Studies on incorporation of membrane protein into liposomes--effect of divalent cations on reconstitution of pig heart mitochondrial H+-ATPase into liposomes.
During the process of reconstitution of pig heart mitochondrial H+-ATPase on liposomes by cholate dialysis method, 1 mM Mg2+ in the dialysis medium can obviously increase activities of the reconstituted H+-ATPase (32Pi-ATP exchange, enzyme activity and its sensitivity to oligomycin or DCCD and ATP-dependent ANS 1) fluorescence). Besides Mg2+, effects of other divalent cations and spermidine on the H+-ATPase reconstitution have been compared. The effectiveness of the divalent cation activation of 32Pi-ATP exchange of the reconstituted H+-ATPase, decreased in the order: Mg2+ greater than Ca2+ greater than Mn2+ greater than Sr2+, while that of increasing the sensitivity to the inhibitors: Ca2+ greater than Mg2+ greater than Mn2+ greater than Sr2+. No significant effect on the H+-ATPase reconstitution has been found with Cd2+, Zn2+ and spermidine3+. Mechanism of action of the divalent cations on reconstitution has been discussed.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D002413:Cations, Divalent; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology*; D008565:Membrane Proteins / Q000378:metabolism*; D008929:Mitochondria, Heart / Q000201:enzymology*; D009840:Oligomycins / Q000494:pharmacology; D013095:Spermidine / Q000494:pharmacology; D013552:Swine
D002413:Cations, Divalent; D008081:Liposomes; D008565:Membrane Proteins; D009840:Oligomycins; D004024:Dicyclohexylcarbodiimide; D000251:Adenosine Triphosphatases; D008274:Magnesium; D013095:Spermidine