1
|
Kim SM, Kang SH, Jeon BW, Kim YH. Tunnel engineering of gas-converting enzymes for inhibitor retardation and substrate acceleration. BIORESOURCE TECHNOLOGY 2024; 394:130248. [PMID: 38158090 DOI: 10.1016/j.biortech.2023.130248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
Carbon monoxide dehydrogenase (CODH), formate dehydrogenase (FDH), hydrogenase (H2ase), and nitrogenase (N2ase) are crucial enzymatic catalysts that facilitate the conversion of industrially significant gases such as CO, CO2, H2, and N2. The tunnels in the gas-converting enzymes serve as conduits for these low molecular weight gases to access deeply buried catalytic sites. The identification of the substrate tunnels is imperative for comprehending the substrate selectivity mechanism underlying these gas-converting enzymes. This knowledge also holds substantial value for industrial applications, particularly in addressing the challenges associated with separation and utilization of byproduct gases. In this comprehensive review, we delve into the emerging field of tunnel engineering, presenting a range of approaches and analyses. Additionally, we propose methodologies for the systematic design of enzymes, with the ultimate goal of advancing protein engineering strategies.
Collapse
Affiliation(s)
- Suk Min Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea.
| | - Sung Heuck Kang
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Byoung Wook Jeon
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea
| | - Yong Hwan Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea; Graduate School of Carbon Neutrality, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea.
| |
Collapse
|
2
|
Dulchavsky M, Mitra R, Wu K, Li J, Boer K, Liu X, Zhang Z, Vasquez C, Clark CT, Funckes K, Shankar K, Bonnet-Zahedi S, Siddiq M, Sepulveda Y, Suhandynata RT, Momper JD, Calabrese AN, George O, Stull F, Bardwell JCA. Directed evolution unlocks oxygen reactivity for a nicotine-degrading flavoenzyme. Nat Chem Biol 2023; 19:1406-1414. [PMID: 37770699 PMCID: PMC10611581 DOI: 10.1038/s41589-023-01426-y] [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: 01/06/2023] [Accepted: 08/23/2023] [Indexed: 09/30/2023]
Abstract
The flavoenzyme nicotine oxidoreductase (NicA2) is a promising injectable treatment to aid in the cessation of smoking, a behavior responsible for one in ten deaths worldwide. NicA2 acts by degrading nicotine in the bloodstream before it reaches the brain. Clinical use of NicA2 is limited by its poor catalytic activity in the absence of its natural electron acceptor CycN. Without CycN, NicA2 is instead oxidized slowly by dioxygen (O2), necessitating unfeasibly large doses in a therapeutic setting. Here, we report a genetic selection strategy that directly links CycN-independent activity of NicA2 to growth of Pseudomonas putida S16. This selection enabled us to evolve NicA2 variants with substantial improvement in their rate of oxidation by O2. The encoded mutations cluster around a putative O2 tunnel, increasing flexibility and accessibility to O2 in this region. These mutations further confer desirable clinical properties. A variant form of NicA2 is tenfold more effective than the wild type at degrading nicotine in the bloodstream of rats.
Collapse
Affiliation(s)
- Mark Dulchavsky
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Rishav Mitra
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Kevin Wu
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Joshua Li
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Karli Boer
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - Xiaomeng Liu
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Zhiyao Zhang
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - Cristian Vasquez
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | | | - Kaitrin Funckes
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - Kokila Shankar
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Selene Bonnet-Zahedi
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Mohammad Siddiq
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Yadira Sepulveda
- School of Pharmacy and Pharmaceutical Science, University of California, San Diego, La Jolla, CA, USA
| | - Raymond T Suhandynata
- School of Pharmacy and Pharmaceutical Science, University of California, San Diego, La Jolla, CA, USA
- Department of Pathology, University of California, San Diego, La Jolla, CA, USA
| | - Jeremiah D Momper
- School of Pharmacy and Pharmaceutical Science, University of California, San Diego, La Jolla, CA, USA
| | - Antonio N Calabrese
- Astbury Centre for Structural Molecular Biology, S chool of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Olivier George
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Frederick Stull
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA
| | - James C A Bardwell
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
3
|
Hancock JT. Are Protein Cavities and Pockets Commonly Used by Redox Active Signalling Molecules? PLANTS (BASEL, SWITZERLAND) 2023; 12:2594. [PMID: 37514209 PMCID: PMC10383989 DOI: 10.3390/plants12142594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/23/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023]
Abstract
It has been well known for a long time that inert gases, such as xenon (Xe), have significant biological effects. As these atoms are extremely unlikely to partake in direct chemical reactions with biomolecules such as proteins, lipids, and nucleic acids, there must be some other mode of action to account for the effects reported. It has been shown that the topology of proteins allows for cavities and hydrophobic pockets, and it is via an interaction with such protein structures that inert gases are thought to have their action. Recently, it has been mooted that the relatively inert gas molecular hydrogen (H2) may also have its effects via such a mechanism, influencing protein structures and actions. H2 is thought to also act via interaction with redox active compounds, particularly the hydroxyl radical (·OH) and peroxynitrite (ONOO-), but not nitric oxide (NO·), superoxide anions (O2·-) or hydrogen peroxide (H2O2). However, instead of having a direct interaction with H2, is there any evidence that these redox compounds can also interact with Xe pockets and cavities in proteins, either having an independent effect on proteins or interfering with the action of inert gases? This suggestion will be explored here.
Collapse
Affiliation(s)
- John T Hancock
- School of Applied Sciences, University of the West of England, Bristol BS16 1QY, UK
| |
Collapse
|
4
|
Jankowska K, Sigurdardóttir SB, Zdarta J, Pinelo M. Co-immobilization and compartmentalization of cholesterol oxidase, glucose oxidase and horseradish peroxidase for improved thermal and H2O2 stability. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.121007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
5
|
Towards crucial post-modification in biosynthesis of terpenoids and steroids: C3 oxidase and acetyltransferase. Enzyme Microb Technol 2022; 162:110148. [DOI: 10.1016/j.enzmictec.2022.110148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/24/2022]
|
6
|
Arshi S, Xiao X, Belochapkine S, Magner E. Electrochemical immobilization of glucose oxidase for the controlled production of H2O2 in a biocatalytic flow reactor. ChemElectroChem 2022; 9:e202200319. [PMID: 36246851 PMCID: PMC9545823 DOI: 10.1002/celc.202200319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/24/2022] [Indexed: 11/09/2022]
Abstract
Electrochemical methods can be used to selectively modify the surfaces of electrodes, enabling the immobilisation of enzymes on defined areas on the surfaces of electrodes. Such selective immobilisation methods can be used to pattern catalysts on surfaces in a controlled manner. Using this approach, the selective patterning of the enzyme glucose oxidase on the electrodes was used to develop a flow reactor for the controlled delivery of the oxidant H2O2. GOx was immobilised on a glassy carbon electrode using polypyrrole, silica films, and diazonium linkers. The rate of production of H2O2 and the stability of the response was dependent on the immobilisation method. GOx encapsulated in polypyrrole was selected as the optimal method of immobilisation, with a rate of production of 91±11 μM h−1 for 4 hours of continuous operation. The enzyme was subsequently immobilised on carbon rod electrodes (surface area of 5.76 cm2) using a polypyrrole/Nafion® film and incorporated into a flow reactor. The rate of production of H2O2 was 602±57 μM h−1, with 100 % retention of activity after 7 h of continuous operation, demonstrating that such a system can be used to prepare H2O2 at continuous and stable rate for use in downstream oxidation reactions.
