Linked Life Data

14570759

Source:http://linkedlifedata.com/resource/pubmed/id/14570759

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2003-10-22
pubmed:abstractText
Sulfation is an important reaction in the biotransformation of steroid hormones, neurotransmitters, drugs, and other xenobiotics, yet little is known about the effects of organic solvents on sulfotransferase (SULT) activities in vitro. Initial experiments found that surprisingly low levels of solvent had dramatic effects on sulfotransferase activity. Consequently, we evaluated the effects of five commonly used solvents (methanol, ethanol, acetonitrile, dimethyl sulfoxide, and dimethyl formamide) on activities of cDNA-expressed sulfotransferase isozymes 1A1 (4-nitrophenol sulfation), 1A3 (dopamine sulfation), 1E1 (ethynylestradiol sulfation), and 2A1 (dehydroepiandrosterone sulfation). In addition, 1-hydroxypyrene was used as a general fluorescent probe for all four sulfotransferase isoforms examined. When substrates were present at their respective isoform-specific Km values, methanol and ethanol (0.4%, v/v) generally had less effect than acetonitrile, dimethyl sulfoxide, and dimethyl formamide on sulfotransferase activities. Acetonitrile, a commonly used solvent in cytochrome P450 studies, inhibited SULT1A1 activities (approximately 40%) at 0.4% (v/v), but activated SULT1E1-mediated 1-hydroxypyrene sulfation approximately 2.6-fold. Assuming a two-site kinetic model, studies revealed that solvent affected Vmax1, Vmax2, and the Ki value of 1-hydroxypyrene sulfation mediated by SULT1E1. In contrast, the Km value was not affected, suggesting that solvent may potentially alter binding interactions of the second substrate molecule, but not the first. Additional experiments with expressed SULT1A1, supplemented with control protein, revealed that the inhibitory effect of solvent (0.4%, v/v) was reduced to <15% for all solvents examined. Thus, it is recommended that ethanol is used as the preferred solvent vehicle and that incubations with expressed enzyme contain >12 microg/ml total protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0090-9556
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1300-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Solvent effect on cDNA-expressed human sulfotransferase (SULT) activities in vitro.
pubmed:affiliation
Department of Drug Metabolism, WP 75A-203, Merck Research Laboratories, West Point, PA 19486, USA.
pubmed:publicationType
Journal Article, Comparative Study