Regulation of the mitochondrial ATP synthase/ATPase complex
The mitochondrial ATP synthase/ATPase (F 0F 1 ATPase) is perhaps the most complex enzyme known. In animal systems it consists of a minimum of 11 different polypeptide chains, 10 (or more) of which appear to be essential for function, and 1 called the “ATPase inhibitor peptide” which is involved in r...
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Published in | Archives of biochemistry and biophysics Vol. 250; no. 1; pp. 1 - 18 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
San Diego, CA
Elsevier Inc
01.10.1986
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The mitochondrial ATP synthase/ATPase (F
0F
1 ATPase) is perhaps the most complex enzyme known. In animal systems it consists of a minimum of 11 different polypeptide chains, 10 (or more) of which appear to be essential for function, and 1 called the “ATPase inhibitor peptide” which is involved in regulation. Recent studies from a variety of laboratories indicate that the ATP synthase/ATPase complex is regulated by several interrelated factors including (a) the thermodynamic poise of the proton gradient across the inner mitochondrial membrane; (b) the ATPase inhibitor peptide; (c) ADP (and/or ADP and
P
i); (d) divalent cations; and perhaps (e) the redox state of SH groups on the F
1 molecule. The central focus of this review is the ATPase inhibitor peptide. A model involving four distinct conformational states of F
1 seems essential to account for the inhibitor's mode of action. The model depicts the ATPase inhibitor protein as acting at the asymmetric center of the F
1 moiety. In addition, it accounts for the “unidirectional” role of the inhibitor peptide as a “down regulator” of ATP hydrolysis and for its binding/debinding dependence on the proton motive force and other regulatory factors. Finally, it is suggested that during any physiological process, where there is an energy demand followed by a resting phase, the F
1 molecule may follow a “cyclic” path involving the four distinct conformational states of the enzyme. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-3 content type line 23 ObjectType-Review-1 |
ISSN: | 0003-9861 1096-0384 |
DOI: | 10.1016/0003-9861(86)90695-8 |