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Discovery of a Fungal Multicopper Oxidase That Catalyzes the Regioselective Coupling of a Tricyclic Naphthopyranone To Produce Atropisomers
Author(s) -
Kawaguchi Mio,
Ohshiro Taichi,
Toyoda Masayuki,
Ohte Satoshi,
Inokoshi Junji,
Fujii Isao,
Tomoda Hiroshi
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201800415
Subject(s) - regioselectivity , atropisomer , multicopper oxidase , chemistry , stereochemistry , heterologous expression , enzyme , catalysis , biochemistry , recombinant dna , gene , laccase
Abstract Atropisomeric dinapinones A1 and A2 (DPA1 and DPA2) were isolated from a culture of Talaromyces pinophilus FKI‐3864. Monapinone coupling enzyme (MCE), which dimerizes naphthopyranone monapinone A (MPA), was purified from a cell‐free extract of T. pinophilus FKI‐3864. MCE regioselectively dimerizes MPA at the 8,8′‐positions to synthesize the atropisomers DPA1 and DPA2 in a ratio of approximately 1:2.5 without a cofactor. The optimal pH value and temperature for MCE were 4.0 and 50 °C, and the apparent K m and V max values for MPA were (72.7±23.2) μ m and (1.21±0.170) μmol min −1 mg −1 protein. The MCE polypeptide is significantly homologous with multicopper oxidases. Heterologous expression of MCE and functional analysis confirmed that MCE catalyzes the regioselective coupling reaction of MPA to produce DPA. No fungal multicopper oxidase has previously been reported to catalyze regioselective intermolecular oxidative phenol coupling to produce naphthopyranone atropisomers.