Collapse
Affiliation(s)
- Simin Arshi
- University of Limerick Department of Chemical Sciences, Bernal Institute IRELAND
| | - Xinxin Xiao
- Technical University of Denmark: Danmarks Tekniske Universitet Department of Chemistry DENMARK
| | - Serguei Belochapkine
- University of Limerick Department of Chemical Sciences, Bernal Institute IRELAND
| | - Edmond Magner
- University of Limerick Materials and Surface Science Institute Plassey IE Co. Limerick IRELAND
| |
Collapse
|
7
|
Kuz’mina LG, Churakov AV. Crystal structure of amino acid peroxosolvates; X-ray diffraction study of norleucine peroxosolvate. Russ Chem Bull 2022. [DOI: 10.1007/s11172-022-3409-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
8
|
Abstract
We have structure, a wealth of kinetic data, thousands of chemical ligands and clinical information for the effects of a range of drugs on monoamine oxidase activity in vivo. We have comparative information from various species and mutations on kinetics and effects of inhibition. Nevertheless, there are what seem like simple questions still to be answered. This article presents a brief summary of existing experimental evidence the background and poses questions that remain intriguing for chemists and biochemists researching the chemical enzymology of and drug design for monoamine oxidases (FAD-containing EC 4.1.3.4).
Collapse
|
9
|
Alteration of Electron Acceptor Preferences in the Oxidative Half-Reaction of Flavin-Dependent Oxidases and Dehydrogenases. Int J Mol Sci 2020; 21:ijms21113797. [PMID: 32471202 PMCID: PMC7312611 DOI: 10.3390/ijms21113797] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/22/2020] [Accepted: 05/24/2020] [Indexed: 11/30/2022] Open
Abstract
In this review, recent progress in the engineering of the oxidative half-reaction of flavin-dependent oxidases and dehydrogenases is discussed, considering their current and future applications in bioelectrochemical studies, such as for the development of biosensors and biofuel cells. There have been two approaches in the studies of oxidative half-reaction: engineering of the oxidative half-reaction with oxygen, and engineering of the preference for artificial electron acceptors. The challenges for engineering oxidative half-reactions with oxygen are further categorized into the following approaches: (1) mutation to the putative residues that compose the cavity where oxygen may be located, (2) investigation of the vicinities where the reaction with oxygen may take place, and (3) investigation of possible oxygen access routes to the isoalloxazine ring. Among these approaches, introducing a mutation at the oxygen access route to the isoalloxazine ring represents the most versatile and effective strategy. Studies to engineer the preference of artificial electron acceptors are categorized into three different approaches: (1) engineering of the charge at the residues around the substrate entrance, (2) engineering of a cavity in the vicinity of flavin, and (3) decreasing the glycosylation degree of enzymes. Among these approaches, altering the charge in the vicinity where the electron acceptor may be accessed will be most relevant.
Collapse
|
10
|
Higashi Y, Mazumder J, Yoshikawa H, Saito M, Tamiya E. Chemically Regulated ROS Generation from Gold Nanoparticles for Enzyme-Free Electrochemiluminescent Immunosensing. Anal Chem 2018; 90:5773-5780. [DOI: 10.1021/acs.analchem.8b00118] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Yui Higashi
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Joyotu Mazumder
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Hiroyuki Yoshikawa
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Masato Saito
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 Japan
- Advanced Photonics and Biosensing Open Innovation Laboratory, AIST-Osaka University, Photonics Center Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Eiichi Tamiya
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 Japan
| |
Collapse
|
11
|
El Hage K, Mondal P, Meuwly M. Free energy simulations for protein ligand binding and stability. MOLECULAR SIMULATION 2018. [DOI: 10.1080/08927022.2017.1416115] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Krystel El Hage
- Department of Chemistry, University of Basel , Basel, Switzerland
| | - Padmabati Mondal
- Department of Chemistry, University of Basel , Basel, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel , Basel, Switzerland
| |
Collapse
|
12
|
Tremey E, Stines-Chaumeil C, Gounel S, Mano N. Designing an O2
-Insensitive Glucose Oxidase for Improved Electrochemical Applications. ChemElectroChem 2017. [DOI: 10.1002/celc.201700646] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Emilie Tremey
- CNRS, CRPP - UPR 8641; 115 Avenue du Docteur Schweitzer 33600 Pessac France
- Univ Bordeaux; 146 rue Léo Saignat 33076 Bordeaux Cedex France
| | - Claire Stines-Chaumeil
- CNRS, CRPP - UPR 8641; 115 Avenue du Docteur Schweitzer 33600 Pessac France
- Univ Bordeaux; 146 rue Léo Saignat 33076 Bordeaux Cedex France
| | - Sébastien Gounel
- CNRS, CRPP - UPR 8641; 115 Avenue du Docteur Schweitzer 33600 Pessac France
- Univ Bordeaux; 146 rue Léo Saignat 33076 Bordeaux Cedex France
| | - Nicolas Mano
- CNRS, CRPP - UPR 8641; 115 Avenue du Docteur Schweitzer 33600 Pessac France
- Univ Bordeaux; 146 rue Léo Saignat 33076 Bordeaux Cedex France
| |
Collapse
|
13
|
Mi L, Yu J, He F, Jiang L, Wu Y, Yang L, Han X, Li Y, Liu A, Wei W, Zhang Y, Tian Y, Liu S, Jiang L. Boosting Gas Involved Reactions at Nanochannel Reactor with Joint Gas–Solid–Liquid Interfaces and Controlled Wettability. J Am Chem Soc 2017; 139:10441-10446. [DOI: 10.1021/jacs.7b05249] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Li Mi
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Jiachao Yu
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Fei He
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Ling Jiang
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Yafeng Wu
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Lijun Yang
- Key
Laboratory of Bioinspired Smart Interface Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiaofeng Han
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Ying Li
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Anran Liu
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Wei Wei
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Yuanjian Zhang
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Ye Tian
- Beijing
National Laboratory for Molecular Sciences (BNLMS), Key Laboratory
of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Songqin Liu
- Key
Laboratory of Environmental Medicine Engineering, Ministry of Education,
Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and
Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Lei Jiang
- Key
Laboratory of Bioinspired Smart Interface Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Li G, Yao P, Gong R, Li J, Liu P, Lonsdale R, Wu Q, Lin J, Zhu D, Reetz MT. Simultaneous engineering of an enzyme's entrance tunnel and active site: the case of monoamine oxidase MAO-N. Chem Sci 2017; 8:4093-4099. [PMID: 30155214 PMCID: PMC6099926 DOI: 10.1039/c6sc05381e] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/30/2017] [Indexed: 12/19/2022] Open
Abstract
A new directed evolution approach is presented to enhance the activity of an enzyme and to manipulate stereoselectivity by focusing iterative saturation mutagenesis (ISM) simultaneously on residues lining the entrance tunnel and the binding pocket. This combined mutagenesis strategy was applied successfully to the monoamine oxidase from Aspergillus niger (MAO-N) in the reaction of sterically demanding substrates which are of interest in the synthesis of chiral pharmaceuticals based on the benzo-piperidine scaffold. Reversal of enantioselectivity of Turner-type deracemization was achieved in the synthesis of (S)-1,2,3,4-tetrahydro-1-methyl-isoquinoline, (S)-1,2,3,4-tetrahydro-1-ethylisoquinoline and (S)-1,2,3,4-tetrahydro-1-isopropylisoquinoline. Extensive molecular dynamics simulations indicate that the altered catalytic profile is due to increased hydrophobicity of the entrance tunnel acting in concert with the altered shape of the binding pocket.
Collapse
Affiliation(s)
- Guangyue Li
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , 45470 , Mülheim an der Ruhr , Germany .
