Characterization of MgATP-Driven H+ uptake in to a microsomal vesicle franction from rat pancreatic acinar cells
- 1 March 1989
- journal article
- research article
- Published by Springer Nature in The Journal of Membrane Biology
- Vol. 107 (3), 263-275
- https://doi.org/10.1007/bf01871941
Abstract
In microsomal vesicles, as isolated from exocrine pancreas cells, MgATP-driven H+ transport was evaluated by measuring H+-dependent accumulation of acridine orange (AO). Active H+ uptake showed an absolute requirement for ATP with simple Michaelis-Menten kinetics (K m for ATP 0.43 mmol/liter) with a Hill coefficient of 0.99. H+ transport was maximal at an external pH of 6.7, generating an intravesicular pH of 4.8. MgATP-dependent H+ accumulatioin was abolished by protonophores. such as nigericin (10−6 mol/liter) or CCCP (10−5 mol/liter), and by inhibitors of nonmitochondria H+ ATPase, such as NEM or NBD-Cl, at a concentration of 10−5 mol/liter. Inhibitors of both mitochondrial and nonmitochondrial H+ pumps, such as DCCD (10−5 mol/liter) or Dio 9 (0.25 mg/ml), reduced microsomal H+ transport by about 90%. Vanadate (2×10−3 mol/liter). a blocker of those ATPases, which form a phosphorylated intermediate, did not inhibit H+ transport. The stilbene derivative DIDS (10−4 mol/liter), which inhibits anion transport systems, abolished H+ transport completely. MgATP-dependent H+ transport was found to be anion dependernt in the sequence Cl−>Br−>gluconate−; in the presence of SO 4 −2 . CH3COO− or No 3 − , no H+ transport was observed. MgATP-dependent H+ accumulation was also cation dependent in the sequence K+>Li+>Na+=choline+, As shown by dissipation experiments in the presence of different ion gradients and ionophores, both a Cl− and a K+ conductance, as well as a small H+ conductance. were found in the microsomal membranes. When membranes containing the H+ pump wer further purified by Percoll gradient centrifugatin (ninefold enrichment comparad to homogenate), no correlation with markers for endoplasmic reticulum., mitochondria, plasma membranes, zymogen graules or Golgi membranes was found. The present data indicate that the H+ pump located in microsomes from rat exocrine pancreas is a vacuolar-or “V”-type H+ ATPase and has most similarities to that described in endoplasmic reticulum. Golgi apparatus or endosomes.This publication has 54 references indexed in Scilit:
- Anion channels in giant liposomes made of endoplasmic reticulum vesicles from rat exocrine pancreasThe Journal of Membrane Biology, 1988
- H+-ATPases from mitochondria, plasma membranes, and vacuoles of fungal cellsThe Journal of Membrane Biology, 1986
- Voltage-dependent chloride conductance of the squid axon membrane and its blockade by some disulfonic stilbene derivatives.The Journal of general physiology, 1985
- The effect of N,N′-dicyclohexylcarbodiimide on enzymes of bioenergetic relevanceBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1984
- Effect of inositol-1,4,5-trisphosphate on isolated subcellular fractions of rat pancreasThe Journal of Membrane Biology, 1984
- Characterization of calcium uptake into rough endoplamic reticulum of rat pancreasThe Journal of Membrane Biology, 1984
- Proton/hydroxyl transport in gastric and intestinal epitheliaThe Journal of Membrane Biology, 1982
- The proton-translocating ATPase of the fungal plasma membraneBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1981
- The anion transport system of the red blood cell The role of membrane protein evaluated by the use of ‘probes’Biochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, 1978
- Membrane proteins related to anion permeability of human red blood cellsThe Journal of Membrane Biology, 1974