INVESTIGADORES
OTTADO Jorgelina
congresos y reuniones científicas
Título:
STRUCTURAL CHARACTERIZATION OF THE LIPOPOLYSACCHARIDE FROM Xanthomonas axonopodis PV. CITRI
Autor/es:
CASABUONO, AC; SILVANA PETROCELLI; JORGELINA OTTADO; ORELLANO, E; COUTO, AS
Lugar:
Villa Carlos Paz
Reunión:
Congreso; XLIV Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular; 2008
Resumen:
Plants have basal perception systems for characteristic patterns
from different classes of microorganisms, named pathogenassociated
molecular patterns (PAMPs), which are recognizable by
the innate immune system of plants. In plant pathogenic bacteria,
lipopolysaccharides (LPSs) are important virulence factors and are
increasingly recognized as major PAMPs for plants. Citrus canker,
one of the most devastating citrus diseases in the world is caused by
Xanthomonas axonopodis pv. citri (Xac). In this context, the
chemical structure characterization of LPSs obtained from the wild
type and mutants is important to understand the role of Xac LPS in
this disease. Lipid A was obtained from purified wild type Xac LPS
by acid hydrolysis. Analysis by TLC showed a heterogeneous
complex pattern. Studies by UV-MALDI-TOF mass spectrometry
revealed the presence of two main cluster ions, using nor-harmane
as matrix in the positive and negative ion mode. One of them, with
ions ranged from m/z 1350 to 1450 corresponding to pentacylated
species that carried two glucosamine and two phosphate groups
with acyl chains of different lengths. The other one, ranged from
m/z 1500 to 1610 attributed to the presence of an additional residue
of 2-aminoethylphosphate and one 2-aminoethyl phosphate
groups. Interestingly, the same analysis performed on lipids A from
mutants evidenced structural differences.