Flexibility of short DNA helices under mechanical stretching

摘要: The flexibility of short DNA fragments is studied by a Hamiltonian model which treats the inter-strand and intra-strand forces at level base pair. elastic response set homogeneous helices to externally applied obtained computing average bending angles between adjacent pairs along molecule axis. ensemble averages are performed over room temperature equilibrium distribution pair separations fluctuations. analysis end-to-end distances persistence lengths shows that even sequences with less than $100$ maintain significant bendability ascribed thermal fluctuational effects kinks large angles. discrepancies outcomes discrete those worm-like-chain examined pointing out inadequacy latter on length scales.