Linked Life Data

19751743

Source:http://linkedlifedata.com/resource/pubmed/id/19751743

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-11-6
pubmed:abstractText
Proteins unfolded by high concentrations of chemical denaturants adopt expanded, largely structure-free ensembles of conformations that are well approximated as random coils. In contrast, globular proteins unfolded under less denaturing conditions (via mutations, or transiently unfolded after a rapid jump to native conditions) and molten globules (arising due to mutations or cosolvents) are often compact. Here we explore the origins of this compaction using a truncated equilibrium-unfolded variant of the 57-residue FynSH3 domain. As monitored by far-UV circular dichroism, NMR spectroscopy, and hydrogen-exchange kinetics, CDelta4 (a 4-residue carboxy-terminal deletion variant of FynSH3) appears to be largely unfolded even in the absence of denaturant. Nevertheless, CDelta4 is quite compact under these conditions, with a hydrodynamic radius only slightly larger than that of the native protein. In order to understand the origins of this molten-globule-like compaction, we have characterized a random sequence polypeptide of identical amino acid composition to CDelta4. Notably, we find that the hydrodynamic radius of this random sequence polypeptide also approaches that of the native protein. Thus, while native-like interactions may contribute to the formation of compact "unfolded" states, it appears that non-sequence-specific monomer-monomer interactions can also account for the dramatic compaction observed for molten globules and the "physiological" unfolded state.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1089-8638
pubmed:author
pubmed:issnType
Electronic
pubmed:day
27
pubmed:volume
394
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
343-50
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Non-sequence-specific interactions can account for the compaction of proteins unfolded under "native" conditions.
pubmed:affiliation
Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural