Insights into Nanoarchitectual Structures to Enhance the Catalysis Properties of Human Liver Microsomes

Abstract

Building a nanoarchitectual structure using 1-Pyrenylbutylamine and functionalized multiwalled carbon nanotubes (MWNT) will create an abundance of aminated sites on an electrode for electrostatic interactions binding Human Liver Microsomes (HLM). This increase in secondary interactions will allow for a higher concentration of HLM to bind to the electrode creating a higher catalytic current and increased stability of the bioprocesses involved. Using inexpensive HLM on this nanostructure with applied potential, without NADPH as an electron source, could prove to be a viable bioreactor for swift drug metabolism and inhibition assays. Using cyclic voltammetry the research confirms that High Purity Graphite (HPG) electrodes structured with aminated MWNTs in conjunction with pi-pi stacking of 1-Pyrenylbutylamine with adsorbed HLM increases the catalytic current over 4x that of HLM directly adsorbed on HPG. This nanostructural design demonstrates an almost 2x higher catalytic current using HLM over costly recombinant created CYP enzymes. The formal potential of -0.46 indicates that the CYP reductase is functioning in the HLM and the first to receive the electron transfer as published previously in this lab with recombinant enzymes. Long term impedances stability tests demonstrate that the carbon electrode with this nanostructure is more stable than a costly gold electrode. Using HPLC to measure the hydroxylation of diclofenac to 4’-hydroxydiclofenac HLM outperforms the recombinant enzymes also. Inhibition of the CYP2C9 enzyme in HLM by the competitive inhibitor sulphenazole shown by HPLC indicates that CYP2C9 is responsible for the reduction of diclofenac. This nanostructure design makes improvements over the plain electrode, and could prove to be a feasible method upon to build an inexpensive platform to examine newly developing drugs.