title: Unmasking of membrane enzyme activities and the problem of subcellular localization of adenylate cyclase in pig lymph node lymphocytes.
abstract: A large-scale purification of plasma membranes from pig lymph node lymphocytes is described. Centrifugation on a discontinuous sucrose density gradient was performed in a zonal rotor. Adenylate cyclase activity of untreated fractions displayed a profile different from that of plasma membrane enzymatic markers and was maximal at higher density. However, when latent adenylate cyclase was unmasked by Lubrol PX treatment, its maximum was shifted to lower density and was no longer significantly different from that of plasma membrane markers. These results are discussed in terms of cell surface topography.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002458:Cell Fractionation; D002462:Cell Membrane / Q000201:enzymology*; D002499:Centrifugation, Density Gradient; D008198:Lymph Nodes / Q000201:enzymology; D008214:Lymphocytes / Q000201:enzymology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D015105:3',5'-Cyclic-AMP Phosphodiesterases; D000262:Adenylyl Cyclases; D000254:Sodium-Potassium-Exchanging ATPase