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Barile A, Graziani C, Antonelli L, Parroni A, Fiorillo A, di Salvo ML, Ilari A, Giorgi A, Rosignoli S, Paiardini A, Contestabile R, Tramonti A. Identification of the pyridoxal 5'-phosphate allosteric site in human pyridox(am)ine 5'-phosphate oxidase. Protein Sci 2024; 33:e4900. [PMID: 38284493 PMCID: PMC10804683 DOI: 10.1002/pro.4900] [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: 11/06/2023] [Revised: 12/18/2023] [Accepted: 12/31/2023] [Indexed: 01/30/2024]
Abstract
Adequate levels of pyridoxal 5'-phosphate (PLP), the catalytically active form of vitamin B6 , and its proper distribution in the body are essential for human health. The PLP recycling pathway plays a crucial role in these processes and its defects cause severe neurological diseases. The enzyme pyridox(am)ine 5'-phosphate oxidase (PNPO), whose catalytic action yields PLP, is one of the key players in this pathway. Mutations in the gene encoding PNPO are responsible for a severe form of neonatal epilepsy. Recently, PNPO has also been described as a potential target for chemotherapeutic agents. Our laboratory has highlighted the crucial role of PNPO in the regulation of PLP levels in the cell, which occurs via a feedback inhibition mechanism of the enzyme, exerted by binding of PLP at an allosteric site. Through docking analyses and site-directed mutagenesis experiments, here we identified the allosteric PLP binding site of human PNPO. This site is located in the same protein region as the allosteric site we previously identified in the Escherichia coli enzyme homologue. However, the identity and arrangement of the amino acid residues involved in PLP binding are completely different and resemble those of the active site of PLP-dependent enzymes. The identification of the PLP allosteric site of human PNPO paves the way for the rational design of enzyme inhibitors as potential anti-cancer compounds.
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Affiliation(s)
- Anna Barile
- Istituto di Biologia e Patologia MolecolariConsiglio Nazionale delle RicercheRomeItaly
| | - Claudio Graziani
- Sapienza Università di RomaIstituto Pasteur Italia‐Fondazione Cenci BolognettiRomeItaly
- Dipartimento di Scienze Biochimiche “A. Rossi Fanelli”Sapienza Università di RomaRomeItaly
| | - Lorenzo Antonelli
- Istituto di Biologia e Patologia MolecolariConsiglio Nazionale delle RicercheRomeItaly
- Dipartimento di Scienze Biochimiche “A. Rossi Fanelli”Sapienza Università di RomaRomeItaly
| | - Alessia Parroni
- Istituto di Biologia e Patologia MolecolariConsiglio Nazionale delle RicercheRomeItaly
| | - Annarita Fiorillo
- Istituto di Biologia e Patologia MolecolariConsiglio Nazionale delle RicercheRomeItaly
- Dipartimento di Scienze Biochimiche “A. Rossi Fanelli”Sapienza Università di RomaRomeItaly
| | - Martino Luigi di Salvo
- Sapienza Università di RomaIstituto Pasteur Italia‐Fondazione Cenci BolognettiRomeItaly
- Dipartimento di Scienze Biochimiche “A. Rossi Fanelli”Sapienza Università di RomaRomeItaly
| | - Andrea Ilari
- Istituto di Biologia e Patologia MolecolariConsiglio Nazionale delle RicercheRomeItaly
| | - Alessandra Giorgi
- Dipartimento di Scienze Biochimiche “A. Rossi Fanelli”Sapienza Università di RomaRomeItaly
| | - Serena Rosignoli
- Dipartimento di Scienze Biochimiche “A. Rossi Fanelli”Sapienza Università di RomaRomeItaly
| | - Alessandro Paiardini
- Dipartimento di Scienze Biochimiche “A. Rossi Fanelli”Sapienza Università di RomaRomeItaly
| | - Roberto Contestabile
- Sapienza Università di RomaIstituto Pasteur Italia‐Fondazione Cenci BolognettiRomeItaly
- Dipartimento di Scienze Biochimiche “A. Rossi Fanelli”Sapienza Università di RomaRomeItaly
| | - Angela Tramonti
- Istituto di Biologia e Patologia MolecolariConsiglio Nazionale delle RicercheRomeItaly
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2
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Liu L, Li J, Gai Y, Tian Z, Wang Y, Wang T, Liu P, Yuan Q, Ma H, Lee SY, Zhang D. Protein engineering and iterative multimodule optimization for vitamin B 6 production in Escherichia coli. Nat Commun 2023; 14:5304. [PMID: 37652926 PMCID: PMC10471632 DOI: 10.1038/s41467-023-40928-0] [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: 03/02/2023] [Accepted: 08/16/2023] [Indexed: 09/02/2023] Open
Abstract
