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Liu Y, Harnden KA, Van Stappen C, Dikanov SA, Lu Y. A designed Copper Histidine-brace enzyme for oxidative depolymerization of polysaccharides as a model of lytic polysaccharide monooxygenase. Proc Natl Acad Sci U S A 2023; 120:e2308286120. [PMID: 37844252 PMCID: PMC10614608 DOI: 10.1073/pnas.2308286120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 09/03/2023] [Indexed: 10/18/2023] Open
Abstract
The "Histidine-brace" (His-brace) copper-binding site, composed of Cu(His)2 with a backbone amine, is found in metalloproteins with diverse functions. A primary example is lytic polysaccharide monooxygenase (LPMO), a class of enzymes that catalyze the oxidative depolymerization of polysaccharides, providing not only an energy source for native microorganisms but also a route to more effective industrial biomass conversion. Despite its importance, how the Cu His-brace site performs this unique and challenging oxidative depolymerization reaction remains to be understood. To answer this question, we have designed a biosynthetic model of LPMO by incorporating the Cu His-brace motif into azurin, an electron transfer protein. Spectroscopic studies, including ultraviolet-visible (UV-Vis) absorption and electron paramagnetic resonance, confirm copper binding at the designed His-brace site. Moreover, the designed protein is catalytically active towards both cellulose and starch, the native substrates of LPMO, generating degraded oligosaccharides with multiturnovers by C1 oxidation. It also performs oxidative cleavage of the model substrate 4-nitrophenyl-D-glucopyranoside, achieving a turnover number ~9% of that of a native LPMO assayed under identical conditions. This work presents a rationally designed artificial metalloenzyme that acts as a structural and functional mimic of LPMO, which provides a promising system for understanding the role of the Cu His-brace site in LPMO activity and potential application in polysaccharide degradation.
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Affiliation(s)
- Yiwei Liu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
| | - Kevin A. Harnden
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Casey Van Stappen
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
| | - Sergei A. Dikanov
- Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
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2
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Bouchey C, Shopov DY, Gruen AD, Tolman WB. Mimicking the Cu Active Site of Lytic Polysaccharide Monooxygenase Using Monoanionic Tridentate N-Donor Ligands. ACS OMEGA 2022; 7:35217-35232. [PMID: 36211076 PMCID: PMC9535706 DOI: 10.1021/acsomega.2c04432] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
In an effort to prepare small molecule mimics of the active site of lytic polysaccharide monooxygenase (LPMO), three monoanionic tridentate N donor ligands comprising a central deprotonated amide group flanked by two neutral donors were prepared, and their coordination chemistry with Cu(I) and Cu(II) was evaluated. With Cu(I), a dimer formed, which was characterized by X-ray crystallography and NMR spectroscopy. A variety of mononuclear and dinuclear Cu(II) species with a range of auxiliary ligands (MeCN, Cl-, OH-, OAc-, OBz-, CO3 2-) were prepared and characterized by X-ray diffraction and various spectroscopies (UV-vis, EPR). The complexes exhibit structural similarities to the LPMO active site.
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Affiliation(s)
- Caitlin
J. Bouchey
- Department
of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - Dimitar Y. Shopov
- Department
of Chemistry, Washington University in St.
Louis, One Brookings Drive, Campus Box 1134, St.
Louis, Missouri 63130, United States
| | - Aaron D. Gruen
- Department
of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - William B. Tolman
- Department
of Chemistry, Washington University in St.
Louis, One Brookings Drive, Campus Box 1134, St.
Louis, Missouri 63130, United States
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3
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Czaikowski ME, McNeece AJ, Boyn JN, Jesse KA, Anferov SW, Filatov AS, Mazziotti DA, Anderson JS. Generation and Aerobic Oxidative Catalysis of a Cu(II) Superoxo Complex Supported by a Redox-Active Ligand. J Am Chem Soc 2022; 144:15569-15580. [PMID: 35977083 PMCID: PMC10017013 DOI: 10.1021/jacs.2c04630] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cu systems feature prominently in aerobic oxidative catalysis in both biology and synthetic chemistry. Metal ligand cooperativity is a common theme in both areas as exemplified by galactose oxidase and by aminoxyl radicals in alcohol oxidations. This has motivated investigations into the aerobic chemistry of Cu and specifically the isolation and study of Cu-superoxo species that are invoked as key catalytic intermediates. While several examples of complexes that model biologically relevant Cu(II) superoxo intermediates have been reported, they are not typically competent aerobic catalysts. Here, we report a new Cu complex of the redox-active ligand tBu,TolDHP (2,5-bis((2-t-butylhydrazono)(p-tolyl)methyl)-pyrrole) that activates O2 to generate a catalytically active Cu(II)-superoxo complex via ligand-based electron transfer. Characterization using ultraviolet (UV)-visible spectroscopy, Raman isotope labeling studies, and Cu extended X-ray absorption fine structure (EXAFS) analysis confirms the assignment of an end-on κ1 superoxo complex. This Cu-O2 complex engages in a range of aerobic catalytic oxidations with substrates including alcohols and aldehydes. These results demonstrate that bioinspired Cu systems can not only model important bioinorganic intermediates but can also mediate and provide mechanistic insight into aerobic oxidative transformations.
