Vandenborre Gianni, Lannoo Nausicaä, Smagghe Guy, Daniel Erica, Breite Andrew, Soin Thomas, Jacobsen Linda, Van Damme Els J M
Department of Molecular Biotechnology, Lab. Biochemistry and Glycobiology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
In Vitro Cell Dev Biol Anim. 2008 Jul-Aug;44(7):228-35. doi: 10.1007/s11626-008-9123-z. Epub 2008 Jun 17.
The Nicotiana tabacum lectin, called Nictaba, is a nucleocytoplasmic plant lectin expressed in tobacco leaves after exogenous application of specific jasmonates and upon insect herbivory. Since the lectin concentrations are rather low, huge amounts of plant material are needed to purify milligram quantities of the protein. In addition, the purified lectin fractions are always contaminated with low molecular weight compounds such as phenols. In an attempt to improve and facilitate the purification of the tobacco lectin in reasonable amounts, an in vitro-coupled transcription/translation system based on an Escherichia coli lysate was used to express the lectin gene. Recombinant expression levels could be enhanced by an adapted codon usage. Recombinant lectin was purified, biochemically characterized and found to be biologically active. The biological activity of the recombinant lectin towards insect epithelial midgut cells was clearly demonstrated in a functional bio-assay and the internal cellular localization was analyzed using immunocytochemical techniques.
烟草凝集素（称为Nictaba）是一种核质植物凝集素，在经外源施加特定茉莉酸酯后以及遭受昆虫取食时在烟草叶片中表达。由于凝集素浓度相当低，需要大量植物材料才能纯化出毫克量的蛋白质。此外，纯化的凝集素级分总是被低分子量化合物如酚类污染。为了以合理的量改进并促进烟草凝集素的纯化，基于大肠杆菌裂解物的体外偶联转录/翻译系统被用于表达凝集素基因。通过调整密码子使用可提高重组表达水平。重组凝集素被纯化、进行生化表征并发现具有生物活性。在功能生物测定中清楚地证明了重组凝集素对昆虫上皮中肠细胞的生物活性，并使用免疫细胞化学技术分析了其细胞内定位。
