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http://hdl.handle.net/2445/166522
Title: | Oxidative Cleavage of Cellobiose by Lytic Polysaccharide Monooxygenase (LPMO)-Inspired Copper Complexes |
Author: | Neira, Andrea. C. Martínez-Alanis, Paulina R. Aullón López, Gabriel Flores Alamo, Marcos Zerón, Paulino Company, Anna Chen, Juan Kasper, Johann B. Browne, Wesley R. Nordlander, Ebbe Castillo, Ivan |
Keywords: | Coure Enzims Polisacàrids Amines Copper Enzymes Polysaccharides Amines |
Issue Date: | 20-Jun-2019 |
Publisher: | American Chemical Society |
Abstract: | The potentially tridentate ligand bis[(1-methyl-2-benzimidazolyl)ethyl]amine (2BB) was employed to prepare copper complexes [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 as bioinspired models of lytic polysaccharide copper-dependent monooxygenase (LPMO) enzymes. Solid-state characterization of [(2BB)CuI]OTf revealed a Cu(I) center with a T-shaped coordination environment and metric parameters in the range of those observed in reduced LPMOs. Solution characterization of [(2BB)CuII(H2O)2](OTf)2 indicates that [(2BB)CuII(H2O)2]2+ is the main species from pH 4 to 7.5; above pH 7.5, the hydroxo-bridged species [{(2BB)CuII(H2O)x}2(μ-OH)2]2+ is also present, on the basis of cyclic voltammetry and mass spectrometry. These observations imply that deprotonation of the central amine of Cu(II)-coordinated 2BB is precluded, and by extension, amine deprotonation in the histidine brace of LPMOs appears unlikely at neutral pH. The complexes [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 act as precursors for the oxidative degradation of cellobiose as a cellulose model substrate. Spectroscopic and reactivity studies indicate that a dicopper(II) side-on peroxide complex generated from [(2BB)CuI]OTf/O2 or [(2BB)CuII(H2O)2](OTf)2/H2O2/NEt3 oxidizes cellobiose both in acetonitrile and aqueous phosphate buffer solutions, as evidenced from product analysis by high-performance liquid chromatography-mass spectrometry. The mixture of [(2BB)CuII(H2O)2](OTf)2/H2O2/NEt3 results in more extensive cellobiose degradation. Likewise, the use of both [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 with KO2 afforded cellobiose oxidation products. In all cases, a common Cu(II) complex formulated as [(2BB)CuII(OH)(H2O)]+ was detected by mass spectrometry as the final form of the complex. |
Note: | Correction published on October 23, 2020 https://doi.org/10.1021/acsomega.0c04910 |
Note: | Reproducció del document publicat a: https://doi.org/10.1021/acsomega.9b00785 |
It is part of: | ACS Omega , 2019, vol. 4, p. 10729-10740 |
URI: | http://hdl.handle.net/2445/166522 |
Related resource: | https://doi.org/10.1021/acsomega.9b00785 https://doi.org/10.1021/acsomega.0c04910 |
ISSN: | 2470-1343 |
Appears in Collections: | Articles publicats en revistes (Química Inorgànica i Orgànica) |
Files in This Item:
File | Description | Size | Format | |
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698725.pdf | 1.91 MB | Adobe PDF | View/Open | |
710484.pdf | Correction | 430.08 kB | Adobe PDF | View/Open |
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