bi0c00435_si_001.pdf (3.57 MB)
Enzyme Stabilization by Virus-Like Particles
journal contribution
posted on 2020-07-28, 14:38 authored by Soumen Das, Liangjun Zhao, Kristen Elofson, M.G. FinnThe
properties of enzymes packaged within the coat protein shell
of virus-like particles (VLPs) were studied to provide a comprehensive
assessment of such factors. Such entrainment did not seem to perturb
enzyme function, but it did significantly enhance enzyme stability
against several denaturing stimuli such as heat, organic solvents,
and chaotropic agents. This improvement in performance was found to
be general and independent of the number of independent subunits required
and of the number of catalytically active enzymes packaged. Packaged
enzymes were found by measurements of intrinsic tryptophan fluorescence
to retain some of their native folded structure even longer than their
catalytic activity, suggesting that protein folding is a significant
component of the observed catalytic benefits. While we are unable
to distinguish between kinetic and thermodynamic effects –
including inhibition of enzyme unfolding, acceleration of refolding,
and biasing of folding equilibria – VLP packaging appears to
represent a useful general strategy for the stabilization of enzymes
that operate on diffusible substrates and products.