Smoldyn

Smoldyn performs spatial stochastic simulations of chemical reaction networks at the cellular scale, modeling individual-molecule diffusion, chemical reactions, and membrane interactions to study spatially resolved intracellular biochemical dynamics.

Key Features:

• Spatial Stochastic Modeling: Simulates random collisions and diffusion of individual protein molecules within cellular geometries to represent spatially resolved stochastic biochemical processes.
• Algorithmic Innovation: Implements algorithms for molecular diffusion, membrane interactions, and chemical reactions at molecular resolution.
• Comparative Efficiency: In benchmark comparisons with MCell and ChemCell, demonstrated superior accuracy and computational efficiency.
• Scalability: Supports simulations of up to 200,000 protein molecules within approximately 7,000 cubic microns over simulated timescales of about 75 minutes and is intended to scale toward modeling entire bacterial cells and smaller eukaryotic cells.

Scientific Applications:

• Pheromone Response System Signaling: Modeled signaling dynamics among yeast cells of opposite mating types, showing how secreted Bar1 protease can refine pheromone concentration gradients and aid mate selection.

Methodology:

Performs molecular-level stochastic simulation to capture the effects of individual-molecule fluctuations and spatial configuration; emphasizes computational efficiency, with reported runtimes such as approximately 10 hours for a detailed yeast cell model.