| 초록 |
The unfolding of “two-letter” heteropolymer subjected to simple shear flow is simulated on a square lattice by a Monte Carlo method. Using Kawasaki-type Ising model on a fully compact n´n lattice conformation as a target structure, the sequences of a heteropolymer that show foldability with a unique native structure are selected in sequence space. The conformations of heteropolymers with the selected sequences are then sampled according to Metropolis criterion with Verdier algorithm. To model a lattice chain under shear flow, a flow field potential is introduced through velocity potential. The unfolding pathway of heteropolymers under shear flow is characterized from the free energy landscape obtained by Monte Carlo sampling and the shear-induced unfolding pathway are compared to the pathway of unfolding induced by temperature. When compared to the free energy landscape in the absence of shear flow, the pathway is altered from a funnel-like path to an attenuated tube-like path as the shear rate increases, suggesting that the shear-induced unfolding pathway is more specific than that of temperature-induced unfolding. |
