DIFFERENTIAL THEOPHYLLINE INHIBITION OF ALKALINE-PHOSPHATASE AND 5'-NUCLEOTIDASE OF BOVINE-MILK FAT GLOBULE MEMBRANES
DIFFERENTIAL THEOPHYLLINE INHIBITION OF ALKALINE-PHOSPHATASE AND 5'-NUCLEOTIDASE OF BOVINE-MILK FAT GLOBULE MEMBRANES
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DOI：
10.1016/0020-711x(91)90047-q
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发表时间：
1991-01-01
期刊：
影响因子：
--
通讯作者：
SNOW, LD
中科院分区：
文献类型：
--
作者：
DAI, XY;SNOW, LD
1. The effects of theophylline (1,3-dimethylxanthine) on alkaline phosphatase and 5'-nucleotidase activities of bovine milk fat globule membranes (MFGM) were examined.2. Theophylline inhibited MFGM alkaline phosphatase in a concentration-dependent manner with 50% inhibition produced by 99 +/- 28-mu-M theophylline.3. The 5'-nucleotidase activity was resistant to theophylline inhibition with 50% inhibition produced by 33.9 +/- 3.1 mM theophylline.4. Theophylline was an uncompetitive inhibitor of MFGM alkaline phosphatase with a K(i) of 126 +/- 15-mu-M.5. The extent of theophylline inhibition of alkaline phosphatase activity was independent of the substrate utilized in the assay.6. The effect of theophylline on bovine MFGM alkaline phosphatase was similar to theophylline effects on other mammalian alkaline phosphatases of liver/bone isoenzyme origin.
