PMID- 2469802
OWN - NLM
STAT- MEDLINE
DCOM- 19890612
LR  - 20190820
IS  - 0022-2631 (Print)
IS  - 0022-2631 (Linking)
VI  - 107
IP  - 3
DP  - 1989 Mar
TI  - Characterization of MgATP-driven H+ uptake into a microsomal vesicle fraction 
      from rat pancreatic acinar cells.
PG  - 263-75
AB  - 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 (Km 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+ accumulation was abolished by 
      protonophores, such as nigericin (10(-6) mol/liter) or CCCP (10(-5) mol/liter), 
      and by inhibitors of nonmitochondrial H+ ATPases, 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 x 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 dependent in the sequence Cl- 
      greater than Br- greater than gluconate-; in the presence of SO2-4, CH3COO- or 
      No-3, no H+ transport was observed. MgATP-dependent H+ accumulation was also 
      cation dependent in the sequence K+ greater than Li+ greater than 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 were further purified by Percoll gradient centrifugation (ninefold 
      enrichment compared to homogenate), no correlation with markers for endoplasmic 
      reticulum, mitochondria, plasma membranes, zymogen granules 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.
FAU - Thevenod, F
AU  - Thevenod F
AD  - Max-Planck-Institut fur Biophysik, Frankfurt/Main, Federal Republic of Germany.
FAU - Kemmer, T P
AU  - Kemmer TP
FAU - Christian, A L
AU  - Christian AL
FAU - Schulz, I
AU  - Schulz I
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Membr Biol
JT  - The Journal of membrane biology
JID - 0211301
RN  - 0 (Ion Channels)
RN  - 0 (Protons)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - F30N4O6XVV (Acridine Orange)
SB  - IM
MH  - Acridine Orange
MH  - Adenosine Triphosphate/*metabolism
MH  - Animals
MH  - Biological Transport, Active/drug effects
MH  - In Vitro Techniques
MH  - Ion Channels/metabolism
MH  - Male
MH  - Microsomes/metabolism
MH  - Pancreas/*metabolism
MH  - *Protons
MH  - Rats
MH  - Rats, Inbred Strains
EDAT- 1989/03/01 00:00
MHDA- 1989/03/01 00:01
CRDT- 1989/03/01 00:00
PHST- 1989/03/01 00:00 [pubmed]
PHST- 1989/03/01 00:01 [medline]
PHST- 1989/03/01 00:00 [entrez]
AID - 10.1007/BF01871941 [doi]
PST - ppublish
SO  - J Membr Biol. 1989 Mar;107(3):263-75. doi: 10.1007/BF01871941.