- Fachbereich Chemie , Philipps-Universität , Hans-Meerwein-Strasse , 35032 Marburg , Germany
| | - Peiyuan Yao
- National Engineering Laboratory for Industrial Enzymes , Tianjin Engineering Center for Biocatalytic Technology , Tianjin Institute of Industrial Biotechnology , Chinese Academy of Sciences , 32 Xi Qi Dao, Tianjin Airport Economic Area , Tianjin 300308 , People's Republic of China . ;
| | - Rui Gong
- National Engineering Laboratory for Industrial Enzymes , Tianjin Engineering Center for Biocatalytic Technology , Tianjin Institute of Industrial Biotechnology , Chinese Academy of Sciences , 32 Xi Qi Dao, Tianjin Airport Economic Area , Tianjin 300308 , People's Republic of China . ;
| | - Jinlong Li
- National Engineering Laboratory for Industrial Enzymes , Tianjin Engineering Center for Biocatalytic Technology , Tianjin Institute of Industrial Biotechnology , Chinese Academy of Sciences , 32 Xi Qi Dao, Tianjin Airport Economic Area , Tianjin 300308 , People's Republic of China . ;
| | - Pi Liu
- National Engineering Laboratory for Industrial Enzymes , Tianjin Engineering Center for Biocatalytic Technology , Tianjin Institute of Industrial Biotechnology , Chinese Academy of Sciences , 32 Xi Qi Dao, Tianjin Airport Economic Area , Tianjin 300308 , People's Republic of China . ;
| | - Richard Lonsdale
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , 45470 , Mülheim an der Ruhr , Germany .
- Fachbereich Chemie , Philipps-Universität , Hans-Meerwein-Strasse , 35032 Marburg , Germany
| | - Qiaqing Wu
- National Engineering Laboratory for Industrial Enzymes , Tianjin Engineering Center for Biocatalytic Technology , Tianjin Institute of Industrial Biotechnology , Chinese Academy of Sciences , 32 Xi Qi Dao, Tianjin Airport Economic Area , Tianjin 300308 , People's Republic of China . ;
| | - Jianping Lin
- National Engineering Laboratory for Industrial Enzymes , Tianjin Engineering Center for Biocatalytic Technology , Tianjin Institute of Industrial Biotechnology , Chinese Academy of Sciences , 32 Xi Qi Dao, Tianjin Airport Economic Area , Tianjin 300308 , People's Republic of China . ;
| | - Dunming Zhu
- National Engineering Laboratory for Industrial Enzymes , Tianjin Engineering Center for Biocatalytic Technology , Tianjin Institute of Industrial Biotechnology , Chinese Academy of Sciences , 32 Xi Qi Dao, Tianjin Airport Economic Area , Tianjin 300308 , People's Republic of China . ;
| | - Manfred T Reetz
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , 45470 , Mülheim an der Ruhr , Germany .
- Fachbereich Chemie , Philipps-Universität , Hans-Meerwein-Strasse , 35032 Marburg , Germany
| |
Collapse
|
16
|
Integrative view of 2-oxoglutarate/Fe(II)-dependent oxygenase diversity and functions in bacteria. Biochim Biophys Acta Gen Subj 2017; 1861:323-334. [DOI: 10.1016/j.bbagen.2016.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 11/09/2016] [Accepted: 12/01/2016] [Indexed: 12/11/2022]
|
17
|
Marques SM, Daniel L, Buryska T, Prokop Z, Brezovsky J, Damborsky J. Enzyme Tunnels and Gates As Relevant Targets in Drug Design. Med Res Rev 2016; 37:1095-1139. [PMID: 27957758 DOI: 10.1002/med.21430] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/11/2016] [Accepted: 11/07/2016] [Indexed: 12/28/2022]
Abstract
Many enzymes contain tunnels and gates that are essential to their function. Gates reversibly switch between open and closed conformations and thereby control the traffic of small molecules-substrates, products, ions, and solvent molecules-into and out of the enzyme's structure via molecular tunnels. Many transient tunnels and gates undoubtedly remain to be identified, and their functional roles and utility as potential drug targets have received comparatively little attention. Here, we describe a set of general concepts relating to the structural properties, function, and classification of these interesting structural features. In addition, we highlight the potential of enzyme tunnels and gates as targets for the binding of small molecules. The different types of binding that are possible and the potential pharmacological benefits of such targeting are discussed. Twelve examples of ligands bound to the tunnels and/or gates of clinically relevant enzymes are used to illustrate the different binding modes and to explain some new strategies for drug design. Such strategies could potentially help to overcome some of the problems facing medicinal chemists and lead to the discovery of more effective drugs.
Collapse
Affiliation(s)
- Sergio M Marques
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Lukas Daniel
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Tomas Buryska
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| |
Collapse
|
18
|
Collazo L, Klinman JP. Control of the Position of Oxygen Delivery in Soybean Lipoxygenase-1 by Amino Acid Side Chains within a Gas Migration Channel. J Biol Chem 2016; 291:9052-9. [PMID: 26867580 PMCID: PMC4861474 DOI: 10.1074/jbc.m115.709154] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/09/2016] [Indexed: 11/06/2022] Open
Abstract
Understanding gas migration pathways is critical to unraveling structure-function relationships in enzymes that process gaseous substrates such as O2, H2, and N2 This work investigates the role of a defined pathway for O2 in regulating the peroxidation of linoleic acid by soybean lipoxygenase 1. Computational and mutagenesis studies provide strong support for a dominant delivery channel that shuttles molecular oxygen to a specific region of the active site, thereby ensuring the regio- and stereospecificity of product. Analysis of reaction kinetics and product distribution in channel mutants also reveals a plasticity to the gas migration pathway. The findings show that a single site mutation (I553W) limits oxygen accessibility to the active site, greatly increasing the fraction of substrate that reacts with oxygen free in solution. They also show how a neighboring site mutation (L496W) can result in a redirection of oxygen toward an alternate position of the substrate, changing the regio- and stereospecificity of peroxidation. The present data indicate that modest changes in a protein scaffold may modulate the access of small gaseous molecules to enzyme-bound substrates.
Collapse
Affiliation(s)
- Lara Collazo
- From the Department of Molecular and Cell Biology, Department of Chemistry, and the California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720
| | - Judith P Klinman
- From the Department of Molecular and Cell Biology, Department of Chemistry, and the California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720
| |
Collapse
|
19
|
Salvi F, Rodriguez I, Hamelberg D, Gadda G. Role of F357 as an Oxygen Gate in the Oxidative Half-Reaction of Choline Oxidase. Biochemistry 2016; 55:1473-84. [PMID: 26907558 DOI: 10.1021/acs.biochem.5b01356] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Choline oxidase from Arthrobacter globiformis catalyzes the oxidation of choline to glycine betaine by using oxygen as an electron acceptor. A partially rate limiting isomerization of the reduced wild-type enzyme during the reaction with oxygen was previously detected using solvent viscosity effects. In this study, we hypothesized that the side chains of M62 and F357, located at the entrance to the active site of choline oxidase, may be related to the slow isomerization detected. We engineered a double-variant enzyme M62A/F357A. The kinetic characterization of the double-variant enzyme showed a lack of the isomerization detected in wild-type choline oxidase, and a lack of saturation with an oxygen concentration as high as 1 mM, while most other kinetic parameters were similar to those of wild-type choline oxidase. The kinetic characterization of the single-variant enzymes established that only the side chain of F357 plays a role in the isomerization of choline oxidase in the oxidative half-reaction. Molecular dynamics studies suggest that the slow isomerization related to F357 is possibly due to the participation of the phenyl ring in a newly proposed gating mechanism for a narrow tunnel, assumed to regulate the access of oxygen to the reduced cofactor.
