title: Isolation of pepsinogen granules from rabbit gastric mucosa.
abstract: Pepsinogen granules were isolated from rabbit stomachs by a combination of differential and isopycnic gradient centrifugation. The isolation procedure utilized 1 M sucrose and alkaline pH to stabilize the granules. The isolated granules were shown to be 8.4-fold enriched in pepsinogen and free of mitochondria and microsome enzyme markers. In addition to pepsinogen, a cation-insensitive but anion-sensitive Mg2+-ATPase co-purified with the zymogen. The enzyme was unaffected by aurovertin, oligomycin, and ouabain, but inhibited by high concentrations of vanadate, N,N'-dicyclohexylcarbodiimide, and azide. The enzyme activity was stimulated by tetrachlorosalicylanilide and the combination of valinomycin and nigericin in K+-containing media. The similarities between this enzyme and other secretory granule ATPases are discussed.
mesh_terms: D000251:Adenosine Triphosphatases / Q000302:isolation & purification / Q000378:metabolism; D000818:Animals; D002413:Cations, Divalent; D002458:Cell Fractionation; D003594:Cytoplasmic Granules / Q000201:enzymology* / Q000648:ultrastructure; D005753:Gastric Mucosa / Q000201:enzymology*; D007425:Intracellular Membranes / Q000201:enzymology / Q000648:ultrastructure; D008854:Microscopy, Electron; D010435:Pepsinogens / Q000378:metabolism*; D011817:Rabbits; D013379:Substrate Specificity; D014461:Ultracentrifugation / Q000379:methods
chemical_list: D002413:Cations, Divalent; D010435:Pepsinogens; D000251:Adenosine Triphosphatases