1
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Tong Y, Kaya SG, Russo S, Rozeboom HJ, Wijma HJ, Fraaije MW. Fixing Flavins: Hijacking a Flavin Transferase for Equipping Flavoproteins with a Covalent Flavin Cofactor. J Am Chem Soc 2023; 145:27140-27148. [PMID: 38048072 PMCID: PMC10722498 DOI: 10.1021/jacs.3c12009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/05/2023]
Abstract
Most flavin-dependent enzymes contain a dissociable flavin cofactor. We present a new approach for installing in vivo a covalent bond between a flavin cofactor and its host protein. By using a flavin transferase and carving a flavinylation motif in target proteins, we demonstrate that "dissociable" flavoproteins can be turned into covalent flavoproteins. Specifically, four different flavin mononucleotide-containing proteins were engineered to undergo covalent flavinylation: a light-oxygen-voltage domain protein, a mini singlet oxygen generator, a nitroreductase, and an old yellow enzyme-type ene reductase. Optimizing the flavinylation motif and expression conditions led to the covalent flavinylation of all four flavoproteins. The engineered covalent flavoproteins retained function and often exhibited improved performance, such as higher thermostability or catalytic performance. The crystal structures of the designed covalent flavoproteins confirmed the designed threonyl-phosphate linkage. The targeted flavoproteins differ in fold and function, indicating that this method of introducing a covalent flavin-protein bond is a powerful new method to create flavoproteins that cannot lose their cofactor, boosting their performance.
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Affiliation(s)
- Yapei Tong
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The
Netherlands
| | - Saniye G. Kaya
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The
Netherlands
| | - Sara Russo
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The
Netherlands
| | - Henriette J. Rozeboom
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The
Netherlands
| | - Hein J. Wijma
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The
Netherlands
| | - Marco W. Fraaije
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The
Netherlands
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2
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Kahlert L, Cox RJ, Skellam E. The same but different: multiple functions of the fungal flavin dependent monooxygenase SorD from Penicillium chrysogenum. Chem Commun (Camb) 2020; 56:10934-10937. [PMID: 32789380 DOI: 10.1039/d0cc03203d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Sorbicillinoids are a large family of fungal secondary metabolites with a diverse range of structures and numerous bioactivites, some of which have pharmaceutical potential. The flavin-dependent monooxygenase SorD from Penicillium chrysogenum (PcSorD) utilizes sorbicillinol to catalyze a broad scope of reactions: formation of oxosorbicillinol and epoxysorbicillinol; intermolecular Diels-Alder and Michael-addition dimerization reactions; and dimerization of a sorbicillinol derivative with oxosorbicillinol. PcSorD shares only 18.3% sequence identity with SorD from Trichoderma reesei (TrSorD) and yet unexpectedly catalyzes many of the same reactions, however, the formation of oxosorbicillinol and bisvertinolone by PcSorD extends the range of reactions catalyzed by a single enzyme. Phylogenetic analysis indicates that PcSorD and TrSorD bind the flavin cofactor covalently but via different residues and point mutations confirm these residues are essential for activity.
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Affiliation(s)
- Lukas Kahlert
- Institute for Organic Chemistry and BMWZ Leibniz University of Hannover Schneiderberg 38, 30167, Hannover, Germany.
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3
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Erban T, Sopko B, Talacko P, Harant K, Kadlikova K, Halesova T, Riddellova K, Pekas A. Chronic exposure of bumblebees to neonicotinoid imidacloprid suppresses the entire mevalonate pathway and fatty acid synthesis. J Proteomics 2019; 196:69-80. [DOI: 10.1016/j.jprot.2018.12.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/07/2018] [Accepted: 12/20/2018] [Indexed: 11/16/2022]
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4
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Heinelt M, Nöll T, Nöll G. Spectroelectrochemical Investigation of Cholesterol Oxidase fromStreptomyces lividansat Different pH Values. ChemElectroChem 2019. [DOI: 10.1002/celc.201801416] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Manuel Heinelt
- University of SiegenDepartment of Chemistry and Biology Organic Chemistry Adolf-Reichwein-Str. 2 57068 Siegen Germany
| | - Tanja Nöll
- University of SiegenDepartment of Chemistry and Biology Organic Chemistry Adolf-Reichwein-Str. 2 57068 Siegen Germany
| | - Gilbert Nöll
- University of SiegenDepartment of Chemistry and Biology Organic Chemistry Adolf-Reichwein-Str. 2 57068 Siegen Germany
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5
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Preparation of Betulone Via Betulin Oxidation Over Ru Nanoparticles Deposited on Graphitic Carbon Nitride. Catal Letters 2019. [DOI: 10.1007/s10562-018-02649-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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6
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Romero E, Gómez Castellanos JR, Gadda G, Fraaije MW, Mattevi A. Same Substrate, Many Reactions: Oxygen Activation in Flavoenzymes. Chem Rev 2018; 118:1742-1769. [DOI: 10.1021/acs.chemrev.7b00650] [Citation(s) in RCA: 216] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Elvira Romero
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - J. Rubén Gómez Castellanos
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy
| | - Giovanni Gadda
- Departments of Chemistry and Biology, Center for Diagnostics and Therapeutics, and Center for Biotechnology and Drug Design, Georgia State University, Atlanta, Georgia 30302-3965, United States
| | - Marco W. Fraaije
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Andrea Mattevi
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy
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7
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Dourado DFAR, Swart M, Carvalho ATP. Why the Flavin Adenine Dinucleotide (FAD) Cofactor Needs To Be Covalently Linked to Complex II of the Electron-Transport Chain for the Conversion of FADH 2 into FAD. Chemistry 2017; 24:5246-5252. [PMID: 29124817 PMCID: PMC5969107 DOI: 10.1002/chem.201704622] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/07/2017] [Indexed: 11/10/2022]
Abstract
A covalently bound flavin cofactor is predominant in the succinate‐ubiquinone oxidoreductase (SQR; Complex II), an essential component of aerobic electron transport, and in the menaquinol‐fumarate oxidoreductase (QFR), the anaerobic counterpart, although it is only present in approximately 10 % of the known flavoenzymes. This work investigates the role of this 8α‐N3‐histidyl linkage between the flavin adenine dinucleotide (FAD) cofactor and the respiratory Complex II. After parameterization with DFT calculations, classical molecular‐dynamics simulations and quantum‐mechanics calculations for Complex II:FAD and Complex II:FADH2, with and without the covalent bond, were performed. It was observed that the covalent bond is essential for the active‐center arrangement of the FADH2/FAD cofactor. Removal of this bond causes a displacement of the isoalloxazine group, which influences interactions with the protein, flavin solvation, and possible proton‐transfer pathways. Specifically, for the noncovalently bound FADH2 cofactor, the N1 atom moves away from the His‐A365 and His‐A254 residues and the N5 atom moves away from the glutamine‐62A residue. Both of the histidine and glutamine residues interact with a chain of water molecules that cross the enzyme, which is most likely involved in proton transfer. Breaking this chain of water molecules could thereby compromise proton transfer across the two active sites of Complex II.
