The lytic mechanism of Escherichia coli α-hemolysin associated to outer membrane vesicles

HTML  Download Download as PDF (Size: 1046KB)  PP. 484-492  
DOI: 10.4236/health.2010.25072    5,304 Downloads   11,545 Views  Citations

Affiliation(s)

.

ABSTRACT

Alpha-hemolysin (HlyA) is an extracellular toxin secreted by Escherichia coli, targeting to plasma membranes of eukaryotic cells. Recently it was found that this toxin is released to external media associated to bacterial outer membrane vesicles (OMVs), but the hemolytic mechanism in this way has not been studied yet. Our results report that HlyA is the only protein present in OMVs that is responsible for erythrocyte lysis, and show that no fusion event is involved in the lytic mechanism of OMVs-HlyA. Furthermore, the specific hemolytic activity is approximately 10 fold higher than that of purified free-HlyA, showing the same relative lysis efficiency and specificity for erythrocytes from different species. OMVs could be an important auxiliary way of secretion, acting mainly as a concentration mechanism of HlyA near the target cells. Cell lysis would occur after toxin transfer from OMVs to target membranes, as demonstrated by hemolysis kinetic studies, lipid mixing and western blot assays.

Share and Cite:

Herlax, V. , Henning, M. , Bernasconi, A. , Goni, F. and Bakas, L. (2010) The lytic mechanism of Escherichia coli α-hemolysin associated to outer membrane vesicles. Health, 2, 484-492. doi: 10.4236/health.2010.25072.

Copyright © 2024 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.