J. Biol. Chem., Vol. 261, Issue 24, 11086-11090, Aug, 1986
NMR studies of pig gastric microsomal H+,K+-ATPase and phospholipid dynamics. Effects of ethanol perturbation
RE Bailey, J Nandi, RA Levine, TK Ray, PN Borer and GC Levy
The effects of ethanol on the gastric H+,K+-ATPase activity and the degree
of mobility of various microsomal phospholipids were assessed using 31P and
1H NMR. This illuminated the role of lipid-protein association in the
function of pig gastric microsomes. Treatment of gastric microsomes with
15% ethanol for 1 min at 37 degrees C inactivated the H+,K+-ATPase
activity, which could largely be reconstituted by supplementation with
phosphatidylcholine isolated from the gastric microsomes. Under similar
conditions, the 1H NMR profile of the microsomal +N(CH3)3 choline moiety
showed dramatic enhancement of peak intensity as well as a break point at
25 degrees C which was restored to the untreated control value after
reconstitution. This break, together with the dramatic enhancement in the
overall lipid profile, compared to the control and reconstituted
microsomes, suggested a greater degree of freedom of movement of the
microsomal lipids following ethanol perturbation. The data demonstrate the
unique ability that a combined approach using 31P and 1H NMR holds as a
noninvasive probe to study the structure-function relationship of
biomembranes.