Vitamin B6 is an essential nutrient with extensive applications in the medicine, food, animal feed, and cosmetics industries. Pyridoxine (PN), the most common commercial form of vitamin B6, is currently chemically synthesized using expensive and toxic chemicals. However, the low catalytic efficiencies of natural enzymes and the tight regulation of the metabolic pathway have hindered PN production by the microbial fermentation process. Here, we report an engineered Escherichia coli strain for PN production. Parallel pathway engineering is performed to decouple PN production and cell growth. Further, protein engineering is rationally designed including the inefficient enzymes PdxA, PdxJ, and the initial enzymes Epd and Dxs. By the iterative multimodule optimization strategy, the final strain produces 1.4 g/L of PN with productivity of 29.16 mg/L/h by fed-batch fermentation. The strategies reported here will be useful for developing microbial strains for the production of vitamins and other bioproducts having inherently low metabolic fluxes.
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Affiliation(s)
- Linxia Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jinlong Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yuanming Gai
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, China
| | - Zhizhong Tian
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yanyan Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Tenghe Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Pi Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Qianqian Yuan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Hongwu Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Sang Yup Lee
- Department of Chemical and Biomolecular Engineering (BK21 four program), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
- National Technology Innovation Center of Synthetic Biology, Tianjin, China.
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
- University of Chinese Academy of Sciences, Beijing, China.
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3
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Aleshin VA, Graf AV, Artiukhov AV, Ksenofontov AL, Zavileyskiy LG, Maslova MV, Bunik VI. Pentylenetetrazole-Induced Seizures Are Increased after Kindling, Exhibiting Vitamin-Responsive Correlations to the Post-Seizures Behavior, Amino Acids Metabolism and Key Metabolic Regulators in the Rat Brain. Int J Mol Sci 2023; 24:12405. [PMID: 37569781 PMCID: PMC10418815 DOI: 10.3390/ijms241512405] [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: 07/20/2023] [Revised: 07/30/2023] [Accepted: 08/02/2023] [Indexed: 08/13/2023] Open
Abstract
Epilepsy is characterized by recurrent seizures due to a perturbed balance between glutamate and GABA neurotransmission. Our goal is to reveal the molecular mechanisms of the changes upon repeated challenges of this balance, suggesting knowledge-based neuroprotection. To address this goal, a set of metabolic indicators in the post-seizure rat brain cortex is compared before and after pharmacological kindling with pentylenetetrazole (PTZ). Vitamins B1 and B6 supporting energy and neurotransmitter metabolism are studied as neuroprotectors. PTZ kindling increases the seizure severity (1.3 fold, p < 0.01), elevating post-seizure rearings (1.5 fold, p = 0.03) and steps out of the walls (2 fold, p = 0.01). In the kindled vs. non-kindled rats, the post-seizure p53 level is increased 1.3 fold (p = 0.03), reciprocating a 1.4-fold (p = 0.02) decrease in the activity of 2-oxoglutarate dehydrogenase complex (OGDHC) controlling the glutamate degradation. Further, decreased expression of deacylases SIRT3 (1.4 fold, p = 0.01) and SIRT5 (1.5 fold, p = 0.01) reciprocates increased acetylation of 15 kDa proteins 1.5 fold (p < 0.01). Finally, the kindling abrogates the stress response to multiple saline injections in the control animals, manifested in the increased activities of the pyruvate dehydrogenase complex, malic enzyme, glutamine synthetase and decreased malate dehydrogenase activity. Post-seizure animals demonstrate correlations of p53 expression to the levels of glutamate (r = 0.79, p = 0.05). The correlations of the seizure severity and duration to the levels of GABA (r = 0.59, p = 0.05) and glutamate dehydrogenase activity (r = 0.58, p = 0.02), respectively, are substituted by the correlation of the seizure latency with the OGDHC activity (r = 0.69, p < 0.01) after the vitamins administration, testifying to the vitamins-dependent impact of the kindling on glutamate/GABA metabolism. The vitamins also abrogate the correlations of behavioral parameters with seizure duration (r 0.53-0.59, p < 0.03). Thus, increased seizures and modified post-seizure behavior in rats after PTZ kindling are associated with multiple changes in the vitamin-dependent brain metabolism of amino acids, linked to key metabolic regulators: p53, OGDHC, SIRT3 and SIRT5.
