[Characteristics of cooperative binding of Na+ and K+ with Na+,K+-ATPase depending upon its oligomeric structure].
It has been shown that the desensibilization of the enzymic preparations of Na+, K+-ATPase by urea, DS-Na, digitonin and CHAPS reduces differently the amount of alpha beta-protomer in the enzymic preparations and the Hill coefficients of Na+ and K+. The factors (urea, DS-Na) which cause a more pronounced decrease in the amount of beta-protomer reduce the nH of Na+ for Na+, K+-ATPase and nH of K+ for Na+, K+-ATPase and K+-pNPPase to unit. The analysis of the effects of ATP and pNPP indicates that ATP has a protective effect only in the case of urea and DS-Na, but this effect is not exerted by pNPP (nonallosteric substrate). A conclusion is drawn that cooperative interactions of Na+, K+-ATPase from the brain with Na+ require more higher level of the oligomeric structure of enzyme than cooperative interactions with K+. At the same time these cooperative interactions in the both cases need subunits interactions in the protomer and interactions between cation sites with relatively high affinity.
Salum
T T
TT
Tsil'mer
M K
MK
Kullisaar
T E
TE
Vikhalemm
T E
TE
Tiakhepyld
L Ia
LIa
D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D007700:Kinetics; D046911:Macromolecular Substances; D011188:Potassium / Q000378:metabolism*; D011487:Protein Conformation; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D046911:Macromolecular Substances; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium
Osobennosti kooperativnogo sviazyvaniia Na+ i K+ s Na+,K+-ATPazoĭ mozga v zavisimosti ot ee oligomernoĭ struktury.