Linked Life Data

8631327

Source:http://linkedlifedata.com/resource/pubmed/id/8631327

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1996-7-3
pubmed:abstractText
Fluorescence spectroscopy was used to examine the interaction between human estradiol 17 beta-dehydrogenase (estrogenic 17 beta-hydroxysteroid dehydrogenase, 17 beta-HSD) and the cofactor NADPH. After the binding of NADPH to the enzyme, there was an emission enhancement at 436 nm following an excitation at 295 nm, as compared to the cofactor alone. This phenomenon was attributed to a radiationless transfer of excitation energy from 17 beta-HSD to the enzyme-bound cofactor. The distance of 2.69 nm, between the bound NADPH and the sole tryptophan residue (Trp46) within one subunit, has been determined using fluorescence energy transfer. This result coincides very well with the same distance, recently calculated from the crystallographic coordinates obtained by Ghosh et al. [Ghosh, D., Pletnev, V. Z., Zhu, D.-W., Wawrzak, Z., Duax, W. L., Pangborn, W., Labrie, F. & Lin, S.-X. (1995) Structure 3, 503-513]. Compared to free NADPH, the fluorescence emission of enzyme-bound NADPH was increased in intensity and its maximum blue-shifted from 457 nm to 436 nm. Binding of NADPH to 17 beta-HSD was studied by fluorescence titration. The enzyme binds two molecules of NADPH with a Kd = 0.73 +/- 0.2 microM. The dissociation constant was further confirmed by the method of coenzyme protection against cold inactivation of the enzyme. The binding was little altered in the presence of estradiol-17 beta. The environment of tryptophan residues on the surface of the enzyme is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
235
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
180-6
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Fluorescence-energy transfer in human estradiol 17 beta-dehydrogenase-NADPH complex and studies on the coenzyme binding,.
pubmed:affiliation
The Medical Research Council Group in Molecular Endocrinology, CHUL Research Center, Laval University, Ste-Foy, Quebec, Canada.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't