Identification of the major pregnancy-specific antigens of cattle and sheep as inactive members of the aspartic proteinase family

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 88; no. 22; pp. 10247 - 10251
• Main Authors: Xie, Sancai, Low, Boon G., Nagel, Robert J., Kramer, Kyle K., Anthony, Russell V., Zoli, Andre P., Beckers, Jean-Francois, Roberts, R. Michael
• Format: Journal Article Web Resource
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 15-11-1991; National Acad Sciences; National Academy of Sciences
• Subjects: acide aspartique; acido aspartico; Active sites; adn; Amino Acid Sequence; Amino acids; Analytical, structural and metabolic biochemistry; Animals; antigene; antigenos; Antigens; Antigens - genetics; Antigens - isolation & purification; aspartic acid; Aspartic Acid Endopeptidases - genetics; Aspartic Acid Endopeptidases - isolation & purification; Biological and medical sciences; bovin; cattle; Cattle - physiology; CDNA libraries; Cloning, Molecular; Complementary DNA; Computer Simulation; diagnosis de la gestacion; diagnostic de gestation; dna; DNA - genetics; DNA - isolation & purification; Enzymes and enzyme inhibitors; Female; Fundamental and applied biological sciences. Psychology; ganado bovino; Gene Expression Regulation, Enzymologic; Gene Library; genes; glicoproteinas; glycoproteine; glycoproteins; Hydrolases; Life sciences; Models, Molecular; Molecular Sequence Data; Molecules; Multigene Family; Médecine vétérinaire & santé animale; Organ Culture Techniques; ovin; ovinos; peptide; peptides; peptidos; Placenta - enzymology; Pregnancy; pregnancy diagnosis; Pregnancy Proteins - genetics; Pregnancy Proteins - isolation & purification; Pregnancy, Animal - physiology; proteasas; protease; proteases; Protein Conformation; proteinas; proteinase; proteine; proteins; RNA, Messenger - genetics; Sciences du vivant; Sequence Homology, Nucleic Acid; Sheep; Sheep - physiology; Trophoblasts; Ungulates; Veterinary medicine & animal health; Bovine; Enzyme; Active site; Biological marker; Antigen; Pregnancy; Northern blotting; Vertebrata; Immunoprecipitation reaction; Mammalia; Aspartic proteinase; Complementary DNA; Sheep; Artiodactyla; Molecular cloning; Ungulata; Aminoacid sequence
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.88.22.10247

Pregnancy in cattle and sheep can be diagnosed by the presence of a conceptus-derived antigen in maternal serum that is secreted by trophoblast and placental tissue primarily as an acidic component of Mr 67,000. Molecular cloning of its cDNA reveals that the antigen belongs to the aspartic proteinase family and has >50% amino acid sequence identity to pepsin, cathepsin D, and cathepsin E. The inferred sequences of the ovine and bovine polypeptides show approximately 73% identity to each other. Critical amino acid substitutions at the active site regions suggest that both proteins are enzymatically inactive. The antigen is a product of trophoblast binucleate cells that invade maternal endometrium at implantation sites.