Collapse
Affiliation(s)
- Francesca Salvi
- Department of Chemistry, ‡Department of Biology, §Center for Biotechnology and Drug Design, and ∥Center for Diagnostics and Therapeutics, Georgia State University , Atlanta, Georgia 30302, United States
| | - Isela Rodriguez
- Department of Chemistry, ‡Department of Biology, §Center for Biotechnology and Drug Design, and ∥Center for Diagnostics and Therapeutics, Georgia State University , Atlanta, Georgia 30302, United States
| | - Donald Hamelberg
- Department of Chemistry, ‡Department of Biology, §Center for Biotechnology and Drug Design, and ∥Center for Diagnostics and Therapeutics, Georgia State University , Atlanta, Georgia 30302, United States
| | - Giovanni Gadda
- Department of Chemistry, ‡Department of Biology, §Center for Biotechnology and Drug Design, and ∥Center for Diagnostics and Therapeutics, Georgia State University , Atlanta, Georgia 30302, United States
| |
Collapse
|
20
|
Cazade PA, Zheng W, Prada-Gracia D, Berezovska G, Rao F, Clementi C, Meuwly M. A comparative analysis of clustering algorithms: O2 migration in truncated hemoglobin I from transition networks. J Chem Phys 2015; 142:025103. [PMID: 25591387 DOI: 10.1063/1.4904431] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The ligand migration network for O2-diffusion in truncated Hemoglobin N is analyzed based on three different clustering schemes. For coordinate-based clustering, the conventional k-means and the kinetics-based Markov Clustering (MCL) methods are employed, whereas the locally scaled diffusion map (LSDMap) method is a collective-variable-based approach. It is found that all three methods agree well in their geometrical definition of the most important docking site, and all experimentally known docking sites are recovered by all three methods. Also, for most of the states, their population coincides quite favourably, whereas the kinetics of and between the states differs. One of the major differences between k-means and MCL clustering on the one hand and LSDMap on the other is that the latter finds one large primary cluster containing the Xe1a, IS1, and ENT states. This is related to the fact that the motion within the state occurs on similar time scales, whereas structurally the state is found to be quite diverse. In agreement with previous explicit atomistic simulations, the Xe3 pocket is found to be a highly dynamical site which points to its potential role as a hub in the network. This is also highlighted in the fact that LSDMap cannot identify this state. First passage time distributions from MCL clusterings using a one- (ligand-position) and two-dimensional (ligand-position and protein-structure) descriptor suggest that ligand- and protein-motions are coupled. The benefits and drawbacks of the three methods are discussed in a comparative fashion and highlight that depending on the questions at hand the best-performing method for a particular data set may differ.
Collapse
Affiliation(s)
- Pierre-André Cazade
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Wenwei Zheng
- Department of Chemistry, Rice University, 6100 Main St., Houston, Texas 77005, USA
| | - Diego Prada-Gracia
- School of Soft Matter Research, Freiburg Institute for Advanced Studies, Albertstrasse 19, 79104 Freiburg im Breisgau, Germany
| | - Ganna Berezovska
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Francesco Rao
- School of Soft Matter Research, Freiburg Institute for Advanced Studies, Albertstrasse 19, 79104 Freiburg im Breisgau, Germany
| | - Cecilia Clementi
- Department of Chemistry, Rice University, 6100 Main St., Houston, Texas 77005, USA
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| |
Collapse
|
21
|
Golden E, Attwood PV, Duff AP, Meilleur F, Vrielink A. Production and characterization of recombinant perdeuterated cholesterol oxidase. Anal Biochem 2015; 485:102-8. [PMID: 26073659 DOI: 10.1016/j.ab.2015.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 06/04/2015] [Accepted: 06/05/2015] [Indexed: 10/23/2022]
Abstract
Cholesterol oxidase (CO) is a FAD (flavin adenine dinucleotide) containing enzyme that catalyzes the oxidization and isomerization of cholesterol. Studies directed toward elucidating the catalytic mechanism of CO will provide an important general understanding of Flavin-assisted redox catalysis. Hydrogen atoms play an important role in enzyme catalysis; however, they are not readily visualized in protein X-ray diffraction structures. Neutron crystallography is an ideal method for directly visualizing hydrogen positions at moderate resolutions because hydrogen and deuterium have comparable neutron scattering lengths to other heavy atoms present in proteins. The negative coherent and large incoherent scattering lengths of hydrogen atoms in neutron diffraction experiments can be circumvented by replacing hydrogen atoms with its isotope, deuterium. The perdeuterated form of CO was successfully expressed from minimal medium, purified, and crystallized. X-ray crystallographic structures of the enzyme in the perdeuterated and hydrogenated states confirm that there are no apparent structural differences between the two enzyme forms. Kinetic assays demonstrate that perdeuterated and hydrogenated enzymes are functionally identical. Together, structural and functional studies indicate that the perdeuterated protein is suitable for structural studies by neutron crystallography directed at understanding the role of hydrogen atoms in enzyme catalysis.
Collapse
Affiliation(s)
- Emily Golden
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA 6009, Australia
| | - Paul V Attwood
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA 6009, Australia
| | - Anthony P Duff
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - Flora Meilleur
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Structural and Molecular Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Alice Vrielink
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA 6009, Australia.
| |
Collapse
|
22
|
Zarychta B, Lyubimov A, Ahmed M, Munshi P, Guillot B, Vrielink A, Jelsch C. Cholesterol oxidase: ultrahigh-resolution crystal structure and multipolar atom model-based analysis. ACTA ACUST UNITED AC 2015; 71:954-68. [PMID: 25849405 DOI: 10.1107/s1399004715002382] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 02/04/2015] [Indexed: 11/10/2022]
Abstract
Examination of protein structure at the subatomic level is required to improve the understanding of enzymatic function. For this purpose, X-ray diffraction data have been collected at 100 K from cholesterol oxidase crystals using synchrotron radiation to an optical resolution of 0.94 Å. After refinement using the spherical atom model, nonmodelled bonding peaks were detected in the Fourier residual electron density on some of the individual bonds. Well defined bond density was observed in the peptide plane after averaging maps on the residues with the lowest thermal motion. The multipolar electron density of the protein-cofactor complex was modelled by transfer of the ELMAM2 charge-density database, and the topology of the intermolecular interactions between the protein and the flavin adenine dinucleotide (FAD) cofactor was subsequently investigated. Taking advantage of the high resolution of the structure, the stereochemistry of main-chain bond lengths and of C=O···H-N hydrogen bonds was analyzed with respect to the different secondary-structure elements.