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Affiliation(s)
- Maia E Czaikowski
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Andrew J McNeece
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Jan-Niklas Boyn
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Kate A Jesse
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Sophie W Anferov
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Alexander S Filatov
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - David A Mazziotti
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - John S Anderson
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
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4
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Hassoon AA, Szorcsik A, Fülöp L, Papp ZI, May NV, Gajda T. Peptide-based chemical models for lytic polysaccharide monooxygenases. Dalton Trans 2022; 51:17241-17254. [DOI: 10.1039/d2dt02836k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Cu(ii)–HPH-NH2 and Cu(ii)–HPHPY-NH2 systems were proved to be relevant functional models of LPMOs, even at neutral pH.
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Affiliation(s)
- Azza A. Hassoon
- Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
- Chemistry Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt
| | - Attila Szorcsik
- Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Lívia Fülöp
- Institute of Medical Chemistry, University of Szeged, Szeged, Hungary
| | - Zita I. Papp
- Institute of Medical Chemistry, University of Szeged, Szeged, Hungary
| | - Nóra V. May
- Centre for Structural Science, Research Centre for Natural Sciences, Budapest, Hungary
| | - Tamás Gajda
- Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
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5
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Castillo I, Torres‐Flores AP, Abad‐Aguilar DF, Berlanga‐Vázquez A, Orio M, Martínez‐Otero D. Cellulose Depolymerization with LPMO‐inspired Cu Complexes. ChemCatChem 2021. [DOI: 10.1002/cctc.202101169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Ivan Castillo
- Instituto de Química Universidad Nacional Autónoma de México Circuito Exterior Cu, 04510 México
| | - Andrea P. Torres‐Flores
- Instituto de Química Universidad Nacional Autónoma de México Circuito Exterior Cu, 04510 México
| | - Diego F. Abad‐Aguilar
- Instituto de Química Universidad Nacional Autónoma de México Circuito Exterior Cu, 04510 México
| | | | - Maylis Orio
- Aix Marseille Université CNRS, Centrale Marseille, iSm2 13397 Marseille France
| | - Diego Martínez‐Otero
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM Carretera Toluca-Atlacomulco km 14.5 Toluca 50200 Estado de México México
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6
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Gerz I, Jannuzzi SAV, Hylland KT, Negri C, Wragg DS, Øien‐Ødegaard S, Tilset M, Olsbye U, DeBeer S, Amedjkouh M. Structural Elucidation, Aggregation, and Dynamic Behaviour of
N,N,N,N
‐Copper(I) Schiff Base Complexes in Solid and in Solution: A Combined NMR, X‐ray Spectroscopic and Crystallographic Investigation. Eur J Inorg Chem 2021; 2021:4762-4775. [PMID: 35874966 PMCID: PMC9298233 DOI: 10.1002/ejic.202100722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/22/2021] [Indexed: 12/30/2022]
Abstract
A series of Cu(I) complexes of bidentate or tetradentate Schiff base ligands bearing either 1‐H‐imidazole or pyridine moieties were synthesized. The complexes were studied by a combination of NMR and X‐ray spectroscopic techniques. The differences between the imidazole‐ and pyridine‐based ligands were examined by 1H, 13C and 15N NMR spectroscopy. The magnitude of the 15Nimine coordination shifts was found to be strongly affected by the nature of the heterocycle in the complexes. These trends showed good correlation with the obtained Cu−Nimine bond lengths from single‐crystal X‐ray diffraction measurements. Variable‐temperature NMR experiments, in combination with diffusion ordered spectroscopy (DOSY) revealed that one of the complexes underwent a temperature‐dependent interconversion between a monomer, a dimer and a higher aggregate. The complexes bearing tetradentate imidazole ligands were further studied using Cu K‐edge XAS and VtC XES, where DFT‐assisted assignment of spectral features suggested that these complexes may form polynuclear oligomers in solid state. Additionally, the Cu(II) analogue of one of the complexes was incorporated into a metal‐organic framework (MOF) as a way to obtain discrete, mononuclear complexes in the solid state.
