Linked Life Data

11790101

Source:http://linkedlifedata.com/resource/pubmed/id/11790101

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2002-1-15
pubmed:abstractText
Site-directed spin-labeling of proteins whereby the spin-label methyl 3-(2,2,5,5-tetramethyl-1-oxypyrrolinyl)methanethiolsulfonate (SLMTS) is reacted with the -SH groups of cysteinyl residues incorporated into a protein by mutagenesis has been successfully applied to investigate secondary structure and conformational transitions of proteins. In these studies, it is expected that the spin-label moiety adopts different conformations dependent on its local environment. To determine the conformation of SLMTS in solution reacted with L-cysteine (SLMTCys) and bound in the active site of the Glu240Cys mutant of TEM-1 beta-lactamase, we have synthesized SLMTS both of natural abundance isotope composition and in site-specifically deuterated forms for electron nuclear double resonance (ENDOR) studies. ENDOR-determined electron-proton distances from the unpaired electron of the nitroxyl group of the spin-label to the methylene and methyl protons of SLMTS showed three conformations of the oxypyrrolinyl ring with respect to rotation around the S-S bond dependent on the solvent dielectric constant. For SLMTCys, two conformations of the molecule were compatible with the ENDOR-determined electron-nucleus distances to the side-chain methylene protons and to H(alpha) and H(beta1,2) of cysteine. To determine SLMTS conformation reacted with the Glu240Cys mutant of TEM-1 beta-lactamase, enzyme was overexpressed in both ordinary and perdeuterated minimal medium. Resonance features of H(alpha) and H(beta1,2) of the Cys240 residue of the mutant and of the side-chain methylene protons within the spin-label moiety yielded electron-proton distances that sterically accommodated the two conformations of free SLMTCys in solution.
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
22
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
797-808
pubmed:dateRevised
2008-8-22
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Structure of spin-labeled methylmethanethiolsulfonate in solution and bound to TEM-1 beta-lactamase determined by electron nuclear double resonance spectroscopy.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, The University of Chicago, Cummings Life Science Center, 920 East 58th Street, Chicago, Illinois 60637, USA. dmustafi@midway.uchicago.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.