Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ 28013-602, Brazil.
Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ 28013-602, Brazil.
Biochim Biophys Acta Gen Subj. 2022 Nov;1866(11):130218. doi: 10.1016/j.bbagen.2022.130218. Epub 2022 Jul 26.
Antimicrobial peptides, natural or synthetic, appear as promising molecules for antimicrobial therapy because of their both broad antimicrobial activity and mechanism of action. Herein, we determine the anti-Candida and antimycobacterial activities, mechanism of action on yeasts, and cytotoxicity on mammalian cells in the presence of the bioinspired peptide CaDef2.1.
CaDef2.1 was designed to attain the following criteria: high positive net charge; low molecular weight (<3000 Da); Boman index ≤2.5; and total hydrophobic ratio ≥ 40%. The mechanism of action was studied by growth inhibition, plasma membrane permeabilization, ROS induction, mitochondrial functionality, and metacaspase activity assays. The cytotoxicity on macrophages, monocytes, and erythrocytes were also determined.
CaDef2.1 showed inhibitory activity against Candida spp. with MIC values ranging from 25 to 50 μM and the standard and clinical isolate of Mycobacterium tuberculosis with MIC of 33.2 and 55.4 μM, respectively. We demonstrate that CaDef2.1 is active against yeasts at different salt concentrations, induced morphological alterations, caused membrane permeabilization, increased ROS, causes loss of mitochondrial functionality, and activation of metacaspases. CaDef2.1 has low cytotoxicity against mammalian cells.
The results obtained showed that CaDef2.1 has great antimicrobial activity against Candida spp. and M. tuberculosis with low toxicity to host cells. For Candida spp., the treatment with CaDef2.1 induces a process of regulated cell death with apoptosis-like features.
We show a new AMP bioinspired with physicochemical characteristics important for selectivity and antimicrobial activity, which is a promising candidate for drug development, mainly to control Candida infections.
由于具有广谱抗菌活性和作用机制，抗菌肽（天然或合成）似乎是一种有前途的抗菌治疗药物。在此，我们确定了仿生肽 CaDef2.1 的抗念珠菌和抗分枝杆菌活性、对酵母的作用机制以及对哺乳动物细胞的细胞毒性。
CaDef2.1 的设计旨在达到以下标准：高正净电荷；低分子量（<3000 Da）；Boman 指数≤2.5；总疏水性比≥40%。通过生长抑制、质膜通透性、ROS 诱导、线粒体功能和介体型半胱氨酸蛋白酶活性测定来研究作用机制。还测定了巨噬细胞、单核细胞和红细胞的细胞毒性。
CaDef2.1 对念珠菌属具有抑制活性，MIC 值范围为 25 至 50 μM，对标准和临床分离的结核分枝杆菌的 MIC 值分别为 33.2 和 55.4 μM。我们证明 CaDef2.1 在不同盐浓度下对酵母有效，引起形态改变，导致膜通透性增加，ROS 增加，线粒体功能丧失，介体型半胱氨酸蛋白酶激活。CaDef2.1 对哺乳动物细胞的细胞毒性较低。
所得结果表明，CaDef2.1 对念珠菌属和结核分枝杆菌具有很强的抗菌活性，对宿主细胞的毒性低。对于念珠菌属，CaDef2.1 的治疗会诱导一种具有凋亡样特征的程序性细胞死亡过程。
我们展示了一种具有物理化学特性的新型 AMP 仿生物，这些特性对于选择性和抗菌活性很重要，是一种有前途的药物开发候选物，主要用于控制念珠菌感染。
