Linked Life Data

8461298

Source:http://linkedlifedata.com/resource/pubmed/id/8461298

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1993-5-5
pubmed:abstractText
Amino acid sequence comparisons reveal that tyrosine-152 and lysine-156 of Drosophila alcohol dehydrogenase (ADH) are conserved in homologous dehydrogenases, suggesting that these residues are important in catalysis. To test this hypothesis, we used site-directed mutagenesis to substitute tyrosine-152 with phenylalanine, histidine, or glutamic acid or to substitute lysine-156 with isoleucine. All of these mutants are catalytically inactive. Two mutants were active: A cysteine mutation of tyrosine-152 has 0.25% of wild-type ADH activity, while an arginine substitution of lysine-156 retains 2.2% of wild-type ADH activity. Kinetic analysis shows that the cysteine mutant increases Km(ethanol) 56-fold and Km(propan-2-ol) 100-fold, while Km(NAD) values are essentially unaltered. The arginine mutant also shows the significant enlargement of Km(ethanol), but not of Km(NAD). Furthermore, the cysteine mutant and arginine mutant have different substrate specificity and behave differently on competitive inhibition than wild-type ADH. These results suggest that both tyrosine-152 and lysine-156 have essential roles in catalysis by Drosophila ADH.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
32
pubmed:geneSymbol
nodG
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3342-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Site-specific mutagenesis of Drosophila alcohol dehydrogenase: evidence for involvement of tyrosine-152 and lysine-156 in catalysis.
pubmed:affiliation
Department of Biochemistry, Louisiana State University, Baton Rouge 70803.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.