Reconstitution of Heavy Chain and Light Chain 1 in Cardiac Subfragment-1 from Hyperthyroid and Euthyroid Rabbit Hearts

  • S. Ueda
  • K. Yamaoki
  • R. Nagai
  • Y. Yazaki


It is now established that cardiac myosin from hyperthyroid rabbit hearts (TXM) exhibits high Ca2+ ATPase activity. The high Ca2+ ATPase activity of TXM was completely retained in cardiac myosin subfragment-1 (S-l) (1.33 ± 0.04 (μmol Pi/mg per min; euthyroid, 0.51 ± 0.04). Cardiac S-1 from hyperthyroid and euthyroid rabbits (TXS-1 and NS-1) had the same pattern in SDS-polyacrylamide gel electrophoresis. The possible influence of heavy and light chains of TXM on increasing the ATPase activity was examined by reconstitution in the S-l preparation. Crosswise reconstitution was performed using cardiac S-l heavy chain (90,000 daltons) and light chain 1 (LCI) (27,000 daltons) from hyperthyroid and euthyroid hearts. Reconstitution was verified by using radiolabeled LCI. More than 95% of S-l was recovered with full ATPase activity. When TXS-1 was reconstituted with LCI from euthyroid hearts, the reconstituted molecule retained high ATPase activity. On the other hand, NS-1 reconstituted with LCI from hyperthyroid hearts failed to increase the ATPase activity. The ATPase activity of S-1 was determined by the source of the heavy chain. These results suggest that the high Ca2+ ATPase activity of cardiac myosin and S-l from hyperthyroid animals arises from the molecular alteration of the heavy chain induced by thyroxine administration.


Light Chain ATPase Activity Heavy Chain Cyanogen Bromide Cardiac Myosin 
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  1. 1.
    Fiske, C. H., and SubbaRow, Y. 1925. Colorimetric determination of phosphorus. J. Biol. Chem. 66:375–400.Google Scholar
  2. 2.
    Flink, I. L., Rader, J. H., and Morkin, E. 1979. Thyroid hormone stimulates synthesis of a cardiac myosin isozyme. Comparison of the two dimensional electrophoretic patterns of the cyanogen bromide peptides of cardiac myosin heavy chains from euthyroid and thyrotoxic rabbits. J. Biol. Chem. 245:3105–3110.Google Scholar
  3. 3.
    Goodkind, M. J., Dambach, G. E., Thyrum, P. T., and Luchi, R. J. 1974. Effects of thyroxine on ventricular myocardial contractility and ATPase activity in guinea pigs. Am. J. Physiol. 226:66–72.PubMedGoogle Scholar
  4. 4.
    Hjalmarson, A. C, Whitefield, C. H., and Mogan, H. E. 1970. Hormone control of heart function and myosin ATPase activity. Biochim. Biophys. Res. Commun. 41:1548–1589.CrossRefGoogle Scholar
  5. 5.
    Hoh, J. F. Y., McGrath, P. A., and Hale, P. T. 1978. Electrophoretic analysis of multiple forms of rat cardiac myosin: Effects of hypophysectomy and thyroxine replacement. J. Mol. Cell Cardiol. 10:1053–1076.PubMedCrossRefGoogle Scholar
  6. 6.
    Katagiri, T., Freedberg, A. S., and Morkin, E. 1974. Effects of N-ethylmaleimide on the ATPase activities of cardiac myosin from thyrotoxic rabbits. Life Sci. 16:1079–1087.CrossRefGoogle Scholar
  7. 7.
    Kuczynski, S. F. 1973. Quantitative and Qualitative Characterizations of Cardiac Acto-myosin in Thyroxine-Induced Hypertrophy. Ph. D. Thesis, New York Medical College, New York.Google Scholar
  8. 8.
    Lowry, O. M., Rosebrough, N. J., Farr, A. L., and Randall, R. J. 1951. Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193:265–275.PubMedGoogle Scholar
  9. 9.
    Thyrum, P. T., Kritcher, E. M., and Luchi, R. J. 1970. Effect of L-thyroxine on the primary structure of cardiac myosin. Biochim. Biophys. Acta 197:335–336.PubMedCrossRefGoogle Scholar
  10. 10.
    Wagner, P. D., and Weeds, A. 1977. Studies on the role of myosin alkali light chains. Recombination and hybridization of light chains and heavy chains in subfragment-1 preparations. J. Mol. Biol. 109:455–473.PubMedCrossRefGoogle Scholar
  11. 11.
    Weber, K., and Osborn, M. 1969. The reliability of molecular weight determinations by dodecyl sulfate-polyacrylamide gel electrophoresis. J. Biol. Chem. 244:4406–4412.PubMedGoogle Scholar
  12. 12.
    Yazaki, Y., and Raben, M. S. 1975. Effect of the thyroid state on the enzymatic characteristics of cardiac myosin. A difference in behavior of rat and rabbit cardiac myosin. Circ. Res. 36:208–215.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1983

Authors and Affiliations

  • S. Ueda
    • 1
  • K. Yamaoki
    • 1
  • R. Nagai
    • 1
  • Y. Yazaki
    • 1
  1. 1.Cardiovascular Research Unit, The Third Department of Internal Medicine, Faculty of MedicineUniversity of TokyoTokyo 113Japan

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