins; D006736:Horses / Q000097:blood*; D006801:Humans; D015151:Immunoblotting; D007136:Immunoglobulins; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000494:pharmacology; D010527:Perissodactyla / Q000097:blood*; D011110:Polymorphism, Genetic
chemical_list: C048566:A1BG protein, human; D000596:Amino Acids; D001798:Blood Proteins; D006023:Glycoproteins; D007136:Immunoglobulins; D009439:Neuraminidase