We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Active Site Local Environment Allows Acidic and Basic Synergy in Enzymatic Ester Hydrolysis by PETase
Summary
This study revealed at atomic resolution how the PET-degrading enzyme PETase exploits both acidic and basic chemistry simultaneously — using high pH for nucleophilic attack while local hydrogen bonds stabilize reaction intermediates — and proposed two engineering strategies to boost its reactivity. These insights advance the development of enzymatic solutions to reduce PET plastic pollution in the environment.
Polyethylene terephthalate (PET) is a commonly used plastic worldwide and reducing its prevalence is crucial to improving environmental pollution. PETase that degrades PET plastic have received a lot of attention recently. This paper evaluates the ester hydrolysis process under both acidic and basic conditions, and shows that the local environment of the protein active site takes advantage of both. High pH in the protein buffer creates a better nucleophile to attack the ester through a proton shuttle channel in the protein, while local hydrogen bonds to the carbonyl of the ester stabilizes the intermediate/transition state of the hydrolysis reaction. With the understanding at the atomic level, we propose two engineering directions that can potentially improve the reactivity of the PETase: 1) increase the alkaline stability of the protein in general; 2) perturb the local hydrogen bond network to increase the partial charge on the PET carbonyl to be hydrolyzed.