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Affiliation(s)
- Daniel F A R Dourado
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, Northern Ireland, UK.,Almac Sciences, Department of Biocatalysis and Isotope Chemistry, Almac House, 20 Seagoe Industrial Estate, Craigavon, BT63 5QD, Northern Ireland, UK
| | - Marcel Swart
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, 17003, Girona, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
| | - Alexandra T P Carvalho
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal
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8
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Su D, Yuan H, Gadda G. A Reversible, Charge-Induced Intramolecular C4a-S-Cysteinyl-Flavin in Choline Oxidase Variant S101C. Biochemistry 2017; 56:6677-6690. [DOI: 10.1021/acs.biochem.7b00958] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dan Su
- Department
of Chemistry, ‡Department of Biology, §Center for Diagnostics and Therapeutics, and ∥Center for Biotechnology
and Drug Design, Georgia State University, Atlanta, Georgia 30302, United States
| | - Hongling Yuan
- Department
of Chemistry, ‡Department of Biology, §Center for Diagnostics and Therapeutics, and ∥Center for Biotechnology
and Drug Design, Georgia State University, Atlanta, Georgia 30302, United States
| | - Giovanni Gadda
- Department
of Chemistry, ‡Department of Biology, §Center for Diagnostics and Therapeutics, and ∥Center for Biotechnology
and Drug Design, Georgia State University, Atlanta, Georgia 30302, United States
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9
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Harb LH, Arooj M, Vrielink A, Mancera RL. Computational site-directed mutagenesis studies of the role of the hydrophobic triad on substrate binding in cholesterol oxidase. Proteins 2017; 85:1645-1655. [PMID: 28508424 DOI: 10.1002/prot.25319] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 04/21/2017] [Accepted: 05/08/2017] [Indexed: 11/10/2022]
Abstract
Cholesterol oxidase (ChOx) is a flavoenzyme that oxidizes and isomerizes cholesterol (CHL) to form cholest-4-en-3-one. Molecular docking and molecular dynamics simulations were conducted to predict the binding interactions of CHL in the active site. Several key interactions (E361-CHL, N485-FAD, and H447-CHL) were identified and which are likely to determine the correct positioning of CHL relative to flavin-adenine dinucleotide (FAD). Binding of CHL also induced changes in key residues of the active site leading to the closure of the oxygen channel. A group of residues, Y107, F444, and Y446, known as the hydrophobic triad, are believed to affect the binding of CHL in the active site. Computational site-directed mutagenesis of these residues revealed that their mutation affects the conformations of key residues in the active site, leading to non-optimal binding of CHL and to changes in the structure of the oxygen channel, all of which are likely to reduce the catalytic efficiency of ChOx. Proteins 2017; 85:1645-1655. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Laith Hisham Harb
- School of Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, Perth, WA, 6845, Australia
| | - Mahreen Arooj
- School of Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, Perth, WA, 6845, Australia
| | - Alice Vrielink
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA, 6009, Australia
| | - Ricardo L Mancera
- School of Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, Perth, WA, 6845, Australia
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10
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Haque S, Khan S, Wahid M, Dar SA, Soni N, Mandal RK, Singh V, Tiwari D, Lohani M, Areeshi MY, Govender T, Kruger HG, Jawed A. Artificial Intelligence vs. Statistical Modeling and Optimization of Continuous Bead Milling Process for Bacterial Cell Lysis. Front Microbiol 2016; 7:1852. [PMID: 27920762 PMCID: PMC5118707 DOI: 10.3389/fmicb.2016.01852] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 11/03/2016] [Indexed: 01/17/2023] Open
Abstract
For a commercially viable recombinant intracellular protein production process, efficient cell lysis and protein release is a major bottleneck. The recovery of recombinant protein, cholesterol oxidase (COD) was studied in a continuous bead milling process. A full factorial response surface methodology (RSM) design was employed and compared to artificial neural networks coupled with genetic algorithm (ANN-GA). Significant process variables, cell slurry feed rate (A), bead load (B), cell load (C), and run time (D), were investigated and optimized for maximizing COD recovery. RSM predicted an optimum of feed rate of 310.73 mL/h, bead loading of 79.9% (v/v), cell loading OD600nm of 74, and run time of 29.9 min with a recovery of ~3.2 g/L. ANN-GA predicted a maximum COD recovery of ~3.5 g/L at an optimum feed rate (mL/h): 258.08, bead loading (%, v/v): 80%, cell loading (OD600nm): 73.99, and run time of 32 min. An overall 3.7-fold increase in productivity is obtained when compared to a batch process. Optimization and comparison of statistical vs. artificial intelligence techniques in continuous bead milling process has been attempted for the very first time in our study. We were able to successfully represent the complex non-linear multivariable dependence of enzyme recovery on bead milling parameters. The quadratic second order response functions are not flexible enough to represent such complex non-linear dependence. ANN being a summation function of multiple layers are capable to represent complex non-linear dependence of variables in this case; enzyme recovery as a function of bead milling parameters. Since GA can even optimize discontinuous functions present study cites a perfect example of using machine learning (ANN) in combination with evolutionary optimization (GA) for representing undefined biological functions which is the case for common industrial processes involving biological moieties.
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Affiliation(s)
- Shafiul Haque
- Department of Biosciences, Jamia Millia Islamia (A Central University)New Delhi, India
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan UniversityJazan, Saudi Arabia
| | - Saif Khan
- Department of Clinical Nutrition, College of Applied Medical Sciences, University of Ha’ilHa’il, Saudi Arabia
| | - Mohd Wahid
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan UniversityJazan, Saudi Arabia
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia (A Central University)New Delhi, India
| | - Sajad A. Dar
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan UniversityJazan, Saudi Arabia
- The University College of Medical Sciences and Guru Teg Bahadur Hospital (University of Delhi)New Delhi, India
| | - Nipunjot Soni
- Department of Biotechnology, Khalsa CollegePatiala, India
| | - Raju K. Mandal
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan UniversityJazan, Saudi Arabia
| | - Vineeta Singh
- Microbiology Division, Council of Scientific and Industrial Research – Central Drug Research InstituteLucknow, India
| | - Dileep Tiwari
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-NatalDurban, South Africa
| | - Mohtashim Lohani
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan UniversityJazan, Saudi Arabia
| | - Mohammed Y. Areeshi
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan UniversityJazan, Saudi Arabia
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-NatalDurban, South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-NatalDurban, South Africa
| | - Arshad Jawed
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan UniversityJazan, Saudi Arabia
- RFCL LimitedNew Delhi, India
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11
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Mäki-Arvela P, Barsukova M, Winberg I, Smeds A, Hemming J, Eränen K, Torozova A, Aho A, Volcho K, Murzin DY. Unprecedented Selective Heterogeneously Catalysed “Green” Oxidation of Betulin to Biologically Active Compounds using Synthetic Air and Supported Ru Catalysts. ChemistrySelect 2016. [DOI: 10.1002/slct.201600731] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Päivi Mäki-Arvela
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
| | - Maria Barsukova
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
| | - Iris Winberg
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
| | - Annika Smeds
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
| | - Jarl Hemming
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
| | - Kari Eränen
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
| | - Alexandra Torozova
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
| | - Atte Aho
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
| | - Konstantin Volcho
- N. N. Vorozhtsov Institute of Organic Chemistry; Russian Academy of Sciences; Novosibirsk 630090 Russia
| | - Dmitry Yu. Murzin
- Johan Gadolin Process Chemistry Centre; Åbo Akademi University; Biskopsgatan 8 FI-20500 Turku Finland
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12
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Protein engineering of microbial cholesterol oxidases: a molecular approach toward development of new enzymes with new properties. Appl Microbiol Biotechnol 2016; 100:4323-36. [DOI: 10.1007/s00253-016-7497-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 03/22/2016] [Accepted: 03/24/2016] [Indexed: 10/22/2022]
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13
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Haque S, Khan S, Wahid M, Mandal RK, Tiwari D, Dar SA, Paul D, Areeshi MY, Jawed A. Modeling and optimization of a continuous bead milling process for bacterial cell lysis using response surface methodology. RSC Adv 2016. [DOI: 10.1039/c5ra26893a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Schematic representation of the modeling and optimization of continuous bead milling process for efficient bacterial cell lysis.
