Microsomal Bioelectrodes Modified with Nanostructures for Rapid Drug Metabolism and Inhibition Assays and Cost-Effective Green Synthesis

Abstract

Purification of membrane-bound enzymes in general and drug metabolizing human liver cytochrome P450 heme enzymes (CYPs)[1] in particular has been a major bottleneck in advancing the field of enzyme electrocatalysis. The ability to use unpurified enzymes and additionally mimic in vivo drug metabolic pathways would accelerate current drug development processes by enabling cost-effective rapid electrochemical drug screening and stereoselective drug metabolite synthesis. For new drug development, human liver microsomes (HLMs) are being used as in vitro systems to study drug metabolism, inhibition, and drug-drug interactions and to identify the specific isoforms of CYPs involved in these processes.[2] Application of liver microsomes or genetically engineered versions of microsomes containing CYPs and CYP-reductase in the development of new biosensing and electrocatalytic systems is an emerging research area.[3] Recently, our laboratory examined the influences of various carbon electrode materials in the direct electron transfer and electrocatalytic properties of immobilized HLMs.[4] We found that electrode roughness and hydrophilic nature offered greater electrocatalytic currents and microsomal film stability on electrodes. As a next step, our goal is to achieve highly enhanced electrocatalytic metabolite production with sufficient electrocatalytic stability and reusability features. For this, we are exploring various nanotechnology strategies to immobilize microsomes in biologically active form. Results from our preliminary findings in this objective utilizing carbon and metal oxide nanomaterials will be discussed. [1] P. R. Ortiz de Montellano, Future Med. Chem. 2013, 5, 213-228. [2] L. C. Wienkers, and T. G. Heath, Nat. Rev. Drug Discov. 2005, 4, 825-833. [3] S. Krishnan, J. B. Schenkman, and J. F. Rusling, J. Phys. Chem. B 2011, 115, 8371-8380. [4] C. Walgama, R. Nerimetla, N. F. Materer, D. Schildkraut, J. F. Elman, and S. Krishnan, Anal. Chem. 2015 , 87 , 4712-4718.