Xanthophyll metabolism regulating its accumulation and decomposition

Research Project

Project/Area Number	18K11081
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 59040:Nutrition science and health science-related
Research Institution	Jumonji University
Principal Investigator	Nagao Akihiko 十文字学園女子大学, 人間生活学部, 教授 (40353958)
Project Period (FY)	2018-04-01 – 2022-03-31
Project Status	Completed (Fiscal Year 2021)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2018: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Keywords	アポカロテナール / カロテノイド / キサントフィル / ゼアキサンチン / 非対称開裂 / ルテイン / 開裂 / 酸化的代謝 / 立体配置 / 代謝 / 蓄積 / 分解
Outline of Final Research Achievements	An asymmetric cleavage of carbon skeleton and oxidation of end group in carotenoid metabolism were investigated in their relation to the accumulation of carotenoids in tissues. The activity of the asymmetric cleavage enzyme expressed in the mouse liver was successfully detected only in the presence of a detergent. Zeaxanthin, lutein, and lactucaxanthin were more readily cleaved than β-cryptoxanthin, while no cleavage product of β-carotene was found. Thus, the asymmetric cleavage enzyme of mouse liver, which was found to be specific for zeaxanthin and lutein, would be an important metabolic factor controlling accumulation of non-provitamin A xanthophylls.
Academic Significance and Societal Importance of the Research Achievements	カロテノイドの非対称開裂酵素の特性は組替え体で研究が進められてきたが、動物組織での開裂産物生成やネイティッブ酵素の活性についての明確な証拠は得られていなかった。本研究によって初めて肝臓に発現する酵素の活性が検出され基質特異性が明らかにされたことは、キサントフィル代謝の研究上意義深い。本酵素はキサントフィルの体内蓄積の重要な代謝上の因子と考えられたことから、この遺伝子の多型とキサントフィル蓄積の関係が今後明らかにされると、テーラーメイド栄養につながるものと期待される。