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Manoj KM. Murburn posttranslational modifications of proteins: Cellular redox processes and murzyme-mediated metabolo-proteomics. J Cell Physiol 2024; 239:e30954. [PMID: 36716112 DOI: 10.1002/jcp.30954] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/04/2023] [Accepted: 01/11/2023] [Indexed: 01/31/2023]
Abstract
Murburn concept constitutes the thesis that diffusible reactive species or DRS are obligatorily involved in routine metabolic and physiological activities. Murzymes are defined as biomolecules/proteins that generate/modulate/sustain/utilize DRS. Murburn posttranslational modifications (PTMs) result because murburn/murzyme functionalism is integral to cellular existence. Cells must incorporate the inherently stochastic nature of operations mediated by DRS. Due to the earlier/inertial stigmatic perception that DRS are mere agents of chaos, several such outcomes were either understood as deterministic modulations sponsored by house-keeping enzymes or deemed as unregulated nonenzymatic events resulting out of "oxidative stress". In the current review, I dispel the myths around DRS-functions, and undertake systematic parsing and analyses of murburn modifications of proteins. Although it is impossible to demarcate all PTMs into the classical or murburn modalities, telltale signs of the latter are evident from the relative inaccessibility of the locus, non-specificities and mechanistic details. It is pointed out that while many murburn PTMs may be harmless, some others could have deleterious or beneficial physiological implications. Some details of reversible/irreversible modifications of amino acid residues and cofactors that may be subjected to phosphorylation, halogenation, glycosylation, alkylation/acetylation, hydroxylation/oxidation, etc. are listed, along with citations of select proteins where such modifications have been reported. The contexts of these modifications and their significance in (patho)physiology/aging and therapy are also presented. With more balanced explorations and statistically verified data, a definitive understanding of normal versus pathological contexts of murburn modifications would be obtainable in the future.
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Manoj KM, Gideon DA, Parashar A, Nirusimhan V, Annadurai P, Jacob VD, Manekkathodi A. Validating the predictions of murburn model for oxygenic photosynthesis: Analyses of ligand-binding to protein complexes and cross-system comparisons. J Biomol Struct Dyn 2022; 40:11024-11056. [PMID: 34328391 DOI: 10.1080/07391102.2021.1953607] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this second half of our treatise on oxygenic photosynthesis, we provide support for the murburn model of the light reaction of photosynthesis and ratify key predictions made in the first part. Molecular docking and visualization of various ligands of quinones/quinols (and their derivatives) with PS II/Cytochrome b6f complexes did not support chartered 2e-transport role of quinols. A broad variety of herbicides did not show any affinity/binding-based rationales for inhibition of photosynthesis. We substantiate the proposal that disubstituted phenolics (perceived as protonophores/uncouplers or affinity-based inhibitors in the classical purview) serve as interfacial modulators of diffusible reactive (oxygen) species or DR(O)S. The DRS-based murburn model is evidenced by the identification of multiple ADP-binding sites on the extra-membraneous projection of protein complexes and structure/distribution of the photo/redox catalysts. With a panoramic comparison of the redox metabolic machinery across diverse organellar/cellular systems, we highlight the ubiquitous one-electron murburn facets (cofactors of porphyrin, flavin, FeS, other metal centers and photo/redox active pigments) that enable a facile harnessing of the utility of DRS. In the summative analyses, it is demonstrated that the murburn model of light reaction explains the structures of membrane supercomplexes recently observed in thylakoids and also accounts for several photodynamic experimental observations and evolutionary considerations. In toto, the work provides a new orientation and impetus to photosynthesis research. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kelath Murali Manoj
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Daniel Andrew Gideon
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Abhinav Parashar
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Vijay Nirusimhan
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Pushparaj Annadurai
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Vivian David Jacob
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Afsal Manekkathodi
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
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Manoj KM, Bazhin NM, Jacob VD, Parashar A, Gideon DA, Manekkathodi A. Structure-function correlations and system dynamics in oxygenic photosynthesis: classical perspectives and murburn precepts. J Biomol Struct Dyn 2022; 40:10997-11023. [PMID: 34323659 DOI: 10.1080/07391102.2021.1953606] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
HIGHLIGHTS Contemporary beliefs on oxygenic photosynthesis are critiqued.Murburn model is suggested as an alternative explanation.In the new model, diffusible reactive species are the main protagonists.All pigments are deemed photo-redox active in the new stochastic mechanism.NADPH synthesis occurs via simple electron transfers, not via elaborate ETC.Oxygenesis is delocalized and not just centered at Mn-Complex.Energetics of murburn proposal for photophosphorylation is provided.The proposal ushers in a paradigm shift in photosynthesis research.
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Affiliation(s)
| | | | - Vivian David Jacob
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Kerala, India
| | - Abhinav Parashar
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Kerala, India
| | | | - Afsal Manekkathodi
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Kerala, India
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Manoj KM, Gideon DA. Structural foundations for explaining the physiological roles of murzymes embedded in diverse phospholipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183981. [PMID: 35690100 DOI: 10.1016/j.bbamem.2022.183981] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/26/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
The advent of improved structural biology protocols and bioinformatics methodologies have provided paradigm-shifting insights on metabolic or physiological processes catalyzed by homo-/hetero- proteins (super)complexes embedded in phospholipid membranes of cells/organelles. In this panoramic review, we succinctly elucidate the structural features of select redox proteins from four systems: hepatocyte/adrenal cortex endoplasmic reticulum (microsomes), inner mitochondrial membrane (cristae), thylakoid membrane (grana), and in the flattened disks of rod/cone cells (in retina). Besides catalyzing fast/crucial (photo)chemical reactions, these proteins utilize the redox-active diatomic gaseous molecule of oxygen, the elixir of aerobic life. Quite contrary to extant perceptions that invoke primarily deterministic affinity-binding or conformation-change based "proton-pump"/"serial electron-relay" type roles, we advocate murzyme functions for the membrane-embedded proteins in these systems. Murzymes are proteins that generate/stabilize/utilize diffusible reactive (oxygen) species (DRS/DROS) based activities. Herein, we present a brief compendium of the recently revealed wealth of structural information and mechanistic concepts on how the membrane proteins use DRS/DROS to aid 'effective charge separation' and facilitate trans-membrane dynamics of diverse species in milieu, thereby enabling the cells to function as 'simple chemical engines'.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Shoranur-2 (PO), Kerala 679122, India.
| | - Daniel Andrew Gideon
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Shoranur-2 (PO), Kerala 679122, India.
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Manoj KM, Bazhin N. The murburn precepts for aerobic respiration and redox homeostasis. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 167:104-120. [DOI: 10.1016/j.pbiomolbio.2021.05.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/13/2021] [Accepted: 05/31/2021] [Indexed: 12/13/2022]
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Advances in enzymatic oxyfunctionalization of aliphatic compounds. Biotechnol Adv 2021; 51:107703. [PMID: 33545329 DOI: 10.1016/j.biotechadv.2021.107703] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/17/2021] [Accepted: 01/25/2021] [Indexed: 12/27/2022]
Abstract
Selective oxyfunctionalizations of aliphatic compounds are difficult chemical reactions, where enzymes can play an important role due to their stereo- and regio-selectivity and operation under mild reaction conditions. P450 monooxygenases are well-known biocatalysts that mediate oxyfunctionalization reactions in different living organisms (from bacteria to humans). Unspecific peroxygenases (UPOs), discovered in fungi, have arisen as "dream biocatalysts" of great biotechnological interest because they catalyze the oxyfunctionalization of aliphatic and aromatic compounds, avoiding the necessity of expensive cofactors and regeneration systems, and only depending on H2O2 for their catalysis. Here, we summarize recent advances in aliphatic oxyfunctionalization reactions by UPOs, as well as the molecular determinants of the enzyme structures responsible for their activities, emphasizing the differences found between well-known P450s and the novel fungal peroxygenases.
