Linked Life Data

9153430

Source:http://linkedlifedata.com/resource/pubmed/id/9153430

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1997-6-9
pubmed:abstractText
The integral membrane protein diacylglycerol kinase (DGK) from Escherichia coli has been reversibly unfolded in a protein/detergent/mixed micelle system by varying the molar ratio of n-decyl beta-D-maltoside (DM) and sodium dodecyl sulfate (SDS). Unfolding was monitored by circular dichroism (CD) and ultraviolet (UV) absorbance spectroscopy. When unfolding is monitored by measuring changes in absorbance at 294 nm, two distinct denaturation phases are observed, indicative of a stable intermediate. When CD is used as a conformational probe, the resulting denaturation curve contains only one major transition, which corresponds to the first unfolding phase observed by absorbance changes. The unfolding behavior of several mutant proteins in which the tryptophan residues were selectively replaced made it possible to assign the first unfolding phase to a denaturation event in a cytoplasmic domain and the second phase to denaturation of the membrane-embedded portion of the protein. The denaturation curves fit well to a model which assumes two cooperative transitions and a linear relationship between unfolding free energy and SDS concentration. Extrapolation back to zero denaturant indicates an unfolding free energy of 6 kcal/mol for the cytoplasmic domain and 16 kcal/mol for the transmembrane domain. The high apparent stability of the transmembrane domain could explain the high degree of tolerance to amino acid substitutions seen for DGK and other membrane proteins. The approach described in this paper may be applicable to other membrane protein systems.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5884-92
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
A method for assessing the stability of a membrane protein.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of California at Los Angeles, 90095-1570, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't