@ARTICLE{Pei_Z._Biological_2018, author={Pei, Z. and Ying, X. and Tang, Y. and Liu, L. and Zhang, H. and Liu, S. and Zhang, D. and Wang, K. and Kong, L. and Gao, Y. and Ma, H.}, volume={vol. 21}, number={No 3}, journal={Polish Journal of Veterinary Sciences}, pages={533–542}, howpublished={online}, year={2018}, publisher={Polish Academy of Sciences Committee of Veterinary Sciences}, publisher={University of Warmia and Mazury in Olsztyn}, abstract={MDAP-2 is a new antibacterial peptide with a unique structure that was isolated from house- flies. However, its biological characteristics and antibacterial mechanisms against bacteria are still poorly understood. To study the biological characteristics, antibacterial activity, hemolytic activi- ty, cytotoxicity to mammalian cells, and the secondary structure of MDAP-2 were detected; the results showed that MDAP-2 displayed high antibacterial activity against all of the tested Gram-negative bacteria. MDAP-2 had lower hemolytic activity to rabbit red blood cells; only 3.4% hemolytic activity was observed at a concentration of 800μg/ml. MDAP-2 also had lower cytotoxicity to mammalian cells; IC50 values for HEK-293 cells, VERO cells, and IPEC-J2 cells were greater than 1000 μg/ml. The circular dichroism (CD) spectra showed that the peptide most- ly has α-helical properties and some β-fold structure in water and in membrane-like conditions. MDAP-2 is therefore a promising antibacterial agent against Gram-negative bacteria. To deter- mine the antibacterial mechanism(s) of action, fluorescent probes, flow cytometry, and transmis- sion electron microscopy (TEM) were used to study the effects of MDAP-2 on membrane perme- ability, polarization ability, and integrity of Gram-negative bacteria. The results indicated that the peptide caused membrane depolarization, increased membrane permeability, and destroyed membrane integrity. In conclusion, MDAP-2 is a broad-spectrum, lower hemolytic activity, and lower cytotoxicity antibacterial peptide, which is mainly effective on Gram-negative bacteria. It exerts its antimicrobial effects by causing bacterial cytoplasm membrane depolarization, increas- ing cell membrane permeability and disturbing the membrane integrity of Gram-negative bacte- ria. MDAP-2 may offer a new strategy to for defense against Gram-negative bacteria.}, type={Artykuły / Articles}, title={Biological characteristics of a new antibacterial peptide and its antibacterial mechanisms against Gram-negative bacteria}, URL={http://journals.pan.pl/Content/108441/PDF/15.pdf}, doi={10.24425/124287}, keywords={antimicrobial peptide, biological characteristics, antibacterial mechanism, Gram-negative bacteria}, }