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Peidro-Guzmán H, Pérez-Llano Y, González-Abradelo D, Fernández-López MG, Dávila-Ramos S, Aranda E, Hernández DRO, García AO, Lira-Ruan V, Pliego OR, Santana MA, Schnabel D, Jiménez-Gómez I, Mouriño-Pérez RR, Aréchiga-Carvajal ET, Del Rayo Sánchez-Carbente M, Folch-Mallol JL, Sánchez-Reyes A, Vaidyanathan VK, Cabana H, Gunde-Cimerman N, Batista-García RA. Transcriptomic analysis of polyaromatic hydrocarbon degradation by the halophilic fungus Aspergillus sydowii at hypersaline conditions. Environ Microbiol 2020; 23:3435-3459. [PMID: 32666586 DOI: 10.1111/1462-2920.15166] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/11/2020] [Accepted: 07/12/2020] [Indexed: 01/22/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are among the most persistent xenobiotic compounds, with high toxicity effects. Mycoremediation with halophilic Aspergillus sydowii was used for their removal from a hypersaline medium (1 M NaCl). A. sydowii metabolized PAHs as sole carbon sources, resulting in the removal of up to 90% for both PAHs [benzo [a] pyrene (BaP) and phenanthrene (Phe)] after 10 days. Elimination of Phe and BaP was almost exclusively due to biotransformation and not adsorption by dead mycelium and did not correlate with the activity of lignin modifying enzymes (LME). Transcriptomes of A. sydowii grown on PAHs, or on glucose as control, both at hypersaline conditions, revealed 170 upregulated and 76 downregulated genes. Upregulated genes were related to starvation, cell wall remodelling, degradation and metabolism of xenobiotics, DNA/RNA metabolism, energy generation, signalling and general stress responses. Changes of LME expression levels were not detected, while the chloroperoxidase gene, possibly related to detoxification processes in fungi, was strongly upregulated. We propose that two parallel metabolic pathways (mitochondrial and cytosolic) are involved in degradation and detoxification of PAHs in A. sydowii resulting in intracellular oxidation of PAHs. To the best of our knowledge, this is the most comprehensive transcriptomic analysis on fungal degradation of PAHs.
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Affiliation(s)
- Heidy Peidro-Guzmán
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Yordanis Pérez-Llano
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Deborah González-Abradelo
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Maikel Gilberto Fernández-López
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Sonia Dávila-Ramos
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Elisabet Aranda
- Instituto Universitario de Investigación del Agua, Universidad de Granada, Granada, Spain
| | | | - Angélica Ortega García
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Verónica Lira-Ruan
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Oscar Ramírez Pliego
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - María Angélica Santana
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Denhi Schnabel
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Irina Jiménez-Gómez
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Rosa R Mouriño-Pérez
- Centro de Investigación Cientifica y Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Elva T Aréchiga-Carvajal
- Facultad de Ciencias Biológicas, Unidad de Manipulación Genética, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico
| | | | - Jorge Luis Folch-Mallol
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Ayixon Sánchez-Reyes
- Cátedras Conacyt - Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | | | - Hubert Cabana
- Faculté de Genié, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Nina Gunde-Cimerman
- Departament of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Ramón Alberto Batista-García
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
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Manoj KM, Ramasamy S, Parashar A, Gideon DA, Soman V, Jacob VD, Pakshirajan K. Acute toxicity of cyanide in aerobic respiration: Theoretical and experimental support for murburn explanation. Biomol Concepts 2020; 11:32-56. [PMID: 32187011 DOI: 10.1515/bmc-2020-0004] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 02/19/2020] [Indexed: 12/30/2022] Open
Abstract
The inefficiency of cyanide/HCN (CN) binding with heme proteins (under physiological regimes) is demonstrated with an assessment of thermodynamics, kinetics, and inhibition constants. The acute onset of toxicity and CN's mg/Kg LD50 (μM lethal concentration) suggests that the classical hemeFe binding-based inhibition rationale is untenable to account for the toxicity of CN. In vitro mechanistic probing of CN-mediated inhibition of hemeFe reductionist systems was explored as a murburn model for mitochondrial oxidative phosphorylation (mOxPhos). The effect of CN in haloperoxidase catalyzed chlorine moiety transfer to small organics was considered as an analogous probe for phosphate group transfer in mOxPhos. Similarly, inclusion of CN in peroxidase-catalase mediated one-electron oxidation of small organics was used to explore electron transfer outcomes in mOxPhos, leading to water formation. The free energy correlations from a Hammett study and IC50/Hill slopes analyses and comparison with ligands ( CO/ H 2 S/ N 3 - ) $\left( {\text{CO}}/{{{{\text{H}}_{2}}\text{S}}/{\text{N}_{3}^{\text{-}}}\;}\; \right)$ provide insights into the involvement of diffusible radicals and proton-equilibriums, explaining analogous outcomes in mOxPhos chemistry. Further, we demonstrate that superoxide (diffusible reactive oxygen species, DROS) enables in vitro ATP synthesis from ADP+phosphate, and show that this reaction is inhibited by CN. Therefore, practically instantaneous CN ion-radical interactions with DROS in matrix catalytically disrupt mOxPhos, explaining the acute lethal effect of CN.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, India-679122
| | - Surjith Ramasamy
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India-781039
| | - Abhinav Parashar
- Department of Biotechnology, Vignan's Foundation for Science, Technology & Research, Vadlamudi, Guntur, India-522213
| | - Daniel Andrew Gideon
- Department of Biotechnology, Bishop Heber College, Tiruchirappalli, Tamil Nadu, India-620017
| | - Vidhu Soman
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India-110016
| | - Vivian David Jacob
- Satyamjayatu: The Science & Ethics Foundation Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, India-679122
| | - Kannan Pakshirajan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India-781039
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Manoj KM. Murburn concept: a paradigm shift in cellular metabolism and physiology. Biomol Concepts 2020; 11:7-22. [PMID: 31961793 DOI: 10.1515/bmc-2020-0002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/02/2020] [Indexed: 12/26/2022] Open
Abstract
Two decades of evidence-based exploratory pursuits in heme-flavin enzymology led to the formulation of a new biological electron/moiety transfer paradigm, called murburn concept. Murburn is a novel literary abstraction from "mured burning" or "mild unrestricted burning". This concept was invoked to explain the longstanding conundrum of maverick physiological dose responses and also applied to remodel the prevailing understanding of drug metabolism and cellular respiration. A conglomeration of simple ideas grounded in the known principles of thermodynamics and reaction chemistry, murburn concept invokes catalytic/functional roles for diffusible reactive species or radicals. Hitherto, diffusible reactive species were primarily seen as toxic agents of chaos, non-conducible to the maintenance of life-order. Since the murburn paradigm offers a distinctly different perspective for several biological phenomena, researchers holding conventional views of cellular metabolism pose a direct conflict of interests to the advancement of murburn concept. Murburn schemes are poised to integrate numerous metabolic motifs with holistic physiological outcomes; redefining pursuits in biology and medicine. To advance this agenda, I present a brief account of murburn concept and point out how redundant ideas are still advocated in some prestigious journals.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation,Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala,India-679122
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Manoj KM, Soman V, David Jacob V, Parashar A, Gideon DA, Kumar M, Manekkathodi A, Ramasamy S, Pakshirajan K, Bazhin NM. Chemiosmotic and murburn explanations for aerobic respiration: Predictive capabilities, structure-function correlations and chemico-physical logic. Arch Biochem Biophys 2019; 676:108128. [PMID: 31622585 DOI: 10.1016/j.abb.2019.108128] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 12/18/2022]