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Affiliation(s)
- Shafiul Haque
- Department of Biosciences
- Jamia Millia Islamia
- A Central University
- New Delhi
- India
| | - Saif Khan
- Department of Clinical Nutrition
- College of Applied Medical Sciences
- University of Ha'il
- Ha'il
- Saudi Arabia
| | - Mohd Wahid
- Research and Scientific Studies Unit
- College of Nursing and Allied Health Sciences
- Jazan University
- Jazan
- Saudi Arabia
| | - Raju K. Mandal
- Research and Scientific Studies Unit
- College of Nursing and Allied Health Sciences
- Jazan University
- Jazan
- Saudi Arabia
| | - Dileep Tiwari
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban
- South Africa
| | - Sajad A. Dar
- Research and Scientific Studies Unit
- College of Nursing and Allied Health Sciences
- Jazan University
- Jazan
- Saudi Arabia
| | - Debarati Paul
- Amity Institute of Biotechnology
- Amity University
- Noida
- India
| | - Mohammed Y. Areeshi
- Research and Scientific Studies Unit
- College of Nursing and Allied Health Sciences
- Jazan University
- Jazan
- Saudi Arabia
| | - Arshad Jawed
- Research and Scientific Studies Unit
- College of Nursing and Allied Health Sciences
- Jazan University
- Jazan
- Saudi Arabia
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14
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Kasabe PJ, Mali GT, Dandge PB. Assessment of alkaline cholesterol oxidase purified from Rhodococcus sp. PKPD-CL for its halo tolerance, detergent and organic solvent stability. Protein Expr Purif 2015; 116:30-41. [DOI: 10.1016/j.pep.2015.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 08/09/2015] [Accepted: 08/10/2015] [Indexed: 10/23/2022]
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15
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Kopečný D, Končitíková R, Popelka H, Briozzo P, Vigouroux A, Kopečná M, Zalabák D, Šebela M, Skopalová J, Frébort I, Moréra S. Kinetic and structural investigation of the cytokinin oxidase/dehydrogenase active site. FEBS J 2015; 283:361-77. [PMID: 26519657 DOI: 10.1111/febs.13581] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/26/2015] [Accepted: 10/28/2015] [Indexed: 12/24/2022]
Abstract
Cytokinins are hormones that regulate plant development and their environmental responses. Their levels are mainly controlled by the cytokinin oxidase/dehydrogenase (CKO), which oxidatively cleaves cytokinins using redox-active electron acceptors. CKO belongs to the group of flavoproteins with an 8α-N1-histidyl FAD covalent linkage. Here, we investigated the role of seven active site residues, H105, D169, E288, V378, E381, P427 and L492, in substrate binding and catalysis of the CKO1 from maize (Zea mays, ZmCKO1) combining site-directed mutagenesis with kinetics and X-ray crystallography. We identify E381 as a key residue for enzyme specificity that restricts substrate binding as well as quinone electron acceptor binding. We show that D169 is important for catalysis and that H105 covalently linked to FAD maintains the enzyme's structural integrity, stability and high rates with electron acceptors. The L492A mutation significantly modulates the cleavage of aromatic cytokinins and zeatin isomers. The high resolution X-ray structures of ZmCKO1 and the E381S variant in complex with N6-(2-isopentenyl)adenosine reveal the binding mode of cytokinin ribosides. Those of ZmCKO2 and ZmCKO4a contain a mobile domain, which might contribute to binding of the N9 substituted cytokinins.
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Affiliation(s)
- David Kopečný
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Radka Končitíková
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Hana Popelka
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Pierre Briozzo
- Institut Jean-Pierre Bourgin, UMR1318 INRA, AgroParisTech, Versailles, France
| | - Armelle Vigouroux
- Institute for Integrative Biology of the Cell (I2BC), CNRS-CEA-Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Martina Kopečná
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - David Zalabák
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Marek Šebela
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Jana Skopalová
- Department of Analytical Chemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Ivo Frébort
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Solange Moréra
- Institute for Integrative Biology of the Cell (I2BC), CNRS-CEA-Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
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16
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Leonida MD, Aurian-Blajeni B. Molecularly "wired" cholesterol oxidase for biosensing. Protein J 2015; 34:68-72. [PMID: 25579496 DOI: 10.1007/s10930-015-9599-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The influence of several factors on the activity of cholesterol oxidase (ChOx) transiently exposed to a room temperature ionic liquid (RTIL) was studied. Presence of flavin adenine dinucleotide (FAD, prosthetic group of ChOx) during exposure to RTIL makes the procedure enzyme-friendly, while the use of RTIL (green reagent) makes it environmentally-friendly. Following exposure to RTIL and its subsequent removal, FAD becomes part of the molecular structure of the refolded protein (a molecular "wire"). This makes the procedure used here a molecular one. The factors studied were: FAD presence in RTIL during modification, water presence during exposure to RTIL, and ratio FAD:RTIL during "wiring". Performance parameters monitored were: enzyme activity before and after "wiring" (expressed as (dA/dt)/mg enzyme, and measured spectrophotometrically), peak current in an amperometric biosensor for cholesterol detection, and linearity of the biosensor response depending on cholesterol concentration. After RTIL removal, the modified enzyme (ME) retained a high percentage of the added FAD, which supplemented that of the native enzyme (functioning as a "wire" and enhancing electron transfer kinetics), and a fraction of the initial activity. Used in an amperometric biosensor, ME showed catalytic activity, linear behavior as a function of cholesterol concentration, and stability.
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Affiliation(s)
- Mihaela D Leonida
- Fairleigh Dickinson University, Metropolitan Campus, 1000 River Rd., Teaneck, NJ, 07666, USA,
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Yehia HM, Hassanein WA, Ibraheim SM. Purification and characterisation of the extracellular cholesterol oxidase enzyme from Enterococcus hirae. BMC Microbiol 2015; 15:178. [PMID: 26369334 PMCID: PMC4570045 DOI: 10.1186/s12866-015-0517-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 09/10/2015] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Recently many efforts are being carried out to reduce cholesterol in foods. Out of the 50 selected isolates that were tested using the agar well diffusion method to assess their ability to decompose cholesterol, 24 bacterial isolates were screened based on their cholesterol-decomposition ability in liquid media. RESULTS The bacterial isolate that displayed the highest cholesterol oxidase activity was identified as Enterococcus hirae. The maximal growth and cholesterol decomposition were achieved with a 1-day incubation under static conditions at 37 °C in cholesterol basal medium adjusted to pH 7 supplemented with 1 g/l cholesterol as the substrate, no additional carbon or nitrogen sources and 0.5 % CaSO4. The cholesterol oxidase enzyme (ChoX) produced by E. hirae was extracted at an (NH4)2SO4 saturation level of 80 % and purified with 79 % yield, resulting in 2.3-fold purification. The molecular weight of (ChoX) was 60 kDa. The optimal conditions required for the maximal activity of the purified COD enzyme produced by E. hirae were 30 min, 40 °C, pH 7.8, substrate concentration of 1 g/l and 200 ppm of MgCl2. The enzyme maintained approximately 36 % and 58.5 % of its activity after 18 days of storage at 4-8 °C. Also, the enzyme loss its activity by gradual thermal treatment, but it maintained 58.5 % of its activity at 95 °C for 2 hr. CONCLUSIONS E. hirae Mil-31 isolated from milk had a great capacity to decompose cholesterol in basal medium supplemented with cholesterol under its optimal growth conditions. Decomposition process of cholesterol by this strain results from its production of cholesterol oxidase enzyme (ChoX). The highest specific enzyme activity and highest purification fold of purified enzyme were achieved after using Sephadex G-100.
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Affiliation(s)
- Hany M Yehia
- Food Science and Nutrition Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia.
- Food Science and Nutrition, Faculty of Home Economics, Helwan University, Helwan, Egypt.
| | - Wesam A Hassanein
- Department of Botany (Microbiology), Faculty of Science, Zagazig University, Zagazig, Egypt.
| | - Shimaa M Ibraheim
- Department of Botany (Microbiology), Faculty of Science, Zagazig University, Zagazig, Egypt.
