Antibacterial and Antibiofilm Activity of Temporin-GHc and Temporin-GHd Against Cariogenic Bacteria, Streptococcus mutans
Antibacterial and Antibiofilm Activity of Temporin-GHc and Temporin-GHd Against Cariogenic Bacteria, Streptococcus mutans
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Temporin-GHc 和 Temporin-GHd 对致龋菌、变形链球菌的抗菌和抗菌膜活性
DOI：
10.3389/fmicb.2019.02854
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发表时间：
2019-12-11
影响因子：
5.2
通讯作者：
Zhang, Yingxia
中科院分区：
文献类型：
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作者：
Zhong, Hengren;Xie, Zhipeng;Zhang, Yingxia
Hylarana guentheri 青蛙产生的 Temporin-GHc (GHc) 和 temporin-GHd (GHd) 对细菌和真菌表现出广谱抗菌活性。在这项研究中，我们研究了它们是否对致龋菌、变形链球菌发挥抗菌和抗生物膜活性。 GHc和GHd在水溶液中采用无规卷曲构象，并通过圆二色光谱仪在膜模拟环境中转化为α-螺旋。它们通过组氨酸带正电，极性和非极性氨基酸位于沿着螺旋的相对面上。两亲性使肽能够靶向细菌膜，导致膜渗透增加并破坏变形链球菌，从而使肽能够与基因组 DNA 结合。 GHc 和 GHd 完全阻碍了生物膜形成的初始附着并破坏了预先形成的变形链球菌生物膜。暴露于 GHc 或 GHd 后，变形链球菌中合成葡萄糖基转移酶的胞外多糖 (EPS) 生物合成基因的表达下调，导致可溶性和不溶性 EPS 的减少。在人红细胞存在的情况下，GHc 和 GHd 对变形链球菌表现出选择性，并且在 200 μM 浓度下未观察到对人口腔上皮细胞的细胞毒性。这些结果为 GHc 和 GHd 作为潜在抗龋齿剂的开发奠定了基础。
Temporin-GHc (GHc) and temporin-GHd (GHd) produced by the frog Hylarana guentheri had shown broad-spectrum antibacterial activities against bacteria and fungi. In this study, we investigated whether they exert antibacterial and antibiofilm activities against cariogenic bacteria, Streptococcus mutans. GHc and GHd adopt the random coil conformation in aqueous solution and convert to α-helix in membrane mimetic environments by using circular dichroism spectroscope. They are positively charged by histidine, with the polar and nonpolar amino acids on opposing faces along the helix. The amphipathicity enabled the peptides to target at bacterial membrane, leading to an increase in membrane permeation and disruption of S. mutans, which allowed the peptides to bind with genomic DNA. GHc and GHd completely impeded the initial attachment of biofilm formation and disrupted preformed S. mutans biofilms. The expression of exopolysaccharide (EPS) biosynthesis genes which synthesize glucosyltransferases in S. mutans was downregulated by exposing to GHc or GHd, contributing to the decrease of soluble and insoluble EPS. GHc and GHd exhibited selectivity toward S. mutans in the presence of human erythrocytes, and no cytotoxicity toward human oral epithelial cells was observed at a concentration of 200 μM. These results laid the foundation for the development of GHc and GHd as potential anti-caries agents.