A Modular Bio-Platform Based on a Versatile Supramolecular Multi-Enzyme Complex Directly Attached to Graphene

Developing generic strategies for building adaptable or multi-functional bio-platforms is challenging, in particular because protein immobilization onto surfaces often causes loss of protein function and multi-functionality usually necessitates specific combinations of heterogeneous elements. Here we introduce a generic, modular bio-platform construction strategy that uses cage-like supramolecular multi-enzyme complexes as highly adaptable building blocks immobilized directly and non-covalently on graphene. Thermoplasma acidophilum dihydrolipoyl acyltransferase (E2) supramolecular complexes organize as a monolayer or can be controllably transferred onto graphene, preserving their supramolecular form with specific molecular recognition capability and capacity for engineering multi-functionality. This E2-graphene platform can bind enzymes (here, E1, E2’s physiological partner) without loss of enzyme function; in this test case, E1 catalytic activity was detected on E2-graphene over six orders of magnitude in substrate concentration. The E2-graphene platform can be multiplexed via patterned co-transfer of differently modified E2 complexes. As the E2 complexes are robust and highly customizable, E2-graphene is a platform onto which multiple functionalities can be built.