Al Kashgry Najla Amin T, Abulreesh Hussein H, El-Sheikh Iman A, Almaroai Yaser A, Salem Reda, Mohamed Ismail, Waly Fatma R, Osman Gamal, Mohamed Mahmoud S M
Biology Department, College of Science, Taif University, Taif, Saudi Arabia.
Department of Biology, Faculty of Applied Science, Umm Al-Qura University, Makkah, Saudi Arabia.
AMB Express. 2020 Nov 25;10(1):208. doi: 10.1186/s13568-020-01146-9.
The search for effective and bioactive antimicrobial molecules to encounter the medical need for new antibiotics is an encouraging area of research. Plant defensins are small cationic, cysteine-rich peptides with a stabilized tertiary structure by disulfide-bridges and characterized by a wide range of biological functions. The heterologous expression of Egyptian maize defensin (MzDef) in Escherichia coli and subsequent purification by glutathione affinity chromatography yielded 2 mg/L of recombinant defensin peptide. The glutathione-S-transferase (GST)-tagged MzDef of approximately 30 kDa in size (26 KDa GST + ~ 4 KDa MzDef peptide) was immunodetected with anti-GST antibodies. The GST-tag was successfully cleaved from the MzDef peptide by thrombin, and the removal was validated by the Tris-Tricine gel electrophoresis. The MzDef induced strong growth inhibition of Rhizoctonia solani, Fusarium verticillioides, and Aspergillus niger by 94.23%, 93.34%, and 86.25%, respectively, whereas relatively weak growth inhibitory activity of 35.42% against Fusarium solani was recorded. Moreover, strong antibacterial activities were demonstrated against E. coli and Bacillus cereus and the moderate activities against Salmonella enterica and Staphylococcus aureus at all tested concentrations (0.1, 0.2, 0.4, 0.8, 1.6, and 3.2 µM). Furthermore, the in vitro MTT assay exhibited promising anticancer activity against all tested cell lines (hepatocellular carcinoma, mammary gland breast cancer, and colorectal carcinoma colon cancer) with IC values ranging from 14.85 to 29.85 µg/mL. These results suggest that the recombinant peptide MzDef may serve as a potential alternative antimicrobial and anticancer agent to be used in medicinal application.
寻找有效且具有生物活性的抗菌分子以满足对新型抗生素的医学需求是一个令人鼓舞的研究领域。植物防御素是一类小的阳离子、富含半胱氨酸的肽，通过二硫键形成稳定的三级结构，并具有广泛的生物学功能。埃及玉米防御素（MzDef）在大肠杆菌中的异源表达以及随后通过谷胱甘肽亲和层析进行的纯化，产生了2mg/L的重组防御素肽。用抗谷胱甘肽-S-转移酶（GST）抗体免疫检测到大小约为30kDa的GST标记的MzDef（26KDa GST + 约4KDa MzDef肽）。GST标签通过凝血酶成功地从MzDef肽上切割下来，并且通过Tris-Tricine凝胶电泳验证了去除情况。MzDef分别对立枯丝核菌、轮枝镰孢菌和黑曲霉具有强烈的生长抑制作用，抑制率分别为94.23%、93.34%和86.25%，而对茄腐镰孢菌的生长抑制活性相对较弱，为35.42%。此外，在所有测试浓度（0.1、0.2、0.4、0.8、1.6和3.2μM）下，对大肠杆菌和蜡样芽孢杆菌表现出强烈的抗菌活性，对肠炎沙门氏菌和金黄色葡萄球菌表现出中等活性。此外，体外MTT试验显示对所有测试细胞系（肝癌、乳腺癌和结肠癌）具有有前景的抗癌活性，IC值范围为14.85至29.85μg/mL。这些结果表明，重组肽MzDef可能作为一种潜在的替代抗菌和抗癌剂用于医学应用。
