ISSN:
0091-7419
Keywords:
red cell membranes
;
ATPase
;
Ca2+
;
Mg2+
;
diamide
;
Life Sciences
;
Molecular Cell Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
An Mg2+-dependent low ATPase activity can be detected in erythrocyte “white membranes,” in addition to that of the well known (Ca2+ + Mg2+)-ATPase. The thiol oxidizing agent diamide affects both activities. The oxidation of neighboring thiols seems to leave the mechanism of the (Ca2+ + Mg2+)-ATPase amplification system evoked by Ca2+ largely unaffected. The perturbation caused by diamide in the membranes seems to affect primarily a step of the ATP hydrolysis mechanism that is common to both ATPase activities. The effectiveness of diamide seems to be the same when either Ca2+ and Mg2+, or Mg2+ alone are present during the reagent action. Reduction of disulfide bonds by DTE after diamide treatment restores the (Ca2+ + Mg2+)-ATPase activity but is unable to take the Mg2+-ATPase activity back to the original level.The hypothesis is discussed that the redox state of one (or more than one) couple of —SH close to each other and possibly connected to the active site, may be an important factor in optimizing the efficiency of Ca action on the (Ca2+ + Mg2+)-ATPase.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jss.400140102
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