Engineering Approaches to Biomolecular Motors

Engineering Approaches to Biomolecular Motors: From in vitro to in vivo Poster Abstracts

13-POS Board 13 Efficient Operation of Stochastically Driven Biomolecular Systems Steven J. Large , David A. Sivak. Simon Fraser University, Burnaby, BC, Canada.

Biomolecular motors convert different forms of energy into work, performing specific functions in their natural fluctuating environments through effective use of cellular resources. However, a theoretical understanding of biomolecular machines’ operational principles has proven difficult due to an essential characteristic of living organisms: they must operate far from thermodynamic equilibrium. Motivated in part by the hypothesis that evolution has provided selective pressure toward minimizing energy loss during molecular machine's nonequilibrium operation, researchers have developed theoretical models predicting minimum-dissipation methods to transition a stochastic system between two states. These theories typically assume deterministic driving (convenient for single-molecule experimental tests), but in vivo molecular motors are driven by stochastic events such as the ATP hydrolysis cycle. We extend the theory of optimal nonequilibrium control to accommodate stochastic driving forces, leading to notably different minimum-dissipation control regimens. In particular, stochastic control imposes additional costs associated with slow operations. The novel characteristics of minimally dissipative stochastic driving processes point to previously underappreciated design principles for efficient molecular machinery.

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