Abstract
The interaction of the wheat antibacterial peptide α-thionin with large unilamellar vesicles has been investigated by means of fluorescence spectroscopy. Binding of the peptide to the vesicles is followed by the release of vesicle contents, vesicle aggregation, and lipid mixing. Vesicle fusion, i.e., mixing of the aqueous contents, was not observed. Peptide binding is governed by electrostatic interactions and shows no cooperativity. The amphipatic nature of wheat α-thionin seems to destabilitize the membrane bilayer and trigger the aggregation of the vesicles and lipid mixing. The presence of distearoylphosphatidylethanolamine-poly(ethylene glycol 2000) (PEG-PE) within the membrane provides a steric barrier that inhibits vesicle aggregation and lipid mixing but does not prevent leakage. Vesicle leakage through discrete membrane channels is unlikely, because the release of encapsulated large fluorescent dextrans is very similar to that of 8- aminonaphthalene-1,3,6,trisulfonic acid (ANTS). A minimum number of 700 peptide molecules must bind to each vesicle to produce complete leakage, which suggests a mechanism in which the overall destabilization of the membrane is due to the formation of transient pores rather than discrete channels.
| Original language | English |
|---|---|
| Pages (from-to) | 2567-2577 |
| Number of pages | 11 |
| Journal | Protein Science |
| Volume | 7 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Jan 1 1998 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Biochemistry
- Molecular Biology
Cite this
Interaction of wheat α-thionin with large unilamellar vesicles. / Martinez Caaveiro, Jose Manuel; Molina, Antonio; Rodríguez-Palenzuela, Pablo; Goñi, Félix M.; González-Mañas, Juan Manuel.
In: Protein Science, Vol. 7, No. 12, 01.01.1998, p. 2567-2577.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Interaction of wheat α-thionin with large unilamellar vesicles
AU - Martinez Caaveiro, Jose Manuel
AU - Molina, Antonio
AU - Rodríguez-Palenzuela, Pablo
AU - Goñi, Félix M.
AU - González-Mañas, Juan Manuel
PY - 1998/1/1
Y1 - 1998/1/1
N2 - The interaction of the wheat antibacterial peptide α-thionin with large unilamellar vesicles has been investigated by means of fluorescence spectroscopy. Binding of the peptide to the vesicles is followed by the release of vesicle contents, vesicle aggregation, and lipid mixing. Vesicle fusion, i.e., mixing of the aqueous contents, was not observed. Peptide binding is governed by electrostatic interactions and shows no cooperativity. The amphipatic nature of wheat α-thionin seems to destabilitize the membrane bilayer and trigger the aggregation of the vesicles and lipid mixing. The presence of distearoylphosphatidylethanolamine-poly(ethylene glycol 2000) (PEG-PE) within the membrane provides a steric barrier that inhibits vesicle aggregation and lipid mixing but does not prevent leakage. Vesicle leakage through discrete membrane channels is unlikely, because the release of encapsulated large fluorescent dextrans is very similar to that of 8- aminonaphthalene-1,3,6,trisulfonic acid (ANTS). A minimum number of 700 peptide molecules must bind to each vesicle to produce complete leakage, which suggests a mechanism in which the overall destabilization of the membrane is due to the formation of transient pores rather than discrete channels.
AB - The interaction of the wheat antibacterial peptide α-thionin with large unilamellar vesicles has been investigated by means of fluorescence spectroscopy. Binding of the peptide to the vesicles is followed by the release of vesicle contents, vesicle aggregation, and lipid mixing. Vesicle fusion, i.e., mixing of the aqueous contents, was not observed. Peptide binding is governed by electrostatic interactions and shows no cooperativity. The amphipatic nature of wheat α-thionin seems to destabilitize the membrane bilayer and trigger the aggregation of the vesicles and lipid mixing. The presence of distearoylphosphatidylethanolamine-poly(ethylene glycol 2000) (PEG-PE) within the membrane provides a steric barrier that inhibits vesicle aggregation and lipid mixing but does not prevent leakage. Vesicle leakage through discrete membrane channels is unlikely, because the release of encapsulated large fluorescent dextrans is very similar to that of 8- aminonaphthalene-1,3,6,trisulfonic acid (ANTS). A minimum number of 700 peptide molecules must bind to each vesicle to produce complete leakage, which suggests a mechanism in which the overall destabilization of the membrane is due to the formation of transient pores rather than discrete channels.
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U2 - 10.1002/pro.5560071210
DO - 10.1002/pro.5560071210
M3 - Article
C2 - 9865951
AN - SCOPUS:0031700044
VL - 7
SP - 2567
EP - 2577
JO - Protein Science
JF - Protein Science
SN - 0961-8368
IS - 12
ER -