A Modular Bioplatform Based on a Versatile Supramolecular Multienzyme Complex Directly Attached to Graphene

Abstract

Developing generic strategies for building adaptable or multifunctional bioplatforms is challenging, in particular because protein immobilization onto surfaces often causes loss of protein function and because multifunctionality usually necessitates specific combinations of heterogeneous elements. Here, we introduce a generic, modular bioplatform construction strategy that uses cage-like supramolecular multienzyme complexes as highly adaptable building blocks immobilized directly and noncovalently 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 multifunctionality. 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 6 orders of magnitude in substrate concentration. The E2-graphene platform can be multiplexed via patterned cotransfer 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.