第60回　先端酵素学研究所セミナー（海外最先端研究者特別講演会）のお知らせ

【講演者】

　Dr. Kuen-Phon Wu

　Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan

【講演タイトル】

　Effectively regulate targeting ubiquitin enzymes by precision design of AI-guided variants or inhibitors

【日時】

　2024年8月7日（水曜日）14:00～15:30

【場所】

　先端酵素学研究所B棟1階 交流ホール

Wu先生は、タンパク質のユビキチン化がSARS・デング熱といった感染症を引き起こすメカニズムの解明と、その薬剤開発を指向し、NMRをはじめとした実験手法とAIとを複合的に用いた研究を推進しておられる研究者です。当日は、蛋白質デザインのAIツールProteinMPNNを使ったユビキチン骨格タンパク質デザインや、NMR、クライオ電子顕微鏡を効果的に利用した阻害剤設計など、最新のトピックについてご講演いただきます。

教職員、大学院生、学部学生など皆さまのご来聴を歓迎いたします

Ubiquitin (Ub) is pivotal in post-translational modifications by directly attaching to substrates and orchestrating a three-tier enzyme cascade (E1, E2, and E3) that imparts diverse functions to substrate proteins. For example, the formation of K48-linked poly-Ub chains typically targets proteins for proteasomal degradation, whereas deubiquitinases (DUBs) reverse this modification by cleaving Ub from substrates. Viral DUBs, such as the papain-like protease domain (PLpro) of SARS-CoV-2 NSP3, counteract host immune responses by targeting Ub-linked proteins. To modulate enzyme activity effectively, we employed small-molecule inhibitors and protein-based modulators. By modifying inhibitors of SARS-CoV-1 PLpro, we successfully developed a sub-µM covalent inhibitor, SR-03, where the propargyl group cross-linked to the catalytic cysteine of PLpro. In contrast to the costly production of inhibitors, we aimed to engineer a tightly binding enzyme-Ub variant (enzyme-UbV) complex using two approaches. Firstly, we analyzed the sidechain dihedral correlation network between MERS PLpro and Ub, identifying key Ub residues for rational mutation (A46F, K48E, and E64Y), resulting in UbV3, which significantly inhibits MERS PLpro activity (IC50 = 14.84 nM) and tightly binds to it (Kd = 2.77 nM). Secondly, leveraging ProteinMPNN and AlphaFold, we transformed Ub into an allosteric activator for Rsp5 E3 ligase. The resulting UbV, R4, exhibited a 25-fold improvement in binding affinity and enhanced Rsp5 transthioesterification, despite containing 33 mutations compared to wild-type Ub, while maintaining its native 3D crystal structure. These findings demonstrate the potential of engineered UbVs as effective regulators of cognate enzymes, offering a proof-of-concept for their utility in enzyme modulation.

お問合せ先： 先端酵素学研究所セミナー 第60回担当

分子生命科学分野・齋尾智英　内線9149　saio [at] tokushima-u.ac.jp

主催：徳島大学先端酵素学研究所