These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Purification and properties of 5-hydroxytryptamine UDP-glucuronyltransferase from rat liver microsomes.
    Author: Abe N, Abe E, Yuasa A.
    Journal: J Biochem; 1988 Sep; 104(3):421-6. PubMed ID: 3149276.
    Abstract:
    5-Hydroxytryptamine UDP-glucuronyltransferase was highly purified from untreated rat liver microsomes. The specific activity towards 5-hydroxytryptamine was increased 178-fold over the starting solubilized microsomes with a final yield of 3%. The final preparation contained two major and one minor Coomassie brilliant blue staining polypeptide bands visible after SDS-polyacrylamide gel electrophoresis. One of the major bands was identified as 3-methylcholanthrene-inducible UDP-glucuronyltransferase, so the other (molecular weight of 55,500) appeared to be 5-hydroxytryptamine UDP-glucuronyltransferase. Concanavalin A reacted with the 55,500-dalton polypeptide. Phospholipid was indispensable for the enzyme activity. The enzyme activity in the final preparation was activated by divalent cations. Simple Michaelis-Menten kinetics were followed with respect to 5-hydroxytryptamine, but deviations from this kinetics were observed with respect to UDP-glucuronic acid and Mg2+. As regards Mg2+ stimulation, further experiments indicated that the added Mg2+ was non-competitive with 5-hydroxytryptamine, but at low concentrations of Mg2+ it was competitive with UDP-glucuronic acid and at high concentrations of Mg2+ it was non-competitive with UDP-glucuronic acid. The final preparation showed high substrate specificity towards 5-hydroxytryptamine among endogenous substrates tested. From these results, it was concluded that the enzyme described here is a new form of UDP-glucuronyltransferase isozyme, and its activity showed a peculiar dependence on Mg2+.
    [Abstract] [Full Text] [Related] [New Search]