Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1999-10-19
pubmed:abstractText
At pH 2.0, acid-denatured CspA undergoes a slow self-assembly process, which results in the formation of insoluble fibrils. 1H-15N HSQC, 3D HSQC-NOESY, and 15N T2 NMR experiments have been used to characterize the soluble components of this reaction. The kinetics of self-assembly show a lag phase followed by an exponential increase in polymerization. A single set of 1H-15N HSQC cross-peaks, corresponding to acid-denatured monomers, is observed during the entire course of the reaction. Under lag phase conditions, 15N resonances of residues that constitute the beta-strands of native CspA are selectively broadened with increasing protein concentration. The dependence of 15N T2 values on spin echo period duration demonstrates that line broadening is due to fast NMR exchange between acid-denatured monomers and soluble aggregates. Exchange contributions to T2 relaxation correlate with the squares of the chemical shift differences between native and acid-denatured CspA, and point to a stabilization of native-like structure upon aggregation. Time-dependent changes in 15N T2 relaxation accompanying the exponential phase of polymerization suggest that the first three beta-strands may be predominantly responsible for association interfaces that promote aggregate growth. CspA serves as a useful model system for exploring the conformational determinants of denatured protein misassembly.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
291
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1191-206
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
An NMR investigation of solution aggregation reactions preceding the misassembly of acid-denatured cold shock protein A into fibrils.
pubmed:affiliation
Department of Structural Biology, University of Basel, Switzerland. alexandrescu@ubaclu.unibas.ch
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't