COLL 313 |
| Lavanya Parthasarathy, Sachin S. Vaidya, and Robert Y. Ofoli. Department of Chemical Engineering and Materials Science, Michigan State University, 2527 Engineering Building, East Lansing, MI 48824 |
| We present a systematic protocol for conducting simultaneous optical and electrochemical measurements on the dynamics of biomacromolecules at biomimetic interfaces in total internal reflection (TIR) geometry. The biomimetic interfaces are created by incorporating selected proteins and/or enzymes into reconstituted bilayer lipid membranes (BLM) deposited on indium tin oxide (ITO)-coated microscope slides. The ITO layer acts as an electrically conductive substrate underlying the BLM, making it possible to conduct cyclic voltammetry (CV) experiments inside the flow cell we use for total internal reflection fluorescence microscopy (TIRFM) experiments. This enables simultaneous characterization of the dynamics of the biomacromolecules by both CV and TIRFM. The evanescent wave generated by TIR allows us to selectively illuminate species, thus limiting the dynamics to BLM-associated proteins and enzymes. We have used the technique successfully to incorporate secondary alcohol dehydrogenase (sADH) enzymes into BLMs, and are currently working on doing the same with the vanilloid receptor (VR1). sADH belongs to the family of enzymes called oxidoreductases, and catalyzes reactions that are well suited for coupling to electrodes. VR1 may serve as a molecular transducer for sodium and water balance and may play a significant functional role in preventing salt-induced increases in blood pressure. In this paper, we will present the details of the procedure, and discuss the results of our work on sADH. The long-term goal of this project is to develop biosensor interfaces that electrochemically couple selected proteins and enzymes with electrode surfaces that are compatible with semiconductor manufacturing methods. |
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Symposium in Memory of Arthur W. Adamson
8:30 AM-11:10 AM, Tuesday, March 30, 2004 Marriott -- Orange County 4, Oral
Division of Colloid and Surface Chemistry |