The mechanism of skeletal muscle myosin ATPase. Interaction of myosin active center with ATP and with ADP
The kinetics of the fluorescence enhancement and the transient release of H+ caused by the binding of ADP to the active center of myosin has been compared to that caused by myosin-ATP interaction. The results show that both the time courses of the fluorescence enhancement and the transient H+ releas...
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Published in | The Journal of biological chemistry Vol. 256; no. 21; pp. 10954 - 10960 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Biochemistry and Molecular Biology
10.11.1981
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Subjects | |
Online Access | Get full text |
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Summary: | The kinetics of the fluorescence enhancement and the transient release of H+ caused by the binding of ADP to the active center
of myosin has been compared to that caused by myosin-ATP interaction. The results show that both the time courses of the fluorescence
enhancement and the transient H+ release caused by ADP binding, like that caused by ATP hydrolysis in the initial burst, are
monophasic exponential processes. The fact that the rates of these two processes are also equal suggests that they both reflect
the same mechanistic event in the mechanism of ADP binding. The kinetics of ADP binding as measured by the fluorescence enhancement
and the H+ release is different from that of ATP. This is in agreement with our previous finding that the enhancement of fluorescence
and the transient release of H+, in the case of ATP, reflect the initial burst of ATP hydrolysis, whereas in the case of ADP,
they represent a conformational change in the myosin-ADP complex. The magnitude of the H+ transient caused by the initial
burst is approximately equal to that caused by ADP binding. The amplitude of the fluorescence enhancement caused by ADP binding
is equal to one-third of that caused by the initial burst. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/S0021-9258(19)68539-X |