CHARACTERIZATION OF LIVER-TYPE ALKALINE-PHOSPHATASE FROM HUMAN GASTRIC-CARCINOMA CELLS (KMK-2) INVITRO

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  • 1 January 1979
    • journal article
    • research article
    • Vol. 39  (11) , 4732-4738
Abstract
Alkaline phosphatase was extracted from human gastric carcinoma cells (KMK-2) under long-term culture and its biochemical and biological properties were investigated. The enzyme was extremely heat labile and was inhibited sinificantly by L-homoarginine, but only slightly by L-phenylalanine, so that it was classified as a liver-type alkaline phosphatase. Comparative studies with liver and early placental alkaline phosphatases revealed that the enzymes all showed a similar extent of inhibition by amino acids, heat stability, immunoloical character, MW and other biochemical properties. KMK-2 alkaline phosphatase was more similar to early placental enzyme in electrophoretic and gel filtration pattern. This liver-type alkaline phosphatase was found on microvilli of KMK-2 cells but not on the lateral surface with interdigitating folds. Prednisolone markedly decreased the content of the present isozyme. Although the present phenotype was stable during long-term culture in regard to the isozyme properties, the original cancer cells from which the cell line had been derived were L-phenylalanine sensitive and moderately L-homoarginine sensitive. Phenotypic change occurred on cultivation of cancer cells in vitro.