Development of new technology for removing viruses from water environment

病毒结合蛋白（Virus-binding proteins，VBPs）是在水环境中人类病毒优先吸附的细菌蛋白。VBPs是从活性污泥中分离得到的细菌培养物中发现的，其中病毒衣壳肽被用作配体。本研究的目的是开发一种新的技术，使用VBPs从环境水中去除病毒。在为期3年的研究期间，取得了以下成果。在研究期间的第一年，进行了VBP生产和纯化的放大，以获得大量的VBP。第二年，利用PCR技术构建了C端有6个连续赖氨酸残基的六赖氨酸标记的VBP基因（LysTagVBP），并将其用于E.杆菌然后，使用硅烷偶联剂和戊二醛将LysTagVBP中的多聚赖氨酸区域与玻璃颗粒表面偶联。LysTagVBP的产生与VBP在载体表面的有效固定直接相关。在研究的第三年，构建了固定化LysTagVBP的病毒去除柱，并评价了该柱的病毒去除效率。结果，在最初的1小时操作期间，约40%的病毒被减少，并且在3小时操作之后，70%的病毒被去除。VBPs去除水中病毒技术的发展是一个全新的挑战，VBPs作为病毒吸附剂的研究成果将有助于VBPs在水中病毒去除中的进一步应用。

Virus-binding proteins (VBPs) are bacterial proteins to which human viruses preferentially adsorb in water environment. VBPs were discovered from a bacterial culture derived from activated sludge with affinity chromatography assay in which a viral capsid peptide was used as a ligand. The purpose of this study was to develop a novel technology using VBPs for virus removal from environmental water. Achievements described below were obtained during the 3-year study duration.At the first year of the study duration, the scale-up of VBP production and purification was conducted in order to obtain large amount of VBP. A handmade column for VBP purification was constructed, which made it possible to obtain about 10 times larger volume of VBP than conventional procedure.At the second year, gene of hexalysine-tagged VBP (LysTagVBP), which has 6-consecutive lysine residues in its C terminus, was fabricated with PCR, and used for production of LysTagVBP with E. coli. Then, polylysine region in LysTagVBP was coupled with the surface of glass particles using silane coupling reagent and glutaraldehyde. The creation of LysTagVBP directly linked to the effective immobilization of VBP on carrier surface.At the third year of the study duration, the virus-removing column in which LysTagVBP was immobilized was constructed, and virus removal efficiency with the column was evaluated. As a result, about 40% of viruses were reduced during the first 1-hour operation, and 70% of viruses were removed after the 3-hour operation. The development of virus removal technology using VBPs is a totally new challenge, and the achievements with regards to the utilization of VBPs as viral adsorbent would be useful in the farther application of VBPs to virus removal from water.