Biosynthetic study of oxaleimides

2018 Fiscal Year Final Research Report

• Project/Area Number: 17H07002
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Bioorganic chemistry
• Research Institution: University of Shizuoka
• Principal Investigator: Sato Michio 静岡県立大学, 薬学部, 講師 (10629695)
• Project Period (FY): 2017-08-25 – 2019-03-31
• Keywords: 生合成 / ポリケタイド / 非リボソームペプチド / シトクロームP450

Outline of Final Research Achievements

We identified the enzymes which are responsible for two key reactions in the biosynthesis of oxaleimides through gene targeting and in vitro reaction. One of the key reactions is the decalin ring modification to indane ring, and another is a rearrangement of the olefin from the amino acid building block to yield the maleimide scaffold compound. We propose oxidation of the decalin ring at C3, followed by hydroxylation at C2 to give a hydroxy ketone compound, which can undergo a semipinacol rearrangement to afford an indane ring compound. We characterized the enzyme PoxD, which is a member of cytochrome P450 enzymes, can catalyze the oxidation of the olefin at C3 in the decalin ring, and PoxK can hydroxylate the C2 carbon. Furthermore, we identified PoxN is involved in the rearrangement of the olefin from the amino acid. We established the purification method of fungal P450 enzymes, which can be a powerful tool to analyze the complex and intriguing reaction catalyzed by P450 enzymes.

Free Research Field

天然物化学

Academic Significance and Societal Importance of the Research Achievements

糸状菌Penicillium oxalicumが生産するoxaleimide類の骨格構築機構の解明を進めるうえで、P450およびそのパートナータンパク質であるNADPH還元酵素の精製法を確立した。両酵素とも膜貫通型のタンパク質であり、微生物の二次代謝に関わるP450を含む膜タンパク質には興味深い反応を触媒するものが多いが、精製が壁となり分子レベルでの解析が困難であった。本研究で用いた精製法は今後の膜タンパク質の研究の強力なツールとなると言える。