Linked Life Data

8136371

Source:http://linkedlifedata.com/resource/pubmed/id/8136371

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1994-4-25
pubmed:abstractText
Magainins from Xenopus skin are antimicrobial peptides with broad spectra, and their action mechanisms are considered to be the permeabilization of bacterial membranes. To elucidate their molecular mechanisms, three analog peptides of magainin 2, each having a Trp residue substituted for Phe at the 5th, 12th, or 16th position, were synthesized, and their interactions with acidic phospholipid membranes were investigated by fluorescence. The Trp substitution did not significantly affect the properties of the parent peptide. The binding isotherms of these peptides to the membranes, which were obtained on the basis of fluorescence changes upon membrane binding of the peptides, were sigmoidal, suggesting the association of the bound peptide molecules. A quantitative analysis indicated that the formed aggregate is a dimer. The observation that the initial rate constant of magainin 2 induced leakage of calcein from liposomes was dependent on the fourth power of the peptide concentration demonstrates the formation of a tetrameric pore. A blue shift and intensity enhancement of Trp fluorescence in the presence of the membranes indicate that those Trp residues are buried in the hydrophobic region of the bilayers. Furthermore, the depths of the Trp residues, which were determined using the n-doxylphosphatidylcholine quenching technique, were about 10 A from the bilayer center irrespective of the peptide aggregational state. Thus, it was concluded that the orientation of the magainin 2 alpha-helix is parallel to the membrane surface. A model of the pore formation will be proposed on the basis of these observations.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3342-9
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:8136371-Amino Acid Sequence, pubmed-meshheading:8136371-Animals, pubmed-meshheading:8136371-Anti-Bacterial Agents, pubmed-meshheading:8136371-Antimicrobial Cationic Peptides, pubmed-meshheading:8136371-Kinetics, pubmed-meshheading:8136371-Lipid Bilayers, pubmed-meshheading:8136371-Liposomes, pubmed-meshheading:8136371-Macromolecular Substances, pubmed-meshheading:8136371-Magainins, pubmed-meshheading:8136371-Molecular Sequence Data, pubmed-meshheading:8136371-Phenylalanine, pubmed-meshheading:8136371-Phospholipids, pubmed-meshheading:8136371-Protein Structure, Secondary, pubmed-meshheading:8136371-Spectrometry, Fluorescence, pubmed-meshheading:8136371-Structure-Activity Relationship, pubmed-meshheading:8136371-Tryptophan, pubmed-meshheading:8136371-Xenopus Proteins, pubmed-meshheading:8136371-Xenopus laevis
pubmed:year
1994
pubmed:articleTitle
Orientational and aggregational states of magainin 2 in phospholipid bilayers.
pubmed:affiliation
Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't