title: The primary structure and the disulfide links of the bovine relaxin-like factor (RLF).
abstract: The relaxin-like factor (RLF), produced by the Leydig cells, is an essential link in the chain of events leading to the proper positioning of the testes during fetal development. The primary structure of RLF, as reported in the literature, is based solely upon cDNA sequences with chain lengths determined according to deduced processing sites and with relaxin-like cross-links. Biochemical characterization of bovine testicular RLF shows clearly that the endogenous hormone does consist of a 26 residue A chain and two forms of B chain, one containing 40 residues, the other 45. In addition, both B chains are 9 residues longer at the C terminus than the cDNA-deduced chain, and about 20% of the B chains have an additional 5 residue extension at the N terminus. Sequence analysis in combination with mass spectrometry and tryptic peptide mapping showed unambiguously that RLF is larger than previously assumed and that it has the relaxin-type disulfide bond distribution that makes it a bona fide member of the relaxin family of hormones.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, PO Box 250509, Charleston, South Carolina 29425, USA. bullesee@musc.edu
authors.forename: Erika E
authors.initials: EE
authors.lastname: Büllesbach
authors.forename: Christian
authors.initials: C
authors.lastname: Schwabe
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004220:Disulfides / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007328:Insulin; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification; D011863:Radioimmunoassay; D011956:Receptors, Cell Surface / Q000378:metabolism; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000737:chemistry; D014357:Trypsin / Q000378:metabolism
chemical_list: D004220:Disulfides; D007328:Insulin; C084797:Leydig insulin-like protein; D010446:Peptide Fragments; D011506:Proteins; D011956:Receptors, Cell Surface; D014357:Trypsin