Abstract Mytichitin-CB was isolated from Mytilus coruscus in 2014. This antimicrobial peptide shows a weak inhibitory effect on Gram-negative bacteria but inhibits the growth of Gram-positive bacteria and fungi efficiently. Here, a C-terminal hemagglutinin and 6×Histidine (HA-6×His) double tagged three tandem repeats of Mytichitin-CB (3×Mytichitin-CB) with a molecular weight of about 21.5 kDa was expressed in Chlamydomonas reinhardtii. The recombinant 3×Mytichitin-CB was stably expressed following continuous sixth passages of cells and inhibited the growth of both Gram-negative and Gram-positive bacteria at maximum inhibitory concentration (MIC) values between 30 and 50 µg/ml. 3×Mytichitin-CB was stable in terms of its antibacterial activity when treated by a wide range of temperatures and pHs and was resistant to digestion by various proteases. C. reinhardtii-derived 3×Mytichitin-CB had low hemolytic activity and cell cytotoxicity. Moreover, 3×Mytichitin-CB efficiently caused changes on the cell morphology by destroying membrane integrity of the tested bacteria. Our data thus, for the first time, show that C. reinhardtii is a suitable host for stably expressing recombinant 3×Mytichitin-CB, which possesses potent antibacterial properties.

中文翻译：

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Chlamydomonas reinhardtii 衍生的多聚体 Mytichitin-CB 具有有效的抗菌特性

摘要 Mytichitin-CB于2014年从Mytilus coruscus中分离得到。该抗菌肽对革兰氏阴性菌的抑制作用较弱，但对革兰氏阳性菌和真菌的生长有有效的抑制作用。在这里，在莱茵衣藻中表达了分子量约为 21.5 kDa 的 C 端血凝素和 6×组氨酸 (HA-6×His) 双标记的三个串联重复的 Mytichitin-CB (3×Mytichitin-CB)。重组 3×Mytichitin-CB 在细胞连续第六次传代后稳定表达，并在 30 和 50 µg/ml 之间的最大抑制浓度 (MIC) 值下抑制革兰氏阴性菌和革兰氏阳性菌的生长。3×Mytichitin-CB 在广泛的温度和 pH 值范围内处理时，其抗菌活性是稳定的，并且对各种蛋白酶的消化具有抗性。C。reinhardtii 来源的 3×Mytichitin-CB 具有低溶血活性和细胞毒性。此外，3×Mytichitin-CB 通过破坏受试细菌的膜完整性有效地引起细胞形态的变化。因此，我们的数据首次表明莱茵衣藻是稳定表达重组 3×Mytichitin-CB 的合适宿主，其具有强效抗菌特性。