Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2011-2-23
pubmed:abstractText
Enzyme I(Ntr) is the first protein in the nitrogen phosphotransferase pathway. Using an array of biochemical and biophysical tools, we characterized the protein, compared its properties to that of EI of the carbohydrate PTS and, in addition, examined the effect of substitution of all nonexchangeable protons by deuterium (perdeuteration) on the properties of EI(Ntr). Notably, we find that the catalytic function (autophosphorylation and phosphotransfer to NPr) remains unperturbed while its stability is modulated by deuteration. In particular, the deuterated form exhibits a reduction of approximately 4°C in thermal stability, enhanced oligomerization propensity, as well as increased sensitivity to proteolysis in vitro. We investigated tertiary, secondary, and local structural changes, both in the absence and presence of PEP, using near- and far-UV circular dichroism and Trp fluorescence spectroscopy. Our data demonstrate that the aromatic residues are particularly sensitive probes for detecting effects of deuteration with an enhanced quantum yield upon PEP binding and apparent decreases in tertiary contacts for Tyr and Trp side chains. Trp mutagenesis studies showed that the region around Trp522 responds to binding of both PEP and NPr. The significance of these results in the context of structural analysis of EI(Ntr) are evaluated.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1096-0384
pubmed:author
pubmed:copyrightInfo
Published by Elsevier Inc.
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
507
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
332-42
pubmed:meshHeading
pubmed-meshheading:21185804-Amino Acid Sequence, pubmed-meshheading:21185804-Arginase, pubmed-meshheading:21185804-Carrier Proteins, pubmed-meshheading:21185804-Deuterium, pubmed-meshheading:21185804-Enzyme Stability, pubmed-meshheading:21185804-Escherichia coli, pubmed-meshheading:21185804-Escherichia coli Proteins, pubmed-meshheading:21185804-Humans, pubmed-meshheading:21185804-Ligands, pubmed-meshheading:21185804-Molecular Sequence Data, pubmed-meshheading:21185804-Phosphoenolpyruvate Sugar Phosphotransferase System, pubmed-meshheading:21185804-Phosphorylation, pubmed-meshheading:21185804-Phosphotransferases (Nitrogenous Group Acceptor), pubmed-meshheading:21185804-Protein Conformation, pubmed-meshheading:21185804-Protein Multimerization, pubmed-meshheading:21185804-Protein Unfolding, pubmed-meshheading:21185804-Temperature, pubmed-meshheading:21185804-alpha-Synuclein
pubmed:year
2011
pubmed:articleTitle
Deuteration of Escherichia coli enzyme I(Ntr) alters its stability.
pubmed:affiliation
The National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA.
pubmed:publicationType
Journal Article