INIBIOLP   05426
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE LA PLATA "PROF. DR. RODOLFO R. BRENNER"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The biography of E.coli alpha hemolysin
Autor/es:
VANESA HERLAX; SABINA MATÉ; ROMINA VAZQUEZ; LAURA BAKÁS
Lugar:
San Javier, Tucumán
Reunión:
Congreso; XLI Reunión Anual de la Sociedad Argentina de Biofísica (SAB); 2012
Institución organizadora:
Sociedad Argentina de Biofísica
Resumen:
Extraintestinal pathogenic Escherichia coli is the causative agent of at least 80% of all uncomplicated urinary-tract infections, these strains are called uropathogenic E. coli. Epidemiological analyses have confirmed that different ExPEC pathotypes share many known as well as putative virulence factors. These latter include a number of secreted toxins, being alpha hemolysin (HlyA) among them. In the last decade the aim of our projects has been related to study the lytic and sublytic mechanisms of the toxin on erythrocytes. Some of the obtained results are: - During the secretion of the toxin across the bacteria membrane, HlyA forms a complex with the lipopolysacharide. The latter gives the toxin thermical and chemical stability. - Although HlyA has its own machinery for export, the toxin is also secreted by outer-membrane vesicles (OMVs). - HlyA forms a proteolipidic pore. - Fatty acids covalently bound to the toxin allow the exposure of intrinsic disorder regions that may participate in toxin oligomerization on target cells membranes. - HlyA oligomerizases in membrane microdomains enriched in sphingomyelin and cholesterol. - HlyA induces the increment of calcium concentration of erythrocytes treated with sublytical concentration of toxin. The purpose of our research is to achieve a detailed knowledge of the lytic mechanism of the toxin, as well as the relationship between its structure and function. This will allow us to use HlyA in the design of toxin-based therapies (eg: immunotoxins).