INVESTIGADORES
VINCENT Paula Andrea
congresos y reuniones científicas
Título:
Chymotrypsin-susceptible microcin J25 derivatives: potencial applicability in food preservation
Autor/es:
MARÍA FERNANDA POMARES; RAÚL SALOMÓN; ANA M. ZENOFF; RICARDO FARÍAS; PAULA A. VINCENT
Lugar:
Tucuman
Reunión:
Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología molecular.; 2009
Resumen:
Microcin J25 (MccJ25) is a 21-residue ribosomally-synthesized lariat-peptide antibiotic. It is active against food-borne diseases causing pathogens such as Salmonella, Shigella, and E. coli, including E. coli O157:H7 and non-O157. MccJ25 is highly resistant to digestion by proteolytic enzymes present in the stomach and intestinal contents. MccJ25 would therefore remain active in the gastrointestinal tract, affecting the normal intestinal microbiota, and limiting the potential use of MccJ25 as a food preservative. In the present work we describe a chymotrypsin-susceptible MccJ25 derivative carrying a Gly12 substitution to Tyr that retained almost full antibiotic activity and efficiently inhibited the growth of pathogenic Salmonella newport and Escherichia coli O157: H7 in skim milk and egg yolk. However, unlike the wild-type MccJ25, the MccJ25(G12Y) variant was inactivated by digestive enzymes both in vitro and in vivo. Further, by means of preliminary experiments, we demonstrated that MccJ25(G12Y) did not affect the rat intestinal microbiota. To our knowledge, our results represent the first example of a rational modification of a microcin aimed at increasing its potential use in food preservation.