An electrogenic proton pump associated with the Golgi apparatus of mouse liver driven by NADH and ATP.
Golgi-apparatus membranes, isolated from mouse liver, pump protons inwards, when supplied with NADH or ATP. The acidification of Golgi-apparatus cisternae and vesicles was detected with neutral red, a permeant dye, as a difference in absorbance at 550 nm minus that at 600 nm. The maximum rates detected with NADH and ATP were between 0.0006-0.0009 and 0.0030-0.0050 delta OD units/mg of protein/min, respectively, at pH 7.5. The outside buffer used was a bovine serum albumin suspension. The acidification of Golgi apparatus was inhibited from 45 to 100% by ionophores and from 22 to 100% by uncouplers. The results implicate both ATP and a redox system coupled to NADH oxidation in the acidification of Golgi-apparatus membranes.
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D005260:Female; D006056:Golgi Apparatus / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000648:ultrastructure*; D051379:Mice; D008985:Monensin / Q000494:pharmacology; D009243:NAD / Q000378:metabolism*; D009499:Neutral Red; D009534:Niclosamide / Q000031:analogs & derivatives / Q000494:pharmacology; D010084:Oxidation-Reduction; D013053:Spectrophotometry
D009243:NAD; C005159:5-chloro-3-tert-butyl-2'-chloro-4'-nitrosalicylanilide; D009499:Neutral Red; D009534:Niclosamide; D000255:Adenosine Triphosphate; D008985:Monensin