Abstract:The present study investigated the antibacterial effected of the peptide Met-Ala-Lys (MAK) on the structure of Pseudomonas aeruginosa based on the NPN fluorescence method, the circular dichroism spectroscopy analysis, and the level of potassium ions and protein were employed respectively to characterize the extracellular membrane permeability, the variation of secondary structure, and the cell surface hydrophobicity and its endometrial permeability induced by the MAK. The results showed that with the increase of time, the secondary-structure, specially the Random coil, of MAK changed, resulting in the leakage of potassium (getting rapidly from the first 10 min) and protein were significantly high (from 4.65 μg/mL to 10.25 μg/mL), indicating that the inner (from 54.03% to 27.33%) and outer (increase rapidly in the first 30 min and basically stable at around 45 after 30 min ) membrane permeability were changed, thus, MAK can change the surface characteristics of Pseudomonas aeruginosa and contribute to the inhibition of bacterial growth. These results may provide some information for further study of antibacterial peptide, especially in the aspect of the mechanism of antibacterial peptide Met-Ala-Lys.
