Occurrence and characteristics of /sup 18/O exchange reactions catalyzed by sodium- and potassium-dependent adenosine triphosphates

Journal Article · Thu May 10 00:00:00 EDT 1973 · J. Biol. Chem.; (United States)

OSTI ID:7339239

Dahms, A S; Boyer, P D

Microsomal preparations of the Na/sup +/, K/sup +/-ATPase from the porcine kidney outer medulla and the Electrophorus electroplax catalyzed a rapid Mg/sup 2 +/- and K/sup +/-dependent exchange of water oxygens with inorganic phosphate in the absence of ATP or ADP. Exchange activity was unaffected by uncouplers and inhibitors of oxidative phosphorylation but was inhibited by Na/sup +/, ouabain, N,N'-dicyclohexylcarbodiimide, or p-mercuribenzoate. No nucleotide requirement for the exchange could be demonstrated. Addition of ATP to a Na/sup +/-inhibited system resulted in an exchange of oxygens of medium P/sub i/ concomitant with ATP hydrolysis. This ATP-induced exchange amounted to 1.5 oxygen atoms per P/sub i/ released. Neither ADP nor adenyly methylenediphosphonate would serve to activate the exchange. Treatment of the preparations with deoxycholate apparently uncoupled the medium P/sub i/ reversible HOH exchange but was without affect on the ATP-induced exchange. The data suggest that the exchange arises by dynamic reversal of a late step in ATP hydrolysis by the Na/sup +/, K/sup +/-ATPase. (auth)

• OSTI ID: 7339239
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 248:9; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ANIMALS
ANIONS
ATP
ATP-ASE
BODY
CARBOHYDRATES
CARDIOTONICS
CELL CONSTITUENTS
CHARGED PARTICLES
CHEMICAL REACTIONS
DECOMPOSITION
DOMESTIC ANIMALS
DRUGS
ELEMENTS
ENZYMES
ESTERASES
EVEN-EVEN NUCLEI
GLYCOSIDES
HYDROLASES
HYDROLYSIS
IMIDES
IONS
ISOTOPES
ISOTOPIC EXCHANGE
KIDNEYS
LIGHT NUCLEI
LYSIS
MAMMALS
MICROSOMES
NONMETALS
NUCLEI
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
ORGANS
OUABAIN
OXYGEN 18
OXYGEN ISOTOPES
PHOSPHATASES
PHOSPHORUS
SODIUM COMPOUNDS
SOLVOLYSIS
STABLE ISOTOPES
STEROIDS
STROPHANTIN
SWINE
VERTEBRATES