Regulation of arylsulfate sulfotransferase from a human intestinal bacterium by nucleotides and magnesium ion.
Arylsulfate sulfotransferase (ASST) from a human intestinal bacterium stoichiometrically catalyzed the transfer of a sulfate group from phenylsulfate esters to phenolic compounds. Pentachlorophenol, one of the selective inhibitors of phenol sulfoconjugation in mammalian tissues, inhibited both phenol and tyramine sulfation by ASST. Nucleotide triphosphates such as ATP, GTP, UTP and CTP, and pyrophosphate inhibited the ASST activity, whereas Mg2+ and Mn2+ activated the enzyme and prevented its inhibition by ATP and pyrophosphate. Equimolar binding of [alpha-] and [gamma-32P]ATP to the enzyme showed that the enzyme protein was not phosphorylated, but bound ATP. These results suggest that nucleotide triphosphates and divalent cations are important modulators in the control of ASST activity.
Konishi-Imamura
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Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.
Kim
D H
DH
Koizumi
M
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Kobashi
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K
D000255:Adenosine Triphosphate / Q000378:metabolism; D015239:Arylsulfotransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002413:Cations, Divalent / Q000494:pharmacology; D011756:Diphosphates / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005051:Eubacterium / Q000201:enzymology*; D006801:Humans; D007422:Intestines / Q000382:microbiology; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology*; D009578:Nitrobenzenes / Q000378:metabolism; D009711:Nucleotides / Q000494:pharmacology*; D010416:Pentachlorophenol / Q000494:pharmacology; D011485:Protein Binding; D014439:Tyramine / Q000378:metabolism
D002413:Cations, Divalent; D011756:Diphosphates; D009578:Nitrobenzenes; D009711:Nucleotides; C023379:4-nitrophenyl sulfate; D000255:Adenosine Triphosphate; D010416:Pentachlorophenol; D015239:Arylsulfotransferase; D008274:Magnesium; D014439:Tyramine