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Frolova TS, Kukina TP, Sinitsyna OI. Genotoxic and mutagenic properties of synthetic betulinic acid and betulonic acid. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2015; 41:462-7. [DOI: 10.1134/s1068162015040056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Aspergillus oryzae pathways that convert phenylalanine into the flavor volatile 2-phenylethanol. Fungal Genet Biol 2015; 77:22-30. [DOI: 10.1016/j.fgb.2015.03.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 02/17/2015] [Accepted: 03/12/2015] [Indexed: 11/24/2022]
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20
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Cheng VWT, Piragasam RS, Rothery RA, Maklashina E, Cecchini G, Weiner JH. Redox state of flavin adenine dinucleotide drives substrate binding and product release in Escherichia coli succinate dehydrogenase. Biochemistry 2015; 54:1043-52. [PMID: 25569225 DOI: 10.1021/bi501350j] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The Complex II family of enzymes, comprising respiratory succinate dehydrogenases and fumarate reductases, catalyzes reversible interconversion of succinate and fumarate. In contrast to the covalent flavin adenine dinucleotide (FAD) cofactor assembled in these enzymes, soluble fumarate reductases (e.g., those from Shewanella frigidimarina) that assemble a noncovalent FAD cannot catalyze succinate oxidation but retain the ability to reduce fumarate. In this study, an SdhA-H45A variant that eliminates the site of the 8α-N3-histidyl covalent linkage between the protein and FAD was examined. Variants SdhA-R286A/K/Y and -H242A/Y that target residues thought to be important for substrate binding and catalysis were also studied. The variants SdhA-H45A and -R286A/K/Y resulted in the assembly of a noncovalent FAD cofactor, which led to a significant decrease (-87 mV or more) in its reduction potential. The variant enzymes were studied by electron paramagnetic resonance spectroscopy following stand-alone reduction and potentiometric titrations. The "free" and "occupied" states of the active site were linked to the reduced and oxidized states of FAD, respectively. Our data allow for a proposed model of succinate oxidation that is consistent with tunnel diode effects observed in the succinate dehydrogenase enzyme and a preference for fumarate reduction catalysis in fumarate reductase homologues that assemble a noncovalent FAD.
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Affiliation(s)
- Victor W T Cheng
- Department of Biochemistry, University of Alberta , Edmonton, Alberta T6G 2H7, Canada
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21
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Krondorfer I, Brugger D, Paukner R, Scheiblbrandner S, Pirker KF, Hofbauer S, Furtmüller PG, Obinger C, Haltrich D, Peterbauer CK. Agaricus meleagris pyranose dehydrogenase: influence of covalent FAD linkage on catalysis and stability. Arch Biochem Biophys 2014; 558:111-9. [PMID: 25043975 PMCID: PMC4148704 DOI: 10.1016/j.abb.2014.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 07/04/2014] [Accepted: 07/09/2014] [Indexed: 10/25/2022]
Abstract
Pyranose dehydrogenase (PDH) is a monomeric flavoprotein belonging to the glucose-methanol-choline (GMC) family of oxidoreductases. It catalyzes the oxidation of free, non-phosphorylated sugars to the corresponding keto sugars. The enzyme harbors an FAD cofactor that is covalently attached to histidine 103 via an 8α-N(3) histidyl linkage. Our previous work showed that variant H103Y was still able to bind FAD (non-covalently) and perform catalysis but steady-state kinetic parameters for several substrates were negatively affected. In order to investigate the impact of the covalent FAD attachment in Agaricus meleagris PDH in more detail, pre-steady-state kinetics, reduction potential and stability of the variant H103Y in comparison to the wild-type enzyme were probed. Stopped-flow analysis revealed that the mutation slowed down the reductive half-reaction by around three orders of magnitude whereas the oxidative half-reaction was affected only to a minor degree. This was reflected by a decrease in the standard reduction potential of variant H103Y compared to the wild-type protein. The existence of an anionic semiquinone radical in the resting state of both the wild-type and variant H103Y was demonstrated using electron paramagnetic resonance (EPR) spectroscopy and suggested a higher mobility of the cofactor in the variant H103Y. Unfolding studies showed significant negative effects of the disruption of the covalent bond on thermal and conformational stability. The results are discussed with respect to the role of covalently bound FAD in catalysis and stability.
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Affiliation(s)
- Iris Krondorfer
- Department of Food Science and Technology, Food Biotechnology Laboratory, BOKU - University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria
| | - Dagmar Brugger
- Department of Food Science and Technology, Food Biotechnology Laboratory, BOKU - University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria
| | - Regina Paukner
- Department of Food Science and Technology, Food Biotechnology Laboratory, BOKU - University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria
| | - Stefan Scheiblbrandner
- Department of Food Science and Technology, Food Biotechnology Laboratory, BOKU - University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria
| | - Katharina F Pirker
- Department of Chemistry, Division of Biochemistry, BOKU - University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Stefan Hofbauer
- Department of Chemistry, Division of Biochemistry, BOKU - University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Paul G Furtmüller
- Department of Chemistry, Division of Biochemistry, BOKU - University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Christian Obinger
- Department of Chemistry, Division of Biochemistry, BOKU - University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Dietmar Haltrich
- Department of Food Science and Technology, Food Biotechnology Laboratory, BOKU - University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria
| | - Clemens K Peterbauer
- Department of Food Science and Technology, Food Biotechnology Laboratory, BOKU - University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria.
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22
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Analysis of covalent flavinylation using thermostable succinate dehydrogenase from Thermus thermophilus and Sulfolobus tokodaii lacking SdhE homologs. FEBS Lett 2014; 588:1058-63. [PMID: 24566086 DOI: 10.1016/j.febslet.2014.02.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/05/2014] [Accepted: 02/05/2014] [Indexed: 11/20/2022]
Abstract
Recent studies have indicated that post-translational flavinylation of succinate dehydrogenase subunit A (SdhA) in eukaryotes and bacteria require the chaperone-like proteins Sdh5 and SdhE, respectively. How does covalent flavinylation occur in prokaryotes, which lack SdhE homologs? In this study, I showed that covalent flavinylation in two hyperthermophilic bacteria/archaea lacking SdhE, Thermus thermophilus and Sulfolobus tokodaii, requires heat and dicarboxylic acid. These thermophilic bacteria/archaea inhabit hot environments and are said to be genetically far removed from mesophilic bacteria which possess SdhE. Since mesophilic bacteria have been effective at covalent bonding in temperate environments, they may have caused the evolution of SdhE.
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23
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An overview on alcohol oxidases and their potential applications. Appl Microbiol Biotechnol 2013; 97:4259-75. [DOI: 10.1007/s00253-013-4842-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/06/2013] [Accepted: 03/07/2013] [Indexed: 10/27/2022]
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24
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Melnikova N, Burlova I, Kiseleva T, Klabukova I, Gulenova M, Kislitsin CAC, Vasin V, Tanaseichuk B. A practical synthesis of betulonic acid using selective oxidation of betulin on aluminium solid support. Molecules 2012; 17:11849-63. [PMID: 23085649 PMCID: PMC6268157 DOI: 10.3390/molecules171011849] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 09/23/2012] [Accepted: 09/24/2012] [Indexed: 11/17/2022] Open
Abstract
The room temperature oxidation of betulin by Cr(VI) compounds in aqueous acetone on solid supports such as alumina, zeolites and silica gel has been studied. The oxidation on alumina support leaded to a single product--betulonic acid--in quantitative yield. One hundred percent selective oxidation during 30 min of betulin up to betulonic aldehyde was determined when silica gel support was used. The oxidation of betulin using zeolites as a support gives a mixture of betulonic acid and aldehyde in a 2:1 ratio. It is proposed the selective oxidation up to betulonic acid is due to the influence of Al³⁺-ions.
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Affiliation(s)
- Nina Melnikova
- Department of Pharmaceutical Chemistry, Nizhny Novgorod State Medical Academy, Minin Sq. 10/1, Nizhny Novgorod 603-000, Russia.
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25
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García JL, Uhía I, Galán B. Catabolism and biotechnological applications of cholesterol degrading bacteria. Microb Biotechnol 2012; 5:679-99. [PMID: 22309478 PMCID: PMC3815891 DOI: 10.1111/j.1751-7915.2012.00331.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Cholesterol is a steroid commonly found in nature with a great relevance in biology, medicine and chemistry, playing an essential role as a structural component of animal cell membranes. The ubiquity of cholesterol in the environment has made it a reference biomarker for environmental pollution analysis and a common carbon source for different microorganisms, some of them being important pathogens such as Mycobacterium tuberculosis. This work revises the accumulated biochemical and genetic knowledge on the bacterial pathways that degrade or transform this molecule, given that the characterization of cholesterol metabolism would contribute not only to understand its role in tuberculosis but also to develop new biotechnological processes that use this and other related molecules as starting or target materials.
