Ribosome-inactivating proteins (RIPs) are enzymes with N-glycosylase activity that remove adenine bases from the ribosomal RNA. In theory, one single RIP molecule internalized into a cell is sufficient to induce cell death. For this reason, RIPs are of high potential as toxic payload for anti-tumor therapy. A considerable number of RIPs are synthesized by plants that belong to the carnation family (Caryophyllaceae). Prominent examples are the RIPs saporin from Saponaria officinalis L. or dianthin from Dianthus caryophyllus L. In this study, we have isolated and characterized a novel RIP (termed gypsophilin-S) from the tiny seeds of Gypsophila elegans M. Bieb. (Caryophyllaceae). It is noteworthy that this is the first study presenting the complete amino acid sequence of a RIP from a Gypsophila species. Gypsophilin-S was isolated from the defatted seed material following ammonium sulphate precipitation and HPLC-based ion exchange chromatography. Gypsophilin-S-containing fractions were analysed by SDS-PAGE and mass spectrometry. The full amino acid sequence of gypsophilin-S was assembled by MALDI-TOF-MS-MS and PCR. Gypsophilin-S exhibited strong adenine releasing activity and its cytotoxicity in human glioblastoma cells was investigated using an impedance-based real-time assay in comparison with recombinant saporin and dianthin.

中文翻译：

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来自满天星 M.Bieb 种子的新型 1 型核糖体失活蛋白。

核糖体失活蛋白 (RIP) 是具有 N-糖基化酶活性的酶，可从核糖体 RNA 中去除腺嘌呤碱基。理论上，内化到细胞中的单个 RIP 分子足以诱导细胞死亡。出于这个原因，RIPs 作为抗肿瘤治疗的有毒有效载荷具有很高的潜力。相当数量的 RIP 是由属于康乃馨科（石竹科）的植物合成的。突出的例子是来自 Saponaria officinalis L. 的 RIPs saporin 或来自 Dianthus caryophyllus L. 的dianthin。在这项研究中，我们从满天星 M. Bieb 的微小种子中分离并表征了一种新型 RIP（称为 gypsophilin-S）。（石竹科）。值得注意的是，这是第一项展示来自满天星物种的 RIP 的完整氨基酸序列的研究。在硫酸铵沉淀和基于 HPLC 的离子交换层析之后，从脱脂种子材料中分离出 Gypsophilin-S。通过 SDS-PAGE 和质谱法分析含满天星蛋白-S 的级分。gypsophilin-S 的完整氨基酸序列通过 MALDI-TOF-MS-MS 和 PCR 组装。Gypsophilin-S 表现出强大的腺嘌呤释放活性，并使用基于阻抗的实时测定与重组皂草素和石竹苷进行比较，研究其在人胶质母细胞瘤细胞中的细胞毒性。