Abstract
The amino acid sequence of the α subunit of equine chorionic gonadotropin (eCG, also pregnant mare serum gonadotropin, PMSG) has been determined. Overlapping peptides from tryptic and chymotrypic digests were isolated by a two-dimensional peptide mapping technique and sequenced by the Edman procedure. The proposed amino acid sequence of eCG α is:
(**Denotes carbohydrate attachment points.) This sequence differs significantly from that proposed by Rathnamet al. (1978) for equine follitropin α subunit; in particular, their sequence lacked the first fourteen residues.
For the β subunit we have placed in sequence 104 amino acid residues by direct sequence determination and peptide overlap procedures; in addition, 37 residues have been placed provisionally by homology with the human chorionic gonadotropin (hCG) sequence and composition and/or sequence data for the peptides isolated in the present studies. Difficulties in the procurement of the hormone have stalled completion of the β-subunit amino acid sequence determination. The data now available indicate that eCG β-subunit is highly homologous to hCG β subunit and the β subunits of luteinizing hormone from the pituitary gland of the several species so far described. The proposed partial sequence of eCG β is:
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References
Bellisario, R., Carlsen, R. B., and Bahl, O. P. (1973).J. Biol. Chem. 248, 6796–6809.
Birken, S., and Canfield, R. E. (1977).J. Biol. Chem. 252, 5386–5392.
Blomback, B. (1967). In (Colowick, S. P., and Kaplan, N. O. (eds.),Methods in Enzymology, Vol. II, Academic Press, New York, pp. 398–411.
Brown, F. F., Parsons, T. F., Sigman, D. S., and Pierce, J. G. (1979).J. Biol. Chem. 254, 4335–4338.
Burleigh, B. D., Liu, W-K., and Ward, D. N. (1976).J. Biol. Chem. 251, 308–315.
Carlsen, R. B., Bahl, O. P., and Swaminathan, N. (1973).J. Biol. Chem. 248, 6810–6825.
Christakos, S., and Bahl, O. (1979).J. Biol. Chem. 254, 4253–4261.
Closset, J., Hennen, G., and Lequin, R. M. (1973).FEBS Lett. 29, 97–100.
Closset, J., Maghuin-Rogister, C., Hennen, G., and Strosberg, A. D. (1978).Eur. J. Biochem. 86, 115–120.
Cole, R. D. (1967). In Colowick, S. P., and Kaplan, N. O. (eds.),Methods in Enzymology, Vol. II, Academic Press, New York, pp. 315–317.
Combarnous, Y. and Henge, M.-H. (1981).J. Biol. Chem. 256, 9567–9572.
Edelhoch, H. (1967).Biochemistry 6, 1948–1954.
Edge, A. S. B., Faltynek, C. R., Hof, L., Reichert, L. E., Jr., and Weber, P. (1981).Anal. Biochem. 118, 131–136.
Fujiki, Y., Rathnam, P., and Saxena, B. B. (1978).J. Biol. Chem. 253, 5363–5368.
Fujiki, Y., Rathnam, P., and Saxena, B. B. (1980).Biochim. Biophys. Acta 624, 428–435.
Hartley, B. S. (1980).Biochem. J. 119, 805–822.
Hugli, T. E., and Moore, S. (1972).J. Biol. Chem. 247, 2828–2834.
Keutmann, H. T., and Williams, R. M. (1977).J. Biol. Chem. 252, 5393–5397.
Keutmann, H. T., Williams, R. M., and Ryan, R. J. (1979).Biochem. Biophys. Res. Commun. 90, 842–847.
Landefeld, T. D., Grimek, H. J., and McShan, W. H. (1972).Biochem. Biophys. Res. Commun. 46, 463–469.
Liao, T.-H., and Pierce, J. G. (1970).J. Biol. Chem. 245, 3275–3281.
Liao, T.-H., and Pierce, J. G. (1971).J. Biol. Chem. 246, 850–865.
Liao, T.-H., Hennen, G., Howard, S. M., Shome, B., and Pierce, J. J. (1969).J. Biol. Chem. 244, 6458–6467.
Liu, W.-K., and Meinhofer, J. (1968).Biochem. Biophys. Res. Commun. 31, 467–473.
Liu, W.-K., Nahm, H. S., Sweeney, C. M., Lamkin, W. M., Baker, H. N., and Ward, D. N. (1972a).J. Biol. Chem. 247, 4351–4364.
