Linked Life Data

7548165

Source:http://linkedlifedata.com/resource/pubmed/id/7548165

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-11-3
pubmed:abstractText
alpha-Sarcin is a ribosome-inactivating protein that translocates across lipid bilayers, these two abilities explaining its cytotoxic character. This protein is composed of a single polypeptide chain with two disulfide bridges. Reduction and carboxyamidomethylation of alpha-sarcin results in protein unfolding, based on the results of the spectroscopic characterization of the chemically modified protein. The absorption and fluorescence emission bands of the tryptophan residues of the modified protein appear blue- and red-shifted, respectively. Far-UV circular dichroism analysis reveals the presence of residual secondary structure (beta-strands and turns) in the alkylated protein. This retains its ability to interact with lipid bilayers. It promotes vesicle aggregation, lipid-mixing between bilayers and leakage of the intravesicular aqueous contents. The modified protein tends to abolish the phase transition of acid phospholipids as detected by differential scanning calorimetry and depolarization measurements of fluorescence-labelled vesicles. The protein gain access to vesicle-entrapped trypsin. The fluorescence emission of the tryptophan residues is blue-shifted upon interaction of the protein with the bilayers, and anthracene incorporated into the hydrophobic core of the membranes quenches the tryptophan fluorescence emission of the protein. The secondary structure of the alkylated protein interacting with lipid vesicles has been studied by infrared spectroscopy. An increase in the alpha-helix and turn contents and a concomitant decrease in the beta-structure content are observed upon interaction with the bilayers. The results obtained are discussed in terms of the structural requirements for the interaction of alpha-sarcin with lipid membranes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
1252
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
43-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Spectroscopic characterization of the alkylated alpha-sarcin cytotoxin: analysis of the structural requirements for the protein-lipid bilayer hydrophobic interaction.
pubmed:affiliation
Departamento de Bioquímica y Biología Molecular, Facultad de Química, Universidad Complutense, Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't