Abstract

Plant lectins are carbohydrate-binding proteins with nonimmune origin, which can reversibly bind with carbohydrates, agglutinate cells, and precipitate polysaccharides and glycoconjugates. Plant lectins have attracted much attention for their anti-virus, anti-proliferation, and pro-apoptosis properties. Thus the exploration of new lectins has received special attention. Here we purified a mannose-binding lectin from the rhizomes of Liparis nervosa by ion exchange chromatography on DEAE-Sepharose, affinity chromatography on Mannose-Sepharose 4B, and gel filtration chromatography on Sephacryl S-100. The purified L. nervosa lectin (LNL) was identified to be a monomeric protein with a molecular mass of 13 kDa. LNL exhibited hemagglutinating activity towards rabbit erythrocytes, and its activity could be strongly inhibited by D-mannose, N-acetyl glucosamine and thyroglobulin. In vitro experiments showed that LNL exhibited a comparable anti-fungal activity against Piricularia oryzae (Cavara), Bipolaris maydis, Fusarium graminearum, and Sclerotium rolfsii, and anti-proliferation activity against tumor cells by inducing apoptosis. The full-length cDNA sequence of LNL is 715 bp in length and contains a 525 bp open reading frame (ORF) encoding a 110-residue mature protein. It was predicted to have three mannose-binding conserved motifs ‘QXDXNXVXY’. The binding pattern of LNL was further revealed by homology modeling and molecular docking. We demonstrated that LNL is not only a potential therapeutic candidate against tumor but also a new anti-fungal agent.

中文翻译：

---

一种新的来自利帕氏酵母的甘露糖结合凝集素，具有抗真菌和抗肿瘤活性。

摘要

植物凝集素是具有非免疫起源的碳水化合物结合蛋白，可与碳水化合物，凝集细胞可逆结合，并沉淀多糖和糖结合物。植物凝集素因其抗病毒，抗增殖和促凋亡特性而备受关注。因此，新凝集素的探索受到了特别的关注。在这里，我们通过DEAE-Sepharose上的离子交换色谱法，Mannose-Sepharose 4B上的亲和色谱法和Sephacryl S-100上的凝胶过滤色谱法，从神经假单胞菌的根茎中纯化了结合甘露糖的凝集素。纯化的神经乳杆菌凝集素（LNL）被鉴定为分子量为13 kDa的单体蛋白。LNL对兔红细胞具有血凝活性，其活性可被D-甘露糖，N-乙酰氨基葡萄糖和甲状腺球蛋白强烈抑制。体外实验表明LNL对米曲霉（Cavara），双极型马氏双歧杆菌，禾谷镰刀菌和小核盘菌具有相当的抗真菌活性以及通过诱导细胞凋亡对肿瘤细胞的抗增殖活性。LNL的全长cDNA序列长度为715 bp，并包含一个525 bp的开放阅读框（ORF），编码110个残基的成熟蛋白。据预测具有三个甘露糖结合的保守基序“ QXDXNXVXY”。通过同源性建模和分子对接进一步揭示了LNL的结合模式。我们证明了LNL不仅是针对肿瘤的潜在治疗候选药物，而且还是一种新型的抗真菌药。