Abstract：
Antimicrobial peptides (AMPs), including beta-defensin from fish, are a crucial class of peptide medicines. The focus of the current study is the molecular and functional attributes of CmDef, a 63-amino acid beta-defensin AMP from Malabar trevally, Carangoides malabaricus. This peptide demonstrated typical characteristics of AMPs, including hydrophobicity, amphipathic nature, and +2.8 net charge. The CmDef was recombinantly expressed and the recombinant peptide, rCmDef displayed a strong antimicrobial activity against bacterial fish pathogens with an MIC of 8 µM for V. proteolyticus and 32 µM for A. hydrophila. The E. tarda and V. harveyi showed an inhibition of 94% and 54%, respectively, at 32 µM concentration. No activity was observed against V. fluvialis and V. alginolyticus. The rCmDef has a multimode of action that exerts an antibacterial effect by membrane depolarization followed by membrane permeabilization and ROS production. rCmDef also exhibited anti-cancer activities in silico without causing hemolysis. The peptide demonstrated stability under various conditions, including different pH levels, temperatures, salts, and metal ions (KCl and CaCl2), and remained stable in the presence of proteases such as trypsin and proteinase K at concentrations up to 0.2 µg/100 µl. The strong antibacterial efficacy and non-cytotoxic nature suggest that rCmDef is a single-edged sword that can contribute significantly to aquaculture disease management.
摘要：
抗菌肽（AMP），包括鱼类的β-防御素,是一类关键的多肽药物。当前研究的重点是CmDef的分子和功能属性，来自马拉巴尔的63个氨基酸的β-防御素AMP，卡拉奇。该肽表现出典型的AMP特征，包括疏水性，两亲性,和+2.8净费用。重组表达CmDef，重组肽，rCmDef对细菌性鱼类病原体表现出很强的抗微生物活性，对蛋白溶弧菌的MIC为8µM，对嗜水菌的MIC为32µM。E.tarda和V.harveyi显示出94％和54％的抑制作用，分别,浓度为32µM。未观察到针对河外弧菌和溶藻弧菌的活性。rCmDef具有通过膜去极化随后膜透化和ROS产生发挥抗菌作用的多模式作用。rCmDef在计算机上也表现出抗癌活性而不引起溶血。该肽在各种条件下表现出稳定性，包括不同的pH值，温度,盐，和金属离子（KCl和CaCl2），并在蛋白酶如胰蛋白酶和蛋白酶K的存在下保持稳定，浓度高达0.2µg/100µl。强大的抗菌功效和非细胞毒性表明，rCmDef是一把单刃剑，可以显着促进水产养殖疾病的管理。