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Affiliation(s)
- Isabelle Gerz
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | | | - Knut T. Hylland
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - Chiara Negri
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - David S. Wragg
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - Sigurd Øien‐Ødegaard
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - Mats Tilset
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - Unni Olsbye
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
| | - Serena DeBeer
- Department of Inorganic Spectroscopy Max Planck Institute for Chemical Energy Conversion Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Mohamed Amedjkouh
- Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway
- Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway
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8
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Yu Z, Thompson Z, Behnke SL, Fenk KD, Huang D, Shafaat HS, Cowan JA. Addition to Metalloglycosidase Mimics: Oxidative Cleavage of Saccharides Promoted by Multinuclear Copper Complexes under Physiological Conditions. Inorg Chem 2020; 59:15561. [DOI: 10.1021/acs.inorgchem.0c02723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Role of zeolite encapsulated Cu(II) complexes in electron transfer as well as peroxy radical intermediates formation during oxidation of thioanisole. J Catal 2020. [DOI: 10.1016/j.jcat.2020.06.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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10
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Yu ZH, Reinhardt CJ, Wong THF, Tong KY, Chan J, Au-Yeung HY. Activity-Based Sensing of Ascorbate by Using Copper-Mediated Oxidative Bond Cleavage. Chemistry 2020; 26:8794-8800. [PMID: 32583898 PMCID: PMC7869848 DOI: 10.1002/chem.202000780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/13/2020] [Indexed: 11/09/2022]
Abstract
Ascorbate is an important biological reductant and enzyme cofactor. Although direct detection through ascorbate-mediated reduction is possible, this approach suffers from poor selectivity due to the wide range of cellular reducing agents. To overcome this limitation, we leverage reduction potential of ascorbate to mediate a copper-mediated oxidative bond cleavage of ether-caged fluorophores. The copper(II) complexes supported by a {bis(2-pyridylmethyl)}benzylamine or a {bis(2-pyridylmethyl)}(2-methoxybenzyl)amine ligand were identified as an ascorbate responsive unit and their reaction with ascorbate yields a copper-based oxidant that enables rapid benzylic oxidation and the release of an ether-caged dye (coumarin or fluorescein). The copper-mediated bond cleavage is specific to ascorbate and the trigger can be readily derivatized for tuning photophysical properties of the probes. The probes were successfully applied for the fluorometric detection of ascorbate in commercial food samples, human plasma, and serum, and within live cells by using confocal microscopy and flow cytometry.
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Affiliation(s)
- Zuo Hang Yu
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Christopher J Reinhardt
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA
| | - Thomas Hin-Fung Wong
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Ka Yan Tong
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Jefferson Chan
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA
| | - Ho Yu Au-Yeung
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
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11
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Fukatsu A, Morimoto Y, Sugimoto H, Itoh S. Modelling a ‘histidine brace’ motif in mononuclear copper monooxygenases. Chem Commun (Camb) 2020; 56:5123-5126. [DOI: 10.1039/d0cc01392g] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A mononuclear copper complex bearing a ‘histidine brace’ is synthesised and characterised as an active-site model of mononuclear copper monooxygenases such as lytic polysaccharide monooxygenases (LPMOs) and particulate methane monooxygenase (pMMO).
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Affiliation(s)
- Arisa Fukatsu
- Department of Material and Life Science
- Division of Advanced Science and Biotechnology
- Graduate School of Engineering
- Osaka University
- Osaka 565-0871
| | - Yuma Morimoto
- Department of Material and Life Science
- Division of Advanced Science and Biotechnology
- Graduate School of Engineering
- Osaka University
- Osaka 565-0871
| | - Hideki Sugimoto
- Department of Material and Life Science
- Division of Advanced Science and Biotechnology
- Graduate School of Engineering
- Osaka University
- Osaka 565-0871
| | - Shinobu Itoh
- Department of Material and Life Science
- Division of Advanced Science and Biotechnology
- Graduate School of Engineering
- Osaka University
- Osaka 565-0871
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12
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Diaz DE, Bhadra M, Karlin KD. Dimethylanilinic N-Oxides and Their Oxygen Surrogacy Role in the Formation of a Putative High-Valent Copper-Oxygen Species. Inorg Chem 2019; 58:13746-13750. [PMID: 31580063 PMCID: PMC6896993 DOI: 10.1021/acs.inorgchem.9b02066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of p-cyano-N,N-dimethylaniline N-oxide, an O-atom donor, with different copper(I) complexes (at room temperature and in acetone) indicates the formation via O-atom transfer of a high-valent copper oxyl species, CuII-O•, a putative key intermediate in the catalytic cycle of copper-containing monooxygenases. The formation of p-cyano-N-hydroxymethyl-N-methylaniline and p-cyano-N-methylaniline as the main products of the reaction highlight the capability of this species to hydroxylate strong C-H bonds (bond dissociation energy ∼ 90 kcal/mol). A plausible mechanism for the reactivity of this catalytic system is proposed.
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Affiliation(s)
- Daniel E. Diaz
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Mayukh Bhadra
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Kenneth D. Karlin
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
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