Abstract
ATP (Adenosine tri-phosphate), one of ribonucleic acids, acts as an intracellular energy transfer. ATP is also used as a substrate to synthesized messenger RNA and as a ligand of inter-cellular signaling. To induce the specific molecular alterations in the molecule we used the monochromatic soft X-rays obtained from the synchrotron facility (SPring-8, BL23SU). In this study, we analyzed the soft X-ray-induced radiation damage of ATP by various biological assessments, such as energy donor activity, genetic information transfer activity and inter-cellular signaling activity. We analyze the luciferase activity to assess the energy transfer activity and the genetic information transfer activity. We also evaluate the change in activity as an inter-cellular signaling molecules by measuring ATP receptor-mediated phosphorylation of extra cellular signal-regulated kinase 1/2 (ERK1/2). In addition to the biological effect, we have also measured the molecular alterations using X-ray absorption and electro spray mass spectrometry (ESIMS). We observed attenuation of ATP receptor-mediated phosphorylation of ERK 1/2 and luciferase activity by the soft X-ray irradiations. Moreover, we observed the reduction of nucleotide from the X-ray absorption spectra and ESIMS. These results suggest that certain alteration of ATP structure induced by soft X-ray affects the biological function of ATP. We will discuss the correlation between the biological effect and the molecular alterations from these results.
