Membrane Anchorage Brings About Fusogenic Properties in a Short Synthetic Peptide
The fusogenic properties of an amphipathic net-negative peptide (wae 11), consisting of 11 amino acid residues, were studied. We demonstrate that, whereas the free peptide displays no significant fusion activity, membrane fusion is strongly promoted when the peptide is anchored to a liposomal membra...
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Published in | Biochemistry (Easton) Vol. 36; no. 13; pp. 3773 - 3781 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
01.04.1997
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Subjects | |
Online Access | Get full text |
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Summary: | The fusogenic properties of an amphipathic net-negative peptide (wae 11), consisting of 11 amino acid residues, were studied. We demonstrate that, whereas the free peptide displays no significant fusion activity, membrane fusion is strongly promoted when the peptide is anchored to a liposomal membrane. The fusion activity of the peptide appears to be independent of pH, and membrane merging is an essentially nonleaky process. Thus, the extents of lipid mixing and contents mixing were virtually indistinguishable. Vesicle aggregation is a prerequisite for fusion. For this process to take place, the target membranes required a positive charge which was provided by incorporating lysine-coupled phosphatidylethanolamine (PElys). The coupled peptide, present in one population, could thus cause vesicle aggregation via nonspecific electrostatic interaction with PElys. However, the free peptide failed to induce aggregation of PElys vesicles, suggesting that the spatial orientation of the coupled peptide codetermined its ability to bring about vesicle aggregation and fusion. With the monitoring of changes in the intrinsic Trp fluorescence, in conjunction with KI-quenching studies, it would appear that hydrophobic interactions facilitate the fusion event, possibly involving (partial) peptide penetration. Such a penetration may be needed to trigger formation of a transient, nonbilayer structure. Since lysophosphatidylcholine inhibited while monoolein strongly stimulated peptide-induced fusion, our data indicate that wae 11-induced fusion proceeds according to a model consistent with the stalk−pore hypothesis for membrane fusion. |
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Bibliography: | istex:EF8D0F1D0C0C66739730315D23872307613238F6 ark:/67375/TPS-7VFLTNZW-T Abstract published in Advance ACS Abstracts, March 1, 1997. We acknowledge the financial support obtained from the Association pour la Recherche contre le Cancer (Grant 4006). ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0006-2960 1520-4995 |
DOI: | 10.1021/bi9622128 |