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Sun L, Sun B, Zhang Y, Chen K. Kinetic properties of glucose 6-phosphate dehydrogenase and inhibition effects of several metal ions on enzymatic activity in vitro and cells. Sci Rep 2024; 14:5806. [PMID: 38461203 PMCID: PMC10924972 DOI: 10.1038/s41598-024-56503-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 03/07/2024] [Indexed: 03/11/2024] Open
Abstract
Due to the non-degradable and persistent nature of metal ions in the environment, they are released into water bodies, where they accumulate in fish. In order to assess pollution in fish, the enzyme, glucose 6-phosphate dehydrogenase (G6PD), has been employed as a biomarker due to sensitivity to various ions. This study investigates the kinetic properties of the G6PD enzyme in yellow catfish (Pelteobagrus fulvidraco), and analyzes the effects of these metal ions on the G6PD enzyme activity in the ovarian cell line (CCO) of channel catfish (Ictalurus punctatus). IC50 values and inhibition types of G6PD were determined in the metal ions Cu2+, Al3+, Zn2+, and Cd2+. While, the inhibition types of Cu2+ and Al3+ were the competitive inhibition, Zn2+ and Cd2+ were the linear mixed noncompetitive and linear mixed competitive, respectively. In vitro experiments revealed an inverse correlation between G6PD activity and metal ion concentration, mRNA levels and enzyme activity of G6PD increased at the lower metal ion concentration and decreased at the higher concentration. Our findings suggest that metal ions pose a significant threat to G6PD activity even at low concentrations, potentially playing a crucial role in the toxicity mechanism of metal ion pollution. This information contributes to the development of a biomonitoring tool for assessing metal ion contamination in aquatic species.
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Affiliation(s)
- Lindan Sun
- School of Life Sciences, Jiangsu University, Zhenjiang, 212000, Jiangsu, China
| | - Binbin Sun
- School of Life Sciences, Jiangsu University, Zhenjiang, 212000, Jiangsu, China
| | - Yulei Zhang
- Guangdong South China Sea Key Laboratory of Aquaculture for Aquatic Economic Animals, Guangdong Ocean University, Zhanjiang, China
| | - Keping Chen
- School of Life Sciences, Jiangsu University, Zhenjiang, 212000, Jiangsu, China.
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2
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Ortiz-Ramírez P, Hernández-Ochoa B, Ortega-Cuellar D, González-Valdez A, Martínez-Rosas V, Morales-Luna L, Arreguin-Espinosa R, Castillo-Rodríguez RA, Canseco-Ávila LM, Cárdenas-Rodríguez N, Pérez de la Cruz V, Montiel-González AM, Gómez-Chávez F, Gómez-Manzo S. Biochemical and Kinetic Characterization of the Glucose-6-Phosphate Dehydrogenase from Helicobacter pylori Strain 29CaP. Microorganisms 2022; 10:microorganisms10071359. [PMID: 35889079 PMCID: PMC9323780 DOI: 10.3390/microorganisms10071359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/02/2022] [Accepted: 07/04/2022] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) has been proposed as the foremost risk factor for the development of gastric cancer. We found that H. pylori express the enzyme glucose-6-phosphate dehydrogenase (HpG6PD), which participates in glucose metabolism via the pentose phosphate pathway. Thus, we hypothesized that if the biochemical and physicochemical characteristics of HpG6PD contrast with the host G6PD (human G6PD, HsG6PD), HpG6PD becomes a potential target for novel drugs against H. pylori. In this work, we characterized the biochemical properties of the HpG6PD from the H.pylori strain 29CaP and expressed the active recombinant protein, to analyze its steady-state kinetics, thermostability, and biophysical aspects. In addition, we analyzed the HpG6PD in silico structural properties to compare them with those of the HsG6PD. The optimal pH for enzyme activity was 7.5, with a T1/2 of 46.6 °C, at an optimum stability temperature of 37 °C. The apparent Km values calculated for G6P and NADP+ were 75.0 and 12.8 µM, respectively. G6P does not protect HpG6PD from trypsin digestion, but NADP+ does protect the enzyme from trypsin and guanidine hydrochloride (Gdn-HCl). The biochemical characterization of HpG6PD contributes to knowledge regarding H. pylori metabolism and opens up the possibility of using this enzyme as a potential target for specific and efficient treatment against this pathogen; structural alignment indicates that the three-dimensional (3D) homodimer model of the G6PD protein from H. pylori is different from the 3D G6PD of Homo sapiens.
