Characterization of biologically active bovine pituitary FSH purified by immunoaffinity chromatography using a monoclonal antibody.
A substantial amount of highly purified, biologically active bovine FSH was isolated from pituitary extracts by immunoaffinity chromatography based on a novel anti-bovine FSH beta-subunit monoclonal antibody. The biological activity was assessed in vitro using a steroidogenic granulosa cell line constitutively expressing the FSH receptor. Amino acid analysis, N-terminal amino acid sequencing, and peptide mass mapping demonstrated that primary structure modifications do not contribute to the heterogeneity of bovine FSH. The monosaccharide composition of the N-linked oligosaccharides was quantified and remarkably two distinct forms of sialic acids, N-acetyl- and N-glycolyl-neuraminic acids were found. In conclusion, we showed that isoform differences in bovine FSH is likely due only to sugar chain heterogeneity, and we give the first evidence that two substituted sialic acids contribute to the diversity of mammalian glycoprotein hormone isoforms.
Borromeo
Vitaliano
V
Department of Veterinary Pathology, Hygiene and Health, Biochemistry and Physiology Unit, University of Milan, Via Celoria 10, I-20133 Milan, Italy.
Amsterdam
Abraham
A
Berrini
Anna
A
Gaggioli
Daniela
D
Dantes
Ada
A
Secchi
Camillo
C
D000818:Animals; D000911:Antibodies, Monoclonal; D001681:Biological Assay; D002417:Cattle; D002846:Chromatography, Affinity; D005260:Female; D005640:Follicle Stimulating Hormone / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D019158:N-Acetylneuraminic Acid / Q000032:analysis / Q000737:chemistry; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry*; D020033:Protein Isoforms; D011962:Receptors, FSH / Q000502:physiology*
D000911:Antibodies, Monoclonal; D009844:Oligosaccharides; D020033:Protein Isoforms; D011962:Receptors, FSH; D005640:Follicle Stimulating Hormone; D019158:N-Acetylneuraminic Acid