Ising-like model for protein mechanical unfolding.
The mechanical unfolding of proteins is studied by extending the Wako-Saitô-Muñoz-Eaton model. This model is generalized by including an external force, and its thermodynamics turns out to be exactly solvable. We consider two molecules, the 27th immunoglobulin domain of titin and protein PIN1. We determine equilibrium force-extension curves for the titin and study the mechanical unfolding of this molecule, finding good agreement with experiments. By using an extended form of the Jarzynski equality, we compute the free energy landscape of the PIN1 as a function of the molecule length.
Imparato
A
A
Dipartimento di Fisica and CNISM, Politecnico di Torino, c. Duca degli Abruzzi 24, Torino, Italy and INFN, Sezione di Torino, Torino, Italy.
Pelizzola
A
A
Zamparo
M
M
D001696:Biomechanical Phenomena; D064211:Connectin; D004548:Elasticity; D007136:Immunoglobulins / Q000737:chemistry; D008962:Models, Theoretical; D009124:Muscle Proteins / Q000737:chemistry*; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D019696:Peptidylprolyl Isomerase / Q000737:chemistry*; D017510:Protein Folding; D011494:Protein Kinases / Q000737:chemistry*; D017434:Protein Structure, Tertiary
D064211:Connectin; D007136:Immunoglobulins; D009124:Muscle Proteins; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D011494:Protein Kinases; D019696:Peptidylprolyl Isomerase