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Affiliation(s)
- Paulina Ortiz-Ramírez
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (P.O.-R.); (V.M.-R.); (L.M.-L.)
| | - Beatriz Hernández-Ochoa
- Laboratorio de Inmunoquímica, Hospital Infantil de México Federico Gómez, Secretaría de Salud, Mexico City 06720, Mexico;
- Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Daniel Ortega-Cuellar
- Laboratorio de Nutrición Experimental, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico;
| | - Abigail González-Valdez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico;
| | - Víctor Martínez-Rosas
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (P.O.-R.); (V.M.-R.); (L.M.-L.)
- Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Laura Morales-Luna
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (P.O.-R.); (V.M.-R.); (L.M.-L.)
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Roberto Arreguin-Espinosa
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico;
| | - Rosa Angélica Castillo-Rodríguez
- Programa Investigadoras e Investigadores por México, CONACYT-Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico;
| | - Luis Miguel Canseco-Ávila
- Facultad de Ciencias Químicas, Campus IV, Universidad Autónoma de Chiapas, Tapachula City 30580, Mexico;
| | - Noemi Cárdenas-Rodríguez
- Laboratorio de Neurociencias, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico;
| | - Verónica Pérez de la Cruz
- Neurobiochemistry and Behavior Laboratory, National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez”, Mexico City 14269, Mexico;
| | - Alba Mónica Montiel-González
- Centro de Investigación en Genética y Ambiente, Universidad Autónoma de Tlaxcala, Aut. San Martín Texmelucan-Tlaxcala Km 10.5, San Felipe Ixtacuixtla, Tlaxcala 90120, Mexico;
| | - Fernando Gómez-Chávez
- Laboratorio de Enfermedades Osteoarticulares e Inmunológicas, Sección de Estudios de Posgrado e Investigación, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City 07320, Mexico;
| | - Saúl Gómez-Manzo
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (P.O.-R.); (V.M.-R.); (L.M.-L.)
- Correspondence: ; Tel.: +52-55-1084-0900 (ext. 1442)
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3
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Morales-Luna L, Hernández-Ochoa B, Ramírez-Nava EJ, Martínez-Rosas V, Ortiz-Ramírez P, Fernández-Rosario F, González-Valdez A, Cárdenas-Rodríguez N, Serrano-Posada H, Centeno-Leija S, Arreguin-Espinosa R, Cuevas-Cruz M, Ortega-Cuellar D, Pérez de la Cruz V, Rocha-Ramírez LM, Sierra-Palacios E, Castillo-Rodríguez RA, Vega-García V, Rufino-González Y, Marcial-Quino J, Gómez-Manzo S. Characterizing the Fused TvG6PD::6PGL Protein from the Protozoan Trichomonas vaginalis, and Effects of the NADP + Molecule on Enzyme Stability. Int J Mol Sci 2020; 21:E4831. [PMID: 32650494 PMCID: PMC7402283 DOI: 10.3390/ijms21144831] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/03/2020] [Accepted: 07/04/2020] [Indexed: 12/30/2022] Open
Abstract
This report describes a functional and structural analysis of fused glucose-6-phosphate dehydrogenase dehydrogenase-phosphogluconolactonase protein from the protozoan Trichomonas vaginalis (T. vaginalis). The glucose-6-phosphate dehydrogenase (g6pd) gene from T. vaginalis was isolated by PCR and the sequence of the product showed that is fused with 6pgl gene. The fused Tvg6pd::6pgl gene was cloned and overexpressed in a heterologous system. The recombinant protein was purified by affinity chromatography, and the oligomeric state of the TvG6PD::6PGL protein was found as tetramer, with an optimal pH of 8.0. The kinetic parameters for the G6PD domain were determined using glucose-6-phosphate (G6P) and nicotinamide adenine dinucleotide phosphate (NADP+) as substrates. Biochemical assays as the effects of temperature, susceptibility to trypsin digestion, and analysis of hydrochloride of guanidine on protein stability in the presence or absence of NADP+ were performed. These results revealed that the protein becomes more stable in the presence of the NADP+. In addition, we determined the dissociation constant for the binding (Kd) of NADP+ in the protein and suggests the possible structural site in the fused TvG6PD::6PGL protein. Finally, computational modeling studies were performed to obtain an approximation of the structure of TvG6PD::6PGL. The generated model showed differences with the GlG6PD::6PGL protein (even more so with human G6PD) despite both being fused.