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Affiliation(s)
- Vasily A. Aleshin
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (V.A.A.)
- Department of Biochemistry, Sechenov University, Trubetskaya, 8, Bld. 2, 119991 Moscow, Russia
| | - Anastasia V. Graf
- Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Faculty of Nano-, Bio-, Informational, Cognitive and Socio-Humanistic Sciences and Technologies at Moscow Institute of Physics and Technology, Maximova Street 4, 123098 Moscow, Russia
| | - Artem V. Artiukhov
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (V.A.A.)
- Department of Biochemistry, Sechenov University, Trubetskaya, 8, Bld. 2, 119991 Moscow, Russia
| | - Alexander L. Ksenofontov
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (V.A.A.)
| | - Lev G. Zavileyskiy
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Maria V. Maslova
- Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Victoria I. Bunik
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (V.A.A.)
- Department of Biochemistry, Sechenov University, Trubetskaya, 8, Bld. 2, 119991 Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia
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4
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Elucidating the Interaction between Pyridoxine 5'-Phosphate Oxidase and Dopa Decarboxylase: Activation of B6-Dependent Enzyme. Int J Mol Sci 2022; 24:ijms24010642. [PMID: 36614085 PMCID: PMC9820991 DOI: 10.3390/ijms24010642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/22/2022] [Accepted: 12/26/2022] [Indexed: 12/31/2022] Open
Abstract
Pyridoxal 5'-phosphate (PLP), the active form of vitamin B6, serves as a cofactor for scores of B6-dependent (PLP-dependent) enzymes involved in many cellular processes. One such B6 enzyme is dopa decarboxylase (DDC), which is required for the biosynthesis of key neurotransmitters, e.g., dopamine and serotonin. PLP-dependent enzymes are biosynthesized as apo-B6 enzymes and then converted to the catalytically active holo-B6 enzymes by Schiff base formation between the aldehyde of PLP and an active site lysine of the protein. In eukaryotes, PLP is made available to the B6 enzymes through the activity of the B6-salvage enzymes, pyridoxine 5'-phosphate oxidase (PNPO) and pyridoxal kinase (PLK). To minimize toxicity, the cell keeps the content of free PLP (unbound) very low through dephosphorylation and PLP feedback inhibition of PNPO and PLK. This has led to a proposed mechanism of complex formation between the B6-salvage enzymes and apo-B6 enzymes prior to the transfer of PLP, although such complexes are yet to be characterized at the atomic level, presumably due to their transient nature. A computational study, for the first time, was used to predict a likely PNPO and DDC complex, which suggested contact between the allosteric PLP tight-binding site on PNPO and the active site of DDC. Using isothermal calorimetry and/or surface plasmon resonance, we also show that PNPO binds both apoDDC and holoDDC with dissociation constants of 0.93 ± 0.07 μM and 2.59 ± 0.11 μM, respectively. Finally, in the presence of apoDDC, the tightly bound PLP on PNPO is transferred to apoDDC, resulting in the formation of about 35% holoDDC.
