Relaxin

Literature References: Polypeptide hormone secreted by the corpora lutea of many mammalian species during pregnancy; also produced in several non-mammalians, including the shark. Facilitates the birth process by causing a softening and lengthening of the pubic symphysis and cervix; also inhibits contraction of the uterus and may play a role in timing of parturition. First discovered in estrogen-primed guinea pigs: F. L. Hisaw, Proc. Soc. Exp. Biol. Med. 23, 661 (1926). Extraction from corpora lutea: Fevold et al., J. Am. Chem. Soc. 52, 3340 (1930); Albert et al., Endocrinology 40, 370 (1947); from pregnant rabbit serum: Abramowitz et al., Anat. Rec. 84, 456 (1942); cf. Hall, Newton, J. Physiol. 106, 18 (1947). Can be obtained commercially from pregnant sows' ovaries. Isoln procedure and purification by resin chromatography: Lehrman et al., J. Am. Pharm. Assoc. 44, 206 (1955); R. L. Kroc, G. E. Phillips, US 2852431; G. E. Phillips, US 2852432 (both 1958 to Warner-Lambert). Isoln from ovarian tissue using glacial acetic acid: Cohen, US 2930737 (1960 to Princeton Laboratories). Alternate method: Keck, US 3008878 (1961 to Thomae). Prepn from hog ovaries: Doczi, US 3096246 (1963 to Warner-Lambert). Porcine relaxin has a mol wt of approx 6000 and consists of two peptide chains, A and B, of 22 and 31 residues respectively, linked covalently by one intra- and two inter-chain disulfide bonds. Purification, characterization of porcine relaxin: O. D. Sherwood, E. O'Byrne, Arch. Biochem. Biophys. 160, 185 (1974). Structure of the A chain: C. Schwabe et al., Biochem. Biophys. Res. Commun. 70, 397 (1976); of the B chain: eidem, ibid. 75, 503 (1977). Relaxin is structurally homologous to insulin and related growth factors: R. A. Bradshaw, Rev. Biochem. 47, 191 (1978); S. Bedarkar et al., Nature 270, 449 (1977); N. Isaacs et al., ibid. 271, 278 (1978). Complete amino acid sequence of porcine relaxin: R. James et al., ibid. 267, 544 (1977); of rat: M. J. John et al., Endocrinology 108, 726 (1981). Isoln, characterization of relaxin from the sand tiger shark (Odontaspis taurus): J. W. Reinig et al., ibid. 109, 537 (1981); structure: L. K. Gowan et al., FEBS Lett. 129, 80 (1981). Demonstration of synthesis of rat relaxin as a preprorelaxin molecule with a connecting peptide of 105 amino acid residues, using molecular cloning: P. Hudson et al., Nature 291, 127 (1981). Structure of a genomic clone from which the amino acid sequence of biologically active human relaxin was predicted: eidem, ibid. 301, 628 (1983). Reviews: C. Schwabe et al., Recent Prog. Horm. Res. 34, 123-211 (1978); Ann. N.Y. Acad. Sci. 380, entitled "Relaxin: Structure, Function, and Evolution", B. G. Steinetz et al., Eds. (1982) pp 1-244.