[Inhibitory effect platinum and palladium complexes as indicator of conformational changes in sarcoplasmic reticulum membranes].
Inhibition of Ca2+-dependent ATPase of sarcoplasmic reticulum membranes (SRM) by platinum and palladium complexes is considerable enhanced during the incubation of these compunds with SRM preparations in the presence of small (10(-5) M) concentrations of ATP or ADP. AMP and nucleotides with non-adenine bases do not have inhibitory effect. To increase the sensitivity of Ca2+-dependent ATPase to platinum and palladium complexes under the action of ATP (but not ADP), the presence of free Ca2+-ions in the medium is required. In the absence of ATP Ca2+-ions do not affect the inhibiting effect of the complexes. The increase in pH of the medium up to 8.5 and the increase of temperature up to 45degree C sharply decrease the ATP ability to enchance the sensitivity of Ca2+-dependent  ATPase to platinum and palladium compunds. It is assumed that the ATP ability to enhance  Ca2+-dependent ATPase inhibition by platinum and palladium complexes is due to ATP-dependent structural changes in SRM, which increase the availability of certain groups of the enzyme to those compounds.
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors*; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium; D006863:Hydrogen-Ion Concentration; D008566:Membranes / Q000201:enzymology; D010165:Palladium / Q000494:pharmacology*; D010984:Platinum / Q000494:pharmacology*; D011487:Protein Conformation; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D013696:Temperature
D010984:Platinum; D010165:Palladium; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D002118:Calcium
Ingibiruiushchie effekty kompleksov platiny i palladiia kak indikator konformatsionnykh perekhodov v membranakh sarkoplazmaticheskogo retikuluma