Inhibitors | Comment | Organism | Structure |
---|---|---|---|
ATP | ATP concentrations over 5 mM induce H+/K+-ATPase activity inhibition, suggesting the existence of ATP-regulatory sites | Cavia porcellus | |
additional information | no inhibition by SCH-28080 and bafilomycin-A | Cavia porcellus | |
Ouabain | - |
Cavia porcellus | |
vanadate | - |
Cavia porcellus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | kinetics at different pH, overview | Cavia porcellus | |
0.0245 | - |
ATP | pH 7.4, temperature not specified in the publication, with optimal concentration of ATP, Mg2+ and K+ | Cavia porcellus | |
0.0494 | - |
ATP | pH 7.0, temperature not specified in the publication, with optimal concentration of ATP, Mg2+ and K+ | Cavia porcellus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
additional information | the H+/K+-ATPase and Na+/K+-ATPase, EC 3.6.3.9, are not located at the same sub-cellular fraction. The ouabain-insensitive K+-ATPase resembles better the distribution of the Na+/K+-ATPase, suggesting that can be associated with the colonocyte basolateral plasma membrane | Cavia porcellus | - |
- |
plasma membrane | apical not basolateral | Cavia porcellus | 5886 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Cs+ | activates | Cavia porcellus | |
K+ | activates, activation by K+ is independent of the accompanying anion, obtaining maximal activity at about 0.5 mM and pH 7.4, Km is 1.9 mM, not effective at pH 6.6 | Cavia porcellus | |
Mg2+ | dependent on, optimally at 5 mM, Km is 3.4 mM or 0.5 mM with optimal ATP concentration | Cavia porcellus | |
additional information | H+/K+-ATPase is Na+-independent, Mg2+-dependent, and activated by K+, Rb+, Cs+, and NH4 + but not by Na+, Li+, or N-methyl-glucamine | Cavia porcellus | |
NH4+ | activates | Cavia porcellus | |
Rb+ | activates | Cavia porcellus |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
100000 | - |
1 * 100000, alpha-subunit, + 1 * 500000, beta-subunit, alpha/beta, SDS-PAGE | Cavia porcellus |
500000 | - |
1 * 100000, alpha-subunit, + 1 * 500000, beta-subunit, alpha/beta, SDS-PAGE | Cavia porcellus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + H2O + H+/in + K+/out | Cavia porcellus | - |
ADP + phosphate + H+/out + K+/in | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Cavia porcellus | - |
male guinea pigs | - |
Posttranslational Modification | Comment | Organism |
---|---|---|
phosphoprotein | the enzyme is phosphorylated from [32P]-gamma-ATP, forming an acyl-phosphate bond, in an Mg2+-dependent, vanadate-sensitive process, and inhibited by hydroxylamine | Cavia porcellus |
Purification (Comment) | Organism |
---|---|
native ouabain-sensitive H+/K+-ATPase 106.5fold from isolated guinea-pig distal colon apical plasma membranes by solubilization with SDS, and discontinuous sucrose gradient centrifugation, separation from the ouabain-insensitive K+-ATPase | Cavia porcellus |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
colon | distal | Cavia porcellus | - |
colonocyte | - |
Cavia porcellus | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.07 | - |
native ouabain-insensitive H+/K+-ATPase from colonic apical plasma membranes, pH not specified in the publication, temperature not specified in the publication | Cavia porcellus |
0.544 | - |
native ouabain-sensitive H+/K+-ATPase from colonic apical plasma membranes, pH not specified in the publication, temperature not specified in the publication | Cavia porcellus |
2.045 | - |
purified native ouabain-sensitive H+/K+-ATPase, pH not specified in the publication, temperature not specified in the publication | Cavia porcellus |
Storage Stability | Organism |
---|---|
-70°C, purified enzyme, loss of over 90% activity without additive, 65% activity remaining with 25% added, over 95% remaining with addtion of 10% DMSO | Cavia porcellus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + H2O + H+/in + K+/out | - |
Cavia porcellus | ADP + phosphate + H+/out + K+/in | - |
? | |
ATP + H2O + H+/in + K+/out | a Na+-independent, ouabain-sensitive H+/K+-exchange. K+ can be replaced by H+ in the enzyme reaction cycle, however pH-induced conformational changes cannot be discarded | Cavia porcellus | ADP + phosphate + H+/out + K+/in | - |
? | |
CTP + H2O + H+/in + K+/out | a Na+-independent, ouabain-sensitive H+/K+-exchange, low activity with CTP | Cavia porcellus | CDP + phosphate + H+/out + K+/in | - |
? | |
GTP + H2O + H+/in + K+/out | a Na+-independent, ouabain-sensitive H+/K+-exchange, low activity with GTP | Cavia porcellus | GDP + phosphate + H+/out + K+/in | - |
? | |
ITP + H2O + H+/in + K+/out | a Na+-independent, ouabain-sensitive H+/K+-exchange, low activity with ITP | Cavia porcellus | IDP + phosphate + H+/out + K+/in | - |
? | |
additional information | the enzyme is phosphorylated from [32P]-gamma-ATP, forming an acyl-phosphate bond, in an Mg2+-dependent, vanadate-sensitive process | Cavia porcellus | ? | - |
? | |
UTP + H2O + H+/in + K+/out | a Na+-independent, ouabain-sensitive H+/K+-exchange, low activity with UTP | Cavia porcellus | UDP + phosphate + H+/out + K+/in | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | 1 * 100000, alpha-subunit, + 1 * 500000, beta-subunit, alpha/beta, SDS-PAGE | Cavia porcellus |
More | H+/K+-ATPase is an alpha/beta-heterodimer, whose subunits, identified by Tandem-mass spectrometry, seem to correspond to HKalpha2 and Na+/K+-ATPase beta1-subunit, respectively | Cavia porcellus |
Synonyms | Comment | Organism |
---|---|---|
H+/K+-ATPase | - |
Cavia porcellus |
ouabain-sensitive H+/K+-ATPase | - |
Cavia porcellus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
6.6 | 7.4 | the optimal pH for the ouabain-sensitive ATPase activity in the presence of K+ is pH 7.4, while the optimum pH for this activity, in the absence of K+, is pH 6.6 | Cavia porcellus |
IC50 Value | IC50 Value Maximum | Comment | Organism | Inhibitor | Structure |
---|---|---|---|---|---|
0.0016 | - |
pH 7.4, temperature not specified in the publication | Cavia porcellus | vanadate | |
0.0017 | - |
pH 7.4, temperature not specified in the publication | Cavia porcellus | Ouabain |
General Information | Comment | Organism |
---|---|---|
physiological function | distal colon absorbs K+ through a Na+-independent, ouabain-sensitive H+/K+-exchange, associated to an apical ouabain-sensitive H+/K+-ATPase | Cavia porcellus |