Effect of Arg145Gly mutation in human cardiac troponin I on the ATPase activity of cardiac myofibrils

Fumi Takahashi-Yanaga, Sachio Morimoto, Iwao Ohtsuki

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

In order to determine the functional consequences of the Arg145Gly mutation in troponin I found in familial hypertrophic cardiomyopathy, human cardiac troponin I and its mutant were expressed in Escherichia coli and purified, and then their effects on the ATPase activity of porcine cardiac myofibrillar preparations from which both troponins C and I had been depleted were examined. Both the wild-type and mutant troponin is suppressed the ATPase activity of the troponin C·I-depleted myofibrils, but the maximum inhibition caused by mutant troponin I was weaker than that by wild-type troponin I. In the Ca2+-activation profile of the myofibrillar ATPase activity after reconstitution with both troponins I and C, the Ca2+- sensitivity with mutant troponin I was higher than that with wild-type troponin I, whereas the maximum level of the ATPase activity with mutant troponin I was lower than that with wild-type troponin I. These findings strongly suggest that the Arg145Gly mutation in human cardiac troponin I modulates the Ca2+-regulation of contraction by impairing the interaction of troponin I with both actin-tropomyosin and troponin C.

Original languageEnglish
Pages (from-to)355-357
Number of pages3
JournalJournal of Biochemistry
Volume127
Issue number3
Publication statusPublished - 2000

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Troponin I
Myofibrils
Adenosine Triphosphatases
Mutation
Troponin C
Troponin
Familial Hypertrophic Cardiomyopathy
Tropomyosin
Escherichia coli
Actins
Swine
Chemical activation

All Science Journal Classification (ASJC) codes

  • Biochemistry

Cite this

Effect of Arg145Gly mutation in human cardiac troponin I on the ATPase activity of cardiac myofibrils. / Takahashi-Yanaga, Fumi; Morimoto, Sachio; Ohtsuki, Iwao.

In: Journal of Biochemistry, Vol. 127, No. 3, 2000, p. 355-357.

Research output: Contribution to journalArticle

Takahashi-Yanaga, F, Morimoto, S & Ohtsuki, I 2000, 'Effect of Arg145Gly mutation in human cardiac troponin I on the ATPase activity of cardiac myofibrils', Journal of Biochemistry, vol. 127, no. 3, pp. 355-357.
Takahashi-Yanaga, Fumi ; Morimoto, Sachio ; Ohtsuki, Iwao. / Effect of Arg145Gly mutation in human cardiac troponin I on the ATPase activity of cardiac myofibrils. In: Journal of Biochemistry. 2000 ; Vol. 127, No. 3. pp. 355-357.
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