Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
47
pubmed:dateCreated
1994-12-28
pubmed:abstractText
To investigate the interaction of the presequence of the precursor of yeast cytochrome C oxidase subunit IV (COX IV) with phospholipid membranes, a series of single- and double-cysteine-substituted peptide variants derived from the 25-residue NH2-terminal presequence has been synthesized and modified with nitroxide spin labels. The immersion depth, orientation, and secondary structure of the peptide in the POPC bilayer containing 10 mol % POPG were determined using electron paramagnetic resonance (EPR) spectroscopy. EPR saturation analysis of singly labeled variants reveals that the nitroxides attached to the NH2-terminal region of the peptide insert into the acyl chain region of the bilayer, approximately 13 A deep from the membrane surface. EPR line shape analysis of doubly labeled variants indicates that the peptide predominantly exists as an extended conformation, with little secondary structure. The experimental results, together with the energetic consideration of peptide-bilayer interactions, suggest that the presequence is located near the interface between the head group region and the acyl chain region, such that the hydrophobic side chains are solvated by the acyl chains and the charged side chains extended toward the polar environment at the bilayer surface.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14221-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Topology of an amphiphilic mitochondrial signal sequence in the membrane-inserted state: a spin labeling study.
pubmed:affiliation
Department of Chemistry, University of California, Berkeley.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't