Mechanism of abnormal protein aggregation in the age-related diseases and the study of the restoration

2016 Fiscal Year Final Research Report

• Project/Area Number: 25288075
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Bio-related chemistry
• Research Institution: Kyoto University
• Principal Investigator: FUJII NORIKO 京都大学, 原子炉実験所, 教授 (90199290)
• Co-Investigator(Kenkyū-buntansha): 加治 優一 筑波大学, 医学医療系, 准教授 (50361332) ; 大神 信孝 名古屋大学, 医学(系)研究科(研究院), 講師 (80424919)
• Co-Investigator(Renkei-kenkyūsha): KINOUCHI TADATOSHI 京都大学, 原子炉実験所, 講師 (90301457)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 老化 / D-アミノ酸 / 蛋白質異常凝集 / 白内障 / アミノ酸の異性化反応 / D-アスパラギン酸 / LC-MS/MS

Outline of Final Research Achievements

Biologically uncommon D-β-, D-α-, L-β-aspartyl (Asp) isomers have been widely detected in proteins from age-related diseases such as cataract, age-related hearing loss and Alzheimer diseases. In this study, we developed a new method for rapidly identifying Asp isomers in proteins based on a combination of LC-MS/MS and isomer-specific enzymes. We detected the isomeric Asp sites precisely, quickly at the fentomole level in lens crystallins. The amount of Asp isomer was greater in the insoluble fraction of lens proteins from elderly donors. The stereoinversion of Asp in lens proteins induce not only the highly aggregate and but also dissociate to monomer. The isomerization of the Asp in the protein was accelerated by UVB-irradiation. We synthesized RNase A which was replaced with L-β-, D-α- and D-β-Asp at the position 121 of L-α-Asp. The Lα-Asp containing RNase A have high catalytic activity, while the L-β-, D-α- and D-β-Asp containing RNase A lost the enzyme activities.

Free Research Field

生化学