Rationally Designed Peptides for Organophosphate Adsorption

Avigail Baruch avigailb@post.bgu.ac.il ¹ Ariel Kushmaro ^2,3,5 Hanna Rapaport ^2,4

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

Organophosphates (OPs) used in pesticides and nerve agents are highly toxic. OPs inhibit the enzyme acetylcholinesterase (AChE), which is responsible for the hydrolysis of the neurotransmitter acetylcholine (ACh) into choline and acetate. 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. We have been developing β-sheet peptides for detection and neutralization of OPs.

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, Thioflavin T assay and adsorption through dialysis bags indicated that Paraoxon binds to the designed peptides at various sensitivities. These interactions depend on peptide sequence, conformations and charge. This study assist in establishing the main factors and rules governing the adsorption of paraoxon by designed peptides towards the development of high sensitivity biomimetic systems.