Linked Life Data

3548821

Source:http://linkedlifedata.com/resource/pubmed/id/3548821

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1987-5-20
pubmed:abstractText
In this study we demonstrate the potential of combining fluorine-19 nuclear magnetic resonance (NMR) spectroscopy with molecular genetics. We are using the membrane-bound enzyme D-lactate dehydrogenase of Escherichia coli as a model system to characterize interactions between proteins and lipids. We have labeled D-lactate dehydrogenase with 4-, 5-, and 6-fluorotryptophans and obtained high-resolution fluorine-19 NMR spectra showing five resonances, in agreement with the five tryptophan residues expected from the DNA sequence. The five 19F resonances in the spectra have been assigned to the specific tryptophan residues in the primary sequence of D-lactate dehydrogenase by site-directed oligonucleotide mutagenesis of the cloned gene. We observe large differences in the relative fluorine-19 chemical shifts of each tryptophan residue when labeled by different isomers of fluorotryptophan. We have determined by NMR methods that two tryptophans are exposed to the solvent and that none of the tryptophan residues are within 10 A of the lipid phase. On the basis of 19F NMR spectroscopy of the labeled tryptophan residues, the conformation of D-lactate dehydrogenase is similar in aqueous solution and in the presence of a variety of lipids and detergents. This result indicates that the presence of lipids or detergents is not required to maintain the tertiary structure of this membrane-bound enzyme. In contrast, Triton X-100 induces a change to an abnormal conformation of the enzyme as judged from both NMR spectroscopy and the effect of temperature on the maximal velocity of the enzyme in the presence of this detergent.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
549-56
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Nuclear magnetic resonance and molecular genetic studies of the membrane-bound D-lactate dehydrogenase of Escherichia coli.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.