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Affiliation(s)
- J L García
- Environmental Biology Department, Centro de Investigaciones Biológicas, CSIC, C/ Ramiro de Maeztu, 9, 28040 Madrid, Spain.
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26
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27
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Xin Y, Yang H, Xiao X, Zhang L, Zhang Y, Tong Y, Wang W. Preparation and characterization of affinity sorbents based on isoalloxazine-like ligands for separation of flavoenzymes. J Sep Sci 2011; 34:2940-9. [DOI: 10.1002/jssc.201100474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 07/25/2011] [Accepted: 07/26/2011] [Indexed: 11/10/2022]
Affiliation(s)
- Yu Xin
- School of Biotechnology, Jiangnan University, Key Laboratory of Industry Biotechnology, Ministry of Education, Wuxi, Jiangsu, P R China.
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28
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Fiorillo A, Federico R, Polticelli F, Boffi A, Mazzei F, Di Fusco M, Ilari A, Tavladoraki P. The structure of maize polyamine oxidase K300M mutant in complex with the natural substrates provides a snapshot of the catalytic mechanism of polyamine oxidation. FEBS J 2011; 278:809-21. [PMID: 21205212 DOI: 10.1111/j.1742-4658.2010.08000.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Polyamine oxidases are FAD-dependent enzymes catalyzing the oxidation of polyamines at the secondary amino groups. Zea mays PAO (ZmPAO) oxidizes the carbon on the endo-side of the N5-nitrogen of spermidine (Spd) and spermine (Spm). The structure of ZmPAO revealed that the active site is formed by a catalytic tunnel in which the N5 atom of FAD lies in close proximity to the K300 side chain, the only active-site residue conserved in all PAOs. A water molecule, (HOH309), is hydrogen-bound to the amino group of K300 and mutation of this residue results in a 1400-fold decrease in the rate of flavin reduction. The structural studies on the catalytically impaired ZmPAO-K300M mutant described here show that substrates are bound in an 'out-of-register' mode and the HOH309 water molecule is absent in the enzyme-substrate complexes. Moreover, K300 mutation brings about a 60 mV decrease in the FAD redox potential and a 30-fold decrease in the FAD reoxidation rate, within a virtually unaltered geometry of the catalytic pocket. Taken together, these results indicate that the HOH309-K300 couple plays a major role in multiple steps of ZmPAO catalytic mechanism, such as correct substrate binding geometry as well as FAD reduction and reoxidation kinetics.
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Affiliation(s)
- Annarita Fiorillo
- Department of Science and Biomedical Technology, University of L'Aquila, Italy
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29
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North MA, Bhattacharyya S, Truhlar DG. Improved Density Functional Description of the Electrochemistry and Structure−Property Descriptors of Substituted Flavins. J Phys Chem B 2010; 114:14907-15. [DOI: 10.1021/jp108024b] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Michael A. North
- Department of Chemistry, University of Wisconsin—Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin 54702, United States, and Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Sudeep Bhattacharyya
- Department of Chemistry, University of Wisconsin—Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin 54702, United States, and Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Donald G. Truhlar
- Department of Chemistry, University of Wisconsin—Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin 54702, United States, and Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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Abstract
Cholesterol oxidase is a bacterial-specific flavoenzyme that catalyzes the oxidation and isomerisation of steroids containing a 3beta hydroxyl group and a double bond at the Delta5-6 of the steroid ring system. The enzyme is a member of a large family of flavin-specific oxidoreductases and is found in two different forms: one where the flavin adenine dinucleotide (FAD) cofactor is covalently linked to the protein and one where the cofactor is non-covalently bound to the protein. These two enzyme forms have been extensively studied in order to gain insight into the mechanism of flavin-mediated oxidation and the relationship between protein structure and enzyme redox potential. More recently the enzyme has been found to play an important role in bacterial pathogenesis and hence further studies are focused on its potential use for future development of novel antibacterial therapeutic agents. In this review the biochemical, structural, kinetic and mechanistic features of the enzyme are discussed.
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31
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Volontè F, Pollegioni L, Molla G, Frattini L, Marinelli F, Piubelli L. Production of recombinant cholesterol oxidase containing covalently bound FAD in Escherichia coli. BMC Biotechnol 2010; 10:33. [PMID: 20409334 PMCID: PMC2890692 DOI: 10.1186/1472-6750-10-33] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 04/21/2010] [Indexed: 11/10/2022] Open
Abstract
Background Cholesterol oxidase is an alcohol dehydrogenase/oxidase flavoprotein that catalyzes the dehydrogenation of C(3)-OH of cholesterol. It has two major biotechnological applications, i.e. in the determination of serum (and food) cholesterol levels and as biocatalyst providing valuable intermediates for industrial steroid drug production. Cholesterol oxidases of type I are those containing the FAD cofactor tightly but not covalently bound to the protein moiety, whereas type II members contain covalently bound FAD. This is the first report on the over-expression in Escherichia coli of type II cholesterol oxidase from Brevibacterium sterolicum (BCO). Results Design of the plasmid construct encoding the mature BCO, optimization of medium composition and identification of the best cultivation/induction conditions for growing and expressing the active protein in recombinant E. coli cells, concurred to achieve a valuable improvement: BCO volumetric productivity was increased from ~500 up to ~25000 U/L and its crude extract specific activity from 0.5 up to 7.0 U/mg protein. Interestingly, under optimal expression conditions, nearly 55% of the soluble recombinant BCO is produced as covalently FAD bound form, whereas the protein containing non-covalently bound FAD is preferentially accumulated in insoluble inclusion bodies. Conclusions Comparison of our results with those published on non-covalent (type I) COs expressed in recombinant form (either in E. coli or Streptomyces spp.), shows that the fully active type II BCO can be produced in E. coli at valuable expression levels. The improved over-production of the FAD-bound cholesterol oxidase will support its development as a novel biotool to be exploited in biotechnological applications.
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Affiliation(s)
- Federica Volontè
- Dipartimento di Biotecnologie e Scienze Molecolari, Università degli Studi dell'Insubria via JH Dunant 3, 21100 Varese, Italy
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Abstract
Cholesterol oxidase is a bacterial FAD-containing flavooxidase that catalyzes the first reaction in cholesterol catabolism. Indeed, this enzyme catalyzes two reactions: the oxidation of the C(3)-OH group of cholesterol (and other sterols) to give cholest-5-en-3-one; and its isomerization to cholest-4-en-3-one. In the past several years, the structural and functional characterization of cholesterol oxidase has been developed together with its application as a biological tool. Cholesterol oxidase has been used in biocatalysis for the production of a number of steroids, as an insecticidal protein against boll weevil larvae and, in particular, as a diagnostic enzyme for determining serum levels of cholesterol. These applications prompted various laboratories worldwide to isolate this flavooxidase from different sources and to improve its properties by protein engineering, further increasing our knowledge on its structure-function relationships. These studies also discovered new physiological roles for cholesterol oxidase (e.g. in virulence and as an antifungal sensor). We assume that the investigations of cholesterol oxidase and its applications will continue to grow quickly in the near future, in particular to uncover unexpected, new areas of application.
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Affiliation(s)
- Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze Molecolari, Università degli studi dell'Insubria, Varese, Italy.
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Abstract
Cholesterol oxidases are bifunctional flavoenzymes that catalyze the oxidation of steroid substrates which have a hydroxyl group at the 3beta position of the steroid ring system. The enzyme is found, in a wide range of bacterial species, in two forms: one with the FAD cofactor bound noncovalently to the enzyme; and one with the cofactor linked covalently to the protein. Here we discuss, compare and contrast the salient biochemical properties of the two forms of the enzyme. Specifically, the structural features are discussed that affect the redox potentials of the flavin cofactor, the chemical mechanism of substrate dehydrogenation by active-center amino acid residues, the kinetic parameters of both types of enzymes and the reactivity of reduced enzymes with molecular dioxygen. The presence of a molecular tunnel that is proposed to serve in the access of dioxygen to the active site and mechanisms of its control by a 'gate' formed by amino acid residues are highlighted.
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Affiliation(s)
- Alice Vrielink
- School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley, Australia.