Abstract
Since mid-1970s, the proton-centric proposal of 'chemiosmosis' became the acclaimed explanation for aerobic respiration. Recently, significant theoretical and experimental evidence were presented for an oxygen-centric 'murburn' mechanism of mitochondrial ATP-synthesis. Herein, we compare the predictive capabilities of the two models with respect to the available information on mitochondrial reaction chemistry and the membrane proteins' structure-function correlations. Next, fundamental queries are addressed on thermodynamics of mitochondrial oxidative phosphorylation (mOxPhos): (1) Can the energy of oxygen reduction be utilized for proton transport? (2) Is the trans-membrane proton differential harness-able as a potential energy capable of doing useful work? and (3) Whether the movement of miniscule amounts of mitochondrial protons could give rise to a potential of ~200 mV and if such an electrical energy could sponsor ATP-synthesis. Further, we explore critically if rotary ATPsynthase activity of Complex V can account for physiological ATP-turnovers. We also answer the question- "What is the role of protons in the oxygen-centric murburn scheme of aerobic respiration?" Finally, it is demonstrated that the murburn reaction model explains the fast kinetics, non-integral stoichiometry and high yield of mOxPhos. Strategies are charted to further demarcate the two explanations' relevance in the cellular physiology of aerobic respiration.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India.
| | - Vidhu Soman
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Vivian David Jacob
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India
| | - Abhinav Parashar
- Department of Biotechnology, Vignan's Foundation for Science, Technology & Research, Vadlamudi, Guntur, 522213, India
| | - Daniel Andrew Gideon
- Department of Biotechnology & Bioinformatics, Bishop Heber College (Autonomous), Tennur, Tiruchirappalli, 620017, India
| | - Manish Kumar
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India
| | - Afsal Manekkathodi
- Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Al-Rayyan PO Box 34110, Qatar
| | - Surjith Ramasamy
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Kannan Pakshirajan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Nikolai Mikhailovich Bazhin
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, St. Institutskaya 3, 630090, Novosibirsk, Russia.
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Manoj KM, Parashar A, David Jacob V, Ramasamy S. Aerobic respiration: proof of concept for the oxygen-centric murburn perspective. J Biomol Struct Dyn 2019; 37:4542-4556. [PMID: 30488771 DOI: 10.1080/07391102.2018.1552896] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The inner mitochondrial membrane protein complexes (I-V) and prokaryotic respiratory machinery are examined for a deeper understanding of their structure-function correlations and dynamics. In silico analysis of the structure of complexes I-IV, docking studies and erstwhile literature confirm that they carry sites which are in close proximity to DROS (diffusible reactive oxygen species) generating redox centers. These findings provide supportive evidence for the newly proposed oxygen-centric chemical-coupling mechanism (murburn concept), wherein DROS catalyzes the esterification of inorganic phosphate to ADP. Further, in a reductionist system, we demonstrate that a DROS (like superoxide) can effectively esterify inorganic phosphate to ADP. The impact of these findings and the interactive dynamics of classical inhibitors (rotenone and cyanide), uncouplers (dinitrophenol and uncoupling protein) and other toxins (atractyloside and oligomycin) are briefly discussed. Highlights • Earlier perception: Complexes (I-IV) pump protons and Complex V make ATP (aided by protons) • Herein: Respiratory molecular machinery is probed for new structure-function correlations • Analyses: Quantitative arguments discount proton-centric ATP synthesis in mitochondria and bacteria • In silico data: ADP-binding sites and O2/ diffusible reactive oxygen species (DROS)-accessible channels are unveiled in respiratory proteins • In vitro data: Using luminometry, ATP synthesis is demonstrated from ADP, Pi and superoxide • Inference: Findings agree with decentralized ADP-Pi activation via oxygen-centric murburn scheme Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - Abhinav Parashar
- Department of Biotechnology, Vignan's Foundation for Science, Technology & Research , Vadlamudi , Guntur, Andhra Pradesh, India
| | | | - Surjith Ramasamy
- Department of Biotechnology, Indian Institute of Technology Guwahati , Guwahati , Assam, India
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Arca-Ramos A, Eibes G, Feijoo G, Lema JM, Moreira MT. Enzymatic reactors for the removal of recalcitrant compounds in wastewater. BIOCATAL BIOTRANSFOR 2017. [DOI: 10.1080/10242422.2017.1315411] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Adriana Arca-Ramos
- Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Gemma Eibes
- Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Gumersindo Feijoo
- Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Juan M. Lema
- Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - María Teresa Moreira
- Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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Exploring the catalase activity of unspecific peroxygenases and the mechanism of peroxide-dependent heme destruction. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcatb.2016.10.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Manoj KM, Parashar A, Gade SK, Venkatachalam A. Functioning of Microsomal Cytochrome P450s: Murburn Concept Explains the Metabolism of Xenobiotics in Hepatocytes. Front Pharmacol 2016; 7:161. [PMID: 27445805 PMCID: PMC4918403 DOI: 10.3389/fphar.2016.00161] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 05/31/2016] [Indexed: 11/13/2022] Open
Abstract
Using oxygen and NADPH, the redox enzymes cytochrome P450 (CYP) and its reductase (CPR) work in tandem to carry out the phase I metabolism of a vast majority of drugs and xenobiotics. As per the erstwhile understanding of the catalytic cycle, binding of the substrate to CYP's heme distal pocket allows CPR to pump electrons through a CPR-CYP complex. In turn, this trigger (a thermodynamic push of electrons) leads to the activation of oxygen at CYP's heme-center, to give Compound I, a two-electron deficient enzyme reactive intermediate. The formation of diffusible radicals and reactive oxygen species (DROS, hitherto considered an undesired facet of the system) was attributed to the heme-center. Recently, we had challenged these perceptions and proposed the murburn ("mured burning" or "mild unrestricted burning") concept to explain heme enzymes' catalytic mechanism, electron-transfer phenomena and the regulation of redox equivalents' consumption. Murburn concept incorporates a one-electron paradigm, advocating obligatory roles for DROS. The new understanding does not call for high-affinity substrate-binding at the heme distal pocket of the CYP (the first and the most crucial step of the erstwhile paradigm) or CYP-CPR protein-protein complexations (the operational backbone of the erstwhile cycle). Herein, the dynamics of reduced nicotinamide nucleotides' consumption, peroxide formation and depletion, product(s) formation, etc. was investigated with various controls, by altering reaction variables, environments and through the incorporation of diverse molecular probes. In several CYP systems, control reactions lacking the specific substrate showed comparable or higher peroxide in milieu, thereby discrediting the foundations of the erstwhile hypothesis. The profiles obtained by altering CYP:CPR ratios and the profound inhibitions observed upon the incorporation of catalytic amounts of horseradish peroxidase confirm the obligatory roles of DROS in milieu, ratifying murburn as the operative concept. The mechanism of uncoupling (peroxide/water formation) was found to be dependent on multiple one and two electron equilibriums amongst the reaction components. The investigation explains the evolutionary implications of xenobiotic metabolism, confirms the obligatory role of diffusible reactive species in routine redox metabolism within liver microsomes and establishes that a redox enzyme like CYP enhances reaction rates (achieves catalysis) via a novel (hitherto unknown) modality.
