Bouqellah Nahla Alsayd, Abdel-Hafez Lina Jamil Mohamed, Mostafa Islam Yousif, Faraag Ahmed Hassan Ibrahim
Biology Department, Science College, Taibah University, 42317-8599, Al Madinah Al Munawwarah, Saudi Arabia.
Lecturer of Microbiology and Immunology, Faculty of Pharmacy, October 6 University, 6 October City, Giza, Egypt.
Int Microbiol. 2025 May;28(Suppl 1):177-194. doi: 10.1007/s10123-024-00591-x. Epub 2024 Oct 2.
Chitinases are glycosyl hydrolase enzymes that break down chitin, an integral component of fungal cell walls. Bacteria such as Bacillus subtilis and Serratia marcescens produce chitinases with antifungal properties. In this study, we aimed to generate hybrid chitinase enzymes with enhanced antifungal activity by combining functional domains from native chitinases produced by B. subtilis and S. marcescens. Chitinase genes were cloned from both bacteria and fused together using overlap extension PCR. The hybrid constructs were expressed in E. coli and the recombinant enzymes purified. Gel electrophoresis and computational analysis confirmed the molecular weights and isoelectric points of the hybrid chitinases were intermediate between the parental enzymes. Antifungal assays demonstrated that the hybrid chitinases inhibited growth of the fungus Fusarium oxysporum significantly more than the native enzymes and also showed fungicidal activity against Candida albicans, Alternaria solani, and Rhizoctonia solani. The results indicate that hybrid bacterial chitinases are a promising approach to engineer novel antifungal proteins. This study provides insight into structure-function relationships of chitinases and strategies for generating biotherapeutics with enhanced bioactive properties. These hybrid chitinases result in a more potent and versatile antifungal agent.
几丁质酶是一种糖基水解酶,可分解几丁质,而几丁质是真菌细胞壁的一个重要组成部分。枯草芽孢杆菌和粘质沙雷氏菌等细菌会产生具有抗真菌特性的几丁质酶。在本研究中,我们旨在通过将枯草芽孢杆菌和粘质沙雷氏菌产生的天然几丁质酶的功能域结合起来,生成具有增强抗真菌活性的杂合几丁质酶。从这两种细菌中克隆了几丁质酶基因,并使用重叠延伸PCR将它们融合在一起。杂合构建体在大肠杆菌中表达,并对重组酶进行了纯化。凝胶电泳和计算分析证实,杂合几丁质酶的分子量和等电点介于亲本酶之间。抗真菌试验表明,杂合几丁质酶对尖孢镰刀菌生长的抑制作用明显强于天然酶,并且对白色念珠菌、番茄早疫病菌和立枯丝核菌也具有杀菌活性。结果表明,杂合细菌几丁质酶是工程化新型抗真菌蛋白的一种有前景的方法。本研究深入了解了几丁质酶的结构-功能关系以及生成具有增强生物活性特性的生物治疗剂的策略。这些杂合几丁质酶产生了一种更有效、更通用的抗真菌剂。