Effects of the antibiotic peptide microcin J25 on liposomes: role of acyl chain length and negatively charged phospholipid.
Biochim Biophys Acta
; 1509(1-2): 65-72, 2000 Dec 20.
Article
em En
| MEDLINE
| ID: mdl-11118518
This paper reports the effects of microcin J25 (MccJ25) on the microviscosity and permeability of phospholipid vesicles of different compositions. The results obtained indicate that MccJ25 interacts with egg L-alpha-phosphatidylcholine (PC) vesicles as demonstrated by peptide intrinsic fluorescence determinations. The interaction depends on the lipid composition of the vesicles. MccJ25 interaction induces a significant fluidity increase of egg PC vesicles. This effect is time and concentration dependent. Both trimethyl ammonium 1,6-diphenyl-1,3,5-hexatriene and 1,6-diphenyl-1, 3,5-hexatriene gave the same results. The microviscosity of L-alpha-phosphatidylcholine dipalmitoyl small unilamellar vesicles (SUVs) was affected while that of L-alpha-phosphatidylcholine dimyristoyl vesicles was not, indicating that the effect was strongly dependent on the chain length of fatty acids. On the other hand, negatively charged L-alpha-phosphatidyl-DL-glycerol (PG) vesicles remarkably inhibited the peptide effect. Nevertheless vesicles composed of L-alpha-phosphatidylethanolamine:PG:cardiolipin (7:2:1), a composition resembling bacterial membrane, were sensitive to the MccJ25 effect. MccJ25 effectively dissipated the valinomycin-induced membrane potential, but induced only a modest leakage (5%) of the trapped Tb(+3)-dipicolinic acid complex. These results indicate that the peptides interact and perturb the bilayer of SUVs. The relationships between this effect and bactericidal action remain to be elucidated.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
/
Bacteriocinas
/
Difenilexatrieno
/
Lipossomos
/
Antibacterianos
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Holanda