title: A simple construction of electrochemical liver microsomal bioreactor for rapid drug metabolism and inhibition assays.
abstract: In order to design a green microsomal bioreactor on suitably identified carbon electrodes, it is important to understand the direct electrochemical properties at the interfaces between various carbon electrode materials and human liver microsomes (HLM). The novelty of this work is on the investigation of directly adsorbed HLM on different carbon electrodes with the goal to develop a simple, rapid, and new bioanalytical platform of HLM useful for drug metabolism and inhibition assays. These novel biointerfaces are designed in this study by a one step adsorption of HLM directly onto polished basal plane pyrolytic graphite (BPG), edge plane pyrolytic graphite (EPG), glassy carbon (GC), or high-purity graphite (HPG) electrodes. The estimated direct electron transfer (ET) rate constant of HLM on the smooth GC surface was significantly greater than that of the other electrodes. On the other hand, the electroactive surface coverage and stability of microsomal films were greater on highly surface defective, rough EPG and HPG electrodes compared to the smooth GC and less defective hydrophobic BPG surfaces. The presence of significantly higher oxygen functionalities and flatness of the GC surface is attributed to favoring faster ET rates of the coated layer of thin HLM film compared to other electrodes. The cytochrome P450 (CYP)-specific bioactivity of the liver microsomal film on the catalytically superior, stable HPG surface was confirmed by monitoring the electrocatalytic conversion of testosterone to 6β-hydroxytestosterone and its inhibition by the CYP-specific ketoconazole inhibitor. The identification of optimal HPG and EPG electrodes to design biologically active interfaces with liver microsomes is suggested to have immense significance in the design of one-step, green bioreactors for stereoselective drug metabolite synthesis and drug metabolism and inhibition assays.
authors: †Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States.
authors: Charuksha
authors: C
authors: Walgama
authors: †Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States.
authors: Rajasekhara
authors: R
authors: Nerimetla
authors: †Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States.
authors: Nicholas F
authors: NF
authors: Materer
authors: ‡Filmetrics Application Lab-Rochester, 250 Packett's Landing, Fairport, New York 14450, United States.
authors: Deniz
authors: D
authors: Schildkraut
authors: ‡Filmetrics Application Lab-Rochester, 250 Packett's Landing, Fairport, New York 14450, United States.
authors: James F
authors: JF
authors: Elman
authors: †Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, United States.
authors: Sadagopan
authors: S
authors: Krishnan
mesh_terms: D055162:Biocatalysis; D019149:Bioreactors; D002244:Carbon / Q000737:chemistry; D065607:Cytochrome P-450 Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D055664:Electrochemical Techniques; D004566:Electrodes; D006801:Humans; D007654:Ketoconazole / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D008862:Microsomes, Liver / Q000737:chemistry* / Q000201:enzymology / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D002244:Carbon; D003577:Cytochrome P-450 Enzyme System; D007654:Ketoconazole