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34
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Chen QH, Liu J, Zhang HF, He GQ, Fu ML. The betulinic acid production from betulin through biotransformation by fungi. Enzyme Microb Technol 2009. [DOI: 10.1016/j.enzmictec.2009.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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35
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Winkler A, Motz K, Riedl S, Puhl M, Macheroux P, Gruber K. Structural and mechanistic studies reveal the functional role of bicovalent flavinylation in berberine bridge enzyme. J Biol Chem 2009; 284:19993-20001. [PMID: 19457868 DOI: 10.1074/jbc.m109.015727] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Berberine bridge enzyme (BBE) is a member of the recently discovered family of bicovalently flavinylated proteins. In this group of enzymes, the FAD cofactor is linked via its 8alpha-methyl group and the C-6 atom to conserved histidine and cysteine residues, His-104 and Cys-166 for BBE, respectively. 6-S-Cysteinylation has recently been shown to have a significant influence on the redox potential of the flavin cofactor; however, 8alpha-histidylation evaded a closer characterization due to extremely low expression levels upon substitution. Co-overexpression of protein disulfide isomerase improved expression levels and allowed isolation and purification of the H104A protein variant. To gain more insight into the functional role of the unusual dual mode of cofactor attachment, we solved the x-ray crystal structures of two mutant proteins, H104A and C166A BBE, each lacking one of the covalent linkages. Information from a structure of wild type enzyme in complex with the product of the catalyzed reaction is combined with the kinetic and structural characterization of the protein variants to demonstrate the importance of the bicovalent linkage for substrate binding and efficient oxidation. In addition, the redox potential of the flavin cofactor is enhanced additively by the dual mode of cofactor attachment. The reduced level of expression for the H104A mutant protein and the difficulty of isolating even small amounts of the protein variant with both linkages removed (H104A-C166A) also points toward a possible role of covalent flavinylation during protein folding.
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Affiliation(s)
- Andreas Winkler
- Institute of Biochemistry, Graz University of Technology, 8010 Graz, Austria
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36
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Heuts DPHM, Scrutton NS, McIntire WS, Fraaije MW. What's in a covalent bond? On the role and formation of covalently bound flavin cofactors. FEBS J 2009; 276:3405-27. [PMID: 19438712 DOI: 10.1111/j.1742-4658.2009.07053.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Many enzymes use one or more cofactors, such as biotin, heme, or flavin. These cofactors may be bound to the enzyme in a noncovalent or covalent manner. Although most flavoproteins contain a noncovalently bound flavin cofactor (FMN or FAD), a large number have these cofactors covalently linked to the polypeptide chain. Most covalent flavin-protein linkages involve a single cofactor attachment via a histidyl, tyrosyl, cysteinyl or threonyl linkage. However, some flavoproteins contain a flavin that is tethered to two amino acids. In the last decade, many studies have focused on elucidating the mechanism(s) of covalent flavin incorporation (flavinylation) and the possible role(s) of covalent protein-flavin bonds. These endeavors have revealed that covalent flavinylation is a post-translational and self-catalytic process. This review presents an overview of the known types of covalent flavin bonds and the proposed mechanisms and roles of covalent flavinylation.
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Affiliation(s)
- Dominic P H M Heuts
- Laboratory of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
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37
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Quaye O, Cowins S, Gadda G. Contribution of flavin covalent linkage with histidine 99 to the reaction catalyzed by choline oxidase. J Biol Chem 2009; 284:16990-16997. [PMID: 19398559 DOI: 10.1074/jbc.m109.003715] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The FAD-dependent choline oxidase has a flavin cofactor covalently attached to the protein via histidine 99 through an 8alpha-N(3)-histidyl linkage. The enzyme catalyzes the four-electron oxidation of choline to glycine betaine, forming betaine aldehyde as an enzyme-bound intermediate. The variant form of choline oxidase in which the histidine residue has been replaced with asparagine was used to investigate the contribution of the 8alpha-N(3)-histidyl linkage of FAD to the protein toward the reaction catalyzed by the enzyme. Decreases of 10-fold and 30-fold in the k(cat)/K(m) and k(cat) values were observed as compared with wild-type choline oxidase at pH 10 and 25 degrees C, with no significant effect on k(cat)/K(O) using choline as substrate. Both the k(cat)/K(m) and k(cat) values increased with increasing pH to limiting values at high pH consistent with the participation of an unprotonated group in the reductive half-reaction and the overall turnover of the enzyme. The pH independence of both (D)(k(cat)/K(m)) and (D)k(cat), with average values of 9.2 +/- 3.3 and 7.4 +/- 0.5, respectively, is consistent with absence of external forward and reverse commitments to catalysis, and the chemical step of CH bond cleavage being rate-limiting for both the reductive half-reaction and the overall enzyme turnover. The temperature dependence of the (D)k(red) values suggests disruption of the preorganization in the asparagine variant enzyme. Altogether, the data presented in this study are consistent with the FAD-histidyl covalent linkage being important for the optimal positioning of the hydride ion donor and acceptor in the tunneling reaction catalyzed by choline oxidase.
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Affiliation(s)
- Osbourne Quaye
- From the Departments of Chemistry, Atlanta, Georgia 30302-4098
| | - Sharonda Cowins
- From the Departments of Chemistry, Atlanta, Georgia 30302-4098; Department of Chemistry, Albany State University, Albany, Georgia 31705
| | - Giovanni Gadda
- From the Departments of Chemistry, Atlanta, Georgia 30302-4098; Biology, Atlanta, Georgia 30302-4098; The Center for Biotechnology and Drug Design, Georgia State University, Atlanta, Georgia 30302-4098.
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38
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Jin J, Mazon H, van den Heuvel RHH, Heck AJ, Janssen DB, Fraaije MW. Covalent flavinylation of vanillyl-alcohol oxidase is an autocatalytic process. FEBS J 2008; 275:5191-200. [PMID: 18793324 DOI: 10.1111/j.1742-4658.2008.06649.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Vanillyl-alcohol oxidase (VAO; EC 1.1.3.38) contains a covalently 8alpha-histidyl bound FAD, which represents the most frequently encountered covalent flavin-protein linkage. To elucidate the mechanism by which VAO covalently incorporates the FAD cofactor, apo VAO was produced by using a riboflavin auxotrophic Escherichia coli strain. Incubation of apo VAO with FAD resulted in full restoration of enzyme activity. The rate of activity restoration was dependent on FAD concentration, displaying a hyperbolic relationship (K(FAD )= 2.3 microM, k(activation) = 0.13 min(-1)). The time-dependent increase in enzyme activity was accompanied by full covalent incorporation of FAD, as determined by SDS/PAGE and ESI-MS analysis. The results obtained show that formation of the covalent flavin-protein bond is an autocatalytic process, which proceeds via a reduced flavin intermediate. Furthermore, ESI-MS experiments revealed that, although apo VAO mainly exists as monomers and dimers, FAD binding promotes the formation of VAO dimers and octamers. Tandem ESI-MS experiments revealed that octamerization is not dependent on full covalent flavinylation.
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Affiliation(s)
- Jianfeng Jin
- Laboratory of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
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39
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Huang CH, Winkler A, Chen CL, Lai WL, Tsai YC, Macheroux P, Liaw SH. Functional roles of the 6-S-cysteinyl, 8alpha-N1-histidyl FAD in glucooligosaccharide oxidase from Acremonium strictum. J Biol Chem 2008; 283:30990-6. [PMID: 18768475 DOI: 10.1074/jbc.m804331200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The crystal structure of glucooligosaccharide oxidase from Acremonium strictum was demonstrated to contain a bicovalent flavinylation, with the 6- and 8alpha-positions of the flavin isoalloxazine ring cross-linked to Cys(130) and His(70), respectively. The H70A and C130A single mutants still retain the covalent FAD, indicating that flavinylation at these two residues is independent. Both mutants exhibit a decreased midpoint potential of approximately +69 and +61 mV, respectively, compared with +126 mV for the wild type, and possess lower activities with k(cat) values reduced to approximately 2 and 5%, and the flavin reduction rate reduced to 0.6 and 14%. This indicates that both covalent linkages increase the flavin redox potential and alter the redox properties to promote catalytic efficiency. In addition, the isolated H70A/C130A double mutant does not contain FAD, and addition of exogenous FAD was not able to restore any detectable activity. This demonstrates that the covalent attachment is essential for the binding of the oxidized cofactor. Furthermore, the crystal structure of the C130A mutant displays conformational changes in several cofactor and substrate-interacting residues and hence provides direct evidence for novel functions of flavinylation in assistance of cofactor and substrate binding. Finally, the wild-type enzyme is more heat and guanidine HCl-resistant than the mutants. Therefore, the bicovalent flavin linkage not only tunes the redox potential and contributes to cofactor and substrate binding but also increases structural stability.
