INVESTIGADORES
ROMAN Ernesto Andres
congresos y reuniones científicas
Título:
pH effect on the folding mechanism of frataxin from Psychromonas ingrahamii: computational approach
Autor/es:
ERNESTO A. ROMAN; PATRICIO O. CRAIG; JAVIER SANTOS
Lugar:
Carlos Paz
Reunión:
Congreso; Reunion Anual de la Sociedad Argentina de Biofísica; 2013
Institución organizadora:
Sociedad Argentina de Biofísica
Resumen:
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Frataxin
is a protein that participates in iron binding and delivery to other protein
partners. Its absence in humans yields Friedreich's Ataxia. In our laboratory
we study the iron binding and folding mechanism of human and Psychromonas
ingrahamii frataxin (pFXN). We previously reported that pFXN stability is
highly modulated by pH in the 6-8 pH range. In this work, we studied the
folding reaction of pFXN as a function of pH by computational techniques. We
used a coarse grained structure based model supplemented with a general
electrostatic potential to extensively sample the folding and unfolding
transitions and evaluate pFXN conformational stability. Residues were reduced
to 3 atoms over which the bonded and non bonded forces were projected. In this
model only the residues that make contact in the native state interact
favorably whereas all the others interact only repulsively through excluded
volume effect. The model was supplemented with a coulombic electrostatic
potential to account for the effect of pH on the stability of the protein.
Preliminary results show that protonation of histidine residues highly modulate
protein stability. The protonation of key residues and their contribution to
the overall effect was also evaluated