Pan Jin-Min, Gao Jie, Liu Ming Jian, Zhu Ke-Cheng, Guo Hua-Yang, Liu Bao-Suo, Zhang Nan, Zhang Dian-Chang
Sanya Tropical Fisheriers Research Institute, Sanya, 572108, Hainan Province, China.
School of Life Science, Sun Yat-Sen University, Guangzhou, 510006, China.
Mar Biotechnol (NY). 2024 Dec 17;27(1):21. doi: 10.1007/s10126-024-10393-x.
Galectins exhibit a variety of biological functions through interactions with their ligands, including galactose and its derivatives. Tandem-repeat galectins, such as Galectin-8, can act as pattern recognition receptors to aggregate and neutralize bacterial pathogens. In this study, Galectin-8 was identified in Trachinotus ovatus (golden pompano). Galectin-8 consists of two carbohydrate recognition domains (CRDs) connected by a linker region. Furthermore, molecular docking analysis suggests that the C-terminal CRD can bind galactose, mannose, and N-acetylglucosamine at similar binding sites. ToGal-8 expression levels were highest in the brain and blood of healthy T. ovatus. However, following infection with Streptococcus agalactiae, expression levels in the spleen and head kidney surged at 48 h, while liver expression significantly decreased by 96 h. Cytoplasmic Galectin-8 expression was upregulated after stimulation by peptidoglycan compared with lipopolysaccharide. Recombinant ToGal-8 (rToGal-8) was produced using a prokaryotic expression system. This protein could agglutinate red blood cells from rabbits, carp, and T. ovatus independently of Ca. Moreover, it was also effective in aggregating and eliminating several bacterial strains, such as Staphylococcus aureus, Bacillus subtilis, Vibrio vulnificus, S. agalactiae, Pseudomonas aeruginosa, and Aeromonas hydrophila. Therefore, this study provides an in-depth analysis of the function of T. ovatus Galectin-8 for the first time, offering guidance for the healthy aquaculture of T. ovatus.
半乳糖凝集素通过与包括半乳糖及其衍生物在内的配体相互作用，展现出多种生物学功能。串联重复半乳糖凝集素，如半乳糖凝集素-8，可作为模式识别受体来聚集并中和细菌病原体。在本研究中，在卵形鲳鲹（金鲳）中鉴定出了半乳糖凝集素-8。半乳糖凝集素-8由两个通过连接区相连的碳水化合物识别结构域（CRD）组成。此外，分子对接分析表明，C端CRD可在相似的结合位点结合半乳糖、甘露糖和N-乙酰葡糖胺。卵形鲳鲹ToGal-8在健康鱼的脑和血液中表达水平最高。然而，感染无乳链球菌后，脾脏和头肾中的表达水平在48小时时激增，而肝脏中的表达在96小时时显著下降。与脂多糖相比，肽聚糖刺激后细胞质半乳糖凝集素-8的表达上调。使用原核表达系统制备了重组ToGal-8（rToGal-8）。该蛋白可独立于钙离子凝集来自兔子、鲤鱼和卵形鲳鲹的红细胞。此外，它在聚集和清除几种细菌菌株方面也很有效，如金黄色葡萄球菌、枯草芽孢杆菌、创伤弧菌、无乳链球菌、铜绿假单胞菌和嗜水气单胞菌。因此，本研究首次对卵形鲳鲹半乳糖凝集素-8的功能进行了深入分析，为卵形鲳鲹的健康养殖提供了指导。
