Helix-Coil Transition of Worm-like Polymers – Gustavo Carri

Date: Thu. April 8th, 2004, 4:15 pm-5:15 pm
Location: Rockefeller 301

Many macromolecules like proteins and polypeptides are known to form secondary structures called a-helices at low enough temperatures or under appropriate solvent conditions. The transition from the ordered state (a-helix) at low temperatures to the disordered one (random coil) at high temperatures is called the helix-coil transition. Simulating this transition and the resulting physical behavior of a-helices has proven to be a very challenging task even for modern computational systems. In this talk I will present a novel geometric approach to the simulation of the helix-coil transition in worm-like polymers. This approach combines the traditional statistical-mechanical concepts proposed by Zimm, Bragg and other researchers with advanced Monte Carlo methods recently developed by Landau and Wang. Explicitly, I will explore the effects of molecular and thermodynamic parameters like temperature, length of the polymer chain and others on the thermodynamic, conformational and configurational properties of the polymer. Comparisons with experimental observations and predictions from other simulations will be shown whenever possible. Finally, I will discuss the theoretical implications of the results obtained from our simulation studies.