Dephosphorylation of adenosine triphosphate in muscular contraction.

Abstract

CONTEMPORARY views on the role of adenosine triphosphate in contractile activity include the assumption that the breakdown of this substance is the immediate chemical source for mechanical energy1,2. However, as has recently been emphasized by A. V. Hill3, there is no proof that such a dephosphorylation occurs as an early event in contraction. Furthermore, it has been shown4 that the effects of adenosine triphosphate upon certain physical properties of actomyosin do not primarily involve splitting of the nucleotide. The experiments reported here were undertaken in order to decide whether, indeed, any dephosphorylation of adenosine triphosphate occurs during the contractile phase of a twitch.