Mechanism of multi-step posttranslational modification involved in biogenesis of amine dehydrogenase and its application to development of bioactive polycyclic peptides

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07691
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied biochemistry
• Research Institution: Hiroshima Institute of Technology (2017-2018); Osaka University (2016)
• Principal Investigator: NAKAI Tadashi 広島工業大学, 生命学部, 准教授 (00333344)
• Co-Investigator(Kenkyū-buntansha): 岡島 俊英 大阪大学, 産業科学研究所, 准教授 (10247968)
• Research Collaborator: OOZEKI Toshinori ; KOZAKAI Kazuki
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 翻訳後修飾 / 補酵素の生合成 / ラジカルSAM酵素 / 分子内チオエーテル架橋 / 環状ペプチド / キノヘムプロテイン / ビルトイン型キノン補酵素 / 酵素触媒機構

Outline of Final Research Achievements

Peptidyl built-in cofactors are produced by posttranslational modification of the cognate enzyme proteins, unlike ordinary cofactors which are mostly bio-synthesized from water soluble vitamins. In this study, we focused on a built-in quinone cofactor-containing enzyme, quinohemoprotein amine dehydrogenase (QHNDH) that contains cysteine tryptophyl quinone (CTQ). The structural genes encoding QHNDH in Gram-negative bacteria constitute a polycistronic operon together with several nearby genes, which are collectively termed qhp. We have biochemically analyzed one of the peripheral genes, Pden_1710, that may be required for the QHNDH biogenesis. Furthermore, we have succeeded in formation of thioether cross-links using substrates with various sequences and multiple cross-linking sites. These results demonstrate that QhpD is useful for development of various polycyclic peptides.

Free Research Field

生化学、構造生物学

Academic Significance and Societal Importance of the Research Achievements

ペプチド分子内チオエーテル架橋形成酵素QhpDを用いてAla繰り返し配列の環状化と複数架橋形成に成功した。その結果、様々な配列と架橋数を有する架橋ペプチドを作り出すツールとしてQhpDが有用であることが判明した。以上の研究成果に基づいて今後QhpDの改変を行うことで、抗菌活性など様々な生理活性をもつ多環状ペプチドの開発に活用できると期待できる。