RADIOPROTECTIVE PROTEIN OF TARDIGRADE DSUP (DAMAGE SUPPRESSOR) IS RESISTANT TO HIGH DOSES OF IONIZING RADIATION

Abstract

The unique Dsup protein of the tardigrade Ramazzottiusvarieornatus increases resistance to radiation and oxidative stress in various species of organisms and in human cell culture. According to modeling data,Dsup forms a complex with DNA with an intermolecular distance of ∼4˚A, as a result of which DNA is lessdamaged by reactive oxygen species formed during exposure to radiation.However, the stability of the Dsupprotein itself under the in uence of ionizing radiation remains unclear, which is important for assessing its radioprotective potential and understanding the molecular mechanisms of the action of this protein under conditions of high doses of radiation. In this work, the radiation degradation of the Dsup protein after γ-ray irradiation by small-angle X-ray scattering (SAXS) and protein electrophoresis in polyacrylamide gel under denaturing conditions (SDS-PAGE) was studied for the rst time.It has been shown that, in contrast to the control bovine serum albumin, the spatial and structural characteristics of the Dsup protein remain almost unchanged even when exposed to high doses of radiation (5 and 10 kGy), which suggests its high radiation stability.