Active Ca2+ transport by vesicles reconstituted from Triton X-100-solubilized pigeon erythrocyte membrane.
Pigeon erythrocyte membrane was solubilized partially, but relatively unselectively by Triton X-100. Vesicles were reconstituted from mixtures of Triton-solubilized membrane and lipid (phosphatidylcholine plus phosphatidyl-ethanolamine plus cholesterol) by addition of bovine high-density lipoprotein. This efficiently removed the Triton X-100. Sodium dodecyl sulfate-polyacrylamide gel electropherograms of reconstituted vesicles showed band patterns resembling those of the original membrane. The reconstituted vesicles showed ATP-dependent active accumulation of 45Ca2+. ATP-dependent 45Ca2+ uptake by the reconstituted vesicles resembled the corresponding activity of the original membrane vesicles; in both preparations the Ca2+ uptake rate depended on the square of the Ca2+ concentration and had similar [Ca2+]1/2 values, 0.16 microM and 0.18 microM, respectively.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000097:blood*; D010856:Columbidae; D004910:Erythrocyte Membrane / Q000378:metabolism* / Q000648:ultrastructure; D004912:Erythrocytes / Q000378:metabolism*; D007700:Kinetics; D008563:Membrane Lipids / Q000097:blood; D011092:Polyethylene Glycols; D012995:Solubility
D008563:Membrane Lipids; D011092:Polyethylene Glycols; D000255:Adenosine Triphosphate; D002118:Calcium