An ATPase from dog gastric mucosa: Changes of outer pH in suspensions of membrane vesicles accompanying ATP hydrolysis

Lee, Joon; Simpson, G. K.; Scholes, P.

doi:10.1016/0006-291x(74)90315-5

Cited by 160 publications

(52 citation statements)

References 13 publications

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“…However, in both types of vesicles, the proton gradient was partially dissipated by the addition of 1 ,M valinomycin and completely dissipated by the subsequent addition of 1 ,uM tetrachlorsalicylanilide as previously noted (12,23 Fig. 5.…”

Section: Resultssupporting

confidence: 80%

An acid transporting enzyme in human gastric mucosa.

Saccomani¹,

Chang²,

Mihas³

et al. 1979

J. Clin. Invest.

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Section: Resultssupporting

confidence: 80%

An acid transporting enzyme in human gastric mucosa.

Saccomani¹,

Chang²,

Mihas³

et al. 1979

J. Clin. Invest.

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“…It is tempting to speculate that epithelial H + transport occurs through a proton-translocating ATPase. Recently, it had been demonstrated that "HCOa-stimulated" ATPases are present in the gastric mucosa (14) and in luminal membranes of the renal tubule (20) and turtle bladder (4). The mitochondrial and bacterial "HCOa-stimulated" ATPase is the locus of H + transport (9,17,24,25).…”

Section: Discussionmentioning

confidence: 99%

Active H+ transport in the turtle urinary bladder. Coupling of transport to glucose oxidation.

Beauwens¹,

Al‐Awqati²

1976

The Journal of General Physiology

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The turtle urinary bladder acidifies the contents of its lumen by actively transporting protons. H + secretion by the isolated bladder was measured simultaneously with the rate of '4CO2 evolution from ['4C]glucose.The application of an adverse pH gradient resulted in a decline in the rate of H + secretion (Jn) and in the rate of glucose oxidation (J~o~). The changes in J. and J~o, were linear functions of the pH difference across the membrane. Hence, JN and J~o~ were linearly related to each other. The slope, OJn/OJ~o2 was found to be similar in half-bladders from the same animal but was seen to vary widely in a population of turtles.To investigate the effect of pH gradients on OJH/OJ~o,, two experiments were performed in each of 14 hemibladders. In one,JH andJ~o2 were altered by changing the luminal pH. In the other, they were altered by changing the ambient pCO2 while the luminal pH was kept constant. The average slope, oJa/OJ~o2, in the presence of pH gradients was 14.45 eq-tool -~. In the absence of gradients in the same hemibladders it was 14.72, A = 0.27 -+ 1.46.The results show that H + transport is organized in such a way that leaks to protons in parallel to the pump are negligible. Analysis of the transport system by use of the Essig-Caplan linear irreversible thermodynamic formalism shows that the system is tightly coupled. The degree of coupling, q, given by that analysis was measured and found to be at or very near the maximum theoretical value.

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“…-stimulated ATPase in frog gastric microsomes [22] and Peter Scholes working in Peter Mitchell's laboratory showed that dog microsomes alkalinized the medium in the presence of K ? in the medium upon addition of MgATP [23].…”

mentioning

confidence: 99%