"Engineering an aldehyde dehydrogenase via structure based directed evo" by Ye Seop Park, Un Jong Choi et al.
 

Title

Engineering an aldehyde dehydrogenase via structure based directed evolution for enhancement of 3-hydroxypropionic acid production

Conference Dates

September 15-19, 2019

Abstract

3-Hydroxypropionic acid (3-HP) can be produced via two enzymatic reactions: dehydration of glycerol to 3-hydroxypropanal (3-HPA) and oxidation to 3-HP. Commercial production of 3-HP has been beset with several problems. Some of these problems are associated with the toxicity of 3-HPA and the efficiency of NAD+ regeneration. We engineered α-ketoglutaric semialdehyde dehydrogenase (KGSADH) for the second reaction to address these issues. The residues in the putative binding sites for the substrates, 3-HPA and NAD+, were randomized, and the libraries were screened for higher activity. Isolated KGSADH variants had lower Km values for both substrates. The enzymes showed higher substrate specificities for aldehyde and NAD+, less inhibition by NADH, and greater resistance to inactivation by 3-HPA than the wild-type enzyme. A recombinant Pseudomonas denitrificans strain with one of the engineered KGSADH variants exhibited less accumulation of 3-HPA, decreased levels of inactivation of the enzymes involved in the production of 3-HP. These attributes facilitated sustained production of 3-HP in to the late stages of culture and enhanced the final titer of 3-HP by approximately 40%.

This document is currently not available here.

Share

COinS