Study of parasporal inclusions by numerical analisis of their SDS-PAGE proteins profiles

ALVAREZ, ANALÍA; PERA, LICIA M.; VIRLA, EDUARDO; BAIGORÍ, MARIO

Rosario (Santa Fé)

Congreso; XLII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Bacillus thuringiensis (Bt) is a Gram-positive endosporeforming bacteria that produces proteinaceous parasporal inclusions during sporulation. These inclusions often contein delta-endotoxin proteins that cause rapid and fatal intoxications of several insect orders. It has been established that the inclusion proteins, encoded by cry genes, are highly heterogeneous in structures and biological activities. We previously reported native Bt RT3 that shows a strong toxicity against Spodoptera frugiperda larvae. The aim of this work  was to study parasporal inclusions by numerical analysis of their SDS-PAGE proteins profile. Standard B. subtilis (1A571) and Bt strains (BGSC): 4A4, 4D3 and 4D1 as well as native were used throughout this study. Proteins were prepared by a rapid washing procedure. SDS-PAGE of standards and inclusions proteins was performed according to Laemmli method. Gels were stained with silver reagent and their were analyzed by using NTSYS program (SM coefficient and UPGMA). Two main groups of Bacillus strains can be differentiated showing a similarity of 90% between them. Proteins profiles from native strains were different from those of standard strains. Bt RT3 displays a similarity of 92% with Bt 4D1. This method was more sensitive to differentiate Bt strains than a set of biochemical tests. This work was supported by grants PICTO 731 and PIP 6062.