Thiol-independent activity of a cholesterol-binding enterohemolysin produced by enteropathogenic Escherichia coli
Braz. j. med. biol. res
;
36(11): 1495-1499, Nov. 2003. ilus
Article
in English
| LILACS
| ID: lil-348281
ABSTRACT
Enterohemolysin produced by Escherichia coli associated with infant diarrhea showed characteristics similar to those of thiol-activated hemolysins produced by Gram-positive bacteria, including inactivation by cholesterol, lytic activity towards eukaryotic cells and thermoinstability. However, enterohemolysin activity was not inactivated by oxidation or by SH group-blocking agents (1 mM HgCl2, 1 mM iodoacetic acid) and the hemolysin (100 æg/ml) was not lethal to mice, in contrast to the lethality of the thiol-activated hemolysin family to animals. Earlier reports showed that intravenous injection of partially purified streptolysin O preparations (0.2 æg) was rapidly lethal to mice. These results suggest that E. coli enterohemolysin is not a thiol-activated hemolysin, despite its ability to bind cholesterol, probably due to the absence of free thiol-group(s) that characterize the active form of the thiol-activated hemolysin molecule.
Full text:
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Index:
LILACS (Americas)
Main subject:
Bacterial Toxins
/
Erythrocytes
/
Escherichia coli
/
Eukaryotic Cells
Limits:
Animals
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2003
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Estadual de Campinas/BR
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