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Engineering Approaches to Biomolecular Motors: From in vitro to in vivo Poster Abstracts
45
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.