[Kinetics of thermoinactivation of kidney Na+-,K+-ATPase].
The studies of Na+,K+-ATPase (the fraction of microsomes and highly active preparation) thermoinactivation in kidneys at 50, 55 and 60 degrees C under conditions of the different ionic composition of the medium has shown that 20 mM K+ protects the enzymic complex from the thermal denaturation more effectively than 182 mM Na+ does. An increase in the Mg2+ concentration in the medium from 1 to 5 mM decreases Na+,K+-ATPase resistance to thermoinactivation. The enzyme half-life becomes almost thrice as low in this case. The results obtained are discussed from the standpoint of specificity of ion-induced conformational states of Na+,K+-ATPase and regulatory role of cations in the process of its functioning.
D000818:Animals; D006207:Half-Life; D006358:Hot Temperature; D066298:In Vitro Techniques; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride; D008861:Microsomes / Q000201:enzymology; D011189:Potassium Chloride / Q000494:pharmacology; D011487:Protein Conformation; D012965:Sodium Chloride / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013552:Swine
D015636:Magnesium Chloride; D012965:Sodium Chloride; D011189:Potassium Chloride; D000254:Sodium-Potassium-Exchanging ATPase; D008274:Magnesium
Kinetika termoinaktivatsii Na+-,K+-Atpazy pochek.