高分子量DNA沉降对离心速度的依赖性。

Dependence of the sedimentation of high molecular weight DNA on centrifuge speed.

作者信息

Hutchinson F, Krasin F

出版信息

Biophys Chem. 1976 Dec;6(1):23-9. doi: 10.1016/0301-4622(76)80058-0.

Abstract

A theory by Zimm [B.H.Zimm, Biophys. Chem. 1-(1974)279] predicts that for a given centrifuge speed, there is a broad maximum in a plot of the sedimentation coefficient of DNA against molecular wight. Experimental measurements of these maxima for various centrifuge speeds were made for double-helical DNA in neutral sucrose gradients and singlestrand DNA in alkaline gradients. The measurements are in quantitative agreement with the theory, providing good evidence for its validity. The existence of the maximum shows that there is a limit to the sedimentation rate under specified conditions for KNA in the linear form. By implication, DNA observed to sediment faster than this limit is not in the linear form to which most sedimentation theory is applicable.

摘要

齐姆[B.H.齐姆，《生物物理化学》1-(1974)279]提出的一种理论预测，对于给定的离心机转速，DNA沉降系数与分子量的关系图中存在一个宽泛的最大值。在中性蔗糖梯度中对双螺旋DNA以及在碱性梯度中对单链DNA，针对不同离心机转速对这些最大值进行了实验测量。测量结果与该理论在定量上相符，为其有效性提供了有力证据。最大值的存在表明，在线性形式下特定条件下KNA的沉降速率存在极限。这意味着，观察到沉降速度快于该极限的DNA并非大多数沉降理论所适用的线性形式。