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Affiliation(s)
| | - Abhinav Parashar
- Hemoproteins Lab, School of Bio Sciences and Technology, VIT University Vellore, India
| | - Sudeep K Gade
- Hemoproteins Lab, School of Bio Sciences and Technology, VIT University Vellore, India
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15
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Atypical profiles and modulations of heme-enzymes catalyzed outcomes by low amounts of diverse additives suggest diffusible radicals' obligatory involvement in such redox reactions. Biochimie 2016; 125:91-111. [DOI: 10.1016/j.biochi.2016.03.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/03/2016] [Indexed: 01/09/2023]
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16
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FRANKO M, LIU M, BOŠKIN A, DELNERI A, PROSKURNIN MA. Fast Screening Techniques for Neurotoxigenic Substances and Other Toxicants and Pollutants Based on Thermal Lensing and Microfluidic Chips. ANAL SCI 2016; 32:23-30. [DOI: 10.2116/analsci.32.23] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Mladen FRANKO
- University of Nova Gorica, Laboratory for Environmental Research
| | - Mingqiang LIU
- University of Nova Gorica, Laboratory for Environmental Research
| | - Aleš BOŠKIN
- University of Nova Gorica, Laboratory for Environmental Research
| | - Ambra DELNERI
- University of Nova Gorica, Laboratory for Environmental Research
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Morozov AN, Pardillo AD, Chatfield DC. Chloroperoxidase-Catalyzed Epoxidation of Cis-β-Methylstyrene: NH-S Hydrogen Bonds and Proximal Helix Dipole Change the Catalytic Mechanism and Significantly Lower the Reaction Barrier. J Phys Chem B 2015; 119:14350-63. [PMID: 26452587 DOI: 10.1021/acs.jpcb.5b06731] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Proximal hydrogen bonding of the axial sulfur with the backbone amides (NH-S) is a conserved feature of heme-thiolate enzymes such as chloroperoxidase (CPO) and cytochrome P450 (P450). In CPO, the effect of NH-S bonds is amplified by the dipole moment of the proximal helix. Our gas-phase DFT studies show that the proximal pocket effect significantly enhances CPO's reactivity toward the epoxidation of olefinic substrates. Comparison of models with and without proximal pocket residues shows that with them, the barrier for Cβ-O bond formation is lowered by about ∼4.6 kcal/mol, while Cα-O-Cβ ring closure becomes barrierless. The dipole moment of the proximal helix was estimated to contribute 1/3 of the decrease, while the rest is attributed to the effect of NH-S bonds. The decrease of the reaction barrier correlates with increased electron density transfer to residues of the proximal pocket. The effect is most pronounced on the doublet spin surface and involves a change in the electron-transfer mechanism. A full enzyme QMMM study on the doublet spin surface gives about the same barrier as the gas-phase DFT study. The free-energy barrier was estimated to be in agreement with the experimental results for the CPO-catalyzed epoxidation of styrene.
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Affiliation(s)
- Alexander N Morozov
- Department of Chemistry and Biochemistry, Florida International University , 11200 Southwest Eighth Street, Miami, Florida 33199, United States
| | - Armando D Pardillo
- Department of Chemistry and Biochemistry, Florida International University , 11200 Southwest Eighth Street, Miami, Florida 33199, United States
| | - David C Chatfield
- Department of Chemistry and Biochemistry, Florida International University , 11200 Southwest Eighth Street, Miami, Florida 33199, United States
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18
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Biocatalytic Performance of Chloroperoxidase from Caldariomyces fumago Immobilized onto TiO2 Based Supports. Top Catal 2015. [DOI: 10.1007/s11244-015-0438-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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Enhancement of operational stability of chloroperoxidase from Caldariomyces fumago by immobilization onto mesoporous supports and the use of co-solvents. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcatb.2015.02.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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20
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Hofrichter M, Kellner H, Pecyna MJ, Ullrich R. Fungal Unspecific Peroxygenases: Heme-Thiolate Proteins That Combine Peroxidase and Cytochrome P450 Properties. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 851:341-68. [DOI: 10.1007/978-3-319-16009-2_13] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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21
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Holtmann D, Krieg T, Getrey L, Schrader J. Electroenzymatic process to overcome enzyme instabilities. CATAL COMMUN 2014. [DOI: 10.1016/j.catcom.2014.03.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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22
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Zhang R, He Q, Chatfield D, Wang X. Paramagnetic nuclear magnetic resonance relaxation and molecular mechanics studies of the chloroperoxidase-indole complex: insights into the mechanism of chloroperoxidase-catalyzed regioselective oxidation of indole. Biochemistry 2013; 52:3688-701. [PMID: 23634952 DOI: 10.1021/bi4002437] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To unravel the mechanism of chloroperoxidase (CPO)-catalyzed regioselective oxidation of indole, we studied the structure of the CPO-indole complex using nuclear magnetic resonance (NMR) relaxation measurements and computational techniques. The dissociation constant (KD) of the CPO-indole complex was calculated to be approximately 21 mM. The distances (r) between protons of indole and the heme iron calculated via NMR relaxation measurements and molecular docking revealed that the pyrrole ring of indole is oriented toward the heme with its 2-H pointing directly at the heme iron. Both KD and r values are independent of pH in the range of 3.0-6.5. The stability and structure of the CPO-indole complex are also independent of the concentration of chloride or iodide ion. Molecular docking suggests the formation of a hydrogen bond between the NH group of indole and the carboxyl O of Glu 183 in the binding of indole to CPO. Simulated annealing of the CPO-indole complex using r values from NMR experiments as distance restraints reveals that the van der Waals interactions were much stronger than the Coulomb interactions in the binding of indole to CPO, indicating that the association of indole with CPO is primarily governed by hydrophobic rather than electrostatic interactions. This work provides the first experimental and theoretical evidence of the long-sought mechanism that leads to the "unexpected" regioselectivity of the CPO-catalyzed oxidation of indole. The structure of the CPO-indole complex will serve as a lighthouse in guiding the design of CPO mutants with tailor-made activities for biotechnological applications.
