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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 have 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
mc2 155 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.

Biography

Sandra Milena Chingaté is Chemist, Magister in Biochemistry Science and doctoral student in Biochemistry Science at the Universidad Nacional De Colombia
. Director of Career Technology in Industrial Chemistry at the Technological Corporation of Bogota. She has developed her research in the area of antimicrobial
peptides as new anti-TB compounds in the research group Biochemistry and Molecular Biology of Mycobacterium at Universidad Nacional De Colombia.