Abstract

The unique protein Dsup of the tardigrade Ramazzottius varieornatus increases resistance to radiation and oxidative stress in various organisms and in human cell culture. According to simulation data, Dsup forms a complex with DNA with an intermolecular distance of \({\sim}4\) Å, as a result of which DNA is less damaged by reactive oxygen species generated during radiation exposure. However, the stability of the Dsup protein itself under the effect of ionizing radiation remains unclear, which is important for assessing its radioprotective potential and understanding the molecular mechanisms of action of this protein under conditions of high doses of radiation. In this work, the radiation degradation of the Dsup protein after irradiation with \(\gamma\)-quanta using small-angle X-ray scattering (SAXS) and electrophoresis of proteins in polyacrylamide gel under denaturing conditions (SDS-PAGE) was studied for the first time. It was shown that, unlike the control protein bovine serum albumin, the spatial-structural characteristics of the Dsup protein remain almost unchanged even when exposed high doses of radiation (5 and 10 kGy), which indicates its high radiation stability.

中文翻译：

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缓步动物的辐射防护蛋白 Dsup（损伤抑制蛋白）可抵抗高剂量的电离辐射

摘要

缓步动物Ramazzottius varieornatus独特的蛋白质 Dsup可增强各种生物体和人类细胞培养物对辐射和氧化应激的抵抗力。根据模拟数据，Dsup 与 DNA 形成分子间距离为\({\sim}4\) Å 的复合物，因此 DNA 较少受到辐射暴露期间产生的活性氧的损伤。然而，Dsup蛋白本身在电离辐射作用下的稳定性仍不清楚，这对于评估其辐射防护潜​​力和了解该蛋白在高剂量辐射条件下作用的分子机制具有重要意义。在这项工作中，利用小角 X 射线散射 (SAXS) 和变性条件下聚丙烯酰胺凝胶中的蛋白质电泳 (SDS-PAGE) 研究了Dsup 蛋白在γ-量子照射后的辐射降解。首次。结果表明，与对照蛋白牛血清白蛋白不同，即使暴露于高剂量辐射（5和10 kGy），Dsup蛋白的空间结构特征也几乎保持不变，这表明其具有较高的辐射稳定性。