title: General equilibrium shape equations of polymer chains.
abstract: The general equilibrium shape equations of polymer chains are analytically derived in this paper. This provides a unified description for many models, such as the well-known wormlike chain (WLC) model, the wormlike rod chain (WLRC) model, carbon nanotubes, and so on. Using the WLC model, we find that the pitch-to-radius ratio of coils, 4.443, agrees with Z-DNA, and the pitch-to-radius ratio from WLRC agrees with the data of B-DNA qualitatively. Using the general shape equations, we discuss a chiral model in which the solutions of straight, helical, and circular biopolymers are given, respectively. We also find that the model suggested by Helfrich [Langmuir 7, 567 (1991)] is very appropriate to describe B-DNA (or other biopolymers) if we choose the four phenomenological parameters as A=50 nm , C=60 nm(2) , alpha=40 nm(3) , and beta=50 nm(2) .
authors.affiliation: Department of Applied Physics, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China. zhangsl@mail.xjtu.edu.cn
authors.forename: Shengli
authors.initials: S
authors.lastname: Zhang
authors.forename: Xianjun
authors.initials: X
authors.lastname: Zuo
authors.forename: Minggang
authors.initials: M
authors.lastname: Xia
authors.forename: Shumin
authors.initials: S
authors.lastname: Zhao
authors.forename: Erhu
authors.initials: E
authors.lastname: Zhang
mesh_terms: D001704:Biopolymers / Q000032:analysis* / Q000737:chemistry*; D003198:Computer Simulation; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004735:Energy Transfer; D008956:Models, Chemical; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D013314:Stress, Mechanical
chemical_list: D001704:Biopolymers; D004247:DNA