Leuven Food Science and Nutrition Research Centre (LFoRCe), Lab Food Microbiology, Department Microbial and Molecular Systems, KU Leuven, B-3001 Leuven, Belgium.
Molecules. 2023 Oct 13;28(20):7071. doi: 10.3390/molecules28207071.
Lysozymes are universal components of the innate immune system of animals that kill bacteria by hydrolyzing their main cell wall polymer, peptidoglycan. Three main families of lysozyme have been identified, designated as chicken (c)-, goose (g)- and invertebrate (i)-type. In response, bacteria have evolved specific protein inhibitors against each of the three lysozyme families. In this study, we developed a serial array of three affinity matrices functionalized with a c-, g-, and i-type inhibitors for lysozyme typing, i.e., to detect and differentiate lysozymes in fluids or extracts from animals. The tool was validated on the blue mussel (), whose genome carries multiple putative i-, g-, and c-type lysozyme genes. Hemolymph plasma of the animals was found to contain both i- and g-type, but not c-type lysozyme. Furthermore, hemolymph survival of and strains lacking or overproducing the i- type or g-type lysozyme inhibitor, respectively, was analyzed to study the role of the two lysozymes in innate immunity. The results demonstrated an active role for the g-type lysozyme in the innate immunity of the blue mussel, but failed to show a contribution by the i-type lysozyme. Lysozyme profiling using inhibitor-based affinity chromatography will be a useful novel tool for studying animal innate immunity.
溶菌酶是动物先天免疫系统的普遍组成部分，通过水解其主要细胞壁聚合物肽聚糖来杀死细菌。已经确定了三种主要的溶菌酶家族，分别命名为鸡（c）型、鹅（g）型和无脊椎动物（i）型。作为回应，细菌已经进化出针对三种溶菌酶家族的每种家族的特异性蛋白抑制剂。在这项研究中，我们开发了一系列三种亲和基质，用 c、g 和 i 型抑制剂对溶菌酶进行分型，即检测和区分动物体液或提取物中的溶菌酶。该工具在贻贝（）上进行了验证，贻贝基因组携带多个假定的 i、g 和 c 型溶菌酶基因。发现动物的血淋巴血浆中既含有 i 型又含有 g 型，但不含 c 型溶菌酶。此外，分析了缺乏或过度产生 i 型或 g 型溶菌酶抑制剂的 和 菌株的血淋巴存活率，以研究这两种溶菌酶在先天免疫中的作用。结果表明 g 型溶菌酶在贻贝的先天免疫中发挥积极作用，但 i 型溶菌酶没有贡献。基于抑制剂的亲和层析的溶菌酶分析将成为研究动物先天免疫的有用新工具。
