Estudos biofísicos de chaperonas de secreção e de interações proteína-ligante / Biophysical studies on secretion chaperones and protein-ligand interactions

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

30/03/2012

RESUMO

So far, the Xanthomonas axonopodis pv. citri (XAC) mechanisms of bacterial virulence is unknown. It is believed that secretion chaperones (CS) are involved in the XAC´s virulence process by first forming complexes with virulence factors, and assisting in their presentation to corresponding secretion systems using ATP as a source of energy. Fluorescence emission, circular dichroism, thermal unfolding and nuclear magnetic resonance NMR H and 2D {N,H} HSQC data from two proteins of XAC, XAC1990 (FlgN) and XACb0033 were collected. For both proteins, 3D structures were proposed using the footprinting analysis with RMSD and SASA restrictions. For the proposed structures were verified which the fluorescence data were consistent with the 3D structure. The CD and NMR data revealed low-helical content and absence of 3D structure. The interaction of the protein FlgN with its partner, FlgK, was suggested by CD and fluorescence analysis. In the second part, the interactions between the orange´s Hsp90 protein with different ligants using Saturation Transfer Difference (STD-NMR) and fluorescence spectroscopy techniques were studied. These analyzes revealed which the data were consistent with the proposed model and moreover showed that the adenine´s hydrogens H-8 and H-2 and ribose´s hydrogen H-1´are located in the protein binding site with the phosphate driven out. By fluorescence values were calculed Kd and it was verified that geldanamycin is a potent inhibitor of orange´s Hsp90.

ASSUNTO(S)

xanthomonas axonopodis pv. citri interação proteina-ligante hsp90 da laranja std xanthomonas axonopodis pv. citri protein-ligand interactions hsp90 from orange std nmr

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