Collapse
Affiliation(s)
- Bartosz Zarychta
- Laboratoire de Cristallographie, Résonance Magnétique et Modélisations (CRM2), CNRS, UMR 7036, Institut Jean Barriol, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy CEDEX, France
| | - Artem Lyubimov
- Howard Hughes Medical Institute, Stanford, CA 94305-5432, USA
| | - Maqsood Ahmed
- Laboratoire de Cristallographie, Résonance Magnétique et Modélisations (CRM2), CNRS, UMR 7036, Institut Jean Barriol, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy CEDEX, France
| | - Parthapratim Munshi
- Laboratoire de Cristallographie, Résonance Magnétique et Modélisations (CRM2), CNRS, UMR 7036, Institut Jean Barriol, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy CEDEX, France
| | - Benoît Guillot
- Laboratoire de Cristallographie, Résonance Magnétique et Modélisations (CRM2), CNRS, UMR 7036, Institut Jean Barriol, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy CEDEX, France
| | - Alice Vrielink
- School of Chemistry and Biochemistry, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Christian Jelsch
- Laboratoire de Cristallographie, Résonance Magnétique et Modélisations (CRM2), CNRS, UMR 7036, Institut Jean Barriol, Faculté des Sciences et Technologies, Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy CEDEX, France
| |
Collapse
|
23
|
Maenpuen S, Watthaisong P, Supon P, Sucharitakul J, Parsonage D, Karplus PA, Claiborne A, Chaiyen P. Kinetic mechanism of L-α-glycerophosphate oxidase from Mycoplasma pneumoniae. FEBS J 2015; 282:3043-59. [PMID: 25712468 DOI: 10.1111/febs.13247] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 02/17/2015] [Accepted: 02/20/2015] [Indexed: 12/16/2022]
Abstract
L-α-glycerophosphate oxidase is an FAD-dependent enzyme that catalyzes the oxidation of L-α-glycerophosphate (Glp) by molecular oxygen to generate dihydroxyacetone phosphate (DHAP) and hydrogen peroxide (H2O2). The catalytic properties of recombinant His6-GlpO from Mycoplasma pneumoniae (His6-MpGlpO) were investigated through transient and steady-state kinetics and ligand binding studies. The results indicate that the reaction mechanism of His6-MpGlpO follows a ping-pong model. Double-mixing mode stopped-flow experiments show that, after flavin-mediated substrate oxidation, DHAP leaves rapidly prior to the oxygen reaction. The values determined for the individual rate constants and kcat (4.2 s(-1) at 4 °C), in addition to the finding that H2 O2 binds to the oxidized enzyme, suggest that H2O2 release is the rate-limiting step for the overall reaction. The results indicate that His6 -MpGlpO contains mixed populations of fast- and slow-reacting species. It is predominantly the fast-reacting species that participates in turnover. In contrast to other GlpO enzymes previously described, His6-MpGlpO is able to catalyze the reverse reaction of reduced enzyme and DHAP. This result may be explained by the standard reduction potential value of His6-MpGlpO (-167 ± 1 mV), which is lower than those of GlpO from other species. We found that D,L-glyceraldehyde 3-phosphate (GAP) may be used as a substrate in the His6-MpGlpO reaction, although it exhibited an approximately 100-fold lower kcat value in comparison with the reaction of Glp. These results also imply involvement of GlpO in glycolysis, as well as in lipid and glycerol metabolism. The kinetic models and distinctive properties of His6-MpGlpO reported here should be useful for future drug development against Mycoplasma pneumoniae infection.
Collapse
Affiliation(s)
- Somchart Maenpuen
- Department of Biochemistry, Faculty of Science, Burapha University, Chonburi, Thailand
| | - Pratchaya Watthaisong
- Department of Biochemistry, Faculty of Science, Burapha University, Chonburi, Thailand
| | - Pacharee Supon
- Department of Biochemistry, Faculty of Science, Burapha University, Chonburi, Thailand
| | - Jeerus Sucharitakul
- Department of Biochemistry, Faculty of Dentistry, Chulalongkorn University, Patumwan, Bangkok, Thailand
| | - Derek Parsonage
- Department of Biochemistry and Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - P Andrew Karplus
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR, USA
| | - Al Claiborne
- Department of Biochemistry and Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Pimchai Chaiyen
- Department of Biochemistry and Center of Excellence in Protein Structure & Function, Faculty of Science, Mahidol University, Bangkok, Thailand
| |
Collapse
|
24
|
Golden E, Karton A, Vrielink A. High-resolution structures of cholesterol oxidase in the reduced state provide insights into redox stabilization. ACTA ACUST UNITED AC 2014; 70:3155-66. [PMID: 25478834 DOI: 10.1107/s139900471402286x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 10/17/2014] [Indexed: 01/09/2023]
Abstract
Cholesterol oxidase (CO) is a flavoenzyme that catalyzes the oxidation and isomerization of cholesterol to cholest-4-en-3-one. The reductive half reaction occurs via a hydride transfer from the substrate to the FAD cofactor. The structures of CO reduced with dithionite under aerobic conditions and in the presence of the substrate 2-propanol under both aerobic and anaerobic conditions are presented. The 1.32 Å resolution structure of the dithionite-reduced enzyme reveals a sulfite molecule covalently bound to the FAD cofactor. The isoalloxazine ring system displays a bent structure relative to that of the oxidized enzyme, and alternate conformations of a triad of aromatic residues near to the cofactor are evident. A 1.12 Å resolution anaerobically trapped reduced enzyme structure in the presence of 2-propanol does not show a similar bending of the flavin ring system, but does show alternate conformations of the aromatic triad. Additionally, a significant difference electron-density peak is observed within a covalent-bond distance of N5 of the flavin moiety, suggesting that a hydride-transfer event has occurred as a result of substrate oxidation trapping the flavin in the electron-rich reduced state. The hydride transfer generates a tetrahedral geometry about the flavin N5 atom. High-level density-functional theory calculations were performed to correlate the crystallographic findings with the energetics of this unusual arrangement of the flavin moiety. These calculations suggest that strong hydrogen-bond interactions between Gly120 and the flavin N5 centre may play an important role in these structural features.
Collapse
Affiliation(s)
- Emily Golden
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Amir Karton
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Alice Vrielink
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, Western Australia 6009, Australia
| |
Collapse
|
25
|
Kapustin EA, Minkov VS, Boldyreva EV. Oxidative stress of H2O2on N,N-dimethylglycine: formation of perhydrate crystals and more. CrystEngComm 2014. [DOI: 10.1039/c4ce01835d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
26
|
|
27
|
Soluble guanylate cyclase in NO signaling transduction. REV INORG CHEM 2013. [DOI: 10.1515/revic-2013-0011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractNitric oxide (NO), a signaling molecule in the cardiovascular system, has been receiving increasing attention since Furchgott, Ignarro, and Murad were awarded the Nobel Prize in Physiology and Medicine for the discovery in 1998. Soluble guanylate cyclase (sGC), as an NO receptor, is a key metalloprotein in mediating NO signaling transduction. sGC is activated by NO to catalyze the conversion of guanosine 5′-triphosphate (GTP) to cyclic guanylate monophosphate (cGMP). The dysfunction of NO signaling results in many pathological disorders, including several cardiovascular diseases, such as arterial hypertension, pulmonary hypertension, heart failure and so on. Significant advances in its structure, function, mechanism, and physiological and pathological roles have been made throughout the past 15 years. We herein review the progress of sGC on structural, functional investigations, as well as the proposed activation/deactivation mechanism. The heme-dependent sGC stimulators and heme-independent sGC activators have also been summarized briefly.
Collapse
|
28
|
Alvi NUH, Gómez VJ, Rodriguez PES, Kumar P, Zaman S, Willander M, Nötzel R. An InN/InGaN quantum dot electrochemical biosensor for clinical diagnosis. SENSORS 2013; 13:13917-27. [PMID: 24132228 PMCID: PMC3859099 DOI: 10.3390/s131013917] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/11/2013] [Accepted: 10/04/2013] [Indexed: 11/20/2022]
Abstract
Low-dimensional InN/InGaN quantum dots (QDs) are demonstrated for realizing highly sensitive and efficient potentiometric biosensors owing to their unique electronic properties. The InN QDs are biochemically functionalized. The fabricated biosensor exhibits high sensitivity of 97 mV/decade with fast output response within two seconds for the detection of cholesterol in the logarithmic concentration range of 1 × 10−6 M to 1 × 10−3 M. The selectivity and reusability of the biosensor are excellent and it shows negligible response to common interferents such as uric acid and ascorbic acid. We also compare the biosensing properties of the InN QDs with those of an InN thin film having the same surface properties, i.e., high density of surface donor states, but different morphology and electronic properties. The sensitivity of the InN QDs-based biosensor is twice that of the InN thin film-based biosensor, the EMF is three times larger, and the response time is five times shorter. A bare InGaN layer does not produce a stable response. Hence, the superior biosensing properties of the InN QDs are governed by their unique surface properties together with the zero-dimensional electronic properties. Altogether, the InN QDs-based biosensor reveals great potential for clinical diagnosis applications.
