[Kinetics of passive transport of Ca2+ in vesicular preparations of myocardial sarcolemma with inside-out oriented cytoplasm].
Using affinity chromatography on a concanavalin A-Sepharose 4B column, two fractions of rabbit myocardium with oppositely oriented sarcolemmal vesicles have been obtained. Analysis of 45Ca2+ release from the vesicles with inside-out oriented cytoplasm demonstrates that this reaction is biphasic and obeys a pseudo-first-order kinetics. The initial rate of Ca2+ release is equal to 0.57 nmol/mg/s. The release of Ca2+ from the vesicles is inhibited via phosphorylation of sarcolemmal proteins by the catalytic subunit of cAMP-dependent protein kinase; the initial rate of this process drops to 0.08 nmol/mg of protein/s. The reaction is also inhibited by Cd2+ greater than Mn2+ greater than Co2+, when the latter are present inside the vesicles.
Vorobets
Z D
ZD
Kurskiĭ
M D
MD
Marchenko
S N
SN
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002846:Chromatography, Affinity; D000242:Cyclic AMP / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011817:Rabbits; D012508:Sarcolemma / Q000201:enzymology / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D000242:Cyclic AMP; D011494:Protein Kinases; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium
Kinetika passivnogo transporta Ca2+ v vezikulirovannykh preparatakh sarkolemmy miokarda, orientirovannykh tsitoplazmaticheskoĭ storonoĭ naruzhu.