Anti-HIV I/II activity and molecular cloning of a novel mannose/sialic acid-binding lectin from rhizome of Polygonatum cyrtonema Hua
Anti-HIV I/II activity and molecular cloning of a novel mannose/sialic acid-binding lectin from rhizome of Polygonatum cyrtonema Hua
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DOI：
10.1111/j.1745-7270.2006.00140.x
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发表时间：
2006-02-01
影响因子：
3.7
通讯作者：
Bao, JK
中科院分区：
文献类型：
--
作者：
An, J;Liu, JZ;Bao, JK
通过比较从黄精根茎中分离出的一种甘露糖和唾液酸结合凝集素在MT - 4和CEM细胞中对艾滋病毒（HIV）感染的抑制活性与其他甘露糖结合凝集素（MBLs）的活性，阐明了其抗人免疫缺陷病毒（HIV）I/II的活性。黄精凝集素（PCL）的抗HIV活性比其他受试的MBLs强10到100倍，且对MT - 4或CEM细胞无明显细胞毒性。为了通过cDNA末端快速扩增（RACE）技术扩增PCL的cDNA，通过测序确定了N端的30个氨基酸，并设计了简并寡核苷酸引物。PCL的全长cDNA包含693个碱基对，其开放阅读框编码一个含160个氨基酸残基的前体蛋白，包括一个28个残基的信号肽、一个22个残基的C端裂解肽和一个110个残基的成熟多肽，该成熟多肽包含三个串联排列的亚结构域，与单子叶植物MBL具有明显的序列同源性。然而，在PCL的亚结构域I中仅发现一个有活性的甘露糖结合位点（QDNVY），亚结构域II和III中的结合位点分别变为HNNVY和PDNVY。PCL中没有内含子，这与其他单子叶植物MBLs一致。PCL的分子建模表明其三维结构类似于雪花莲凝集素。通过对接，在PCL中发现了一个有活性的唾液酸结合位点。PCL的mRNA翻译起始区（TIR）的不稳定性有利于其在根茎中的高表达。
The anti-human immunodeficiency virus (HIV) I/II activity of a mannose and sialic acid binding lectin isolated from rhizomes of Polygonatum cyrtonema Hua was elucidated by comparing its HIV infection inhibitory activity in MT-4 and CEM cells with that of other mannose-binding lectins (MBLs). The anti-HIV activity of Polygonatum cyrtonema Hua lectin (PCL) was 10- to 100-fold more potent than other tested MBLs, but without significant cytotoxicity towards MT-4 or CEM cells. To amplify cDNA of PCL by 3'/5'-rapid amplification of cDNA ends (RACE), the 30 amino acids of N-terminal were determined by sequencing and the degenerate oligonucleotide primers were designed. The full-length cDNA of PCL contained 693 bp with an open reading frame encoding a precursor protein of 160 amino acid residues, consisting of a 28-residue signal peptide, a 22-residue C-terminal cleavage peptide and a 110-residue mature polypeptide which contained three tandemly arranged subdomains with an obvious sequence homology to the monocot MBL. However, only one active mannose-binding site (QDNVY) was found in subdomain I of PCL, that of subdomain II and III changed to HNNVY and PDNVY, respectively. There was no intron in PCL, which was in good agreement with other monocot MBLs. Molecular modeling of PCL indicated that its three-dimensional structure resembles that of the snowdrop agglutinin. By docking, an active sialic acid-binding site was found in PCL. The instabilization of translation initiation region (TIR) in mRNA of PCL benefits its high expression in rhizomes.