SUPERFICIAL STRUCTURES INVOLVED IN THE INTERACTION LACTOBACILLUS KEFIR - ESCHERICHIA COLI

ESTEBAN GERBINO; PAULA CARASI; PABLO MOBILI; MARIA DE LOS ANGELES SERRADELL; PATRICIO DE URRAZA; VERONIQUE ARLUISON; ANDREA GOMEZ-ZAVAGLIA

Salta, Argentina

Congreso; 3 Latin American Protein Society Meeting; 2010

Latin American Protein Society

The S-layer is a crystalline bidimensional array of (glyco)proteic subunits, linked non-covalently to each other underlying cell-wall of some bacteria [1]. Several lactobacilli strains bearing an S-layer structure play an essential role as probiotics for humans and animals [2]. In this work, strategies to analyze the interaction of S-layers with the outer membranes (OM) of Gram(-) will be presented with the aim of understanding the molecular mechanisms involved in certain probiotic properties. S-layer proteins were extracted from bacteria using LiCl 5M. FTIR spectroscopy was used to study the secondary structure of S-layer proteins from lactobacilli. The differences in the secondary structures of the investigated S-layers proteins were correlated with the investigated probiotic properties. The assembly of these various macromolecular structures and strategies adopted to analyze the interaction of E. coli OM with L. kefir S-layer will be presented herein, with the aim to understand the molecular mechanisms involved in the interaction. 1. Sleytr UB and Beveridge TJ, Trends Microbiol. 7, 253 (1999). 2. Del Re B, Sgorbati B, Miglioli M and Palenzona D. Lett. Appl. Microbiol. 31, 438 (2000). Acknowledgments: This work has been supported by the Argentinean Agency for Scientific and Technological Promotion (ANPCyT PICT(2006)/00068 and MinCyt-ECOS (bilateral grant A09B02).