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Affiliation(s)
- Laura Morales-Luna
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico; (L.M.-L.); (E.J.R.-N.); (V.M.-R.); (P.O.-R.); (F.F.-R.)
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico
| | - Beatriz Hernández-Ochoa
- Laboratorio de Inmunoquímica, Hospital Infantil de México Federico Gómez, Secretaría de Salud, 06720 Ciudad de México, Mexico;
- Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340 Ciudad de México, Mexico
| | - Edson Jiovany Ramírez-Nava
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico; (L.M.-L.); (E.J.R.-N.); (V.M.-R.); (P.O.-R.); (F.F.-R.)
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico
| | - Víctor Martínez-Rosas
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico; (L.M.-L.); (E.J.R.-N.); (V.M.-R.); (P.O.-R.); (F.F.-R.)
- Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340 Ciudad de México, Mexico
| | - Paulina Ortiz-Ramírez
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico; (L.M.-L.); (E.J.R.-N.); (V.M.-R.); (P.O.-R.); (F.F.-R.)
| | - Fabiola Fernández-Rosario
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico; (L.M.-L.); (E.J.R.-N.); (V.M.-R.); (P.O.-R.); (F.F.-R.)
| | - Abigail González-Valdez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico;
| | - Noemí Cárdenas-Rodríguez
- Laboratorio de Neurociencias, Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico;
| | - Hugo Serrano-Posada
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Laboratorio de Agrobiotecnología, Tecnoparque CLQ, Universidad de Colima, Carretera los Limones-Loma de Juárez, 28629 Colima, Mexico; (H.S.-P.); (S.C.-L.)
| | - Sara Centeno-Leija
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Laboratorio de Agrobiotecnología, Tecnoparque CLQ, Universidad de Colima, Carretera los Limones-Loma de Juárez, 28629 Colima, Mexico; (H.S.-P.); (S.C.-L.)
| | - Roberto Arreguin-Espinosa
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico; (R.A.-E.); (M.C.-C.)
| | - Miguel Cuevas-Cruz
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico; (R.A.-E.); (M.C.-C.)
| | - Daniel Ortega-Cuellar
- Laboratorio de Nutrición Experimental, Instituto Nacional de Pediatría, 04530 Secretaría de Salud, Mexico;
| | - Verónica Pérez de la Cruz
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Secretaria de Salud, 14269 Ciudad de México, Mexico;
| | - Luz María Rocha-Ramírez
- Unidad de Investigación en Enfermedades Infecciosas, Hospital Infantil de México Federico Gómez, Dr. Márquez No. 162, Col Doctores, 06720 Delegación Cuauhtémoc, Mexico;
| | - Edgar Sierra-Palacios
- Colegio de Ciencias y Humanidades, Plantel Casa Libertad, Universidad Autónoma de la Ciudad de México, 09620 Ciudad de México, Mexico;
| | - Rosa Angélica Castillo-Rodríguez
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico;
| | - Vanesa Vega-García
- Facultad de Ciencias, Universidad Nacional Autónoma de México, 04510 Ciudad de México, Mexico;
| | - Yadira Rufino-González
- Laboratorio de Parasitología Experimental, Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico;
| | - Jaime Marcial-Quino
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico;
| | - Saúl Gómez-Manzo
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, 04530 Ciudad de México, Mexico; (L.M.-L.); (E.J.R.-N.); (V.M.-R.); (P.O.-R.); (F.F.-R.)