Collapse
Affiliation(s)
- Naveed ul Hassan Alvi
- ISOM Institute for Systems based on Optoelectronics and Microtechnology, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain; E-Mails: (V.J.G.); (P.E.D.S.R.); (P.K.)
- Authors to whom correspondence should be addressed; E-Mails: (N.H.A.); (R.N.); Tel.: +34-91549-57-00 (ext. 8065)
| | - Victor J. Gómez
- ISOM Institute for Systems based on Optoelectronics and Microtechnology, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain; E-Mails: (V.J.G.); (P.E.D.S.R.); (P.K.)
| | - Paul E.D. Soto Rodriguez
- ISOM Institute for Systems based on Optoelectronics and Microtechnology, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain; E-Mails: (V.J.G.); (P.E.D.S.R.); (P.K.)
| | - Praveen Kumar
- ISOM Institute for Systems based on Optoelectronics and Microtechnology, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain; E-Mails: (V.J.G.); (P.E.D.S.R.); (P.K.)
| | - Saima Zaman
- Department of Science and Technology (ITN), Campus Norrköping, Linköping University, Norrköping 60174, Sweden; E-Mails: (S.Z.); (M.W.)
| | - Magnus Willander
- Department of Science and Technology (ITN), Campus Norrköping, Linköping University, Norrköping 60174, Sweden; E-Mails: (S.Z.); (M.W.)
| | - Richard Nötzel
- ISOM Institute for Systems based on Optoelectronics and Microtechnology, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain; E-Mails: (V.J.G.); (P.E.D.S.R.); (P.K.)
- Authors to whom correspondence should be addressed; E-Mails: (N.H.A.); (R.N.); Tel.: +34-91549-57-00 (ext. 8065)
| |
Collapse
|
29
|
Affiliation(s)
- Artur Gora
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Centre for Clinical
Research, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| |
Collapse
|
30
|
Kojima K, Kobayashi T, Tsugawa W, Ferri S, Sode K. Mutational analysis of the oxygen-binding site of cholesterol oxidase and its impact on dye-mediated dehydrogenase activity. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2012.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
31
|
Cazade PA, Meuwly M. Oxygen migration pathways in NO-bound truncated hemoglobin. Chemphyschem 2012; 13:4276-86. [PMID: 23161831 DOI: 10.1002/cphc.201200608] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 09/28/2012] [Indexed: 11/10/2022]
Abstract
Atomistic simulations of dioxygen (O(2)) dynamics and migration in nitric oxide-bound truncated Hemoglobin N (trHbN) of Mycobacterium tuberculosis are reported. From more than 100 ns of simulations the connectivity network involving the metastable states for localization of the O(2) ligand is built and analyzed. It is found that channel I is the primary entrance point for O(2) whereas channel II is predominantly an exit path although access to the protein active site is also possible. For O(2) a new site compared to nitric oxide, from which reaction with the heme group can occur, was found. As this site is close to the heme iron, it could play an important role in the dioxygenation mechanism as O(2) can remain there for hundreds of picoseconds after which it can eventually leave the protein, while NO is localized in Xe2. The present study supports recent experimental work which proposed that O(2) docks in alternative pockets than Xe close to the reactive site. Similar to other proteins, a phenylalanine residue (Phe62) plays the role of a gate along the access route in channel I. The most highly connected site is the Xe3 pocket which is a "hub" and free energy barriers between the different metastable states are ≈1.5 kcal mol(-1) which allows facile O(2) migration within the protein.
Collapse
Affiliation(s)
- Pierre-André Cazade
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056, Basel, Switzerland
| | | |
Collapse
|
32
|
Torres AC, Ghica ME, Brett CMA. Poly(Neutral Red)/Cholesterol Oxidase Modified Carbon Film Electrode for Cholesterol Biosensing. ELECTROANAL 2012. [DOI: 10.1002/elan.201200111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
33
|
Mechanistic insight into the blocking of CO diffusion in [NiFe]-hydrogenase mutants through multiscale simulation. Proc Natl Acad Sci U S A 2012; 109:6399-404. [PMID: 22493222 DOI: 10.1073/pnas.1121176109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
[NiFe]-hydrogenases are fascinating biological catalysts with potential application in biofuel cells. However, a severe problem in practical application is the strong sensitivity of hydrogenase to gaseous inhibitor molecules such as CO and O(2). Recently, a number of successful protein engineering studies have been reported that aimed at lowering the access of diatomic inhibitors to the active site pocket, but the molecular mechanism conferring increased resistance remained unclear. Here we use a multiscale simulation approach combining molecular dynamics with a master equation formalism to explain the steady drop in CO diffusion rate observed for the mutants V74M L122A, V74M L122M, and V74M of Desulfovibrio fructosovorans [NiFe]-hydrogenase. We find that diffusion in these variants is controlled by two gates, one between residues 74 and 476 and the other between residues 74 and 122. The existence of two control points in different locations explains why the reduction in the experimental diffusion rate does not simply correlate with the width of the main gas channel. We also find that in the more effective mutation (V74M) CO molecules are still able to reach the active site through transitions that are gated by the microsecond dihedral motions of the side chain of R476 and the thermal fluctuations of the width of the gas channel defined by M74 and L122. Reflecting on the molecular information gained from simulation, we discuss future mutation experiments that could further lower the diffusion rates of small ligands inhibiting [NiFe]-hydrogenase.
Collapse
|
34
|
Gadda G. Oxygen Activation in Flavoprotein Oxidases: The Importance of Being Positive. Biochemistry 2012; 51:2662-9. [DOI: 10.1021/bi300227d] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Giovanni Gadda
- Department
of Chemistry, ‡Department of Biology, and §The Center for Biotechnology and Drug Design, Georgia State University, Atlanta, Georgia
30302-4098, United States
| |
Collapse
|
35
|
Daithankar VN, Wang W, Trujillo JR, Thorpe C. Flavin-linked Erv-family sulfhydryl oxidases release superoxide anion during catalytic turnover. Biochemistry 2011; 51:265-72. [PMID: 22148553 DOI: 10.1021/bi201672h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Typically, simple flavoprotein oxidases couple the oxidation of their substrates with the formation of hydrogen peroxide without release of significant levels of the superoxide ion. However, two evolutionarily related single-domain sulfhydryl oxidases (Erv2p; a yeast endoplasmic reticulum resident protein and augmenter of liver regeneration, ALR, an enzyme predominantly found in the mitochondrial intermembrane) release up to ~30% of the oxygen they reduce as the superoxide ion. Both enzymes oxidize dithiol substrates via a redox-active disulfide adjacent to the flavin cofactor within the helix-rich Erv domain. Subsequent reduction of the flavin is followed by transfer of reducing equivalents to molecular oxygen. Superoxide release was initially detected using tris(3-hydroxypropyl)phosphine (THP) as an alternative reducing substrate to dithiothreitol (DTT). THP, and other phosphines, showed anomalously high turnover numbers with Erv2p and ALR in the oxygen electrode, but oxygen consumption was drastically suppressed upon the addition of superoxide dismutase. The superoxide ion initiates a radical chain reaction promoting the aerobic oxidation of phosphines with the formation of hydrogen peroxide. Use of a known flux of superoxide generated by the xanthine/xanthine oxidase system showed that one superoxide ion stimulates the reduction of 27 and 4.5 molecules of oxygen using THP and tris(2-carboxyethyl)phosphine (TCEP), respectively. This superoxide-dependent amplification of oxygen consumption by phosphines provides a new kinetic method for the detection of superoxide. Superoxide release was also observed by a standard chemiluminescence method using a luciferin analogue (MCLA) when 2 mM DTT was employed as a substrate of Erv2p and ALR. The percentage of superoxide released from Erv2p increased to ~65% when monomeric mutants of the normally homodimeric enzyme were used. In contrast, monomeric multidomain quiescin sulfhydryl oxidase enzymes that also contain an Erv FAD-binding fold release only 1-5% of their total reduced oxygen species as the superoxide ion. Aspects of the mechanism and possible physiological significance of superoxide release from these Erv-domain flavoproteins are discussed.
