Linked Life Data

7690029

Source:http://linkedlifedata.com/resource/pubmed/id/7690029

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
1993-10-7
pubmed:abstractText
Insect defensins are cationic, cysteine-rich peptides (approximately 4 kDa) that appear after bacterial challenge or injury in the hemolymph of insects belonging to a large variety of orders. These peptides possess anti-Gram-positive activity and participate in the potent antibacterial defense reactions of insects. Using recombinant insect defensin and the strain Micrococcus luteus as a test organism, we have investigated the mode of action of this peptide. We show that defensin disrupts the permeability barrier of the cytoplasmic membrane of M. luteus, resulting in a loss of cytoplasmic potassium, a partial depolarization of the inner membrane, a decrease in cytoplasmic ATP, and an inhibition of respiration. Potassium loss is inhibited below the order-disorder transition of the lipid hydrocarbon chains. It is also inhibited by divalent cations and by a decrease in the membrane potential below a threshold of 110 mV. We propose that these permeability changes reflect the formation of channels in the cytoplasmic membrane by defensin oligomers. This proposal is supported by patch-clamp experiments that show that insect defensins form channels in giant liposomes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19239-45
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Insect defensin, an inducible antibacterial peptide, forms voltage-dependent channels in Micrococcus luteus.
pubmed:affiliation
Laboratoire de Biologie Générale, Université Louis Pasteur, URA 1490 Centre National de la Recherche Scientifique Bases Cellulaires et Moléculaires de la Réponse Immunitaire des Insectes, Strasbourg, France.
pubmed:publicationType
Journal Article