Liu, W.-K., Nahm, H. S., Sweeney, C. M., Holcomb, G. N., and Ward, D. N. (1972b).J. Biol. Chem. 247, 5365–4381.
Maghuin-Rogister, G., and Hennen, G. (1973).Eur. J. Biochem. 39 235–253.
Maghuin-Rogister, G., Combarnous, Y., and Hennen, G. (1973).Eur. J. Biochem. 39, 255–263.
Maghuin-Rogister, G., Hennen, G., and Closset, J. (1976).Eur. J. Biochem. 61, 157–163.
Malsky, M. L., Bullock, D. W., Willard, J. J., and Ward, D. N. (1979).J. Biol. Chem. 254, 1580–1585.
Moore, W. T., Jr., and Ward, D. N. (1980a).J. Biol. Chem. 255, 6923–6929.
Moore, W. T., Jr., and Ward, D. N. (1980b).J. Biol. Chem. 255, 6930–6936.
Moore, W. T., Jr., Ward, D. N., and Burleigh, B. D. (1979).Fed. Proc. 38, 462–463.
Moore, W. T., Jr., Burleigh, B. D., and Ward, D. N. (1980). In Segal, S. J. (ed.),Chorionic Gonadotropin, Plenum Press, New York, pp. 89–126.
Morgan, F. J., Birken, S., and Canfield, R. E. (1973).Molec. Cell. Biochem. 2, 97–99.
Mort, A. J., and Lamport, D. T. A. (1977).Anal. Biochem. 82, 289–309.
Mueller, J. M., Pierce, J. G., Davoll, H., and duVigneaud, V. (1951).J. Biol. Chem. 191, 309–313.
Nuti, L. C., Grimek, H. J., Braselton, W. E., and McShan, W. H. (1972).Endocrinology 91, 1418–1422.
Offord, R. E. (1966).Nature 211, 591–593.
Papkoff, H., Bewley, T. A., and Ramachandran, J. (1978).Biochim. Biophys. Acta 532, 185–194.
Pierce, J. G., and Parsons, T. F. (1981).Annu. Rev. Biochem. 50, 465–495.
Rathnam, P., and Saxena, B. B. (1975).J. Biol. Chem. 250, 6735–6746.
Rathnam, P., Fujiki, Y., Landefeld, T. D., and Saxena, B. B. (1978).J. Biol. Chem. 253, 5355–5362.
Sairam, M. R. (1981a).Biochem. J. 197, 535–540.
Sairam, M. R. (1981b).Biochem. J. 197, 541–546.
Sairam, M. R., and Li, C.-H. (1973).Biochem. Biophys. Res. Commun. 54, 426–431.
Sairam, M. R., and Li, C.-H. (1975).Biochim. Biophys. Acta 412, 70–81.
Sairam, M. R., Samy, T. S. A., Papkoff, H., and Li, C.-H. (1972a).Arch. Biochem. Biophys. 153, 572–586.
Sairam, M. R., Papkoff, H., and Li, C.-H. (1972b).Biochem. Biophys. Res. Commun. 48, 530–537.
Saxena, B. B., and Rathnam, P. (1976).J. Biol. Chem. 251, 993–1005.
Shome, B., and Parlow, A. F. (1973a).J. Clin. Endocrinol. Metab. 36, 618–621.
Shome, B., and Parlow, A. F. (1973b). In 55th National Endocrine Meeting, Abstract A-60, No. 22, Chicago, Illinois.
Shome, B., and Parlow, A. F. (1974a).J. Clin. Endocrinol. Metab. 39, 199–202.
Shome, B., and Parlow, A. F. (1974b).J. Clin. Endocrinol. Metab. 39, 203–205.
Ward, D. N., Reichert, L. E., Jr., Liu, W.-K., Nahm, H. S., and Lamkin, W. M. (1972). In Saxena, B. B., Beling, C. G., and Gandy, H. M. (eds.),Gonadotropins, Wiley, New York, pp. 132–143.
Ward, D. N., Reichert, L. E., Jr., Liu, W.-K., Nahm, H. S., Hsia, J., Lamkin, W. M., and Jones, N. S. (1973).Recent Prog. Horm. Res. 29, 533–561.
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Ward, D.N., Moore, W.T. & Burleigh, B.D. Structural studies on equine chorionic gonadotropin. J Protein Chem 1, 263–280 (1982). https://doi.org/10.1007/BF01039552
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DOI: https://doi.org/10.1007/BF01039552