Strategies to improve the cholinesterase inhibitory activity of a novel peptide isolated from the skin secretions of Hysiboas pulchellus (Anura: Hylidae).

SIANO A; ANDUJAR S; ENRIZ D; LAJMANOVICH R,; TONARELLI G

Córdoba

Congreso; 3º REUNIÓN INTERNACIONAL DE CIENCIAS FARMACÉUTICAS?; 2014

.The butyrylcholinesterase (BChE) may represent an important therapeutic target for Alzheimer Disease (AD), and the search for new dual AChE (acetylcholinesterase) and BChE inhibitors is mandatory to find new alternative treatments for AD patients that do not respond to selective AChE inhibitors.P1-Hp-1971 (TKPTLLGLPLGAGPAAGPGKR) is a proline-glycine rich peptide which was identified in the skin secretions of Hypsiboas pulchellus. It was found that this peptide inhibited BChE and AChE enzymes (35% and 20% respectively at 400 μM).In this work, molecular docking calculations were carried out on BChE protein model (pdb-1P0M) to get better insights about the interaction peptide-enzyme, in order to delineate smaller bioactive analogs. According to these results five shorter sequences showed the highest in silico interactions, and were further synthesized by Fmoc (9-Fluorenylmethoxycarbonyl) chemistry.The cholinesterase inhibitory activity of the different peptides was determined by Ellman‟s method. Hemolysis assay was performed using human red blood cells (hRBCs) and following previously described protocols.Low hemolytic activity was found for all the analogs in the whole range of concentrations tested (50?400 μM) and the one covering region 5-21 was the most hemolytic (22% at 200 μM). Analogs 7-21 and 5-21 presented the highest inhibitory effect against both enzymes (over 45% at 100 μM) while the shortest peptides (8-16 and 11-16) showed similar inhibitory activity like P1-Hp-1971.The results suggest that this strategy was useful for designing shorter peptides with improved inhibitory activity against AChE and BChE, and with low cytotoxicity against eukaryotic cells.