Sung Woo Sang, Lee Juneyoung, Lee Dong Gun
School of Life Sciences & Biotechnology, College of Natural Sciences, Kyungpook National University, 1370 Sankyukdong, Puk-ku, Daegu 702-701, Republic of Korea.
Biol Pharm Bull. 2008 Oct;31(10):1906-10. doi: 10.1248/bpb.31.1906.
Piscidin, a 22-residue cationic peptide isolated from the mast cells of hybrid striped bass, has potent antimicrobial activities. In the present study, we investigated the fungicidal activity and mode of action of piscidins. Fungicidal and hemolytic assays were examined in order to assess their potency and toxicity, respectively. The results showed that fungicidal and hemolytic activities were higher for piscidin 1 (P1) than piscidin 3 (P3). Additionally, the abilities to permeabilize the model phospholipids membranes were also higher for P1 than P3, which were consistent with the biological activities of P1 and P3. These results suggest that the biological action of the peptides may be carried out through the lipid membrane. To understand the fungicidal properties of P1, we focused on a membrane-active mechanism of the peptide by in vivo testing against Candida albicans as the model organism. Flow cytometric analysis by using bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC(4)(3)] and protoplast regeneration experiments showed that P1 caused fungal membrane damage. Furthermore, fluorescence analysis, using 1,6-diphenyl-1,3,5-hexatriene, revealed that these peptides created pores in fungal membranes. Thus, the present study demonstrated that piscidins exert their fungicidal effects by disrupting fungal membrane through pore formation.
杀鱼菌素是一种从杂交条纹鲈肥大细胞中分离出的由22个氨基酸残基组成的阳离子肽，具有强大的抗菌活性。在本研究中，我们研究了杀鱼菌素的杀真菌活性和作用方式。分别通过杀真菌和溶血试验来评估它们的效力和毒性。结果表明，杀鱼菌素1（P1）的杀真菌和溶血活性高于杀鱼菌素3（P3）。此外，P1使模型磷脂膜通透性增加的能力也高于P3，这与P1和P3的生物学活性一致。这些结果表明，这些肽的生物学作用可能是通过脂质膜来实现的。为了解P1的杀真菌特性，我们以白色念珠菌为模式生物，通过体内试验着重研究了该肽的膜活性机制。使用双（1,3 - 二丁基巴比妥酸）三甲川氧杂羰花青[DiBAC(4)(3)]进行的流式细胞术分析和原生质体再生实验表明，P1会导致真菌膜损伤。此外，使用1,6 - 二苯基 - 1,3,5 - 己三烯进行的荧光分析表明，这些肽会在真菌膜上形成孔。因此，本研究表明，杀鱼菌素通过形成孔破坏真菌膜来发挥其杀真菌作用。