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Affiliation(s)
- Rui Zhang
- Department of Chemistry and Biochemistry, Florida International University , Miami, Florida 33199, United States
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23
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Collins DP, Isaac IS, Coulter ED, Hager PW, Ballou DP, Dawson JH. Reaction of ferric Caldariomyces fumago chloroperoxidase with meta-chloroperoxybenzoic acid: sequential formation of compound I, compound II and regeneration of the ferric state using one reactant. J PORPHYR PHTHALOCYA 2013. [DOI: 10.1142/s1088424612501234] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The mechanism of the reaction between ferric Caldariomyces fumago chloroperoxidase (CCPO) and meta-chloroperoxybenzoic acid (mCPBA) has been examined. It has previously been established that an Fe(IV) -oxo porphyrin radical species known as Compound I (Cpd I) is formed by two-electron oxidation of the native ferric enzyme by a variety of oxidants including organic peracids and hydroperoxides. Cpd I can return to the ferric state either by direct oxygen insertion into an organic substrate (e.g. a P450 oxygenase-like reaction), or by two consecutive one-electron additions, the first resulting in an intermediate Fe(IV) -oxo species known as Compound II (Cpd II). There has been much debate over the role of Cpd II and the details of its structure. In the present study, both CCPO Fe(IV) -oxo intermediates are formed, but unlike most CCPO reactions, Cpd I and Cpd II are formed using the same reactant, mCPBA. Thus, the peracid is used as an oxo donor to produce Cpd I and then as a reductant to reduce Cpd I to Cpd II, and finally, Cpd II to the ferric state. The observation of saturation kinetics with respect to mCPBA concentration for each step is consistent with the formation of CCPO-mCPBA complexes in each phase of the reaction. The original reaction mechanism for ferric CCPO with mCPBA was hypothesized to involve a scrambling mechanism with a unique Fe -OOO-C(O)R intermediate formed with no observed Cpd II intermediate. The data reported herein clearly demonstrate the formation of Cpd II in returning the oxidized enzyme back to its native ferric state.
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Affiliation(s)
- Daniel P. Collins
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Issa S. Isaac
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Eric D. Coulter
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Paul W. Hager
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - David P. Ballou
- Department of Biological Chemistry, Medical School, University of Michigan, Ann Arbor, MI 48109, USA
| | - John H. Dawson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
- School of Medicine, University of South Carolina, Columbia, SC 29208, USA
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Pešić M, López C, Álvaro G, López-Santín J. A novel immobilized chloroperoxidase biocatalyst with improved stability for the oxidation of amino alcohols to amino aldehydes. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.molcatb.2012.04.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Morozov AN, Chatfield DC. Chloroperoxidase-catalyzed epoxidation of cis-β-methylstyrene: distal pocket flexibility tunes catalytic reactivity. J Phys Chem B 2012; 116:12905-14. [PMID: 23020548 DOI: 10.1021/jp302763h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chloroperoxidase, the most versatile heme protein, has a hybrid active site pocket that shares structural features with peroxidases and cytochrome P450s. The simulation studies presented here show that the enzyme possesses a remarkable ability to efficiently utilize its hybrid structure, assuming structurally different peroxidase-like and P450-like distal pocket faces and thereby enhancing the inherent catalytic capability of the active center. We find that, during epoxidation of cis-β-methylstyrene (CBMS), the native peroxidase-like aspect of the distal pocket is diminished as the polar Glu183 side chain is displaced away from the active center and the distal pocket takes on a more hydrophobic, P450-like, aspect. The P450-like distal pocket provides a significant enthalpic stabilization of ∼4 kcal/mol of the 14 kcal/mol reaction barrier for gas-phase epoxidation of CMBS by an oxyferryl heme-thiolate species. This stabilization comes from breathing of the distal pocket. As until recently the active site of chloroperoxidase was postulated to be inflexible, these results suggest a new conceptual understanding of the enzyme's versatility: catalytic reactivity is tuned by flexibility of the distal pocket.
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Affiliation(s)
- Alexander N Morozov
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States.
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26
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Pešić M, López C, Álvaro G. Chloroperoxidase catalyzed oxidation of Cbz-ethanolamine to Cbz-glycinal. Biochem Eng J 2012. [DOI: 10.1016/j.bej.2012.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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Gade SK, Bhattacharya S, Manoj KM. Redox active molecules cytochrome c and vitamin C enhance heme-enzyme peroxidations by serving as non-specific agents for redox relay. Biochem Biophys Res Commun 2012; 419:211-4. [DOI: 10.1016/j.bbrc.2012.01.149] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 01/30/2012] [Indexed: 10/14/2022]
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28
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Thirty years of heme catalases structural biology. Arch Biochem Biophys 2011; 525:102-10. [PMID: 22209752 DOI: 10.1016/j.abb.2011.12.011] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 12/13/2011] [Accepted: 12/15/2011] [Indexed: 11/23/2022]
Abstract
About thirty years ago the crystal structures of the heme catalases from Penicillium vitale (PVC) and, a few months later, from bovine liver (BLC) were published. Both enzymes were compact tetrameric molecules with subunits that, despite their size differences and the large phylogenetic separation between the two organisms, presented a striking structural similarity for about 460 residues. The high conservation, confirmed in all the subsequent structures determined, suggested a strong pressure to preserve a functional catalase fold, which is almost exclusively found in these mono-functional heme catalases. However, even in the absence of the catalase fold an efficient catalase activity is also found in the heme containing catalase-peroxidase proteins. The structure of these broad substrate range enzymes, reported for the first time less than ten years ago from the halophilic archaebacterium Haloarcula marismortui (HmCPx) and from the bacterium Burkholderia pseudomallei (BpKatG), showed a heme pocket closely related to that of plant peroxidases, though with a number of unique modifications that enable the catalase reaction. Despite the wealth of structural information already available, for both monofunctional catalases and catalase-peroxidases, a number of unanswered major questions require continuing structural research with truly innovative approaches.
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29
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Wojaczyńska E, Wojaczyński J. Enantioselective synthesis of sulfoxides: 2000-2009. Chem Rev 2010; 110:4303-56. [PMID: 20415478 DOI: 10.1021/cr900147h] [Citation(s) in RCA: 324] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Elzbieta Wojaczyńska
- Department of Organic Chemistry, Faculty of Chemistry, Wrocław University of Technology, Wybrzeze Wyspiańskiego 27, 50 370 Wrocław, Poland.
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30
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Ayala M, Batista CV, Vazquez-Duhalt R. Heme destruction, the main molecular event during the peroxide-mediated inactivation of chloroperoxidase from Caldariomyces fumago. J Biol Inorg Chem 2010; 16:63-8. [DOI: 10.1007/s00775-010-0702-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 08/27/2010] [Indexed: 11/30/2022]
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31
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Roepcke CBS, Muench SB, Schulze H, Bachmann TT, Schmid RD, Hauer B. Analysis of phosphorothionate pesticides using a chloroperoxidase pretreatment and acetylcholinesterase biosensor detection. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:8748-8756. [PMID: 20614938 DOI: 10.1021/jf1013204] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Acetylcholinesterase (AChE) is responsible for the hydrolysis of acetylcholine in the nervous system. It is inhibited by organophosphate and carbamate pesticides. However, this enzyme is only slightly inhibited by organophosphorothionates, which makes the detection of these pesticides analytically very difficult. A new enzymatic method for the activation and detection of phosphorothionates was developed with the capability to be used directly in food samples without the need of laborious solvent extraction steps. Chloroperoxidase (CPO) from Caldariomyces fumago was combined with tert-butyl hydroperoxide and two halides. Chlorpyrifos and triazophos were completely oxidized. Fenitrothion, methidathion and parathion methyl showed conversion rates between 54 and 61%. Furthermore, the oxidized solution was submitted to an AChE biosensor assay. Chlorpyrifos spiked in organic orange juice was oxidized, where its oxon product was detected in concentrations down to 5 microg/L (final concentration food sample: 25 microg/L). The complete duration of the method takes about 2 h.
