Serial femtosecond X-ray crystallography of an anaerobically formed catalytic intermediate of copper amine oxidase

In this study, SFX measurements using a liquid-jet system were performed on microcrystals of bacterial copper amine oxidase anaerobically premixed with a substrate amine solution. The structure determined at 1.94   Å resolution indicated that the peptidyl quinone cofactor is in equilibrium between the aminoresorcinol and semiquinone radical intermediates, which accumulate only under anaerobic single-turnover conditions. These results show that anaerobic conditions were well maintained throughout the liquid-jet SFX measurements, preventing the catalytic intermediates from reacting with dioxygen. These results also provide a necessary framework for performing time-resolved MISC to study enzymic reaction mechanisms under anaerobic conditions.

Source: Acta Crystallographica Section D - November 25, 2022 Category: Biochemistry Authors: Murakawa, T. Suzuki, M. Fukui, K. Masuda, T. Sugahara, M. Tono, K. Tanaka, T. Iwata, S. Nango, E. Yano, T. Tanizawa, K. Okajima, T. Tags: serial femtosecond X-ray crystallography copper amine oxidases catalytic intermediates mix-and-inject method peptidyl quinone cofactor research papers Source Type: research