Antimicrobial peptide trichokonin VI-induced alterations in the morphological and nanomechanical properties of Bacillus subtilis.
Antimicrobial peptides are promising alternative antimicrobial agents compared to conventional antibiotics. Understanding the mode of action is important for their further application. We examined the interaction between trichokonin VI, a peptaibol isolated from Trichoderma pseudokoningii, and Bacillus subtilis, a representative Gram-positive bacterium. Trichokonin VI was effective against B. subtilis with a minimal inhibitory concentration of 25 µM. Trichokonin VI exhibited a concentration- and time-dependent effect against B. subtilis, which was studied using atomic force microscopy. The cell wall of B. subtilis collapsed and the roughness increased upon treatment with trichokonin VI. Nanoindentation experiments revealed a progressive decrease in the stiffness of the cells. Furthermore, the membrane permeabilization effect of trichokonin VI on B. subtilis was monitored, and the results suggest that the leakage of intracellular materials is a possible mechanism of action for trichokonin VI, which led to alterations in the morphological and nanomechanical properties of B. subtilis.
State Key Laboratory of Crystal Materials, Marine Biotechnology Research Center, Shandong University, Jinan, People's Republic of China.
Hai-Nan
HN
Su
Zhi-Hua
ZH
Chen
Xiao-Yan
XY
Song
Xiu-Lan
XL
Chen
Mei
M
Shi
Bai-Cheng
BC
Zhou
Xian
X
Zhao
Yu-Zhong
YZ
Zhang
D000408:Alamethicin / Q000031:analogs & derivatives* / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology; D001412:Bacillus subtilis / Q000378:metabolism*; D018450:Disease Progression; D008826:Microbial Sensitivity Tests; D018625:Microscopy, Atomic Force / Q000379:methods; D015233:Models, Statistical; D036103:Nanotechnology / Q000379:methods*; D010455:Peptides / Q000737:chemistry; D010539:Permeability; D013234:Stem Cells; D013314:Stress, Mechanical; D013499:Surface Properties; D014466:Ultraviolet Rays
D000890:Anti-Infective Agents; D010455:Peptides; D000408:Alamethicin; C092827:trichokonin VI