Linked Life Data

7756275

Source:http://linkedlifedata.com/resource/pubmed/id/7756275

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1995-6-29
pubmed:abstractText
Multienzyme complexes of fatty acid oxidation from Escherichia coli with either an alpha/Glu139-->Gln or an alpha/Arg134-->Gln mutation in the large alpha-subunit have been overproduced and characterized. The catalytic properties of the five different component enzymes of the alpha/Arg134-->Gln mutant complex showed no significant changes as compared with those of the wild type complex. In contrast, the 3-hydroxyacyl-coenzyme A (CoA) epimerase activity of the alpha/Glu139-->Gln mutant complex was not detected, and this mutant complex has lost almost all of the enoyl-CoA hydratase activity due to a greater than 3000-fold decrease in the kcat of the enoyl-CoA hydratase without a significant change in the Km value. The catalytic properties of 3-ketoacyl-CoA thiolase and L-3-hydroxyacyl-CoA dehydrogenase were virtually unaffected by the mutation. Together, these observations lead to the conclusion that the gamma-carboxylic group of Glu139 functions as a catalytic base in the dehydration of both D- and L-3-hydroxyacyl-CoA. These findings also support a dehydration/hydration mechanism for 3-hydroxyacyl-CoA epimerase but do not agree with an epimerase activity independent of enoyl-CoA hydratase as proposed for the glyoxysomal tetrafunctional protein [Preisig-Müller, R., Gühnemann-Schäfer, K., & Kindl, H. (1994) J. Biol. Chem. 269, 20475-20481]. Since this mutation caused the kcat of delta 3-cis-delta 2-trans-enoyl-CoA isomerase to decrease by only 60%, even though the Km value was significantly increased, it seems that Glu139 of the E. coli multifunctional protein does not function as a catalytic residue in the isomerization reaction.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6441-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:7756275-3-Hydroxyacyl CoA Dehydrogenases, pubmed-meshheading:7756275-Acetyl-CoA C-Acyltransferase, pubmed-meshheading:7756275-Acyl Coenzyme A, pubmed-meshheading:7756275-Amino Acid Sequence, pubmed-meshheading:7756275-Animals, pubmed-meshheading:7756275-Base Sequence, pubmed-meshheading:7756275-Binding Sites, pubmed-meshheading:7756275-Carbon-Carbon Double Bond Isomerases, pubmed-meshheading:7756275-Catalysis, pubmed-meshheading:7756275-DNA Primers, pubmed-meshheading:7756275-Enoyl-CoA Hydratase, pubmed-meshheading:7756275-Escherichia coli, pubmed-meshheading:7756275-Glutamates, pubmed-meshheading:7756275-Isomerases, pubmed-meshheading:7756275-Molecular Sequence Data, pubmed-meshheading:7756275-Racemases and Epimerases, pubmed-meshheading:7756275-Rats, pubmed-meshheading:7756275-Sequence Alignment, pubmed-meshheading:7756275-Sequence Homology, Amino Acid
pubmed:year
1995
pubmed:articleTitle
Glutamate 139 of the large alpha-subunit is the catalytic base in the dehydration of both D- and L-3-hydroxyacyl-coenzyme A but not in the isomerization of delta 3, delta 2-enoyl-coenzyme A catalyzed by the multienzyme complex of fatty acid oxidation from Escherichia coli.
pubmed:affiliation
Department of Pharmacology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island 10314, USA.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't