Brisabois A, Goullet P
Laboratoire de Microbiologie, Faculté de Médecine X. Bichat, Université Paris 7, France.
J Appl Bacteriol. 1993 Aug;75(2):176-83. doi: 10.1111/j.1365-2672.1993.tb02764.x.
Three esterases (Est-) hydrolysing alpha-naphthyl acetate: Est-E1, Est-E3 and Est-E4 produced by Salmonella enterica serovar Typhimurium, strain LT2 were separated by DEAE chromatography and gel filtration. Est-E3, the major component of this set of enzymes, clearly differed from the two other esterases by its apparent molecular weight, titration curve, substrate specificity and inactivation. Immunoglobulins raised against Est-E3 completely neutralized the activity of Est-E3 but did not react with Est-E1 or Est-E4; it showed no cross reaction with carboxylesterase B of Escherichia coli or with carboxylesterases from other enterobacteria. Est-E3 showed electrophoretic variants which were biochemically and immunologically detected in the seven subspecies of the genus Salmonella. These findings suggest that variants of Est-E3 are the products of very closely related loci originating from a common ancestral gene. The esterase could be a phylogenetic marker of the genus and a suitable molecular tool for taxonomy and epidemiology.
