Linked Life Data

15184026

Source:http://linkedlifedata.com/resource/pubmed/id/15184026

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-6-8
pubmed:abstractText
We investigate the refolding of ubiquitin Phe45Trp/Ile61Ala (Ub(*)I61A) in a low-temperature, high-viscosity buffer, where folding is slowed so that apparent two-state and three-state mechanisms are readily distinguishable. Ub(*)I61A forms a compact ensemble rapidly (as judged from stopped-flow, small-angle X-ray scattering) with a secondary structure signature similar to that of the native state (as judged from stopped-flow circular dichroism from 215 nm to 250 nm), but the fluorescence signature still resembles the guanidinium-denatured state. The compact ensemble forms over a range of solvent and temperature conditions. The native fluorescence signature, which requires the tryptophan residue to be packed tightly, is acquired at least 500 times more slowly. Molecular dynamics simulations at 495 K show no contraction of the backbone in ethylene glycol buffer compared to pure aqueous buffer, and no significant effect on the local backbone structure of the unfolded protein. Only at higher simulation temperature does a backbone contraction appear. Thus, it appears unlikely that the aqueous ethylene glycol buffer fundamentally changes the folding mechanism of ubiquitin. We suggest that ubiquitin forms a compact ensemble with native-like secondary structure, but without tight packing, long before the native state.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
340
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
115-25
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Multiple probes reveal a native-like intermediate during low-temperature refolding of ubiquitin.
pubmed:affiliation
Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't