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5
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Bunik V, Aleshin V, Nogues I, Kähne T, Parroni A, Contestabile R, Salvo ML, Graf A, Tramonti A. Thiamine‐dependent regulation of mammalian brain pyridoxal kinase
in vitro
and
in vivo. J Neurochem 2022; 161:20-39. [DOI: 10.1111/jnc.15576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 01/04/2022] [Accepted: 01/10/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Victoria Bunik
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University 19991 Moscow Russia
- Faculty of Bioengineering and Bioinformatics Lomonosov Moscow State University Moscow 119991 Russia
- Sechenov University 119048 Moscow Russia
| | - Vasily Aleshin
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University 19991 Moscow Russia
- Sechenov University 119048 Moscow Russia
| | - Isabel Nogues
- Research Institute of Terrestrial Ecosystems Italian National Research Council Via Salaria Km. 29 300–00015 Monterotondo Scalo
| | - Thilo Kähne
- Institute of Exptl. Internal Medicine Otto‐von‐Guericke‐Universität Magdeburg 39120 Magdeburg Germany
| | - Alessia Parroni
- Istituto Pasteur Italia‐ Fondazione Cenci Bolognetti Department of Biochemical Sciences “A. Rossi Fanelli” Sapienza University of Rome P.le A. Moro 5 ‐ 00185 Rome Italy
| | - Roberto Contestabile
- Istituto Pasteur Italia‐ Fondazione Cenci Bolognetti Department of Biochemical Sciences “A. Rossi Fanelli” Sapienza University of Rome P.le A. Moro 5 ‐ 00185 Rome Italy
| | - Martino Luigi Salvo
- Istituto Pasteur Italia‐ Fondazione Cenci Bolognetti Department of Biochemical Sciences “A. Rossi Fanelli” Sapienza University of Rome P.le A. Moro 5 ‐ 00185 Rome Italy
| | - Anastasia Graf
- Moscow Institute of Physics and Technology 123098 Moscow Russia
- Faculty of Biology Lomonosov Moscow State University 19991 Moscow Russia
| | - Angela Tramonti
- Istituto Pasteur Italia‐ Fondazione Cenci Bolognetti Department of Biochemical Sciences “A. Rossi Fanelli” Sapienza University of Rome P.le A. Moro 5 ‐ 00185 Rome Italy
- Istitute of Molecular Biology and Pathology Italian National Research Council P.le A. Moro 5 ‐ 00185 Rome Italy
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6
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Characterization of Novel Pathogenic Variants Causing Pyridox(am)ine 5'-Phosphate Oxidase-Dependent Epilepsy. Int J Mol Sci 2021; 22:ijms222112013. [PMID: 34769443 PMCID: PMC8584306 DOI: 10.3390/ijms222112013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 11/17/2022] Open
Abstract
Several variants of the enzyme pyridox(am)ine 5′-phosphate oxidase (PNPO), responsible for a rare form of vitamin B6-dependent neonatal epileptic encephalopathy known as PNPO deficiency (PNPOD), have been reported. However, only a few of them have been characterised with respect to their structural and functional properties, despite the fact that the knowledge of how variants affect the enzyme may clarify the disease mechanism and improve treatment. Here, we report the characterisation of the catalytic, allosteric and structural properties of recombinantly expressed D33V, R161C, P213S, and E50K variants, among which D33V (present in approximately 10% of affected patients) is one of the more common variants responsible for PNPOD. The D33V and E50K variants have only mildly altered catalytic properties. In particular, the E50K variant, given that it has been found on the same chromosome with other known pathogenic variants, may be considered non-pathogenic. The P213S variant has lower thermal stability and reduced capability to bind the FMN cofactor. The variant involving Arg161 (R161C) largely decreases the affinity for the pyridoxine 5′-phosphate substrate and completely abolishes the allosteric feedback inhibition exerted by the pyridoxal 5′-phosphate product.
