SEMINAR @ SISSA, SBP, dr. P. Bruscolini - Dec. 17, at 14.00 hrs.

[Barbara Corzani]

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STATISTICAL AND BIOLOGICAL PHYSICS SEMINAR
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Dr. Pierpaolo Bruscolini
(Universidad de Zaragoza)

Title:
"Quantitative Prediction of Protein Folding Behaviors from a Simple
Statistical Model"

Fri 17 Dec. 2010 @ 02.00 p.m.

SISSA - A Building - first floor, room 132
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ABSTRACT:

The statistical nature of protein folding process requires the use of
equally detailed yet simple models that lend themselves to
characterize experiments. One such model is the Wako-Saito-Muñoz-Eaton
model, that we extend here to include solvation effects (WSME-S),
introduced via empirical terms. We employ the novel version to analyze
the folding of two proteins, gpW and SH3, that have similar size and
thermodynamic stability but with the former folding 3 orders of
magnitude faster than SH3. A quantitative analysis reveals that gpW
presents at most marginal barriers,
in contrast to SH3 that folds following a simple two-state approximation. We
reproduce the observed experimental differences in melting temperature 
in gpW
as seen by different experimental spectroscopic probes and the shape of the
rate-temperature plot. In parallel, we predict the folding complexity 
expected
in gpW from the analysis of both the residue-level thermodynamics and
kinetics. SH3 serves as a stringent control with neither folding complexity
nor dispersion in melting temperatures being observed. The extended model
presented here serves as an ideal tool to not only characterize folding data
but also to make experimentally testable predictions.