Transport characteristics of frog gastric membranes.
ATP-induced transport by fractions of frog gastric microsomes prepared either by density gradient centrifugation of by free flow electrophoresis were K+ dependent and hence considered due to a K+-activated ATPase. Significant activity of this enzyme was, however, only found in the anodic peak of the free flow electrophoretic separation, which in addition to separating transporting from non-transporting particles, also separated membranes containing a phosphorylatable peptide (Mr=105 000) region as the major peptide on SDS-polyacrylamide gel electrophoresis from those containing a peptide (Mr=44 000) on SDS-polyacrylamide gel electrophoresis. H+ uptake, measured either by acridine orange or 3,3'-diethyloxadicarbocyanine + tetrachlorosalicylanilide absorbance changes was dependent on K+ intravesicularly. Using 86Rb+, active extrusion of the cation followed ATP addition. SCN-, an inhibitor of acid secretion did not affect the latter, but blocked signals due to H+ uptake, in contrast to mammalian preparations.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001001:Anura; D002458:Cell Fractionation; D004586:Electrophoresis; D005753:Gastric Mucosa / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism*; D007700:Kinetics; D008861:Microsomes / Q000378:metabolism* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D011892:Rana catesbeiana
D000251:Adenosine Triphosphatases