Title: Relaxin
CAS Registry Number: 9002-69-1
Trademarks: Cervilaxin; Releasin (formerly) (Warner-Chilcott)
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.
Properties: Amorphous powder. Diffusion constant 12.6 ´ 10-7 cm2/sec. Sedimentation constant 1.6 ´ 10-13 sec. Isoelec pt around pH 7.0. uv max (water, pH 7.0): 277.5 nm (E1%1cm 7.20). Slightly sol in water and 95% alcohol. Sol in acid or alkaline solns. Insol in abs alcohol, ether, acetone, petr ether, benzene. Dec above pH 9. Neutral or acid solns which are free from oxidizing agents, are stable. Ampuled solns at pH 7.0 and 3.2 have been kept in refrigerator for one year without loss of activity.
Absorption maximum: uv max (water, pH 7.0): 277.5 nm (E1%1cm 7.20)
Therap-Cat: Hormone (ovarian).
Keywords: Ovarian Hormone. |