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Affiliation(s)
- Chun-Hsiang Huang
- Department of Life Sciences, National Yang-Ming University, Taipei, Taiwan
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40
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Piubelli L, Pedotti M, Molla G, Feindler-Boeckh S, Ghisla S, Pilone MS, Pollegioni L. On the oxygen reactivity of flavoprotein oxidases: an oxygen access tunnel and gate in brevibacterium sterolicum cholesterol oxidase. J Biol Chem 2008; 283:24738-47. [PMID: 18614534 DOI: 10.1074/jbc.m802321200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The flavoprotein cholesterol oxidase from Brevibacterium sterolicum (BCO) possesses a narrow channel that links the active center containing the flavin to the outside solvent. This channel has been proposed to serve for the access of dioxygen; it contains at its "bottom" a Glu-Arg pair (Glu-475-Arg-477) that was found by crystallographic studies to exist in two forms named "open" and "closed," which in turn was suggested to constitute a gate functioning in the control of oxygen access. Most mutations of residues that flank the channel have minor effects on the oxygen reactivity. Mutations of Glu-311, however, cause a switch in the basic kinetic mechanism of the reaction of reduced BCO with dioxygen; wild-type BCO and most mutants show a saturation behavior with increasing oxygen concentration, whereas for Glu-311 mutants a linear dependence is found that is assumed to reflect a "simple" second order process. This is taken as support for the assumption that residue Glu-311 finely tunes the Glu-475-Arg-477 pair, forming a gate that functions in modulating the access/reactivity of dioxygen.
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Affiliation(s)
- Luciano Piubelli
- Department of Biotechnology and Molecular Sciences, University of Insubria, 21100 Varese, Italy
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41
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Ye D, Lei J, Li W, Ge F, Wu K, Xu W, Yong B. Purification and characterization of extracellular cholesterol oxidase from Enterobacter sp. World J Microbiol Biotechnol 2008. [DOI: 10.1007/s11274-008-9734-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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42
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Preparation and some properties of cholesterol oxidase from Rhodococcus sp. R14-2. World J Microbiol Biotechnol 2008. [DOI: 10.1007/s11274-008-9722-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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43
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Caldinelli L, Iametti S, Barbiroli A, Fessas D, Bonomi F, Piubelli L, Molla G, Pollegioni L. Relevance of the flavin binding to the stability and folding of engineered cholesterol oxidase containing noncovalently bound FAD. Protein Sci 2008; 17:409-19. [PMID: 18218720 DOI: 10.1110/ps.073137708] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The flavoprotein cholesterol oxidase (CO) from Brevibacterium sterolicum is a monomeric flavoenzyme containing one molecule of FAD cofactor covalently linked to His69. The elimination of the covalent link following the His69Ala substitution was demonstrated to result in a significant decrease in activity, in the midpoint redox potential of the flavin, and in stability with respect to the wild-type enzyme, but does not modify the overall structure of the enzyme. We used CO as a model system to dissect the changes due to the elimination of the covalent link between the flavin and the protein (by comparing the wild-type and H69A CO holoproteins) with those due to the elimination of the cofactor (by comparing the holo- and apoprotein forms of H69A CO). The apoprotein of H69A CO lacks the characteristic tertiary structure of the holoprotein and displays larger hydrophobic surfaces; its urea-induced unfolding does not occur by a simple two-state mechanism and is largely nonreversible. Minor alterations in the flavin binding region are evident between the native and the refolded proteins, and are likely responsible for the low refolding yield observed. A model for the equilibrium unfolding of H69A CO that also takes into consideration the effects of cofactor binding and dissociation, and thus may be of general significance in terms of the relationships between cofactor uptake and folding in flavoproteins, is presented.
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Affiliation(s)
- Laura Caldinelli
- Department of Biotechnology and Molecular Sciences, University of Insubria, 21100 Varese, Italy
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44
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Hassan-Abdallah A, Zhao G, Jorns MS. Covalent Flavinylation of Monomeric Sarcosine Oxidase: Identification of a Residue Essential for Holoenzyme Biosynthesis. Biochemistry 2008; 47:1136-43. [DOI: 10.1021/bi702077q] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alshaimaa Hassan-Abdallah
- Department of Biochemistry and Molecular Biology, Drexel University, College of Medicine, Philadelphia, Pennsylvania 19102
| | - Guohua Zhao
- Department of Biochemistry and Molecular Biology, Drexel University, College of Medicine, Philadelphia, Pennsylvania 19102
| | - Marilyn Schuman Jorns
- Department of Biochemistry and Molecular Biology, Drexel University, College of Medicine, Philadelphia, Pennsylvania 19102
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45
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Aparicio JF, Martín JF. Microbial cholesterol oxidases: bioconversion enzymes or signal proteins? MOLECULAR BIOSYSTEMS 2008; 4:804-9. [DOI: 10.1039/b717500k] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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46
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Kujawa M, Volc J, Halada P, Sedmera P, Divne C, Sygmund C, Leitner C, Peterbauer C, Haltrich D. Properties of pyranose dehydrogenase purified from the litter-degrading fungus Agaricus xanthoderma. FEBS J 2007; 274:879-94. [PMID: 17227387 DOI: 10.1111/j.1742-4658.2007.05634.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We purified an extracellular pyranose dehydrogenase (PDH) from the basidiomycete fungus Agaricus xanthoderma using ammonium sulfate fractionation and ion-exchange and hydrophobic interaction chromatography. The native enzyme is a monomeric glycoprotein (5% carbohydrate) containing a covalently bound FAD as its prosthetic group. The PDH polypeptide consists of 575 amino acids and has a molecular mass of 65 400 Da as determined by MALDI MS. On the basis of the primary structure of the mature protein, PDH is a member of the glucose-methanol-choline oxidoreductase family. We constructed a homology model of PDH using the 3D structure of glucose oxidase from Aspergillus niger as a template. This model suggests a novel type of bi-covalent flavinylation in PDH, 9-S-cysteinyl, 8-alpha-N3-histidyl FAD. The enzyme exhibits a broad sugar substrate tolerance, oxidizing structurally different aldopyranoses including monosaccharides and oligosaccharides as well as glycosides. Its preferred electron donor substrates are D-glucose, D-galactose, L-arabinose, and D-xylose. As shown by in situ NMR analysis, D-glucose and D-galactose are both oxidized at positions C2 and C3, yielding the corresponding didehydroaldoses (diketoaldoses) as the final reaction products. PDH shows no detectable activity with oxygen, and its reactivity towards electron acceptors is rather limited, reducing various substituted benzoquinones and complexed metal ions. The azino-bis-(3-ethylbenzthiazolin-6-sulfonic acid) cation radical and the ferricenium ion are the best electron acceptors, as judged by the catalytic efficiencies (k(cat)/K(m)). The enzyme may play a role in lignocellulose degradation.
