Chelation of mercury by ouabain-sensitive and ouabain-resistant renal Na,K-ATPase.
The SH-reactive HgCl2 inhibits the Na,K-ATPase activity potently in a manner antagonized only partially by EDTA or cysteine; solely dimercaprol, a dithiol antidote for mercury, blocks the HgCl2 effects entirely as confirmed also by 203Hg-binding experiments. The results reveal the presence of a chelating component in pure Na,K-ATPase with an affinity for mercury superior to EDTA. The mercury-sensitivity of the Na,K-ATPase is not related to the ouabain-sensitivity. This criterion will be useful for the distinction between ouabain-like and mercury-like inhibitors from body fluids and tissues.
Anner
B M
BM
Department of Pharmacology, Geneva University Medical Center, Switzerland.
Moosmayer
M
M
Imesch
E
E
D000818:Animals; D003545:Cysteine / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D007679:Kidney Medulla / Q000201:enzymology*; D007700:Kinetics; D008627:Mercuric Chloride / Q000378:metabolism* / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology*; D011485:Protein Binding; D011817:Rabbits; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000302:isolation & purification
D008627:Mercuric Chloride; D010042:Ouabain; D004492:Edetic Acid; D000254:Sodium-Potassium-Exchanging ATPase; D003545:Cysteine