Identification and structural insights of three novel antimicrobial peptides isolated from green coconut water

Infections caused by pathogenic bacteria could cause an expressive negative impact on human health. A significant enhance in resistance to commercial antibiotics has been observed in all kinds of pathogenic bacteria. In order to find novel approaches to control such common infections, a wide number of defense peptides with bactericidal properties have been characterized. In this report, three peptides lower than 3 kDa were purified and identified from green coconut (Cocos nucifera L.) water by using reversed phase-high performance liquid chromatography (HPLC), showing molecular masses of 858 Da, 1249 Da and 950 Da. First one, named Cn-AMP1, was extremely efficient against both Gram-positive and Gram-negative bacteria, being MICs calculated for three peptides. All complete sequences were determined by MALDI-ToF analysis showing no identity in databanks. Moreover, peptide net charge and hydrophobicity of each peptide was in silico evaluated. Finally molecular modeling and dynamics were also applied generating peptides three-dimensional structures, indicating a better explanation to probable mechanisms of action. Cn-AMPs here reported show remarkable potential to contribute in the development of novel antibiotics from natural sources. (c) 2008 Elsevier Inc. All rights reserved.