Effect of Na3VO4 and membrane potential on the structure of sarcoplasmic reticulum membrane.
Two-dimensional crystalline arrays of Ca2+-ATPase molecules develop after treatment of sarcoplasmic reticulum vesicles with Na3VO4 in a Ca2+-free medium. The influence of membrane potential upon the rate of crystallization was studied by ion substitution using oxonol VI and 3,3'-diethyl-2,2'-thiadicarbocyanine (Di-S-C2(5] to monitor inside positive or inside negative membrane potentials, respectively. Positive transmembrane potential accelerates the rate of crystallization of Ca2+-ATPase, while negative potential disrupts preformed Ca2+-ATPase crystals, suggesting an influence of transmembrane potential upon the conformation of Ca2+-ATPase.
D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002794:Choline / Q000494:pharmacology; D003460:Crystallization; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D007425:Intracellular Membranes / Q000187:drug effects* / Q000648:ultrastructure; D007555:Isoxazoles / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects*; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000187:drug effects*; D014638:Vanadates; D014639:Vanadium / Q000494:pharmacology*
D005971:Glutamates; D007555:Isoxazoles; D014639:Vanadium; D018698:Glutamic Acid; D014638:Vanadates; C031184:oxonol VI; D000252:Calcium-Transporting ATPases; D002794:Choline