通过核小体纤维模型的构建,利用MontoCarlo方法模拟其在各种钠离子浓度的溶液中结构变化的过程.模拟结果显示当溶液的钠离子浓度增大时,核小体由锯齿状结构转变为螺旋状结构.在常温所得到的核小体结构参数与实验结果接近,较好地解释了溶液中的钠离子浓度对核小体纤维结构的影响.In this paper, using Monte Carlo simulation, we obtain different structures of chromatin fibers with different ionic concentration. The result shows that as the ionic concentration is increased, the fiber undergoes a conformational change from sawtooth state to super-helix state. The structural parameters obtained by simulation agree well with the experimental results, indicating that our model is useful in explaining the conformational change of chromatin fibers in different ionic solutions.国家自然科学基金(批准号:10225420,90206039,20021002)资助的课题~