Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2002-3-26
pubmed:abstractText
Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is an inborn error of ketone body and isoleucine metabolism. We identified and characterized 6 mutations, DelE85, K124R, A127V, Q145E, G152A, and E345V in 5 Spanish T2-deficient patients. Transient expression of mutant cDNAs was done at 37 and at 30 degrees C. Expression of the Q145E mutant cDNA resulted in about 12.5% normal amount at 37 degrees C and it retained 15% residual T2, indicating that specific activity of Q145E mutant protein was almost normal. This mutation reduced the heat stability of T2 activity. Although no significant residual activity was detected in either the G152A and A127V substitution, mutant proteins were detected, at 12.5% the normal amount at 37 degrees C and one-half normal at 30 degrees C for A127V, and 25 % only at 30 degrees C for G152A. Mutant proteins with Q145E, G152A, or A127V accumulated at 30 degrees C expression were stable for 48 h at 37 degrees C after cycloheximide treatment. Expression of DelE85, K124R, and E345V cDNAs gave neither residual T2 protein nor T2 activity. We constructed an improved tertiary structural model of T2 based on the X-ray crystal structure of acetoacetyl-CoA thiolase of Zoogloea ramigera. On the basis of this model, K124, A127, and G152 are located near the active site, mutations of which might affect catalytic function whereas Q145E, De185E, and E345V are distant from the active site with mutants being expected to destabilize the tertiary structure, especially during protein folding and dimerization.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1096-7192
pubmed:author
pubmed:issnType
Print
pubmed:volume
75
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
235-43
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11914035-Acetyl-CoA C-Acyltransferase, pubmed-meshheading:11914035-Amino Acid Sequence, pubmed-meshheading:11914035-Amino Acid Substitution, pubmed-meshheading:11914035-DNA, pubmed-meshheading:11914035-DNA, Complementary, pubmed-meshheading:11914035-DNA Mutational Analysis, pubmed-meshheading:11914035-Enzyme Stability, pubmed-meshheading:11914035-Female, pubmed-meshheading:11914035-Humans, pubmed-meshheading:11914035-Immunoblotting, pubmed-meshheading:11914035-Infant, pubmed-meshheading:11914035-Metabolism, Inborn Errors, pubmed-meshheading:11914035-Mitochondria, pubmed-meshheading:11914035-Models, Molecular, pubmed-meshheading:11914035-Molecular Sequence Data, pubmed-meshheading:11914035-Mutation, pubmed-meshheading:11914035-Protein Structure, Tertiary, pubmed-meshheading:11914035-Sequence Homology, Amino Acid
pubmed:year
2002
pubmed:articleTitle
Characterization of six mutations in five Spanish patients with mitochondrial acetoacetyl-CoA thiolase deficiency: effects of amino acid substitutions on tertiary structure.
pubmed:affiliation
Department of Pediatrics, Gifu University School of Medicine, Gifu, Gifu 500-8076, Japan. toshi-gif@umin.ac.jp
pubmed:publicationType
Journal Article, Case Reports, Research Support, Non-U.S. Gov't