Artificial multienzyme supramolecular device: highly ordered self-assembly of oligomeric enzymes in vitro and in vivo.

A strategy for scaffold-free self-assembly of multiple oligomeric enzymes was developed by exploiting enzyme oligomerization and protein-protein interaction properties, and was tested both in vitro and in vivo. Octameric leucine dehydrogenase and dimeric formate dehydrogenase were fused to a PDZ (PSD95/Dlg1/zo-1) domain and its ligand, respectively. The fusion proteins self-assembled into extended supramolecular interaction networks. Scanning-electron and atomic-force microscopy showed that the assemblies assumed two-dimensional layer-like structures. A fluorescence complementation assay indicated that the assemblies were localized to the poles of cells. Moreover, both in vitro and in vivo assemblies showed higher NAD(H) recycling efficiency and structural stability than did unassembled structures when applied to a coenzyme recycling system. This work provides a novel method for developing artificial multienzyme supramolecular devices and for compartmentalizing metabolic enzyme cascades in living cells.