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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
2001-5-29
pubmed:abstractText
Dehydroepiandrosterone sulfate is the most abundant sulfated steroid transformed in human tissues and serves as a precursor for steroid hormones. Recombinant human dehydroepiandrosterone sulfotransferase (DHEA-ST) expressed in glutathione sulfotransferase fusion form in E. coli was purified using glutathione sepharose 4B affinity adsorption chromatography, a Factor Xa cleavage step, and Q-sepharose fast flow column chromatography. The homogeneous preparation had an activity toward dehydroepiandrosterone (DHEA) of 150+/-40 nmol/min per mg of protein under the assay conditions at an overall yield of 38.4%. The recombinant human DHEA-ST was shown to have a subunit mass of 34 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis, while having a molecular mass of 67.2 kDa by Superose-12 gel filtration. Our results indicate that the active recombinant enzyme expressed in E. coli is a homodimer.Biochemical properties for purified DHEA-ST were studied using DHEA as a substrate. The optimum pH ranged from pH 7 to 8, and the optimum temperature 40-45 degrees C. Ninety percent of basal DHEA-ST activity remained even after the enzyme was treated at 45 degrees C for 15 min. The 50% inactivation concentration of NaCl for DHEA-ST activity was determined to be around 500 mM. The K(m) value for DHEA was 1.9+/-0.3 microM and V(max)=190+/-18 nmol/min per mg of protein at 37 degrees C, pH 7.5.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0960-0760
pubmed:author
pubmed:issnType
Print
pubmed:volume
77
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
159-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Human dehydroepiandrosterone sulfotransferase: purification and characterization of a recombinant protein.
pubmed:affiliation
MRC Group in Oncology and Molecular Endocrinology Laboratory, CHUL Research Center and Laval University, 2705 Laurier Boulevard, Sainte-Foy, Quebec, Canada G1V 4G2.
pubmed:publicationType
Journal Article