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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
1995-9-18
pubmed:abstractText
Fatty acid acylation is a posttranslational modification found in membrane proteins that have hydrophobic sequences serving as transmembrane segments as well as those that do not have them. The fatty acids myristate and palmitate are linked through an amide bond to N-terminal glycine and SH of cysteine via a thioester bond, respectively. In order to elucidate whether or how fatty acid acylation would modulate peptide structure, especially in hydrophobic environment, we have carried out circular dichroism studies on synthetic peptides both hydrophobic and hydrophilic in nature, corresponding to fatty acylation sites and their fatty acyl derivatives. The hydrophilic peptides were approximately 12 residues in length as studies on proteins modified by site-directed mutagenesis indicated that a peptide segment of approximately 12 residues is sufficient to direct acylation as well as membrane association, especially when the fatty acid is myristic acid. The peptide corresponding to a transmembrane segment composed of 31 residues as well as its palmitoyl derivative was found to adopt alpha-helical structure. Acylation appeared to favor increased partitioning into miscelles even in the case of a hydrophobic peptide. The hydrophilic peptides and their myristoyl or palmitoyl derivatives showed very little ordered structure in micelles. Our results suggest that the myristoyl and the palmitoyl moieties do not have the ability to "force" a hydrophilic peptide segment into a hydrophobic micellar environment. Thus, the mere presence of a fatty acid moiety may not be sufficient for membrane binding and recycling as is assumed especially in proteins in which no hydrophobic segment is present.
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
18
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19439-45
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Conformations of peptides corresponding to fatty acylation sites in proteins. A circular dichroism study.
pubmed:affiliation
Center for Cellular and Molecular Biology, Hyderabad, India.
pubmed:publicationType
Journal Article