title: Alkaline phosphodiesterase I and alkaline phosphatase I in plasma membranes of herpes simplex virus type 1 transformed hamster cells.
abstract: Plasma membrane extracts from Herpes simplex virus type 1 transformed hamster embryo fibroblasts were chromatographed on Lens culinaris lectin coupled to Sepharose (LcH-Sepharose) and analysed by dodecyl sulphate polyacrylamide gel electrophoresis. Coomassie blue-staining revealed two major protein bands with apparent molecular weights of 125 000 and of about 75 000-90 000. In plasma membranes isolated from these tumor cells prior labeled with [3H]fucose or [3H]glucosamine these bands contained the highest amounts of incorporated radioactivity. Separation by LcH-Sepharose-affinity chromatography as well as metabolic labeling clearly demonstrates their glycoprotein character. The 125 000 protein coincides with alkaline phosphodiesterase I activity with a Km of 6 . 10(-4) M for TMP p-nitrophenyl ester and is competitively inhibited by UDP-N-acetylglucosamine. This enzymatic activity is also present in normal hamster embryo fibroblasts. Gel electrophoresis of the Lens culinaris lectin-binding glycoproteins from plasma membranes of normal hamster embryo fibroblasts additionally revealed a strong alkaline phosphatase activity represented by an apparent molecular weight of 150 000, while HSV1 hamster tumor cells contain only a very weak activity of this enzyme activity. HSV-lytically infected cells, however, have unchanged levels of alkaline phosphatase activity, whereas alkaline phosphodiesterase activity increases slightly.
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics*; D000818:Animals; D002051:Burkitt Lymphoma; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology*; D002471:Cell Transformation, Neoplastic; D002522:Chlorocebus aethiops; D006224:Cricetinae; D004622:Embryo, Mammalian; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D007668:Kidney; D043264:Phosphodiesterase I; D010727:Phosphoric Diester Hydrolases / Q000235:genetics*; D018139:Simplexvirus / Q000201:enzymology / Q000235:genetics*
chemical_list: D007527:Isoenzymes; D000469:Alkaline Phosphatase; D010727:Phosphoric Diester Hydrolases; D043264:Phosphodiesterase I