At present, expressing antimicrobial peptides in bacterial models is considered a routine lab bench work. However, low expression yields of these types of proteins are usually obtained. In this work, the antimicrobial peptide human β-defensin 2 (HBD2) was obtained in low expression yields in Escherichia coli BL21(DE3). To improve the expression yields of HBD2, some variables such as cell density, temperature, and length of induction, as well as the inducer concentration, were investigated using a 24-factorial design of experiments (DoE). This approach allowed us to identify the identification of critical variables (main effects and interactions among factors) affecting bacterial HBD2 expression. After the evaluation of 19 different combination, the best condition to express HBD2 had a pre-induction temperature of 37 °C, a cell density of 1.0 U (600 nm), an induction temperature of 20 °C and a 0.1 mM of gene expression inducer (IPTG) over four hours. Under such conditions, the expression yield of the HBD2 peptide was one order of magnitude higher than the peptide expression performed initially.

中文翻译：

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使用实验设计改善人β-防御素2（HBD2）的异源表达。

目前，在细菌模型中表达抗菌肽被认为是常规的实验室工作。然而，通常获得这些类型蛋白质的低表达产量。在这项工作中，在大肠杆菌BL21（DE3）中以低表达量获得了抗菌肽人β-防御素2（HBD2）。为了提高HBD2的表达产量，使用24因子实验设计（DoE）研究了一些变量，例如细胞密度，温度和诱导长度以及诱导剂浓度。这种方法使我们能够识别影响细菌HBD2表达的关键变量（主要影响和因素之间的相互作用）的识别。在评估了19种不同的组合后，表达HBD2的最佳条件是诱导前温度为37°C，细胞密度为1。0 U（600 nm），20°C的诱导温度和0.1 mM的基因表达诱导剂（IPTG），历时4小时。在这样的条件下，HBD2肽的表达产量比最初进行的肽表达高一个数量级。