Conformationally Adaptive Peptide Derived Biosensors

Shlomo Yitzchaik, Chemistry, The Hebrew University, Jerusalem, Israel (sy@cc.huji.ac.il)

In this contribution we’ll exemplified the usefulness of label free electrochemical biosensors that utilizes proteins and peptides conformational changes for improved biosensing. Molecular recognition events accompanied with conformational alternation are prone to undergo collective structural change when assembled in monolayers. This phenomenon is demonstrated for ions, small molecules and proteins biosensing. A case study for neurodegenerative disease will be described in depth.  

Zinc and copper are essential metal ions for numerous biological processes. Their levels are tightly maintained in all body organs. Impairment of the Zn²⁺ to Cu²⁺ ratio in serum was found to correlate with many disease states, including immunological and inflammatory disorders. Oxytocin (OT) is a neuropeptide, and its activity is modulated by zinc and copper ion binding. Harnessing the intrinsic properties of OT is one of the attractive ways to develop valuable metal ion sensors. In this talk, we report an OT-based metal ion sensor prepared by immobilizing the neuropeptide onto a glassy carbon electrode. The developed impedimetric biosensor was ultrasensitive to Zn²⁺ and Cu²⁺ ions at physiological pH and not to other biologically relevant ions. Selective masking of Zn²⁺ and Cu²⁺ was used to allow for the simultaneous determination of zinc to copper ions ratio by the OT sensor. The OT sensor was able to distinguish between healthy control and multiple sclerosis patients diluted sera samples by determining the Zn/Cu ratio similar to the state-of-the-art techniques. The OT sensor presented herein is likely to have numerous applications in biomedical research and pave the way to other types of neuropeptide-derived sensors.

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Short Biography of Presenting Author

Prof. Shlomo Yitzchaik received his Ph.D. in macromolecular chemistry of photochromic mesophases from the Weizmann Institute of Science, Israel, in 1991. Between 1992-1995 he pursued postdoctoral research in the field of surface chemistry of chromophoric superlattices, at Northwestern University - USA, in the lab of Prof. Tobin J. Marks. In 1996 he joined the institute of chemistry at the Hebrew University of Jerusalem, Israel. Since 2006 he is Professor of Chemistry at the Hebrew University. His major research interests are macromolecular and surface chemistry; he developed the topotactic self-assembly and the molecular layer epitaxy methodologies for assembling nanolayers for electronics and photonics uses. He has also developed a modular method to link molecular transducers to various surfaces achieving useful biosensing devices detecting ions, neurotransmitters, biomolecules, and neuronal activity. Prof. Yitzchaik won the outstanding young scientist prize from the Israeli Chemical Society, the Richard-Willstätter award from the German Chemical Society, the Applied Materials Research Excellence Prize from the Israel Vacuum Society, the Kaye Innovation award from the Hebrew University, The Braun-Roger-Siegel prize from the Israel Science Foundation, and The John van Geuns award from the University of Amsterdam. Currently he holds the Binjamin H. Birstein Chair in Chemistry.