微观吸引作用对DNA膜弹性性质的影响  

Influence of Microscale Attractive Interaction on Elastic Property of DNA Biofilm

作　　者：李孝斌 叶益民 卢伟 周眉宏 张能辉[1,2] LI Xiaobin;YE Yimin;LU Wei;ZHOU Meihong;ZHANG Nenghui(Shanghai Key Laboratory of Mechanics in Energy Engineering,Shanghai Institute of Applied Mathematics and Mechanics,Shanghai 2000？2,China;Department of Mechanics,College of Sciences,Shanghab University,Shanghai200444,China)

机构地区：[1]上海市应用数学和力学研究所,上海市力学在能源工程中的应用重点实验室,上海200072 [2]上海大学理学院,力学系,上海200444

出　　处：《医用生物力学》2018年第4期348-353,共6页Journal of Medical Biomechanics

基　　金：国家自然科学基金项目(11772182,11272193,10872121).

摘　　要：目的研究高价盐下微观吸引作用对DNA膜弹性性质的影响。方法采用Kornyshev静电拉链模型描述高价盐下DNA链间的相互作用势能;采用思想实验法和宏观连续介质弹性杆模型,预测单向应力状态下DNA膜的应力-应变关系、预应力和弹性模量。结果在给定封装条件下,DNA膜具有拉伸预应力和负的弹性模量,预应力为-1.52～1.17 MPa,弹性模量为-4.2～64 MPa。结论与单价盐下的情形不同,随着封装密度和盐浓度的变化,高价盐作用下微观吸引作用使得DNA膜弹性性能展现出非单调的变化,而且拉压弹性性能明显不同,拉伸预应力和压缩预应力以及正负弹性模量会出现转换。研究结果有助于进一步理解病毒复制的机制,并为基因检测和基因治疗提供参考。Objective To investigate the influence of the microscale attractive interaction on the elastic properties of DNA film in multivalent ion solutions. Methods Kornyshev＇s electrostatic zipper model was employed to describe the interaction energy between the DNA strands. The thought experiment method and macroscopic continuum bar model were combined to predict the stress-strain relationship,prestress,and elastic modulus of the DNA biofilm. Results Given the packing conditions,the DNA film exhibited a tensile prestress and negative elastic modulus. The prestress of the DNA biofilm ranged from -1. 52MPa to 1. 17 MPa,and its elastic modulus ranged from -4. 2MPa to 64 MPa. Conclusions In contrast with monovalent solutions,the microscopic attractive interactions in multivalent solutions caused the elastic properties of the DNA film to exhibit a non-monotonous relationship with the variation in the packing density and salt concentration. The tensile elastic properties were significantly different from the compressive ones,and the tensile/compressive prestress as well as the positive/negative elastic modulus transformed each other. These results can contribute to understanding the mechanism of viral replication and provide references for gene detection and gene therapy.

关 键 词：DNA膜 微观吸引作用 静电拉链模型 拉伸预应力 负弹性模量 

分 类 号：R318.01[医药卫生—生物医学工程]