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7
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Aleshin VA, Graf AV, Artiukhov AV, Boyko AI, Ksenofontov AL, Maslova MV, Nogués I, di Salvo ML, Bunik VI. Physiological and Biochemical Markers of the Sex-Specific Sensitivity to Epileptogenic Factors, Delayed Consequences of Seizures and Their Response to Vitamins B1 and B6 in a Rat Model. Pharmaceuticals (Basel) 2021; 14:ph14080737. [PMID: 34451834 PMCID: PMC8400147 DOI: 10.3390/ph14080737] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 01/28/2023] Open
Abstract
The disturbed metabolism of vitamins B1 or B6, which are essential for neurotransmitters homeostasis, may cause seizures. Our study aims at revealing therapeutic potential of vitamins B1 and B6 by estimating the short- and long-term effects of their combined administration with the seizure inductor pentylenetetrazole (PTZ). The PTZ dose dependence of a seizure and its parameters according to modified Racine’s scale, along with delayed physiological and biochemical consequences the next day after the seizure are assessed regarding sexual dimorphism in epilepsy. PTZ sensitivity is stronger in the female than the male rats. The next day after a seizure, sex differences in behavior and brain biochemistry arise. The induced sex differences in anxiety and locomotor activity correspond to the disappearance of sex differences in the brain aspartate and alanine, with appearance of those in glutamate and glutamine. PTZ decreases the brain malate dehydrogenase activity and urea in the males and the phenylalanine in the females. The administration of vitamins B1 and B6 24 h before PTZ delays a seizure in female rats only. This desensitization is not observed at short intervals (0.5–2 h) between the administration of the vitamins and PTZ. With the increasing interval, the pyridoxal kinase (PLK) activity in the female brain decreases, suggesting that the PLK downregulation by vitamins contributes to the desensitization. The delayed effects of vitamins and/or PTZ are mostly sex-specific and interacting. Our findings on the sex differences in sensitivity to epileptogenic factors, action of vitamins B1/B6 and associated biochemical events have medical implications.
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Affiliation(s)
- Vasily A. Aleshin
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia; (V.A.A.); (A.V.A.); (A.I.B.)
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (A.V.G.); (A.L.K.)
| | - Anastasia V. Graf
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (A.V.G.); (A.L.K.)
- Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia;
- Faculty of Nano-, Bio-, Informational, Cognitive and Socio-Humanistic Sciences and Technologies at Moscow Institute of Physics and Technology, 123098 Moscow, Russia
| | - Artem V. Artiukhov
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia; (V.A.A.); (A.V.A.); (A.I.B.)
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (A.V.G.); (A.L.K.)
| | - Alexandra I. Boyko
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia; (V.A.A.); (A.V.A.); (A.I.B.)
| | - Alexander L. Ksenofontov
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (A.V.G.); (A.L.K.)
| | - Maria V. Maslova
- Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia;
| | - Isabel Nogués
- Research Institute of Terrestrial Ecosystems, National Research Council, Via Salaria km 29.300, Monterotondo, 00015 Rome, Italy;
| | - Martino L. di Salvo
- Department of Biological Sciences A. Rossi Fanelli, Sapienza University, 00185 Rome, Italy;
| | - Victoria I. Bunik
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia; (V.A.A.); (A.V.A.); (A.I.B.)
- A.N. Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (A.V.G.); (A.L.K.)