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Affiliation(s)
- Clarisse B S Roepcke
- University of Stuttgart, Institute of Technical Biochemistry, Allmandring 31, 70569 Stuttgart, Germany.
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32
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Vlasits J, Jakopitsch C, Bernroitner M, Zamocky M, Furtmüller PG, Obinger C. Mechanisms of catalase activity of heme peroxidases. Arch Biochem Biophys 2010; 500:74-81. [DOI: 10.1016/j.abb.2010.04.018] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 04/23/2010] [Accepted: 04/24/2010] [Indexed: 11/15/2022]
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33
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Versatile capacity of shuffled cytochrome P450s for dye production. Appl Microbiol Biotechnol 2008; 82:203-10. [PMID: 19107474 DOI: 10.1007/s00253-008-1812-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 11/21/2008] [Accepted: 12/05/2008] [Indexed: 10/21/2022]
Abstract
DNA family shuffling is a relatively new method of directed evolution used to create novel enzymes in order to improve their existing properties or to develop new features. This method of evolution in vitro has one basic requirement: a high similarity of initial parental sequences. Cytochrome P450 enzymes are relatively well conserved in their amino acid sequences. Members of the same family can have more than 40% of sequence identity at the protein level and are therefore good candidates for DNA family shuffling. These xenobiotic-metabolising enzymes have an ability to metabolise a wide range of chemicals and produce a variety of products including blue pigments such as indigo. By applying the specifically designed DNA family shuffling approach, catalytic properties of cytochrome P450 enzymes were further extended in the chimeric progeny to include a new range of blue colour formations. This mini-review evokes the possibility of exploiting directed evolution of cytochrome P450s and the novel enzymes created by DNA family shuffling for the production of new dyes.
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Spreti N, Germani R, Incani A, Savelli G. Stabilization of Chloroperoxidase by Polyethylene Glycols in Aqueous Media: Kinetic Studies and Synthetic Applications. Biotechnol Prog 2008; 20:96-101. [PMID: 14763829 DOI: 10.1021/bp034167i] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chloroperoxidase (CPO) is one of the most versatile of the heme peroxidase enzymes for synthetic applications. Despite the potential use of CPO, commercial processes have not been developed because of the low water solubility of many organic substrates of synthetic interest and the limited stability due to inactivation by H(2)O(2). CPO catalytic properties have been studied in aqueous solutions in the presence of short-chain poly(ethylene glycol)s (PEGs), and the sulfoxidation of thioanisole, as model substrate, has been investigated. The addition of PEGs allows a better substrate solubilization in the reaction mixture and the enzyme to retain more of its initial activity, with respect to pure buffer. Kinetic studies were performed to optimize the experimental conditions, and complete enantioselective conversion to the (R)-sulfoxide (ee = 99%) was observed in the presence of PEG 200 and tri(ethylene glycol). The relevant stabilization of chloroperoxidase due to the presence of PEGs allows the enzyme to convert the substrate with significant product yields even after 10 days, with a consequent increase in enzyme productivity. This is a promising result in view of industrial application of the enzyme.
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Affiliation(s)
- Nicoletta Spreti
- Dipartimento di Chimica, Ingegneria Chimica e Materiali, Via Vetoio, Coppito 2, 67010 Coppito (AQ), Italy
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35
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Gil‐Rodríguez P, Ferreira‐Batista C, Vázquez‐Duhalt R, Valderrama B. A Novel Heme Peroxidase fromRaphanus sativusIntrinsically Resistant to Hydrogen Peroxide. Eng Life Sci 2008. [DOI: 10.1002/elsc.200700073] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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36
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Tzialla A, Kalogeris E, Gournis D, Sanakis Y, Stamatis H. Enhanced catalytic performance and stability of chloroperoxidase from Caldariomyces fumago in surfactant free ternary water–organic solvent systems. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.molcatb.2007.10.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Affiliation(s)
- Kelath Murali Manoj
- Department of Biochemistry, University of Illinois at Urbana–Champaign, 6000 South Mathews Avenue, Urbana, Illinois 61801
| | - Lowell P. Hager
- Department of Biochemistry, University of Illinois at Urbana–Champaign, 6000 South Mathews Avenue, Urbana, Illinois 61801
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38
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Walz I, Schwack W. Cutinase inhibition by means of insecticidal organophosphates and carbamates. 3. Oxidation of phosphorothionates by chloroperoxidase from Caldariomyces fumago. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:8177-86. [PMID: 17824663 DOI: 10.1021/jf071598y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Chloroperoxidase (CPO) from Caldariomyces fumago combined with hydrogen peroxide and chloride proved to be most efficient for the transformation of organophosphorothionate pesticides, i.e., chlorpyrifos, chlorpyrifos-methyl, parathion, and parathion-methyl, into their more potent serine esterase inhibiting oxon analogues. Following CPO pre-oxidation steps, the detection limit of a recently described spectrophotometric cutinase assay could be increased by about 2 orders of magnitude as a consequence of increased inhibition rates of the organophosphates. This type of enzymatic oxidation is easier to perform and more efficient, as compared to bromine or N-bromosuccinimide, used for acetylcholine esterase (AChE) assay in water analyses, but is insufficient for complex matrices such as plant sample extracts. The performance of a complete assay, including sample preparation, oxidation, and inhibition, takes about 3 h. Performing oxidations of organophosphorus compounds, two significant anomalies were observed. Upon CPO oxidation, chlorpyrifos-methyl showed a very strong cutinase inhibition as compared to the corresponding oxon standard, and oxidized malathion, contrarily to malaoxon, revealed cutinase inhibition, which however obeyed a reversible reaction mechanism in contrast to the usually irreversible reactions of organophosphates. Except for methomyl, no significant effects of CPO oxidation on the inhibition strength of insecticidal carbamates could be detected. The applicability of the assay was tested with fruit samples spiked with chlorpyrifos at 0.2-0.5 mg/kg, thereby regarding the role of the latter as the pesticide detected most often in fruits. Mean recoveries ranged between 30-50%. An enhanced recovery of 84% was obtained for an apple juice sample spiked with parathion-methyl (0.5 mg/L).
