Investigation for unrevealed lytic pathway of polysaccharides initiated with oxidation of a hydroxyl group

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K19070
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 38:Agricultural chemistry and related fields
• Research Institution: Niigata University
• Principal Investigator: Kitaoka Motomitsu 新潟大学, 自然科学系, 教授 (60353984)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 水酸基の酸化 / 多糖分解 / 酵素反応 / 新規分解経路

Outline of Final Research Achievements

2-Keto-cellobiose, a model compound representing oxidized cellulose at the position 2 of the reducing-end glucose residue, has successfully been synthesized from cellobiose by the concerted actions of cellobiose phosphorylase and pyranose oxidase at 10 °C in the presence of a catalytic amount of phosphate. It was degraded by β-elimination reaction at pH 7.0 and 30°C with a half-life of 103 hours. Because 1-deoxy-2-ketocellobiose, a model compound representing oxidized cellulose at the position 2 of the internal glucose residue of cellulose, has already been shown to degrade with a half-life of 17 hours under the same conditions, it was proved that when the hydroxy group at position 2 of cellulose is oxidized, the bond is generally eliminated even at room temperature under neutral pH.

Free Research Field

酵素科学

Academic Significance and Societal Importance of the Research Achievements

本研究により、セルロースなどの多糖類の水酸基が酸化されることにより結合が自動的に分解されることが証明された。このことから水酸基酸化酵素による未知の多糖分解経路の存在する可能性が示されたことになる。この成果をもとに、特に難分解性の結晶性多糖の新規な分解経路の発見が期待される。