- Department of Biochemistry, Sechenov University, Trubetskaya, 8, bld. 2, 119991 Moscow, Russia
- Correspondence:
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8
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Barile A, Battista T, Fiorillo A, di Salvo ML, Malatesta F, Tramonti A, Ilari A, Contestabile R. Identification and characterization of the pyridoxal 5'-phosphate allosteric site in Escherichia coli pyridoxine 5'-phosphate oxidase. J Biol Chem 2021; 296:100795. [PMID: 34019876 PMCID: PMC8215295 DOI: 10.1016/j.jbc.2021.100795] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/10/2021] [Accepted: 05/14/2021] [Indexed: 11/16/2022] Open
Abstract
Pyridoxal 5’-phosphate (PLP), the catalytically active form of vitamin B6, plays a pivotal role in metabolism as an enzyme cofactor. PLP is a very reactive molecule and can be very toxic unless its intracellular concentration is finely regulated. In Escherichia coli, PLP formation is catalyzed by pyridoxine 5’-phosphate oxidase (PNPO), a homodimeric FMN-dependent enzyme that is responsible for the last step of PLP biosynthesis and is also involved in the PLP salvage pathway. We have recently observed that E. coli PNPO undergoes an allosteric feedback inhibition by PLP, caused by a strong allosteric coupling between PLP binding at the allosteric site and substrate binding at the active site. Here we report the crystallographic identification of the PLP allosteric site, located at the interface between the enzyme subunits and mainly circumscribed by three arginine residues (Arg23, Arg24, and Arg215) that form an “arginine cage” and efficiently trap PLP. The crystal structure of the PNPO–PLP complex, characterized by a marked structural asymmetry, presents only one PLP molecule bound at the allosteric site of one monomer and sheds light on the allosteric inhibition mechanism that makes the enzyme-substrate–PLP ternary complex catalytically incompetent. Site-directed mutagenesis studies focused on the arginine cage validate the identity of the allosteric site and provide an effective means to modulate the allosteric properties of the enzyme, from the loosening of the allosteric coupling (in the R23L/R24L and R23L/R215L variants) to the complete loss of allosteric properties (in the R23L/R24L/R21L variant).
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Affiliation(s)
- Anna Barile
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Roma, Italy; Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Sapienza Università di Roma, Roma, Italy
| | - Theo Battista
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Roma, Italy; Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Sapienza Università di Roma, Roma, Italy
| | - Annarita Fiorillo
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Roma, Italy; Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Sapienza Università di Roma, Roma, Italy
| | - Martino Luigi di Salvo
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Sapienza Università di Roma, Roma, Italy
| | - Francesco Malatesta
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Sapienza Università di Roma, Roma, Italy
| | - Angela Tramonti
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Roma, Italy; Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Sapienza Università di Roma, Roma, Italy
| | - Andrea Ilari
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Roma, Italy
| | - Roberto Contestabile
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Sapienza Università di Roma, Roma, Italy.
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9
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Abstract
Vitamin B6 is an ensemble of six interconvertible vitamers: pyridoxine (PN), pyridoxamine (PM), pyridoxal (PL), and their 5'-phosphate derivatives, PNP, PMP, and PLP. Pyridoxal 5'-phosphate is a coenzyme in a variety of enzyme reactions concerning transformations of amino and amino acid compounds. This review summarizes all known and putative PLP-binding proteins found in the Escherichia coli MG1655 proteome. PLP can have toxic effects since it contains a very reactive aldehyde group at its 4' position that easily forms aldimines with primary and secondary amines and reacts with thiols. Most PLP is bound either to the enzymes that use it as a cofactor or to PLP carrier proteins, protected from the cellular environment but at the same time readily transferable to PLP-dependent apoenzymes. E. coli and its relatives synthesize PLP through the seven-step deoxyxylulose-5-phosphate (DXP)-dependent pathway. Other bacteria synthesize PLP in a single step, through a so-called DXP-independent pathway. Although the DXP-dependent pathway was the first to be revealed, the discovery of the widespread DXP-independent pathway determined a decline of interest in E. coli vitamin B6 metabolism. In E. coli, as in most organisms, PLP can also be obtained from PL, PN, and PM, imported from the environment or recycled from protein turnover, via a salvage pathway. Our review deals with all aspects of vitamin B6 metabolism in E. coli, from transcriptional to posttranslational regulation. A critical interpretation of results is presented, in particular, concerning the most obscure aspects of PLP homeostasis and delivery to PLP-dependent enzymes.
