Linked Life Data

12429500

Source:http://linkedlifedata.com/resource/pubmed/id/12429500

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-11-13
pubmed:abstractText
17beta-Hydroxysteroid dehydrogenase type 3 (17beta-HSD-3) is a member of the short-chain dehydrogenase/reductase (SDR) family and is essential for the reductive conversion of inactive C(19)-steroid, androstenedione, to the biologically active androgen, testosterone, which plays a central role in the development of the male phenotype. Mutations that inactivate this enzyme give rise to a rare form of male pseudohermaphroditism, referred to as 17beta-HSD-3 deficiency. One such mutation is the replacement of arginine at position 80 with glutamine, compromising enzyme activity by increasing the cofactor binding constant 60-fold. In the absence of a 17beta-HSD-3 crystal structure, we have grafted its amino acid sequence for the NADPH binding site on the X-ray crystal structures of glutathione reductase (Protein Data Bank code 1gra) and 17beta-HSD type 1 (Protein Data Bank codes 1fdv and 1fdu) where we find the trunk of the arginine 80 side chain forms part of the hydrophobic pocket for the purine ring of adenosine while its guanidinium moiety interacts with the 2'-phosphate to both stabilize cofactor binding and neutralize its intrinsic negative charge through two hydrogen bonds. To qualitatively assess the role arginine 80 plays in both selecting and stabilizing NADPH binding, it was replaced with each amino acid and the mutant enzymes subjected to enzymatic analysis. There are only seven enzymes exhibiting any measurable enzymatic activity with arginine approximately lysine>leucine>glutamine>methionine>tyrosine>isoleucine. With an aspartic acid at position 58 in 17beta-HSD-3 occupying the equivalent space in the cofactor binding pocket as arginine 224 in glutathione reductase or serine 12 in 17beta-HSD-1, there was an expectation that some of the mutants might use NADH as a cofactor. In no case was NADH found to substitute for NADPH.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
1601
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29-37
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Amino acid substitution of arginine 80 in 17beta-hydroxysteroid dehydrogenase type 3 and its effect on NADPH cofactor binding and oxidation/reduction kinetics.
pubmed:affiliation
Merck Research Laboratories, Merck & Co., Inc., RY50-105, 126 East Lincoln Avenue, Rahway, NJ 07065, USA. brian_mckeever@merck.com
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.