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4
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Ramírez-Nava EJ, Ortega-Cuellar D, González-Valdez A, Castillo-Rodríguez RA, Ponce-Soto GY, Hernández-Ochoa B, Cárdenas-Rodríguez N, Martínez-Rosas V, Morales-Luna L, Serrano-Posada H, Sierra-Palacios E, Arreguin-Espinosa R, Cuevas-Cruz M, Rocha-Ramírez LM, Pérez de la Cruz V, Marcial-Quino J, Gómez-Manzo S. Molecular Cloning and Exploration of the Biochemical and Functional Analysis of Recombinant Glucose-6-Phosphate Dehydrogenase from Gluconoacetobacter diazotrophicus PAL5. Int J Mol Sci 2019; 20:ijms20215279. [PMID: 31652968 PMCID: PMC6862599 DOI: 10.3390/ijms20215279] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 11/17/2022] Open
Abstract
Gluconacetobacter diazotrophicus PAL5 (GDI) is an endophytic bacterium with potential biotechnological applications in industry and agronomy. The recent description of its complete genome and its principal metabolic enzymes suggests that glucose metabolism is accomplished through the pentose phosphate pathway (PPP); however, the enzymes participating in this pathway have not yet been characterized in detail. The objective of the present work was to clone, purify, and biochemically and physicochemically characterize glucose-6-phosphate dehydrogenase (G6PD) from GDI. The gene was cloned and expressed as a tagged protein in E. coli to be purified by affinity chromatography. The native state of the G6PD protein in the solution was found to be a tetramer with optimal activity at pH 8.8 and a temperature between 37 and 50 °C. The apparent Km values for G6P and nicotinamide adenine dinucleotide phosphate (NADP+) were 63 and 7.2 μM, respectively. Finally, from the amino acid sequence a three-dimensional (3D) model was obtained, which allowed the arrangement of the amino acids involved in the catalytic activity, which are conserved (RIDHYLGKE, GxGGDLT, and EKPxG) with those of other species, to be identified. This characterization of the enzyme could help to identify new environmental conditions for the knowledge of the plant–microorganism interactions and a better use of GDI in new technological applications.
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Affiliation(s)
- Edson Jiovany Ramírez-Nava
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México 04530, Mexico.
| | - Daniel Ortega-Cuellar
- Laboratorio de Nutrición Experimental, Instituto Nacional de Pediatría, Secretaría de Salud 04530, Mexico.
| | - Abigail González-Valdez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de Mexico 04510, Mexico.
| | - Rosa Angélica Castillo-Rodríguez
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de Mexico 04530, Mexico.
| | - Gabriel Yaxal Ponce-Soto
- Institute for Bio- and Geosciences (IBG-2: Plant Sciences), Forschungszentrum Jülich, Wilhelm Johnen Straße, 52428 Jülich, Germany.
| | - Beatriz Hernández-Ochoa
- Laboratorio de Inmunoquímica, Hospital Infantil de México Federico Gómez, Secretaría de Salud, Ciudad de Mexico 06720, Mexico.
| | - Noemí Cárdenas-Rodríguez
- Laboratorio de Neurociencias, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México 04530, Mexico.
| | - Víctor Martínez-Rosas
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México 04530, Mexico.
| | - Laura Morales-Luna
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México 04530, Mexico.
| | - Hugo Serrano-Posada
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Laboratorio de Agrobiotecnología, Tecnoparque CLQ, Universidad de Colima, Carretera los Limones-Loma de Juárez, Colima 28629, Mexico.
| | - Edgar Sierra-Palacios
- Colegio de Ciencias y Humanidades, Plantel Casa Libertad, Universidad Autónoma de la Ciudad de México, Ciudad de Mexico 09620, Mexico.
| | - Roberto Arreguin-Espinosa
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de Mexico, Ciudad de Mexico 04510, Mexico.
