Stochastic Modeling of CTB-GM1 Binding Kinetics
Dongheon Lee (1,2), Alec Mohr(1), Joseph S. Kwon(1,2), Hung-Jen Wu(1)
1. Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX
2. Texas A&M Energy Institute, Texas A&M University, College Station, TX
Cholera toxin (CTx) is a toxin protein, which can lead to lethal cholera. CTx is an AB5 protein that consists of an enzymatic A-subunit and five identical cholera toxin B-subunits (CTB). CTB binds with gangliosides such as GM1 on host cell membrane, which facilitates the endocytosis of CTx and the development of cholera. How cholera toxin subunit B (CTB) binds to its receptor on host cell membrane is still not fully understood due to its complex nature. Since the binding events highly depend on the current surface configuration, the kinetic Monte Carlo methodology is applied to simulate the complex interactions between CTB and GM1 microscopically. The proposed kMC model considers receptor migration, CTB attachment and detachment, and surface forward and backward reactions as discrete microscopic events. At every moment, an event to be executed is selected randomly based on the rates of all possible events, and this procedure continues till the end of simulation. In summary, we utilize theoretical modeling to explore cholera pathogenesis and offers a systematic tool for the biomedical community to reveal the pathogenesis of other diseases.
Keywords: Systems biology, cholera toxin, kinetic Monte Carlo, mathematical biology