Biology subjects

Eason, M. G.

Publications and source records attributed to Eason, M. G..

2 recordsLinked to original sources

bioRxiv2022

Computational remodeling of an enzyme conformational landscape for altered substrate selectivity

Structural plasticity of enzymes dictates their function. Yet, our ability to rationally remodel enzyme conformational landscapes to tailor catalytic properties remains limited. Here, we report a computational procedure for tuning conformational landscapes that is based on multistate design. Using this method, we redesigned the conformational landscape of a natural aminotransferase to preferentially stabilize a less populated but reactive conformation, and thereby increase catalytic efficiency with a non-native substrate to alter substrate selectivity. Steady-state kinetics of designed variants revealed selectivity switches of up to 1900-fold, and structural analyses by room-temperature X-ray crystallography and multitemperature nuclear magnetic resonance spectroscopy confirmed that conformational equilibria favoured the target conformation. Our computational approach opens the door to the fine-tuning of enzyme conformational landscapes to create designer biocatalysts with tailored functionality.

biophysics↗

bioRxiv2020

Genetically-encoded fluorescent biosensor for rapid detection of protein expression

Fluorescent proteins are widely used as fusion tags to detect protein expression in vivo. To become fluorescent, these proteins must undergo chromophore maturation, a slow process with a half-time of 5 to >30 min that causes delays in real-time detection of protein expression. Here, we engineer a genetically-encoded fluorescent biosensor to enable detection of protein expression within seconds in live cells. This sensor for transiently-expressed proteins (STEP) is based on a fully matured but dim green fluorescent protein in which pre-existing fluorescence increases 11-fold in vivo following the specific and rapid binding of a protein tag (Kd 120 nM, kon 1.7 x 105 M-1s-1). In live E. coli cells, our STEP biosensor enables detection of protein expression twice as fast as the use of standard fluorescent protein fusions. Our biosensor opens the door to the real-time study of short-timescale processes in research model animals with high spatiotemporal resolution.

synthetic biology↗