Engineering of Metabolic Pathways by Artificial Enzyme Channels

Abstract

Application of industrial enzymes for production of valuable chemical compounds has greatly benefited from recent developments in Systems and Synthetic Biology. Both, in vivo and in vitro systems have been established, allowing conversion of simple into complex compounds. Metabolic engineering in living cells needs to be balanced which is achieved by controlling gene expression levels, translation, scaffolding, compartmentation, and flux control. In vitro applications are often hampered by limited protein stability/half-life and insufficient rates of substrate conversion. To improve stability and catalytic activity, proteins are post-translationally modified and arranged in artificial metabolic channels. Within the review article, we will first discuss the supramolecular organization of enzymes in living systems and second summarize current and future approaches to design artificial metabolic channels by additive manufacturing for the efficient production of desired products.

Synthetic redesign of plant lipid metabolism

“…In the future, structural analysis and a greater understanding of protein–protein interactions may enable the organization of artificial pathways in ordered and regulated arrays within specific compartments of plant cells, thereby matching enzyme activity to the metabolic context. Synthetic scaffolds could offer a modular and highly flexible tool for rationally, post‐translationally organizing/co‐localizing multiple functionally related enzymes in a controllable manner (Pröschel et al ., ).…”

Post‐translational Assembly of Protein Parts into Complex Devices by Using SpyTag/SpyCatcher Protein Ligase

“…The engineering of metabolic pathways, reviewed by Pröschel et al. envisioned that functional trimer or oligomer proteins could be assembled by using the SpyTag/SpyCatcher system to construct multienzyme modules whereby covalent enzyme “pipes” can facilitate metabolic channelling . The specificity of the SpyTag/SpyCatcher system would allow programming of the enzyme position and ratio to design complex metabolic pathway modules.…”

Expanding the boundary of biocatalysis: design and optimization of in vitro tandem catalytic reactions for biochemical production

“…Besides the application for the assembly of enzymes that are directly involved in the product synthesis, another application is to fuse the enzymes with their redox partners, such as the widely used fusion protein of P450 with the NAD(P)H reductase (Andre et al, 2013; Peters et al, 2017). In addition to using linkers to form enzyme complex, adding peptide/protein tags to the enzymes can serve as an alternative approach (Han et al, 2017; Liu et al, 2017; Proschel et al, 2015). …”