Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, PR China; Guangdong Technology Research Center for Marine Algal Bioengineering, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, PR China.
Shenzhen Base of South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shenzhen, 518121, PR China.
Fish Shellfish Immunol. 2019 Jun;89:384-392. doi: 10.1016/j.fsi.2019.03.049. Epub 2019 Apr 2.
Antimicrobial peptides (AMPs) are an essential component of innate immunity of invertebrates. Anti-lipopolysaccharide factor (ALF), as a main type of AMPs in crustaceans, attends in the disease prevention in general. In this research, a novel Group D ALF was identified and characterized from Penaeus monodon, named PenmonALF8. It was an anionic peptide, with both the full-length peptide and lipopolysaccharide binding domain (LBD) a low isoelectric point. PenmonALF8, composed of a signal peptide of 26 amino acids and a mature peptide of 98 amino acids, probably contained three alpha helixes and four beta sheets. Moreover, PenmonALF8 was detected in all tested tissues of P. monodon, and the expression level in hemocyte and intestine was relatively high. When challenged by Vibrio parahaemolyticus, PenmonALF8 showed 30-100 times higher expression level in all the tissues except in hemocyte and intestine, indicating that PenmonALF8 played a very important role in the immune response of P. monodon. By fusing to a SUMO protein, PenmonALF8 was successfully over-expressed in E. coli and purified by affinity chromatography. Additionally, the reconstituted PenmonALF8 and its LBD region displayed modest antimicrobial activity. This is the first research about the Group D ALF in P. monodon, which provides more information for humoral immunity study of shrimps.
抗菌肽 (AMPs) 是无脊椎动物先天免疫的重要组成部分。抗脂多糖因子 (ALF) 作为甲壳类动物中 AMPs 的主要类型，通常参与疾病预防。在这项研究中，从斑节对虾中鉴定和表征了一种新型 D 组 ALF，命名为 PenmonALF8。它是一种阴离子肽，全长肽和脂多糖结合域 (LBD) 的等电点均较低。PenmonALF8 由 26 个氨基酸的信号肽和 98 个氨基酸的成熟肽组成，可能含有三个α螺旋和四个β片层。此外，PenmonALF8 在斑节对虾的所有检测组织中均有检测到，在血细胞和肠组织中的表达水平相对较高。当受到副溶血弧菌的攻击时，PenmonALF8 在除血细胞和肠组织外的所有组织中的表达水平提高了 30-100 倍，表明 PenmonALF8 在斑节对虾的免疫反应中发挥了非常重要的作用。通过与 SUMO 蛋白融合，PenmonALF8 在大肠杆菌中成功过表达，并通过亲和层析进行纯化。此外，重组的 PenmonALF8 及其 LBD 区域显示出适度的抗菌活性。这是对斑节对虾 D 组 ALF 的首次研究，为虾类体液免疫研究提供了更多信息。
