Stretching of homopolymers and contact order.
Mechanical stretching of self-interacting homopolymers is studied through molecular dynamics simulations in which the polymers are pulled with constant speed. At temperatures below the compactification temperature, the force-extension curves show a plateau that corresponds to the situation in which the polymer adopts "ball-string" configurations. The dependence of rupture distances on contact order and the effects of temperature are similar to those found in the case of model proteins. The dependence of behavior on the pulling speed is logarithmic. In the entropic limit, above the compactification temperature, the rupturing of contacts shows a monotonic decrease of extension with the contact order. The attainment of this limit depends on the system size and the pulling speed.
Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
Marek
M
Cieplak
Trinh Xuan
TX
Hoang
Mark O
MO
Robbins
D001704:Biopolymers / Q000737:chemistry*; D003198:Computer Simulation; D004548:Elasticity; D046911:Macromolecular Substances; D008846:Micromanipulation / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D009691:Nucleic Acid Denaturation; D010812:Physical Stimulation / Q000379:methods; D011489:Protein Denaturation; D013314:Stress, Mechanical; D013696:Temperature
D001704:Biopolymers; D046911:Macromolecular Substances