Molecular dynamics provides insights into an engineered oxidoreductase with altered cofactor specificity
September 15-19, 2019
The aldehyde dehydrogenase from Thermoplasma acidophilum is one of the key enzymes in a previously established synthetic cell-free reaction cascade for the production of alcohols. In order alter the cofactor specificity of this enzyme from NADP+ to NAD+, we applied the CSR-salad tool and investigated further amino acid positions based on its crystal structure. Introduction of five point mutations reduced the Km for NAD+ from 18 mM to 0.6 mM and simultaneously increased the activity for D-glyceraldehyde from 0.4 U/mg to 1.5 U/mg. In order to understand the structural basis of the beneficial mutations, we performed molecular dynamics simulations that showed a significant flexibility gain at the cofactor binding site of the final variant. This increased flexibility facilitates a loop movement that largely contributes to the gain in activity and cofactor specificity. We envision a future optimization potential for aldehyde dehydrogenases based on our results.
Josef M. y Sperl, Volker Sieber, and Tobias Gmelch, "Molecular dynamics provides insights into an engineered oxidoreductase with altered cofactor specificity" in "Enzyme Engineering XXV", Huimin Zhao, University of Illinois at Urbana-Champaign, USA John Wong, Pfizer, USA Eds, ECI Symposium Series, (2019). https://dc.engconfintl.org/enzyme_xxv/57