Work

BesC Initiates C–C Cleavage through a Substrate-Triggered and Reactive Diferric-Peroxo Intermediate

Year: 2021

Type: article

Abstract: BesC catalyzes the iron- and O 2 -dependent cleavage of 4-chloro- l -lysine to form 4-chloro- l -allylglycine, formaldehyde, and ammonia. This process is a critical step for a biosynthetic pathway that generates a terminal alkyne amino acid which can be leveraged as a useful bio-orthogonal handle for protein labeling. As a member of an emerging family of diiron enzymes that are typified by their heme oxygenase-like fold and a very similar set of coordinating ligands, recently termed HDOs, BesC performs an unusual type of carbon–carbon cleavage reaction that is a significant departure from reactions catalyzed by canonical dinuclear-iron enzymes. Here, we show that BesC activates O 2 in a substrate-gated manner to generate a diferric-peroxo intermediate. Examination of the reactivity of the peroxo intermediate with a series of lysine derivatives demonstrates that BesC initiates this unique reaction trajectory via cleavage of the C4–H bond; this process represents the rate-limiting step in a single turnover reaction. The observed reactivity of BesC represents the first example of a dinuclear-iron enzyme that utilizes a diferric-peroxo intermediate to capably cleave a C–H bond as part of its native function, thus circumventing the formation of a high-valent intermediate more commonly associated with substrate monooxygenations.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.1c11109

Authors: Olivia M. Manley, Haoyu Tang, Shan Xue, Yisong Guo, Wei-chen Chang, Thomas M. Makris

Institutions: North Carolina State University, Carnegie Mellon University

Language: English

Topic: Metal-Catalyzed Oxygenation Mechanisms

Subfield: Inorganic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences