Automated Solution-Phase Synthesis of Insect Glycans to Probe the Binding Affinity of Pea Enation Mosaic Virus.
Automated Solution-Phase Synthesis of Insect Glycans to Probe the Binding Affinity of Pea Enation Mosaic Virus.
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DOI：
10.1021/acs.joc.5b01428
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发表时间：
2015-11-06
期刊：
影响因子：
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通讯作者：
Pohl NL
中科院分区：
文献类型：
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作者：
Tang SL;Linz LB;Bonning BC;Pohl NL
豌豆代花叶病毒（PEMV）是一种仅由蚜虫传播的植物RNA病毒，可引起多种粮食作物的病害。然而，人们对疾病传播所需的蚜虫-病毒相互作用知之甚少。对于病毒传播，在豌豆蚜虫的肠道中，PEMV与一个高度糖基化的受体氨基肽酶N结合，在蚜虫进食时释放到唾液中，然后通过肠上皮转胞进入蚜虫体腔。为了研究聚糖在pemv -蚜虫相互作用中的作用，并探索通过阻断聚糖相互作用来控制病毒的可能性，我们采用自动液相合成方法合成了昆虫n-聚糖末端三萜苷。该路线的特点是甘露糖构建块与C-5酯加强β-键，这也为后续链延伸提供了一个位点。用荧光微阵列分析得到的带氟标记的昆虫n -聚糖末端三萜苷与异硫氰酸荧光素标记的PEMV的结合；然而，没有检测到昆虫聚糖与PEMV之间的特异性结合。为了证实这些微阵列结果，我们从三萜苷中去除含氟标签，用未标记的PEMV进行等温滴定量热研究。ITC的研究证实了微阵列的结果，并表明这种特殊的聚糖- pemv相互作用不参与病毒在蚜虫中的摄取和运输。
Pea enation mosaic virus (PEMV)—a plant RNA virus transmitted exclusively by aphids—causes disease in multiple food crops. However, the aphid-virus interactions required for disease transmission are poorly understood. For virus transmission, PEMV binds to a heavily glycosylated receptor aminopeptidase N in the pea aphid gut and is transcytosed across the gut epithelium into the aphid body cavity prior to release in saliva as the aphid feeds. To investigate the role of glycans in PEMV–aphid interactions and explore the possibility of viral control through blocking a glycan interaction, we synthesized insect N-glycan terminal trimannosides by automated solution-phase synthesis. The route features a mannose building block with C-5 ester enforcing a β-linkage, which also provides a site for subsequent chain extension. The resulting insect N-glycan terminal trimannosides with fluorous tags were used in a fluorous microarray to analyze binding with fluorescein isothiocyanate-labeled PEMV; however, no specific binding between the insect glycan and PEMV was detected. To confirm these microarray results, we removed the fluorous tag from the trimannosides for isothermal titration calorimetry studies with unlabeled PEMV. The ITC studies confirmed the microarray results and suggested that this particular glycan–PEMV interaction is not involved in virus uptake and transport through the aphid.