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. 1973 Nov;70(11):3205–3209. doi: 10.1073/pnas.70.11.3205

Regulatory Properties of Myocardial Myosin

Claudia Fenner *, Dean T Mason †,*, Robert Zelis †,*, Joan Wikman-Coffelt *,‡
PMCID: PMC427201  PMID: 4522299

Abstract

The ATPase activity of purified myocardial myosin was activated by either K+ or Ca++; the addition of one in the presence of the other caused inhibition. According to Hill-plot analyses the K+-saturation curves were sigmoidal (n = 2.92), while the Ca++-saturation curves were hyperbolic (n = 1.25). Ca++-saturation curves in the presence of K+ were inhibitory with sigmoidicity (n = 4.11), while K+-saturation curves in the presence of Ca++ followed the Michaelis-Menten inhibition kinetics (n = 1.11). Substrate saturation curves were hyperbolic for both Ca++ and K+ systems. There was no enzymatic activity when Na+ was used as the activating metal; furthermore, Na+ inhibited in the presence of either K+ or Ca++. Both Na+ curves of inhibition followed the Michaelis-Menten relationship.

Keywords: ATPase activity, K+, Ca++

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BOWEN W. J., KERWIN T. D. A study of the effects of ethylenediamine-tetra-acetic acid on myosin adenosinetriphosphatase. J Biol Chem. 1954 Nov;211(1):237–247. [PubMed] [Google Scholar]
  2. BRAHMS J., KAY C. M. Molecular and enzymatic properties of cardiac myosin A as compared with those of skeletal myosin A. J Biol Chem. 1963 Jan;238:198–205. [PubMed] [Google Scholar]
  3. Brutsaert D. L., Claes V. A., Goethals M. A. Effect of calcium on force-velocity-length relations of heart muscle of the cat. Circ Res. 1973 Mar;32(3):385–392. doi: 10.1161/01.res.32.3.385. [DOI] [PubMed] [Google Scholar]
  4. Busselen P., Carmeliet E. Protagonistic effects of Na and Ca on tension development in cardiac muscle at low extracellular Na concentrations. Nat New Biol. 1973 May 9;243(123):57–59. [PubMed] [Google Scholar]
  5. Bárány M. ATPase activity of myosin correlated with speed of muscle shortening. J Gen Physiol. 1967 Jul;50(6 Suppl):197–218. doi: 10.1085/jgp.50.6.197. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  7. LUCHI R. J., KRITCHER E. M., CONN H. L., Jr MOLECULAR CHARACTERISTICS OF CANINE CARDIAC MYOSIN. Circ Res. 1965 Jan;16:74–82. doi: 10.1161/01.res.16.1.74. [DOI] [PubMed] [Google Scholar]
  8. Luchi R. J., Kritcher E. M. Cardiac myosin adenosinetriphosphatase activity. Modifying factors and comparison with skeletal muscle myosin adenosinetriphosphatase activity. Circ Res. 1966 Aug;19(2):283–294. doi: 10.1161/01.res.19.2.283. [DOI] [PubMed] [Google Scholar]
  9. MUELLER H., PERRY S. V. The degradation of heavy meromyosin by trypsin. Biochem J. 1962 Dec;85:431–439. doi: 10.1042/bj0850431. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Margossian S. S., Lowey S. Substructure of the myosin molecule. 3. Preparation of single-headed derivatives of myosin. J Mol Biol. 1973 Mar 5;74(3):301–311. doi: 10.1016/0022-2836(73)90375-6. [DOI] [PubMed] [Google Scholar]
  11. Margossian S. S., Lowey S. Substructure of the myosin molecule. IV. Interactions of myosin and its subfragments with adenosine triphosphate and F-actin. J Mol Biol. 1973 Mar 5;74(3):313–330. doi: 10.1016/0022-2836(73)90376-8. [DOI] [PubMed] [Google Scholar]
  12. Maruyama K., Weber A. Binding of adenosine triphosphate to myofibrils during contraction and relaxation. Biochemistry. 1972 Aug 1;11(16):2990–2998. doi: 10.1021/bi00766a010. [DOI] [PubMed] [Google Scholar]
  13. Spudich J. A., Watt S. The regulation of rabbit skeletal muscle contraction. I. Biochemical studies of the interaction of the tropomyosin-troponin complex with actin and the proteolytic fragments of myosin. J Biol Chem. 1971 Aug 10;246(15):4866–4871. [PubMed] [Google Scholar]
  14. Wikman-Coffelt J., Zelis R., Fenner C., Mason D. T. Myosin chains of myocardial tissue. I. Purification and immunological properties of myosin heavy chains. Biochem Biophys Res Commun. 1973 Apr 16;51(4):1097–1104. doi: 10.1016/0006-291x(73)90040-5. [DOI] [PubMed] [Google Scholar]
  15. Wikman-Coffelt J., Zelis R., Fenner C., Mason D. T. Studies on the synthesis and degradation of light and heavy chains of cardiac myosin. J Biol Chem. 1973 Jul 25;248(14):5206–5207. [PubMed] [Google Scholar]

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