Mechanisms of molecular changes in amino acids due to inner shell ionization

内壳电离导致氨基酸分子变化的机制

• 批准号: 04453162
• 负责人: KOBAYASHI Katsumi
• 金额: $ 1.92万
• 依托单位: National Laboratory for High Energy Physics
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04453162/
• 关键词: Monochromatic soft X-rays; Amino acids; Synchrotron radiation; Radiolysis; K-shell photoabsorption; Inner shell excitation

It was reported that the radiobiological effects are enhanced when monochromatic soft X-rays corresponding to the absorption edges of the constituent atoms are irradiated. We have been studying this enhancement mechanism. In this research, we investigated the mechanisms of molecular changes of sulfur-containing amino acids irradiated with monochromatic soft X-rays around sulfur K-shell absorption edge, expecting that this might be a underlying mechanism of the biological enhancement.Research results are summarized as follows.a)Covalent bonds including the inner shell ionized atom are cleaved more effectively than the other bonds.b)Carbon-sulfur bonds are sensitive not only to the photoabsorption of sulfur but also to that of the other constituent atoms.c)When irradiated in aqueous solution, OH adducts of the fragments are observed.d)Cleavage efficiency of the sulfur-carbon bond is not affected by the addition of OH radical scavenger, indicating that cleavage of the bond mainly occurs via direct action of the radiation.Since we could not identify the all fragments observed in the HPLC chart, we are considering new identification methods such as the use of radioisotope tracers.

据报道，当对应于组成原子的吸收边的单色软X射线照射时，放射生物学效应增强。我们一直在研究这种增强机制。本研究以含硫氨基酸为研究对象，探讨了含硫氨基酸在单色软X射线辐照下，在硫K壳层吸收边附近的分子变化机制，研究结果如下：a）共价键（包括内壳电离原子）的断裂比其他键更有效; B）碳-硫键不仅对硫的光吸收敏感，而且对其它组成原子的光吸收敏感。c）当在水溶液中照射时，观察到碎片的OH加合物。d）硫-碳键的裂解效率不受OH自由基清除剂的加入的影响，由于我们无法鉴定HPLC图中观察到的所有碎片，我们正在考虑新的鉴定方法，例如使用放射性同位素示踪剂。

项目成果

小林克己: "放射光を用いたオージェ治療の可能性" 放射線医学物理. 13. 178-185 (1993)

Katsumi Kobayashi：“使用同步加速器辐射进行俄歇治疗的可能性”《放射物理学》13. 178-185 (1993)。

小林,克己: "放射光を用いたオージェ治療の可能性" 放射線医学物理. 13. 178-185 (1993)

Katsumi Kobayashi：“使用同步加速器辐射进行俄歇治疗的可能性”《放射物理学》13. 178-185 (1993)。

K.Kobayashi: "Fragmentation of Amino Acids due to Inner Shell X-ray Absorption in Sultur Atoms" Biophysical Aspects of Auger Processess,AAPM Symosium Series NO.8 American Inst.Phys.14-23 (1992)

K.Kobayashi：“硫原子中内壳 X 射线吸收导致的氨基酸碎片”俄歇过程的生物物理方面，AAPM Symosium Series NO.8 American Inst.Phys.14-23 (1992)

K.Kobayashi: "Radiation Biology of Inner Shell Ionization/Exciation" SR in Biosciences,Oxford Univ.Press. (in press). (1994)

K.Kobayashi：“内壳电离/激发的辐射生物学”SR，生物科学，牛津大学出版社。

T.Ito: "Dissociation of a Model Compound dApdA by Monochromatic Soft-X-ray in Solids" Int. J. Rodiat. Biol.62. 129-136 (1992)

T.Ito：“通过单色软 X 射线在固体中解离模型化合物 dApdA”Int。