Linked Life Data

17429619

Source:http://linkedlifedata.com/resource/pubmed/id/17429619

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2007-8-16
pubmed:abstractText
The chromophore of a green fluorescent protein (GFP) mutant engineered to enhance emission and stability is known to display erratic switchings among a few of its chemical substates and, in particular, between the anionic A and the neutral N substates, whose difference is associated with a proton exchange and a consequent conformation rearrangement. However, when close to unfolding, the A-N switchings suddenly become very regular as shown by fluorescence oscillations that have been recently observed for molecules embedded in wet silica gel. In order to establish whether the matrix hosting the protein is responsible for these oscillations, we investigated the effect of another medium (silanized surfaces), of a different denaturant (urea) and of cosolvents (D(2)O and glycerol). The occurrence of periodic A-N switchings, in the last milliseconds before GFP unfolding, is observed under all investigated conditions, together with three specific frequency values that characterize the pre-unfolding fluorescence. Urea and guanidinium, the denaturants employed in order to unfold GFP, do not lead to appreciable differences in the observed switching parameters, whereas the different media embedding the protein give rise only to frequency shifts that scale with the viscosity of the host. The periodicity of the GFP A-N switchings and their dependence on cosolvents suggest that they could be associated with oscillatory motions between meta-stable conformations of the beta-barrel surrounding the chromophore near protein unfolding.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0175-7571
pubmed:author
pubmed:issnType
Print
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
795-803
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Environment effects on the oscillatory unfolding kinetics of GFP.
pubmed:affiliation
Department of Physics, University of Milano-Bicocca, Milan, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't