Reactive intermediates in multicopper oxidase catalysis
Abstract
In the past few decades, there has been growing interest in using metalloenzymes for improved biomass degrdn. and utilization. Multicopper oxidases (MCOs) are lignin degrading enzymes with four copper sites (Figure 1): a type 1 Cu center (Cu_(T1)) is involved in substrate oxidn. and electron transfer to a trinuclear Cu center (TNC) where O_2 is reduced to H_2O. The MCO of interest in this study is from the HB27 strain of the thermophilic bacterium Thermus thermophilus; it is stable and active even above 90°C. The enzyme is active for lignin oxidn., although the potential of Cu_(T1) (E°(Cu2+/+) = 0.53 V vs. NHE, pH 4.5) is lower than that expected for one-electron oxidn. of methoxy phenols. It is important, therefore, to elucidate the mechanistic details of substrate oxidn. by characterizing electron-transfer pathways and trapping reactive intermediates crit. for enzyme catalysis and function. Detn. of crit. residues for enzyme catalysis as well as gaining a deeper understanding of the redox chem. involved in the catalytic pathways of MCOs will facilitate the development of more energy-efficient and environmentally friendly biocatalysts.
Additional Information
© 2019 American Chemical Society.Additional details
- Eprint ID
- 97751
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- CaltechAUTHORS:20190812-090439146
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2019-08-12Created from EPrint's datestamp field
- Updated
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2019-11-22Created from EPrint's last_modified field