Radiation Biochemistry and Biological Function


  • KINOUCHI, Tadatoshi e-mail: kinouchi<atmark>

Assistant Professor

  • SAITO, Takeshi e-mail: ta-saito<atmark>

* replace <atmark> with @rri.kyoto-u.ac.jp

Our study is focused on the various post-translational modifications of proteins in lens, brain and skin which include processes such as: deamidation, racemization, stereoinversion, isomerization, truncation, phosphorylation, oxidation and the increased intramolecular disulfide bonding of inert proteins. While these post-translational modifications are spontaneously generated during the aging process, their probability of occurrence are also increased by UV (ultraviolet) and gamma ray irradiation.

Our aim is to elucidate the post-translational modifications which can induce the partial unfolding of the proteins, that results in a reduction of the protein functions and eventually lead to the folding diseases such as cataract, age-related macular degeneration (AMD), Alzheimer disease, solar elastosis, arteriosclerosis, etc. The current research includes the following projects;

  1. Study of racemization of amino acid residues in proteins and abnormal aggregation of proteins induced by aging, UV and gamma irradiation.
  2. Study of mechanism of D-amino acid formation in protein.
  3. The identification of D-beta-Asp containing protein in UV-irradiated skin from elderly human donors.
  4. A rapid comprehensive LC-MS/MS based survey of the individual amino acid isomers in proteins from the age-related diseases.
  5. Identification and characterization of a specific degrading enzyme (DAEP) for the D-Asp-containing protein.
  6. Study of the radioresistant bacterium Deinococcus radiodurans

Key words: abnormal aggregation of protein, aging, cataract, crystallin, D-aspartic acid, enzyme, gamma-irradiation, isomerization, lens, racemization, radioresistant, repair, skin, ultraviolet,

D-amino acid and abnormal aggregation of protein.
D-amino acid and abnormal aggregation of protein.

D-amino acids in abnormal aggregated proteins and age-related disease.
D-amino acids in abnormal aggregated proteins and age-related disease.