The mobility and reactivity of maleimide-binding proteins in the rat erythrocyte membrane. Effects of dietary zinc deficiency and incubation with zinc in vitro.
Erythrocyte ghosts, prepared from rats fed zinc-deficient diets, were analyzed for the mobility of membrane proteins by electron spin resonance spectroscopy of the sulfhydryl-binding spin probe, 4-maleimido-2,2,6,6-tetramethylpiperidine-N-oxyl. Compared with erythrocyte membranes from rats fed zinc-adequate diets ad libitum or pair-fed, erythrocyte membranes from zinc-deficient rats had a significantly increased ratio of weakly immobilized to strongly immobilized probe-binding proteins. This suggests that dietary zinc deficiency causes a conformational change in erythrocyte membrane proteins. Dietary zinc deficiency did not significantly affect N-ethylmaleimide (NEM)-induced thermal sensitivity or NEM-induced mechanical fragility in rat erythrocytes; however, the addition of zinc in vitro to red cells significantly inhibits NEM-induced mechanical fragility.
Kubow
S J
SJ
Department of Nutritional Sciences, College of Biological Science, University of Guelph, Ont., Canada.
Bettger
W J
WJ
D000818:Animals; D002352:Carrier Proteins / Q000097:blood*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D005033:Ethylmaleimide / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008301:Maleimides / Q000097:blood*; D008565:Membrane Proteins / Q000378:metabolism; D009996:Osmotic Fragility / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D015032:Zinc / Q000172:deficiency* / Q000494:pharmacology
D002352:Carrier Proteins; D008301:Maleimides; D008565:Membrane Proteins; D015032:Zinc; D005033:Ethylmaleimide