A nucleobase- driven P450 peroxidase system enables regio- and stereo- specific formation of C―C and C―N bonds

• 成果类型: Article
• 署名作者: Wei, Guangzheng; Duan, Borui; Zhou, Tai-Ping; Tian, Wenya; Sun, Chenghai; Lin, Zhi; Deng, Zixin; Wang, Binju; Zhang, Zhengyu; Qu, Xudong
• 署名单位: Wuhan University; Wuhan University; Shanghai Jiao Tong University; Shanghai Jiao Tong University; Xiamen University; Xiamen University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9963
• DOI: 10.1073/pnas.2412890121
• 发表日期: 2024-11-12
• 关键词: cross-coupling reactions; acid-base catalysis; molecular-mechanism; cytochrome-p450; activation

摘要

P450 peroxidase activities are valued for their ability to catalyze complex chemical transformations using economical H2O2; however, they have been largely underexplored compared to their monooxygenase and peroxygenase activities. In this study, we identified an unconventional P450 enzyme, PtmB, which catalyzes the dimerization of purine nucleobases and tryptophan- containing diketopiperazines (TDKPs), yielding C3- nucleobase pyrroloindolines and nucleobase-TDKP dimers. Unlike typical TDKP P450 enzymes reliant on NAD(P)H cofactors and electron transfer systems, PtmB, and its analogs exhibit remarkable peroxidase activity in synthesizing adenine and other modified 6- aminopurine nucleobase-TDKP dimers. Structural analysis of the PtmB-substrate complex, mutation assays, and computational investigations reveal adenine's dual role as both substrate and acid-base catalyst in activating H2O2 to generate Compound I (Cpd I). This initiates a specific radical cascade reaction, facilitating the formation of precise C & horbar;C and C & horbar;N bonds. Biochemical assays and molecular dynamics simulations demonstrate that adenine's 6-NH2 hydrogen- bonding networks induce necessary conformational changes for H2O2 activation, thereby driving peroxidase activity.This study unveils an unusual catalytic mechanism for the P450 peroxidase system and underscores the pivotal role of nucleobases in enzyme- mediated reactions, which offers different prospects for developing P450 peroxidases and nucleobase-based biocatalysts.