Tamilarasan Kamalanathan, Annapoorani Angusamy, Manikandan Ramar, Janarthanan Sundaram
Department of Zoology, University of Madras, Guindy Campus, Chennai 600 025, India.
Department of Zoology, University of Madras, Guindy Campus, Chennai 600 025, India.
Int J Biol Macromol. 2021 Jul 31;183:1119-1135. doi: 10.1016/j.ijbiomac.2021.05.054. Epub 2021 May 8.
Lectins are renowned hemagglutinins and multivalent proteins with a well known quality for sugar-binding specificity that participate significantly in invertebrate defense functions. Studies on biological activity of lectin from coleopteran insect are very scarce. In this study, lectin from the hemolymph in the grub of banana pest, Odoiporus longicollis was subjected to purification, biochemical and functional characterizations. The lectin was purified by PEG precipitation and ion-exchange chromatography using Q-Sepharose as a matrix. The purified lectin showed hemagglutination activity against rat erythrocytes, heat-labile, cation independent and insensitive to EDTA. Further, the carbohydrate affinity of this lectin was found with mannitol, adonitol, L-arabinose, L-rhamnose, D-galactose and sorbitol. The native form of purified lectin was calculated as 360 kDa by FPLC system. Denatured gel electrophoresis of the purified lectin consisted of five distinct polypeptides with molecular weights approximately 160, 60, 52, 40 and 38 kDa, respectively. The amino acid sequences obtained through peptide mass fingerprinting analysis exhibited homologies to the known conserved regions of galactose binding lectins. Further, the purified lectin exhibited bacterial inhibition with LPS from Serratia marcescens. In addition, isolated lectin also exerted bacterial agglutination, antibacterial and anti-proliferative activity against Mycobacterium smegmatis, Bacillus pumilus and Neuro 2a cell line, respectively.
凝集素是著名的血细胞凝集素和多价蛋白，具有众所周知的糖结合特异性，在无脊椎动物的防御功能中发挥着重要作用。关于鞘翅目昆虫凝集素生物活性的研究非常少。在本研究中，对香蕉害虫长角扁谷盗幼虫血淋巴中的凝集素进行了纯化、生化和功能特性分析。该凝集素通过聚乙二醇沉淀和以Q-琼脂糖为基质的离子交换色谱法进行纯化。纯化后的凝集素对大鼠红细胞表现出血凝活性，对热不稳定，不依赖阳离子，且对乙二胺四乙酸不敏感。此外，发现该凝集素与甘露醇、阿东糖醇、L-阿拉伯糖、L-鼠李糖、D-半乳糖和山梨醇具有碳水化合物亲和力。通过FPLC系统计算纯化凝集素的天然形式为360 kDa。纯化凝集素的变性凝胶电泳由五条不同的多肽组成，分子量分别约为160、60、52、40和38 kDa。通过肽质量指纹图谱分析获得的氨基酸序列与已知的半乳糖结合凝集素保守区域具有同源性。此外，纯化后的凝集素对粘质沙雷氏菌的脂多糖表现出细菌抑制作用。此外，分离得到的凝集素分别对耻垢分枝杆菌、短小芽孢杆菌和Neuro 2a细胞系表现出细菌凝集、抗菌和抗增殖活性。