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Ghatge MS, Al Mughram M, Omar AM, Safo MK. Inborn errors in the vitamin B6 salvage enzymes associated with neonatal epileptic encephalopathy and other pathologies. Biochimie 2021; 183:18-29. [PMID: 33421502 PMCID: PMC11273822 DOI: 10.1016/j.biochi.2020.12.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 12/28/2022]
Abstract
Pyridoxal 5'-phosphate (PLP), the active cofactor form of vitamin B6 is required by over 160 PLP-dependent (vitamin B6) enzymes serving diverse biological roles, such as carbohydrates, amino acids, hemes, and neurotransmitters metabolism. Three key enzymes, pyridoxal kinase (PL kinase), pyridoxine 5'-phosphate oxidase (PNPO), and phosphatases metabolize and supply PLP to PLP-dependent enzymes through the salvage pathway. In born errors in the salvage enzymes are known to cause inadequate levels of PLP in the cell, particularly in neuronal cells. The resulting PLP deficiency is known to cause or implicated in several pathologies, most notably seizures. One such disorder, PNPO-dependent neonatal epileptic encephalopathy (NEE) results from natural mutations in PNPO and leads to null or reduced enzymatic activity. NEE does not respond to conventional antiepileptic drugs but may respond to treatment with the B6 vitamers PLP and/or pyridoxine (PN). In born errors that lead to PLP deficiency in cells have also been reported in PL kinase, however, to date none has been associated with epilepsy or seizure. One such pathology is polyneuropathy that responds to PLP therapy. Phosphatase deficiency or hypophosphatasia disorder due to pathogenic mutations in alkaline phosphatase is known to cause seizures that respond to PN therapy. In this article, we review the biochemical features of in born errors pertaining to the salvage enzyme's deficiency that leads to NEE and other pathologies. We also present perspective on vitamin B6 treatment for these disorders, along with attempts to develop zebrafish model to study the NEE syndrome in vivo.
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Affiliation(s)
- Mohini S Ghatge
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Mohammed Al Mughram
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Abdelsattar M Omar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Alsulaymanyah, Jeddah, 21589, Saudi Arabia; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University, Cairo, 11884, Egypt
| | - Martin K Safo
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, 23298, USA.
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Barile A, Nogués I, di Salvo ML, Bunik V, Contestabile R, Tramonti A. Molecular characterization of pyridoxine 5'-phosphate oxidase and its pathogenic forms associated with neonatal epileptic encephalopathy. Sci Rep 2020; 10:13621. [PMID: 32788630 PMCID: PMC7424515 DOI: 10.1038/s41598-020-70598-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/31/2020] [Indexed: 01/18/2023] Open
Abstract
Defects of vitamin B6 metabolism are responsible for severe neurological disorders, such as pyridoxamine 5'-phosphate oxidase deficiency (PNPOD; OMIM: 610090), an autosomal recessive inborn error of metabolism that usually manifests with neonatal-onset severe seizures and subsequent encephalopathy. At present, 27 pathogenic mutations of the gene encoding human PNPO are known, 13 of which are homozygous missense mutations; however, only 3 of them have been characterised with respect to the molecular and functional properties of the variant enzyme forms. Moreover, studies on wild type and variant human PNPOs have so far largely ignored the regulation properties of this enzyme. Here, we present a detailed characterisation of the inhibition mechanism of PNPO by pyridoxal 5'-phosphate (PLP), the reaction product of the enzyme. Our study reveals that human PNPO has an allosteric PLP binding site that plays a crucial role in the enzyme regulation and therefore in the regulation of vitamin B6 metabolism in humans. Furthermore, we have produced, recombinantly expressed and characterised several PNPO pathogenic variants responsible for PNPOD (G118R, R141C, R225H, R116Q/R225H, and X262Q). Such replacements mainly affect the catalytic activity of PNPO and binding of the enzyme substrate and FMN cofactor, leaving the allosteric properties unaltered.
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Affiliation(s)
- Anna Barile
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Rome, Italy.,Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Sapienza Università di Roma, Rome, Italy
| | - Isabel Nogués
- Istituto di Ricerca sugli Ecosistemi Terrestri, Consiglio Nazionale delle Ricerche, 00015, Monterotondo, Rome, Italy
| | - Martino L di Salvo
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Sapienza Università di Roma, Rome, Italy
| | - Victoria Bunik
- Belozersky Institute of Physico-Chemical Biology, Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia.,Department of Biochemistry, Sechenov University, Trubetskaya, 8/2, Moscow, 119991, Russia
| | - Roberto Contestabile
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Sapienza Università di Roma, Rome, Italy.
| | - Angela Tramonti
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Rome, Italy. .,Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Sapienza Università di Roma, Rome, Italy.
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