Yu Hui-Yuan, Yip Bak-Sau, Tu Chih-Hsiang, Chen Heng-Li, Chu Hung-Lun, Chih Ya-Han, Cheng Hsi-Tsung, Sue Shih-Che, Cheng Jya-Wei
Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan.
Biochim Biophys Acta. 2013 Nov;1828(11):2720-8. doi: 10.1016/j.bbamem.2013.07.020. Epub 2013 Jul 27.
The efficacies of many antimicrobial peptides are greatly reduced in the presence of high salt concentrations therefore limiting their development as pharmaceutical compounds. PEM-2-W5K/A9W, a short Trp-rich antimicrobial peptide developed based on the structural studies of PEM-2, has been shown to be highly active against various bacterial strains with less hemolytic activity. Here, correlations between membrane immersion depth, orientation, and salt-resistance of PEM-2 and PEM-2-W5K/A9W have been investigated via solution structure and paramagnetic resonance enhancement studies. The antimicrobial activities of PEM-2-W5K/A9W and PEM-2 against various bacterial and fungal strains including multidrug-resistant and clinical isolates under high salt conditions were tested. The activities of the salt-sensitive peptide PEM-2 were reduced and diminished at high salt concentrations, whereas the activities of PEM-2-W5K/A9W were less affected. The results indicated that the strong salt-resistance of PEM-2-W5K/A9W may arise from the peptide positioning itself deeply into microbial cell membranes and thus able to disrupt the membranes more efficiently.
