Linked Life Data

12681501

Source:http://linkedlifedata.com/resource/pubmed/id/12681501

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
2003-4-8
pubmed:abstractText
Although previous chemical modification studies have suggested several residues to be involved in the maintenance of the quaternary structure of glutamate dehydrogenase (GDH), there are conflicting views for the polymerization process and no clear evidence has been reported yet. In the present study, cassette mutagenesis at seven putative positions (Lys333, Lys337, Lys344, Lys346, Ser445, Gly446, and His454) was performed using a synthetic human GDH gene to examine the polymerization process. Of the mutations at the seven different sites, only the mutagenesis at His454 results in depolymerization of the hexameric GDH into active trimers as determined by HPLC gel filtration analysis and native gradient polyacrylamide gel electrophoresis. The mutagenesis at His454 has no effects on expression or stability of the protein. The K(M) values for NADH and 2-oxoglutarate were 1.5-fold and 2.5-fold greater, respectively, for the mutant GDH than for wild-type GDH, indicating that substitution at position 454 had appreciable effects on the affinity of the enzyme for both NADH and 2-oxoglutarate. The V(max) values were similar for wild-type and mutant GDH. The k(cat)/K(M) value of the mutant GDH was reduced up to 2.8-fold. The decreased efficiency of the mutant, therefore, results from the increase in K(M) values for NADH and 2-oxoglutarate. The results with cassette mutagenesis and HPLC gel filtration analysis suggest that His454 is involved in the polymerization process of human GDH.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-5793
pubmed:author
pubmed:copyrightInfo
Copyright 2003 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
540
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
163-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Histidine 454 plays an important role in polymerization of human glutamate dehydrogenase.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul, South Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't