Enzyme Engineering for Chemical Synthesis and Water Absorbing Performance
Time: Fri 2025-03-28 10.00
Location: Kollegiesalen, Brinellvägen 8, Stockholm
Video link: https://kth-se.zoom.us/j/62430600641
Language: English
Subject area: Chemistry
Doctoral student: Luyao Zhao , Industriell bioteknologi, BioCat group
Opponent: Associate Professor Fabio Parmeggiani, Politecnico di Milano, Italien
Supervisor: Professor Per Berglund, Industriell bioteknologi, KTH Royal Institute of Technology; Assistant Professor Christian Schnepel, Durham University, England
QC 20250303
Embargo till och med 2026-03-28 godkänt av skolchef Amelie Eriksson Karlström via e-post 2025-03-21
Abstract
Enzyme engineering is a powerful approach to enhancing biocatalytic performanceand optimizing protein-based materials for diverse applications. This study employsancestral sequence reconstruction (ASR), rational design, and process conditionoptimization to improve enzyme stability, catalytic efficiency, and functionalproperties. Four key areas are explored: transaminase engineering for chiral aminesynthesis, enzymatic amide bond formation, Baeyer-Villiger oxidation selectivitycontrol, and protein-based water-absorbing materials. To enhance thethermostability and substrate scope of ω-transaminase from Silicibacter pomeroyi(Sp-ATA), ASR was used to identify stabilizing mutations, improving its industrialsuitability. For amide bond formation, rational design optimized Pseudomonasaeruginosa N-acyltransferase (PaAT), coupled with the adenylation domain ofSegniliparus rugosus carboxylic acid reductase (CARsr-A). The engineeredY72S/F206N variant significantly enhanced conversion rates for pharmaceuticallyrelevant carboxylic acids, providing a sustainable alternative to chemical synthesis.In Baeyer-Villiger oxidation, process optimization was investigated to controlregioselectivity. Engineered Baeyer-Villiger monooxygenases (BVMOs) fromAcinetobacter and Arthrobacter species shifted product distribution toward the"normal" lactone by increasing oxygen availability. For protein-based waterabsorbingmaterials, patatin mutagenesis altered charged amino acid composition. As demonstrated by molecular dynamics simulations, variants enriched in Lys andAsp doubled water absorption, demonstrating the potential of enzyme engineering insustainable absorbent material development. This study integrates computationaland experimental enzyme engineering strategies to improve biocatalysis for chemicalsynthesis and functional biomaterials, offering novel solutions for industrialbiotechnology and sustainable material science.