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Affiliation(s)
- Ingrid Walz
- Universität Hohenheim, Institut für Lebensmittelchemie, Garbenstrasse 28, D-70599 Stuttgart, Germany
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39
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Grey CE, Hedström M, Adlercreutz P. A Mass Spectrometric Investigation of Native and Oxidatively Inactivated Chloroperoxidase. Chembiochem 2007; 8:1055-62. [PMID: 17492739 DOI: 10.1002/cbic.200700091] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The enzyme chloroperoxidase (CPO) found in Caldariomyces fumago is able to catalyze several stereoselective oxidation reactions by using a clean oxidant, usually hydrogen peroxide (H(2)O(2)), without the need for expensive cofactor generation. CPO's lack of operational stability, however, is a major limitation for its commercial use. In the present study, a capillary-LC on-line trypsin-digestion system combined with reversed-phase chromatography and mass spectrometric detection was optimized for studying the primary sequence of CPO. Samples containing native CPO, CPO treated with H(2)O(2), and CPO oxidatively inactivated by the use of indole and H(2)O(2) were analyzed and compared. Three oxidized peptides were found in the samples treated with H(2)O(2). Two additional oxidized peptides were found in the CPO samples that were completely inactivated, one of which contained an oxidized cysteine residue, Cys50, which is an essential amino acid due to its function as the axial ligand to the iron in the heme--the prosthetic group in CPO. In addition, the heme group was absent in the inactivated samples but was readily detected in other samples.
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Affiliation(s)
- Carl Elovson Grey
- Department of Biotechnology, Lund University, P.O. Box 124, SE-22 100 Lund, Sweden
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Kluge MG, Ullrich R, Scheibner K, Hofrichter M. Spectrophotometric assay for detection of aromatic hydroxylation catalyzed by fungal haloperoxidase–peroxygenase. Appl Microbiol Biotechnol 2007; 75:1473-8. [PMID: 17410351 DOI: 10.1007/s00253-007-0942-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 03/08/2007] [Accepted: 03/08/2007] [Indexed: 11/29/2022]
Abstract
Agrocybe aegerita peroxidase (AaP) is a versatile heme-thiolate protein that can act as a peroxygenase and catalyzes, among other reactions, the hydroxylation of aromatic rings. This paper reports a rapid and selective spectrophotometric method for directly detecting aromatic hydroxylation by AaP. The weakly activated aromatic compound naphthalene served as the substrate that was regioselectively converted into 1-naphthol in the presence of the co-substrate hydrogen peroxide. Formation of 1-naphthol was followed at 303 nm (epsilon (303) = 2,010 M(-1) cm(-1)), and the apparent Michaelis-Menten (K (m)) and catalytic (k (cat)) constants for the reaction were estimated to be 320 microM and 166 s(-1), respectively. This method will be useful in screening of fungi and other microorganisms for extracellular peroxygenase activities and in comparing and assessing different catalytic activities of haloperoxidase-peroxygenases.
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Affiliation(s)
- Martin G Kluge
- Unit of Environmental Biotechnology, International Graduate School of Zittau, Markt 23, 02763 Zittau, Germany
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Murali Manoj K. Chlorinations catalyzed by chloroperoxidase occur via diffusible intermediate(s) and the reaction components play multiple roles in the overall process. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:1325-39. [PMID: 16870515 DOI: 10.1016/j.bbapap.2006.05.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 05/29/2006] [Accepted: 05/30/2006] [Indexed: 11/21/2022]
Abstract
The chlorination mechanism of the fungal enzyme chloroperoxidase (CPO) has been debated for (1) active site chlorination and (2) diffusible species mediated chlorination. Based upon the conversion of approximately 35 different substrates belonging to different reactive groups, it was found that substrate dimensions and topography had no pronounced effect on rates of CPO chlorination reaction. Epoxidation of indene was dependent on its concentration where as chlorination was not. Also, effective conversion was seen in the chlorination mixture for substrates that could not be epoxidized or sulfoxidized. Some insoluble substrates and certain molecules that exceeded the active site dimensions were chlorinated at rates comparable to the rates required for CPO's more natural substrate, monochlorodimedone. By terminating the enzymatic reaction with an active site ligand (azide), the amount of diffusible species was correlated to CPO in the reaction mixture. The preferential utilization of a substrate, earlier attributed to the active site, is found to be due to the specificity afforded by the reaction environment. It was found that the reaction medium components of peroxide, chloride and hydronium ions affected the reaction rates through varying roles in the enzymatic and non-enzymatic process. Besides these experimental evidences, key mechanistic and kinetic arguments are presented to infer that the final chlorine transfer occurs outside the active site via a diffusible species.
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Affiliation(s)
- Kelath Murali Manoj
- Department of Biochemistry, 600 South Mathews Avenue, University of Illinois at Urbana-Champaign, Urbana, IL-61801, USA.
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Hofrichter M, Ullrich R. Heme-thiolate haloperoxidases: versatile biocatalysts with biotechnological and environmental significance. Appl Microbiol Biotechnol 2006; 71:276-88. [PMID: 16628447 DOI: 10.1007/s00253-006-0417-3] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 03/06/2006] [Accepted: 03/06/2006] [Indexed: 11/24/2022]
Abstract
Heme-thiolate haloperoxidases are undoubtedly the most versatile biocatalysts of the hemeprotein family and share catalytic properties with at least three further classes of heme-containing oxidoreductases, namely, classic plant and fungal peroxidases, cytochrome P450 monooxygenases, and catalases. For a long time, only one enzyme of this type--the chloroperoxidase (CPO) of the ascomycete Caldariomyces fumago--has been known. The enzyme is commercially available as a fine chemical and catalyzes the unspecific chlorination, bromination, and iodation (but no fluorination) of a variety of electrophilic organic substrates via hypohalous acid as actual halogenating agent. In the absence of halide, CPO resembles cytochrome P450s and epoxidizes and hydroxylates activated substrates such as organic sulfides and olefins; aromatic rings, however, are not susceptible to CPO-catalyzed oxygen-transfer. Recently, a second fungal haloperoxidase of the heme-thiolate type has been discovered in the agaric mushroom Agrocybe aegerita. The UV-Vis adsorption spectrum of the isolated enzyme shows little similarity to that of CPO but is almost identical to a resting-state P450. The Agrocybe aegerita peroxidase (AaP) has strong brominating as well as weak chlorinating and iodating activities, and catalyzes both benzylic and aromatic hydroxylations (e.g., of toluene and naphthalene). AaP and related fungal peroxidases could become promising biocatalysts in biotechnological applications because they seemingly fill the gap between CPO and P450 enzymes and act as "self-sufficient" peroxygenases. From the environmental point of view, the existence of a halogenating mushroom enzyme is interesting because it could be linked to the multitude of halogenated compounds known from these organisms.
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Affiliation(s)
- Martin Hofrichter
- Unit of Environmental Biotechnology, International Graduate School of Zittau, Germany.
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Groves JT. High-valent iron in chemical and biological oxidations. J Inorg Biochem 2006; 100:434-47. [PMID: 16516297 DOI: 10.1016/j.jinorgbio.2006.01.012] [Citation(s) in RCA: 452] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2006] [Accepted: 01/16/2006] [Indexed: 11/26/2022]
Abstract
Various aspects of the reactivity of iron(IV) in chemical and biological systems are reviewed. Accumulated evidence shows that the ferryl species [Fe(IV)O](2+) can be formed under a variety of conditions including those related to the ferrous ion-hydrogen peroxide system known as Fenton's reagent. Early evidence that such a species could hydroxylate typical aliphatic C-H bonds included regioselectivities and stereospecificities for cyclohexanol hydroxylation that could not be accounted for by a freely diffusing hydroxyl radical. Iron(IV) porphyrin complexes are also found in the catalytic cycles of cytochrome P450 and chloroperoxidase. Model oxo-iron(IV) porphyrin complexes have shown reactivity similar to the proposed enzymatic intermediates. Mechanistic studies using mechanistically diagnostic substrates have implicated a radical rebound scenario for aliphatic hydroxylation by cytochrome P450. Likewise, several non-heme diiron hydroxylases, AlkB (Omega-hydroxylase), sMMO (soluble methane monooxygenase), XylM (xylene monooxygenase) and T4moH (toluene monooxygenase) all show clear indications of radical rearranged products indicating that the oxygen rebound pathway is a ubiquitous mechanism for hydrocarbon oxygenation by both heme and non-heme iron enzymes.
