ISSN:
0091-7419
Keywords:
Life Sciences
;
Molecular Cell Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
1,N6-Ethenoadenosine diphosphate (∊-ADP) inhibits reverse electron flow (succinate → NAD+ driven by ATP) by competing with ATP, in contrast to ADP which we have shown previously to be a noncompetitive inhibitor. From these and other data it is concluded that the noncompetitive inhibition noted with ADP results from a combination of competitive inhibition plus non- or uncompetitive inhibition, the former occuring at a relatively nonspecific catalytic site and the latter at an extracatalytic site apparently quite specific for ADP.ADP, which stimulates ATP ⇌ H2O and Pi ⇌ H2O exchanges appears to be necessary for inhibition by arsenate of these exchanges. It is suggested that the ATP-supported Pi ⇌ H2O exchange may be predominantly of the medium or intermediate type, depending on the concentrations of the Mg2+ complexes of ADP and Pi. Thus only exchanges involving medium ADP and Pi would be expected to show arsenate sensitivity.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jss.400030308
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