Structurally Guided Design of a Stand-Alone Acyltransferase

This research project focuses on the computer-aided design of enzymes for environmentally friendly chemical reactions. Enzymes are biological catalysts that can accelerate chemical reactions and make them more efficient even outside their natural environment, offering a more sustainable approach to chemical synthesis. The overarching vision of computational enzyme design is to transfer time-consuming, expensive, and environmentally impactful screening processes from a traditional laboratory setting, or wet lab, to a computational environment, or dry lab. Our goal is to better understand and consequently optimize the structure of a specific enzyme, the acyltransferase from Pseudomonas protegens (PpATase). This enzyme can very precisely produce certain chemical compounds that are important in pharmacy. Specifically, PpATase has the ability to selectively transfer acyl groups to phloroglucinol and resorcinol derivatives, which represents the biocatalytic counterpart to Friedel-Crafts acylation. This provides access to valuable polyketide scaffolds, which possess diverse bioactive properties. Using comprehensive computational modeling, the complex structure of the enzyme is first analyzed. By studying the movements and changes in enzyme conformation, it is possible to identify which parts of the enzyme are crucial for its function, stability and structural integrity. Based on this information, targeted modifications can optimize the enzyme. Specifically, in our case, this involves simplifying it so that it functions independently, without relying on other parts of its structure. The computer-aided predictions are then verified through laboratory experiments, and the results can feed back into the design process. Beyond the immediate benefit of potentially optimizing an industrially relevant biocatalyst, the central innovation of our project is to demonstrate the effectiveness of the conformation-driven enzyme design process.