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Affiliation(s)
- John T Groves
- Department of Chemistry, Princeton University, Washington Road, Princeton, NJ 08544, USA.
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Toti P, Petri A, Gambicorti T, Osman AM, Bauer C. Inactivation studies on native and silica gel non-homogeneous immobilized chloroperoxidase. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.molcatb.2005.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Toti P, Petri A, Pelaia V, Osman AM, Paolini M, Bauer C. A linearization method for low catalytic activity enzyme kinetic analysis. Biophys Chem 2005; 114:245-51. [PMID: 15829359 DOI: 10.1016/j.bpc.2004.12.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Revised: 12/17/2004] [Accepted: 12/17/2004] [Indexed: 10/26/2022]
Abstract
A kinetic analysis was made and a linear plot based on the general rate equation derived by Laidler [Can. J. Chem. 33, 1614-1624] is proposed. This linearization method allows determining the kinetic parameters (K(m), k(cat)) and [E](0) for enzymes with low catalytic activity. The method was applied to chloroperoxidase from Caldariomyces fumago [EC 1.11.1.10], whose kinetic parameters K(m)(app), k(cat)(app), and [E](0) with monochlorodimedone as substrate, were obtained by using the linearization plot and the V(max) value (calculated by Eadie-Hofstee plot). This plot could also be useful to the study of abenzyme kinetics provided the concentration of the latter is either higher or equal than K(m) value.
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Affiliation(s)
- Paolo Toti
- Department of Physiology and Biochemistry, Biochemistry Unit, University of Pisa, Italy
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Toti P, Petri A, Gambicorti T, Osman AM, Bauer C. Kinetic and stability studies on the chloroperoxidase complexes in presence of tert-butyl hydroperoxide. Biophys Chem 2005; 113:105-13. [PMID: 15617816 DOI: 10.1016/j.bpc.2004.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/09/2004] [Accepted: 08/09/2004] [Indexed: 11/24/2022]
Abstract
The inactivation of native chloroperoxidase (CPO) from Caldariomyces fumago in the presence of tert-butyl hydroperoxide (tert-BuOOH) was investigated. A kinetic analysis was made and the inactivation constants (V(3) and K(3)) were evaluated. In prolonged times, uni-exponential equation describes the enzyme time course inactivation. A method based on the rate of inactivation of the enzyme in the presence of the inactivating molecule tert-BuOOH was also performed. A second group of inactivation constants (j(3) and K) was obtained, which is sufficiently close to the first two, thus verifying that the decreasing of enzyme absorbance corresponds to the decay of activity.
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Affiliation(s)
- Paolo Toti
- Unità di Biochimica, Dipartimento di Fisiologia e Biochimica, Università di Pisa, via S. Zeno 51, 56027 Pisa, Italy
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Barloy-Hubler F, Chéron A, Hellégouarch A, Galibert F. Smc01944, a secreted peroxidase induced by oxidative stresses in Sinorhizobium meliloti 1021. Microbiology (Reading) 2004; 150:657-664. [PMID: 14993315 DOI: 10.1099/mic.0.26764-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sequencing of the Sinorhizobium meliloti strain 1021 genome led to the detection of 6204 open reading frames, 41 % of which have no hypothetical function. To help annotate this genome, a transcriptome analysis was carried out with a dedicated microarray consisting of 146 genes belonging to three different classes: (i) no hypothetical function; (ii) potentially involved in oxidative stress responses; (iii) known to participate in oxidative stress responses (e.g. catalase and superoxide dismutase genes). This transcriptome analysis, together with biological experiments and in silico investigations, identified new genes induced by exogenous H(2)O(2). The smc01944 gene was the most strongly induced: quantitative PCR showed that the amount of smc01944 mRNA increased 50-fold following the addition of 10 mM H(2)O(2), whereas the amount of katA mRNA (encoding a catalase) only increased 10-fold. Smc01944 is a non-haem chloroperoxidase (Cpo). The only member of this family to have been so far characterized is encoded by prxC of Pseudomonas fluorescens. Unexpectedly, the NH(2)-terminus of Smc01944 includes a signal peptide and Smc01944 is secreted into the supernatant. Interestingly, smc01944 is preceded by smc01945, encoding an OhrR-like regulator (MarR family). Thus, Smc01944 is the first exported Cpo encoded by a gene possibly regulated by an OhrR regulator. It was also shown that smc01944 is induced by t-butyl and cumene hydroperoxides but only slightly by menadione. The study of Smc01944 described in this work showed that the oxidative stress response of S. meliloti seems to differ from that of other bacteria characterized to date.
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Affiliation(s)
- Frédérique Barloy-Hubler
- Laboratoire de Génétique et Développement, UMR6061-CNRS, 2 Avenue du Pr Léon Bernard, 35043 Rennes cedex, France
| | - Angélique Chéron
- Laboratoire de Génétique et Développement, UMR6061-CNRS, 2 Avenue du Pr Léon Bernard, 35043 Rennes cedex, France
| | - Adeline Hellégouarch
- Laboratoire de Génétique et Développement, UMR6061-CNRS, 2 Avenue du Pr Léon Bernard, 35043 Rennes cedex, France
| | - Francis Galibert
- Laboratoire de Génétique et Développement, UMR6061-CNRS, 2 Avenue du Pr Léon Bernard, 35043 Rennes cedex, France
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Petri A, Gambicorti T, Salvadori P. Covalent immobilization of chloroperoxidase on silica gel and properties of the immobilized biocatalyst. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcatb.2003.10.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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49
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Groves JT. The bioinorganic chemistry of iron in oxygenases and supramolecular assemblies. Proc Natl Acad Sci U S A 2003; 100:3569-74. [PMID: 12655056 PMCID: PMC152962 DOI: 10.1073/pnas.0830019100] [Citation(s) in RCA: 282] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The bioinorganic chemistry of iron is central to life processes. Organisms must recruit iron from their environment, control iron storage and trafficking within cells, assemble the complex, iron-containing redox cofactors of metalloproteins, and manage a myriad of biochemical transformations by those enzymes. The coordination chemistry and the variable oxidation states of iron provide the essential mechanistic machinery of this metabolism. Our current understanding of several aspects of the chemistry of iron in biology are discussed with an emphasis on the oxygen activation and transfer reactions mediated by heme and nonheme iron proteins and the interactions of amphiphilic iron siderophores with lipid membranes.
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Affiliation(s)
- John T Groves
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
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50
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Bougioukou DJ, Smonou I. Chloroperoxidase-catalyzed cyclodimerization of methyl (2E)-2,4-pentadienoate: a [4+2] cycloaddition product. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1381-1177(02)00042-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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