RATIONALLY DESIGNED PEPTIDES FOR ORGANOPHOSPHATE BIOSENSING

Avigail Baruch ¹ Ariel Kushmaro ^2,3,5 Hanna Rapaport ^2,4

¹Unit of Environmental Engineering, Ben-Gurion University of the Negev, Beer-Sheva
²Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva
³National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, Beer-Sheva
⁴The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva
⁵School of Materials Science and Engineering, Nanyang Technological University, Singapore

Organophosphates (OPs) used in pesticides and nerve agents are highly toxic to the nervous system. OPs inhibit the enzyme acetylcholinesterase (AChE), which responsible for the hydrolysis of the neurotransmitter acetylcholine (ACh), into choline and acetate. In the present study we are developing fluorescently labeled peptides for detection of OPs. Biosensors based on fluorescent labeling of the enzyme AChE for OPs detection have been previously developed, however the manufacturing of these compounds is highly expensive.

Peptides in β-strand structure were designed to include the enzyme’s catalytic three amino acid residues and Paraoxon was used as a model OP in adsorption and binding studies. Results from various analytical measurements including: circular dichroism, electron microscopy and Thioflavin T assay indicated that Paraoxon binds to the designed peptides at various sensitivities, which could be related to the peptide sequence of amino acids and conformations. This study assist in the establishing the main factors and rules governing the detection ability of designed peptides towards future improved sensitivities of such biomimetic systems.