Collapse
Affiliation(s)
- Vidyadhar N Daithankar
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716-2522, United States
| | | | | | | |
Collapse
|
36
|
Savard PY, Daigle R, Morin S, Sebilo A, Meindre F, Lagüe P, Guertin M, Gagné SM. Structure and dynamics of Mycobacterium tuberculosis truncated hemoglobin N: insights from NMR spectroscopy and molecular dynamics simulations. Biochemistry 2011; 50:11121-30. [PMID: 21999759 DOI: 10.1021/bi201059a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The potent nitric oxide dioxygenase (NOD) activity (trHbN-Fe²⁺-O₂ + (•)NO → trHbN-Fe³⁺-OH₂ + NO₃⁻) of Mycobacterium tuberculosis truncated hemoglobin N (trHbN) protects aerobic respiration from inhibition by (•)NO. The high activity of trHbN has been attributed in part to the presence of numerous short-lived hydrophobic cavities that allow partition and diffusion of the gaseous substrates (•)NO and O₂ to the active site. We investigated the relation between these cavities and the dynamics of the protein using solution NMR spectroscopy and molecular dynamics (MD). Results from both approaches indicate that the protein is mainly rigid with very limited motions of the backbone N-H bond vectors on the picoseconds-nanoseconds time scale, indicating that substrate diffusion and partition within trHbN may be controlled by side-chains movements. Model-free analysis also revealed the presence of slow motions (microseconds-milliseconds), not observed in MD simulations, for many residues located in helices B and G including the distal heme pocket Tyr33(B10). All currently known crystal structures and molecular dynamics data of truncated hemoglobins with the so-called pre-A N-terminal extension suggest a stable α-helical conformation that extends in solution. Moreover, a recent study attributed a crucial role to the pre-A helix for NOD activity. However, solution NMR data clearly show that in near-physiological conditions these residues do not adopt an α-helical conformation and are significantly disordered and that the helical conformation seen in crystal structures is likely induced by crystal contacts. Although this lack of order for the pre-A does not disagree with an important functional role for these residues, our data show that one should not assume an helical conformation for these residues in any functional interpretation. Moreover, future molecular dynamics simulations should not use an initial α-helical conformation for these residues in order to avoid a bias based on an erroneous initial structure for the N-termini residues. This work constitutes the first study of a truncated hemoglobin dynamics performed by solution heteronuclear relaxation NMR spectroscopy.
Collapse
Affiliation(s)
- Pierre-Yves Savard
- Département de biochimie, de microbiologie et de bio-informatique, Université Laval and PROTEO, Québec, Canada
| | | | | | | | | | | | | | | |
Collapse
|
37
|
McDonald CA, Fagan RL, Collard F, Monnier VM, Palfey BA. Oxygen reactivity in flavoenzymes: context matters. J Am Chem Soc 2011; 133:16809-11. [PMID: 21958058 DOI: 10.1021/ja2081873] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many flavoenzymes--oxidases and monooxygenases--react faster with oxygen than free flavins do. There are many ideas on how enzymes cause this. Recent work has focused on the importance of a positive charge near N5 of the reduced flavin. Fructosamine oxidase has a lysine near N5 of its flavin. We measured a rate constant of 1.6 × 10(5) M(-1) s(-1) for its reaction with oxygen. The Lys276Met mutant reacted with a rate constant of 291 M(-1) s(-1), suggesting an important role for this lysine in oxygen activation. The dihydroorotate dehydrogenases from E. coli and L. lactis also have a lysine near N5 of the flavin. They react with O(2) with rate constants of 6.2 × 10(4) and 3.0 × 10(3) M(-1) s(-1), respectively. The Lys66Met and Lys43Met mutant enzymes react with rate constants that are nearly the same as those for the wild-type enzymes, demonstrating that simply placing a positive charge near N5 of the flavin does not guarantee increased oxygen reactivity. Our results show that the lysine near N5 does not exert an effect without an appropriate context; evolution did not find only one mechanism for activating the reaction of flavins with O(2).
Collapse
Affiliation(s)
- Claudia A McDonald
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0606, USA
| | | | | | | | | |
Collapse
|
38
|
Hernández-Ortega A, Lucas F, Ferreira P, Medina M, Guallar V, Martínez AT. Modulating O2 reactivity in a fungal flavoenzyme: involvement of aryl-alcohol oxidase Phe-501 contiguous to catalytic histidine. J Biol Chem 2011; 286:41105-14. [PMID: 21940622 DOI: 10.1074/jbc.m111.282467] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aryl-alcohol oxidase (AAO) is a flavoenzyme responsible for activation of O(2) to H(2)O(2) in fungal degradation of lignin. The AAO crystal structure shows a buried active site connected to the solvent by a hydrophobic funnel-shaped channel, with Phe-501 and two other aromatic residues forming a narrow bottleneck that prevents the direct access of alcohol substrates. However, ligand diffusion simulations show O(2) access to the active site following this channel. Site-directed mutagenesis of Phe-501 yielded a F501A variant with strongly reduced O(2) reactivity. However, a variant with increased reactivity, as shown by kinetic constants and steady-state oxidation degree, was obtained by substitution of Phe-501 with tryptophan. The high oxygen catalytic efficiency of F501W, ∼2-fold that of native AAO and ∼120-fold that of F501A, seems related to a higher O(2) availability because the turnover number was slightly decreased with respect to the native enzyme. Free diffusion simulations of O(2) inside the active-site cavity of AAO (and several in silico Phe-501 variants) yielded >60% O(2) population at 3-4 Å from flavin C4a in F501W compared with 44% in AAO and only 14% in F501A. Paradoxically, the O(2) reactivity of AAO decreased when the access channel was enlarged and increased when it was constricted by introducing a tryptophan residue. This is because the side chain of Phe-501, contiguous to the catalytic histidine (His-502 in AAO), helps to position O(2) at an adequate distance from flavin C4a (and His-502 Nε). Phe-501 substitution with a bulkier tryptophan residue resulted in an increase in the O(2) reactivity of this flavoenzyme.
Collapse
Affiliation(s)
- Aitor Hernández-Ortega
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | | | | | | | | | | |
Collapse
|
39
|
Wang PH, Best RB, Blumberger J. A microscopic model for gas diffusion dynamics in a [NiFe]-hydrogenase. Phys Chem Chem Phys 2011; 13:7708-19. [PMID: 21409188 DOI: 10.1039/c0cp02098b] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We describe and apply a microscopic model for the calculation of gas diffusion rates in a [NiFe]-hydrogenase. This enzyme has attracted much interest for use as a H(2) oxidising catalyst in biofuel cells, but a major problem is their inhibition by CO and O(2). In our model, the diffusive hopping of gas molecules in the protein interior is coarse grained using a master equation approach with transition rates estimated from equilibrium and non-equilibrium pulling simulations. Propagating the rate matrix in time, we find that the probability for a gas molecule to reach the enzyme active site follows a mono-exponential increase. Fits to a phenomenological rate law give an effective diffusion rate constant for CO that is in very good agreement with experimental measurements. We find that CO prefers to move along the canonical 'hydrophobic' main channel towards the active site, in contrast to O(2) and H(2), which were previously shown to explore larger fractions of the protein. Differences in the diffusion of the three gases are discussed in light of recent efforts to engineer a gas selectivity filter in the enzyme.
