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Seminario
"Determining Protein Folding Pathways using a Quantum-Mechanical Formalism"

Relatore: Dr Pietro Faccioli- UniversitÓ di Trento

Sala Feynman
24 Ottobre 2006 ore 16.00

Abstract
We present a recenlty developed theoretical framework to determine the protein folding pathways in full atomistic detail. Our approach is based on the formal analogy between the stochastic Langevin diffusion and the Quantum- Mechanical evolution in imaginary time. By means of the path-integral formalism we derive a modified Hamilton-Jacobi least-action principle which allows to determine directly the most probable reaction pathways, without involving time in the calculation. As a result, the numerical difficulties associated with the existence of very different time scales in the protein folding problem are bypassed. We test our method by studying the conformational changes of alanine di-peptide in an all-atom model. We determine the transition state and compute the transition rate.