Volume 135, Issue 7 e202212053
Zuschrift

Mechanistic Insight into Peptidyl-Cysteine Oxidation by the Copper-Dependent Formylglycine-Generating Enzyme

Yao Wu

Yao Wu

Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing, 100872 China

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Cong Zhao

Cong Zhao

Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing, 100872 China

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Yanzhuang Su

Yanzhuang Su

Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing, 100872 China

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Prof. Dr. Sason Shaik

Corresponding Author

Prof. Dr. Sason Shaik

Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904 Israel

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Prof. Dr. Wenzhen Lai

Corresponding Author

Prof. Dr. Wenzhen Lai

Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing, 100872 China

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First published: 22 December 2022

Abstract

The copper-dependent formylglycine-generating enzyme (FGE) catalyzes the oxygen-dependent oxidation of specific peptidyl-cysteine residues to formylglycine. Our QM/MM calculations provide a very likely mechanism for this transformation. The reaction starts with dioxygen binding to the tris-thiolate CuI center to form a triplet CuII-superoxide complex. The rate-determining hydrogen atom abstraction involves a triplet-singlet crossing to form a CuII−OOH species that couples with the substrate radical, leading to a CuI-alkylperoxo intermediate. This is accompanied by proton transfer from the hydroperoxide to the S atom of the substrate via a nearby water molecule. The subsequent O−O bond cleavage is coupled with the C−S bond breaking that generates the formylglycine and a CuII-oxyl complex. Moreover, our results suggest that the aldehyde oxygen of the final product originates from O2, which will be useful for future experimental work.

Data Availability Statement

The data that support the findings of this study are available in the Supporting Information of this article.

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