223rd iCeMS Seminar: Prof Henry Hess

Prof Henry Hess
Department of Biomedical Engineering, Columbia University, US

Engineering with biomolecular motors
Motor proteins, including kinesin, can serve as biological components in engineered hybrid
nanosystems. Our recent work focused on degradation mechanisms in these nanosystems,
including microtubule breaking and shrinking. Mechanical failure of such biological
nanostructures due to forces exerted by biomolecular motors has been studied by us in
functionality and and explained with the principles of mechanochemistry and mechanical
fatigue. Molecular motors also introduce an interesting new element into self-assembly
processes by accelerating transport, reducing unwanted connections, and enabling the
formation of non-equilibrium structures. Our recent work created a molecular system that is
capable of dynamically assembling and disassembling its building blocks while retaining its
functionality and demonstrates the possibility of self- healing and adaptation. Secondly, the
observed enhancement of the throughput of enzymatic cascades on scaffolds will be
discussed. Using the cascade reaction carried out by glucose oxidase and horseradish
peroxidase as a model system, we studied the kinetics of the cascade reaction. Our findings
challenge the notion of a proximity effect and provide new insights into the role of scaffolds,
compartments, and of the enzyme environment. Finally, I will critically discuss “enhanced
diffusion”, the observed increase of enzyme diffusion coefficients when the enzymes are
catalytically active.