Zhang Jie, Wu Xi, Zhang Shuang-Quan
Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, Nanjing Normal University, Nanjing 210046, China.
Biotechnol Lett. 2008 Dec;30(12):2157-63. doi: 10.1007/s10529-008-9819-x. Epub 2008 Aug 12.
Antibacterial peptide, CM4 (ABP-CM4), a 35 amino acid peptide from Chinese silkworm-Bombyx mori, displayed a strong antifungal activity against Aspergillus niger, Trichoderma viride and Gibberella saubinetii. Scanning electron microcopy showed that the morphology of conidia became more irregular and swelled when treated with ABP-CM4 at its minimal inhibitory concentration (MIC) of 8 muM. A cell wall regeneration assay indicated that the plasma membrane was the prime target of ABP-CM4 action. Confocal laser scanning microscopy showed that the cytoskeleton of A. niger was destroyed when treated with ABP-CM4 at 8 muM. Furthermore, transmission electron microscopy showed that the membrane and the cellular organelles of fungus were disrupted and there were many vacuoles in the fungal cellular space after the treatment with ABP-CM4. A gel-retardation assay showed that ABP-CM4 bound the DNA of A. niger. Our results suggest that ABP-CM4 exerts its antifungal activity by disrupting the structure of cell membranes and the cytoskeleton and interacts with the organelles, such as the mitochondrion and with the DNA in the fungal cell, subsequently resulting in cell death.
抗菌肽CM4（ABP-CM4）是一种来自中国家蚕——桑蚕的由35个氨基酸组成的肽，对黑曲霉、绿色木霉和小麦赤霉显示出强大的抗真菌活性。扫描电子显微镜显示，当用最小抑菌浓度（MIC）为8 μM的ABP-CM4处理时，分生孢子的形态变得更加不规则且肿胀。细胞壁再生试验表明，质膜是ABP-CM4作用的主要靶点。共聚焦激光扫描显微镜显示，用8 μM的ABP-CM4处理黑曲霉时，其细胞骨架被破坏。此外，透射电子显微镜显示，用ABP-CM4处理后，真菌的膜和细胞器被破坏，真菌细胞空间内有许多液泡。凝胶阻滞试验表明，ABP-CM4与黑曲霉的DNA结合。我们的结果表明，ABP-CM4通过破坏细胞膜和细胞骨架的结构并与细胞器（如线粒体）以及真菌细胞中的DNA相互作用来发挥其抗真菌活性，随后导致细胞死亡。
