Open AccessCharacterization of TnmH as an O-Methyltransferase Revealing Insights into Tiancimycin Biosynthesis and Enabling a Biocatalytic Strategy To Prepare Antibody–Tiancimycin Conjugates
Author(s) -
Ajeeth Adhikari,
Christia. Teijaro,
Xiaohui Yan,
Chin-Yuan Chang,
Chun Gui,
Yu Chen Liu,
Ivana Crnovčić,
Dong Yang,
Thibault Annaval,
Christoph Rader,
Ben Shen
Publication year - 2020
Publication title -
journal of medicinal chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.01
H-Index - 261
eISSN - 1520-4804
pISSN - 0022-2623
DOI - 10.1021/acs.jmedchem.0c00799
Subject(s) - chemistry , conjugate , o methyltransferase , combinatorial chemistry , biosynthesis , stereochemistry , biocatalysis , substrate (aquarium) , molecule , alkylation , methyltransferase , reactivity (psychology) , methylation , enzyme , biochemistry , organic chemistry , catalysis , dna , reaction mechanism , mathematical analysis , oceanography , mathematics , geology , medicine , alternative medicine , pathology
The enediynes are among the most cytotoxic molecules known, and their use as anticancer drugs has been successfully demonstrated by targeted delivery. Clinical advancement of the anthraquinone-fused enediynes has been hindered by their low titers and lack of functional groups to enable the preparation of antibody-drug conjugates (ADCs). Here we report biochemical and structural characterization of TnmH from the tiancimycin (TNM) biosynthetic pathway, revealing that (i) TnmH catalyzes regiospecific methylation at the C-7 hydroxyl group, (ii) TnmH exhibits broad substrate promiscuity toward hydroxyanthraquinones and S-alkylated SAM analogues and catalyzes efficient installation of reactive alkyl handles, (iii) the X-ray crystal structure of TnmH provides the molecular basis to account for its broad substrate promiscuity, and (iv) TnmH as a biocatalyst enables the development of novel conjugation strategies to prepare antibody-TNM conjugates. These findings should greatly facilitate the construction and evaluation of antibody-TNM conjugates as next-generation ADCs for targeted chemotherapy.