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Affiliation(s)
- Magdalena Kujawa
- Division of Food Biotechnology, Department of Food Sciences and Technology, BOKU - University of Natural Resources and Applied Life Sciences, Vienna, Austria
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47
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Lim L, Molla G, Guinn N, Ghisla S, Pollegioni L, Vrielink A. Structural and kinetic analyses of the H121A mutant of cholesterol oxidase. Biochem J 2006; 400:13-22. [PMID: 16856877 PMCID: PMC1635447 DOI: 10.1042/bj20060664] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cholesterol oxidase is a monomeric flavoenzyme that catalyses the oxidation of cholesterol to cholest-5-en-3-one followed by isomerization to cholest-4-en-3-one. The enzyme from Brevibacterium sterolicum contains the FAD cofactor covalently bound to His121. It was previously demonstrated that the H121A substitution results in a approximately 100 mV decrease in the midpoint redox potential and a approximately 40-fold decrease in turnover number compared to wild-type enzyme [Motteran, Pilone, Molla, Ghisla and Pollegioni (2001) Journal of Biological Chemistry 276, 18024-18030]. A detailed kinetic analysis of the H121A mutant enzyme shows that the decrease in turnover number is largely due to a corresponding decrease in the rate constant of flavin reduction, whilst the re-oxidation reaction is only marginally altered and the isomerization reaction is not affected by the substitution and precedes product dissociation. The X-ray structure of the mutant protein, determined to 1.7 A resolution (1 A identical with 0.1 nm), reveals only minor changes in the overall fold of the protein, namely: two loops have slight movements and a tryptophan residue changes conformation by a rotation of 180 degrees about chi1 compared to the native enzyme. Comparison of the isoalloxazine ring moiety of the FAD cofactor between the structures of the native and mutant proteins shows a change from a non-planar to a planar geometry (resulting in a more tetrahedral-like geometry for N5). This change is proposed to be a major factor contributing to the observed alteration in redox potential. Since a similar distortion of the flavin has not been observed in other covalent flavoproteins, it is proposed to represent a specific mode to facilitate flavin reduction in covalent cholesterol oxidase.
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Affiliation(s)
- Louis Lim
- *Department of Chemistry and Biochemistry, Sinsheimer Laboratory, University of California at Santa Cruz, 1156 High Street, Santa Cruz, CA, 95064, U.S.A
| | - Gianluca Molla
- †Department of Biotechnology and Molecular Sciences, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy
| | - Nicole Guinn
- *Department of Chemistry and Biochemistry, Sinsheimer Laboratory, University of California at Santa Cruz, 1156 High Street, Santa Cruz, CA, 95064, U.S.A
| | - Sandro Ghisla
- ‡Fachbereich Biologie, University of Konstanz, Konstanz, Germany
| | - Loredano Pollegioni
- †Department of Biotechnology and Molecular Sciences, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy
| | - Alice Vrielink
- *Department of Chemistry and Biochemistry, Sinsheimer Laboratory, University of California at Santa Cruz, 1156 High Street, Santa Cruz, CA, 95064, U.S.A
- To whom correspondence should be addressed (email )
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48
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Hassan-Abdallah A, Zhao G, Jorns MS. Role of the covalent flavin linkage in monomeric sarcosine oxidase. Biochemistry 2006; 45:9454-62. [PMID: 16878980 DOI: 10.1021/bi0607352] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Monomeric sarcosine oxidase (MSOX) is a prototypical member of a recently recognized family of amine-oxidizing enzymes that all contain covalently bound flavin. Mutation of the covalent flavin attachment site in MSOX produces a catalytically inactive apoprotein (apoCys315Ala) that forms an unstable complex with FAD (K(d) = 100 muM), similar to that observed with wild-type apoMSOX where the complex is formed as an intermediate during covalent flavin attachment. In situ reconstitution of sarcosine oxidase activity is achieved by assaying apoCys315Ala in the presence of FAD or 8-nor-8-chloroFAD, an analogue with an approximately 55 mV higher reduction potential. After correction for an estimated 65% reconstitutable apoprotein, the specific activity of apoCys315Ala in the presence of excess FAD or 8-nor-8-chloroFAD is 14% or 80%, respectively, of that observed with wild-type MSOX. Unlike oxidized flavin, apoCys315Ala exhibits a high affinity for reduced flavin, as judged by results obtained with reduced 5-deazaFAD (5-deazaFADH(2)) where the estimated binding stoichiometry is unaffected by dialysis. The Cys315Ala.5-deazaFADH(2) complex is also air-stable but is readily oxidized by sarcosine imine, a reaction accompanied by release of weakly bound oxidized 5-deazaFAD. The dramatic difference in the binding affinity of apoCys315Ala for oxidized and reduced flavin indicates that the protein environment must induce a sizable increase in the reduction potential of noncovalently bound flavin (DeltaE(m) approximately 120 mV). The covalent flavin linkage prevents loss of weakly bound oxidized FAD and also modulates the flavin reduction potential in conjunction with the protein environment.
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Affiliation(s)
- Alshaimaa Hassan-Abdallah
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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49
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Ghanem M, Gadda G. Effects of reversing the protein positive charge in the proximity of the flavin N(1) locus of choline oxidase. Biochemistry 2006; 45:3437-47. [PMID: 16519539 DOI: 10.1021/bi052514m] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A protein positive charge near the flavin N(1) locus is a distinguishing feature of most flavoprotein oxidases, with mechanistic implications for the modulation of flavin reactivity. A recent study showed that in the active site of choline oxidase the protein positive charge is provided by His(466). Here, we have reversed the charge by substitution with aspartate (CHO-H466D) and, for the first time, characterized a flavoprotein oxidase with a negative charge near the flavin N(1) locus. CHO-H466D formed a stable complex with choline but lost the ability to oxidize the substrate. In contrast to the wild-type enzyme, which binds FAD covalently in a 1:1 ratio, CHO-H466D contained approximately 0.3 FAD per protein, of which 75% was not covalently bound to the enzyme. Anaerobic reduction of CHO-H466D resulted in the formation of a neutral hydroquinone, with no stabilization of the flavin semiquinone; in contrast, the anionic semiquinone and hydroquinone species were observed with the wild type and a H466A variant of the enzyme. The midpoint reduction potential for the oxidized-reduced couple in CHO-H466D was approximately 160 mV lower than that of the wild-type enzyme. Finally, CHO-H466D lost the ability to form complexes with glycine betaine or sulfite. Thus, with a reversal of the protein charge near the FAD N(1) locus, choline oxidase lost the ability to stabilize negative charges in the active site, irrespective of whether they develop on the flavin or are borne on ligands, resulting in defective flavinylation of the protein, the decreased electrophilicity of the flavin, and the consequent loss of catalytic activity.
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Affiliation(s)
- Mahmoud Ghanem
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302-4098, USA
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50
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Matsumura K, Hisada H, Obata H, Hata Y, Kawato A, Abe Y, Akita O. A novel amine oxidase-encoding gene from Aspergillus oryzae. J Biosci Bioeng 2005; 98:359-65. [PMID: 16233720 DOI: 10.1016/s1389-1723(04)00296-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2004] [Accepted: 08/27/2004] [Indexed: 11/22/2022]
Abstract
We cloned a novel gene (aoxA) encoding amine oxidase (AOX) from Aspergillus oryzae. One cDNA clone showing extreme homology to the AOX-encoding genes was found in an expressed sequence tag (EST) library of A. oryzae. Molecular analysis revealed that the aoxA carried four exons interrupted by three introns and had an open reading frame encoding 672 amino acid residues. The deduced amino acid sequence showed about 83.5% identity to the Aspergillus niger AO-I. The strictly conserved residues for co-factor and copper binding in copper/quinine-containing AOXs were also preserved at Tyr 405, His 456, His 458 and His 617 in the cDNA sequence. When the aoxA was overexpressed in the homologous hyperexpression system of A. oryzae, AOX activity in the transformant was enhanced 75-fold. An apparent molecular weight of 159,000 by gel filtration and a subunit molecular weight of 75,000 by SDS-PAGE of the purified enzyme were estimated, suggesting that the enzyme molecule is a homo-dimer similar to other copper/quinine-containing AOXs. The A. oryzae AOXA preferentially oxidized aliphatic monoamines of C2-C6 rather than aromatic amines or diamines. From these results, the aoxA gene product obtained by homologous hyperexpression system of A. oryzae is undoubtedly a functional AOX.
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Affiliation(s)
- Kengo Matsumura
- Research Institute, Gekkeikan Sake Co. Ltd., 300 Katahara-cho, Fushimi-ku, Kyoto 612-8361, Japan.
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