Mielke Steven P, Benham Craig J, Grønbech-Jensen Niels
NASA Goddard Institute for Space Studies, New York, New York 10025, USA.
J Phys Chem A. 2009 Apr 23;113(16):4213-6. doi: 10.1021/jp8107599.
The persistence length of DNA has been studied for decades; however, experimentally obtained values of this quantity have not been entirely consistent. We report results from Brownian dynamics simulations that address this issue, validating and demonstrating the utility of an explicitly double-stranded model for mesoscale DNA dynamics. We find that persistence lengths calculated from rotational relaxation increase with decreasing ionic strength, corroborating experimental evidence, but contradicting results obtained from wormlike coil assumptions. Further, we find that natural curvature does not significantly affect the persistence length, corroborating cyclization efficiency measurements, but contradicting results from cryo-EM.
DNA的持续长度已经研究了几十年;然而,通过实验获得的这个量的值并不完全一致。我们报告了布朗动力学模拟的结果,该结果解决了这个问题,验证并证明了用于中尺度DNA动力学的明确双链模型的实用性。我们发现,从旋转弛豫计算出的持续长度随着离子强度的降低而增加,这证实了实验证据,但与从蠕虫状线圈假设获得的结果相矛盾。此外,我们发现自然曲率对持续长度没有显著影响,这证实了环化效率测量结果,但与冷冻电镜的结果相矛盾。