title: Identification of bovine trophoblast protein-1, a secretory protein immunologically related to ovine trophoblast protein-1.
abstract: This paper demonstrates that a group of proteins, representing a major secretory component of cattle conceptuses, is immunologically related to ovine trophoblast protein-1 (oTP-1), a principal product of culture Day 13 to 21 sheep conceptuses. Conceptuses from cows (Day 17-18) and ewes (Day 16-17) were cultured for 24 h in the presence of L-[3H]leucine. By using a rabbit antiserum to oTP-1 and Ouchterlony double-immunodiffusion analysis it was shown that material in the bovine conceptus culture medium was serologically related, but not identical, to oTP-1. A solid-phase radiobinding assay indicated that the cross-reacting bovine secretory component had an affinity for anti-oTP-1 antibody similar to that of oTP-1. Anti-oTP-1 antiserum specifically immunoprecipitated a group of 6-8 polypeptides from culture medium of cow conceptuses which, when analysed by two-dimensional gel electrophoresis, fell into two major molecular weight classes (22,000 and 24,000) with isoelectric points between 6.5 and 6.7. These immunoprecipitated polypeptides, defined as bTP-1, constituted the major secretory products of Day 16-25 cow conceptuses. They were larger and more basic than oTP-1 polypeptides (Mr about 18,000; pI 5.4-5.7). Anti-oTP-1 antiserum also recognized the major translation product of Day 17 bovine conceptus mRNA, a polypeptide significantly smaller (Mr approximately 18,000) than the secreted protein. It is suggested that oTP-1 and the homologous bovine protein may play similar roles in the phenomenon of maternal recognition of pregnancy in the two species.
mesh_terms: D000818:Animals; D002417:Cattle; D003340:Corpus Luteum Maintenance; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D004622:Embryo, Mammalian / Q000276:immunology; D005260:Female; D005779:Immunodiffusion; D007370:Interferon Type I; D008186:Luteolytic Agents / Q000037:antagonists & inhibitors*; D008970:Molecular Weight; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000276:immunology*; D011270:Pregnancy, Animal; D011869:Radioligand Assay; D012756:Sheep
chemical_list: D007370:Interferon Type I; D008186:Luteolytic Agents; D011257:Pregnancy Proteins; C020947:interferon tau