Collapse
Affiliation(s)
- Po-hung Wang
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | | | | |
Collapse
|
40
|
Wang PH, Best RB, Blumberger J. Multiscale simulation reveals multiple pathways for H2 and O2 transport in a [NiFe]-hydrogenase. J Am Chem Soc 2011; 133:3548-56. [PMID: 21341658 DOI: 10.1021/ja109712q] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrogenases are enzymes that catalyze the reversible conversion of hydrogen molecules to protons and electrons. The mechanism by which the gas molecules reach the active site is important for understanding the function of the enzyme and may play a role in the selectivity for hydrogen over inhibitor molecules. Here, we develop a general multiscale molecular simulation approach for the calculation of diffusion rates and determination of pathways by which substrate or inhibitor gases can reach the protein active site. Combining kinetic data from both equilibrium simulations and enhanced sampling, we construct a master equation describing the movement of gas molecules within the enzyme. We find that the time-dependent gas population of the active site can be fit to the same phenomenological rate law used to interpret experiments, with corresponding diffusion rates in very good agreement with experimental data. However, in contrast to the conventional picture, in which the gases follow a well-defined hydrophobic tunnel, we find that there is a diverse network of accessible pathways by which the gas molecules can reach the active site. The previously identified tunnel accounts for only about 60% of the total flux. Our results suggest that the dramatic decrease in the diffusion rate for mutations involving the residue Val74 could be in part due to the narrowing of the passage Val74-Arg476, immediately adjacent to the binding site, explaining why mutations of Leu122 had only a negligible effect in experiment. Our method is not specific to the [NiFe]-hydrogenase and should be generally applicable to the transport of small molecules in proteins.
Collapse
Affiliation(s)
- Po-hung Wang
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | | | | |
Collapse
|
41
|
Gimpl G, Gehrig-Burger K. Probes for studying cholesterol binding and cell biology. Steroids 2011; 76:216-31. [PMID: 21074546 DOI: 10.1016/j.steroids.2010.11.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 11/03/2010] [Accepted: 11/05/2010] [Indexed: 11/20/2022]
Abstract
Cholesterol is a multifunctional lipid in eukaryotic cells. It regulates the physical state of the phospholipid bilayer, is crucially involved in the formation of membrane microdomains, affects the activity of many membrane proteins, and is the precursor for steroid hormones and bile acids. Thus, cholesterol plays a profound role in the physiology and pathophysiology of eukaryotic cells. The cholesterol molecule has achieved evolutionary perfection to fulfill its different functions in membrane organization. Here, we review basic approaches to explore the interaction of cholesterol with proteins, with a particular focus on the high diversity of fluorescent and photoreactive cholesterol probes available today.
Collapse
Affiliation(s)
- Gerald Gimpl
- Institute of Pharmacy and Biochemistry, Department of Biochemistry, Johannes Gutenberg-University of Mainz, Mainz, Germany.
| | | |
Collapse
|
42
|
Lautier T, Ezanno P, Baffert C, Fourmond V, Cournac L, Fontecilla-Camps JC, Soucaille P, Bertrand P, Meynial-Salles I, Léger C. The quest for a functional substrate access tunnel in FeFe hydrogenase. Faraday Discuss 2011; 148:385-407; discussion 421-41. [DOI: 10.1039/c004099c] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
43
|
Prikhodchenko PV, Medvedev AG, Tripol'skaya TA, Churakov AV, Wolanov Y, Howard JAK, Lev O. Crystal structures of natural amino acid perhydrates. CrystEngComm 2011. [DOI: 10.1039/c0ce00481b] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
44
|
Rosini E, Molla G, Ghisla S, Pollegioni L. On the reaction of d-amino acid oxidase with dioxygen: O2 diffusion pathways and enhancement of reactivity. FEBS J 2010; 278:482-92. [DOI: 10.1111/j.1742-4658.2010.07969.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
45
|
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.
Collapse
|
46
|
Wittrup Larsen M, Zielinska DF, Martinelle M, Hidalgo A, Jensen LJ, Bornscheuer UT, Hult K. Suppression of Water as a Nucleophile in Candida antarctica Lipase B Catalysis. Chembiochem 2010; 11:796-801. [DOI: 10.1002/cbic.200900743] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
47
|
Finnegan S, Agniswamy J, Weber IT, Gadda G. Role of Valine 464 in the Flavin Oxidation Reaction Catalyzed by Choline Oxidase,. Biochemistry 2010; 49:2952-61. [DOI: 10.1021/bi902048c] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Irene T. Weber
- Departments of Chemistry
- Biology
- The Center for Biotechnology and Drug Design
| | - Giovanni Gadda
- Departments of Chemistry
- Biology
- The Center for Biotechnology and Drug Design
| |
Collapse
|
48
|
Abstract
Cholesterol is a major constituent of the plasma membrane in eukaryotic cells. It regulates the physical state of the phospholipid bilayer and is crucially involved in the formation of membrane microdomains. Cholesterol also affects the activity of several membrane proteins, and is the precursor for steroid hormones and bile acids. Here, methods are described that are used to explore the binding and/or interaction of proteins to cholesterol. For this purpose, a variety of cholesterol probes bearing radio-, spin-, photoaffinity- or fluorescent labels are currently available. Examples of proven cholesterol binding molecules are polyene compounds, cholesterol-dependent cytolysins, enzymes accepting cholesterol as substrate, and proteins with cholesterol binding motifs. Main topics of this report are the localization of candidate membrane proteins in cholesterol-rich microdomains, the issue of specificity of cholesterol- protein interactions, and applications of the various cholesterol probes for these studies.
Collapse
Affiliation(s)
- Gerald Gimpl
- Institut für Biochemie, Johannes Gutenberg-Universität, Johann-Joachim-Becherweg 30, Mainz, Germany.
| |
Collapse
|
49
|
A nitric oxide/cysteine interaction mediates the activation of soluble guanylate cyclase. Proc Natl Acad Sci U S A 2009; 106:21602-7. [PMID: 20007374 DOI: 10.1073/pnas.0911083106] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Nitric oxide (NO) regulates a number of essential physiological processes by activating soluble guanylate cyclase (sGC) to produce the second messenger cGMP. The mechanism of NO sensing was previously thought to result exclusively from NO binding to the sGC heme; however, recent studies indicate that heme-bound NO only partially activates sGC and additional NO is involved in the mechanism of maximal NO activation. Furthermore, thiol oxidation of sGC cysteines results in the loss of enzyme activity. Herein the role of cysteines in NO-stimulated sGC activity investigated. We find that the thiol modifying reagent methyl methanethiosulfonate specifically inhibits NO activation of sGC by blocking a non-heme site, which defines a role for sGC cysteine(s) in mediating NO binding. The nature of the NO/cysteine interaction was probed by examining the effects of redox active reagents on NO-stimulated activity. These results show that NO binding to, and dissociation from, the critical cysteine(s) does not involve a change in the thiol redox state. Evidence is provided for non-heme NO in the physiological activation of sGC in context of a primary cell culture of human umbilical vein endothelial cells. These findings have relevance to diseases involving the NO/cGMP signaling pathway.
Collapse
|
50
|
Relating diffusion along the substrate tunnel and oxygen sensitivity in hydrogenase. Nat Chem Biol 2009; 6:63-70. [DOI: 10.1038/nchembio.276] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 10/26/2009] [Indexed: 11/08/2022]
|