Linked Life Data

1860847

Source:http://linkedlifedata.com/resource/pubmed/id/1860847

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
1991-9-4
pubmed:abstractText
We have examined the comparative membrane interaction properties of synthetic peptides corresponding to the wild-type and an export-defective, mutated signal sequence from the Escherichia coli outer membrane protein, OmpA. As part of a collaborative study of the effects of various alterations on the function of the OmpA signal sequence and the biophysical properties of the corresponding synthetic peptides, we incorporated the small, neutral polar residue, asparagine, into the hydrophobic core in place of Ile-8. This seemingly minor perturbation to the signal sequence caused a complete block of export in vivo (J. Goldstein, S. Lehnhardt, and M. Inouye, following paper). We now explore in detail the difference in the properties of the wild-type and the Ile-8----Asn OmpA signal peptides. The fluorescent residue Trp was substituted in both peptides in place of the wild-type Phe at position 15. This mutation is silent phenotypically and provides a superb probe of membrane interaction. We find that the Asn substitution leaves the conformational properties of the signal sequence essentially unchanged, but prevents any significant interaction of the peptide with a lipid bilayer. Asparagines are very underrepresented among known signal sequences. We believe this low frequency to be due to the lowering of mean residue hydrophobicity caused by incorporation of Asn and the consequent reduced ability to bind and insert into membranes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14406-12
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
A peptide corresponding to an export-defective mutant OmpA signal sequence with asparagine in the hydrophobic core is unable to insert into model membranes.
pubmed:affiliation
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9041.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't