Sandra Milena Chingaté
National University of Colombia, Colombia
Title: In silico design of analogue peptides derived of bombina species with improved antimycobacterial activity in vitro
Biography
Biography: Sandra Milena Chingaté
Abstract
Tuberculosis has become a major public health problem due to the emergence of multidrug-resistant Mycobacterium tuberculosis strains therefore the development of new anti-TB compounds is necessary. The secretions from the skin of the Bombina species has antimicrobial peptides with broad-spectrum activity. In this work, using the server (http://www.imtech.res.in/raghava/antibp/index.html) and database (APD, http://aps.unmc.edu/AP/main.php), derived amino acid sequences of Bombinin and Maximin 1 that displayed the best antibacterial score, cationic and helical structure that improve their interaction with the mycobacterial membrane were obtained. The same analysis was used to modify the primary structure of the selected amino acid sequences in order to increase their antimycobacterial features. The designed peptides were synthesized by the Fmoc technique, characterized by MALDI-TOF and their activity was determined on M.smegmatis mc2155 cells using resazurin. In addition, were assessed the hemolytic activity, their ability to interfere the basal ATPase activity of M. smegmatis mc2155 plasma membrane and cytotoxic activity on murine macrophages J774. The experimental strategy allowed to find the 15 amino acid sequence derived of Bombinin and Maximin 1 with the best antibacterial characteristics and helical structure (peptide-A). The replacement of some amino acids of the peptide-A enabled to find a new sequence (peptide-B) with helical structure to be found, also improved positive charge and augmented antibacterial value. The peptide Maximin 1-B showed a lower MIC (2400µg/mL to 150µg/mL), and Maximin 1-A showed a higher inhibition of the basal ATPase activity of M. smegmatis mc2155 plasma membrane (24,4%), and the peptides don’t show toxicity over murine macrophages.