| | - Miguel Cuevas-Cruz
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de Mexico, Ciudad de Mexico 04510, Mexico.
| | - Luz María Rocha-Ramírez
- Departamento de Infectología, Hospital Infantil de México Federico Gómez, Dr. Márquez No. 162, Col Doctores, Delegación Cuauhtémoc 06720, Mexico.
| | - Verónica Pérez de la Cruz
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, S.S.A., Ciudad de Mexico 14269, Mexico.
| | - Jaime Marcial-Quino
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de Mexico 04530, Mexico.
| | - Saúl Gómez-Manzo
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México 04530, Mexico.
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De Lillo A, Cardi M, Landi S, Esposito S. Mechanism(s) of action of heavy metals to investigate the regulation of plastidic glucose-6-phosphate dehydrogenase. Sci Rep 2018; 8:13481. [PMID: 30194387 PMCID: PMC6128849 DOI: 10.1038/s41598-018-31348-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 08/07/2018] [Indexed: 12/26/2022] Open
Abstract
The regulation of recombinant plastidic glucose-6P dehydrogenase from Populus trichocarpa (PtP2-G6PDH - EC 1.1.1.49) was investigated by exposing wild type and mutagenized isoforms to heavy metals. Nickel and Cadmium caused a marked decrease in PtP2-G6PDH WT activity, suggesting their poisoning effect on plant enzymes; Lead (Pb++) was substantially ineffective. Copper (Cu++) and Zinc (Zn++) exposition resulted in strongest decrease in enzyme activity, thus suggesting a physiological competition with Magnesium, a well-known activator of G6PDH activity. Kinetic analyses confirmed a competitive inhibition by Copper, and a mixed inhibition by (Cd++). Mutagenized enzymes were differently affected by HMs: the reduction of disulfide (C175–C183) exposed the NADP+ binding sites to metals; C145 participates to NADP+ cofactor binding; C194 and C242 are proposed to play a role in the regulation of NADP+/NADPH binding. Copper (and possibly Zinc) is able to occupy competitively Magnesium (Mg++) sites and/or bind to NADP+, resulting in a reduced access of NADP+ sites on the enzyme. Hence, heavy metals could be used to describe specific roles of cysteine residues present in the primary protein sequence; these results are discussed to define the biochemical mechanism(s) of inhibition of plant plastidic G6PDH.
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Affiliation(s)
- Alessia De Lillo
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Manuela Cardi
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Simone Landi
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy
| | - Sergio Esposito
- Dipartimento di Biologia, Università di Napoli Federico II, Naples, Italy.
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6
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Biochemical Characterization and Structural Modeling of Fused Glucose-6-Phosphate Dehydrogenase-Phosphogluconolactonase from Giardia lamblia. Int J Mol Sci 2018; 19:ijms19092518. [PMID: 30149622 PMCID: PMC6165198 DOI: 10.3390/ijms19092518] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 08/18/2018] [Accepted: 08/22/2018] [Indexed: 11/17/2022] Open
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) is the first enzyme in the pentose phosphate pathway and is highly relevant in the metabolism of Giardialamblia. Previous reports suggested that the G6PD gene is fused with the 6-phosphogluconolactonase (6PGL) gene (6pgl). Therefore, in this work, we decided to characterize the fused G6PD-6PGL protein in Giardialamblia. First, the gene of g6pd fused with the 6pgl gene (6gpd::6pgl) was isolated from trophozoites of Giardialamblia and the corresponding G6PD::6PGL protein was overexpressed and purified in Escherichia coli. Then, we characterized the native oligomeric state of the G6PD::6PGL protein in solution and we found a catalytic dimer with an optimum pH of 8.75. Furthermore, we determined the steady-state kinetic parameters for the G6PD domain and measured the thermal stability of the protein in both the presence and absence of guanidine hydrochloride (Gdn-HCl) and observed that the G6PD::6PGL protein showed alterations in the stability, secondary structure, and tertiary structure in the presence of Gdn-HCl. Finally, computer modeling studies revealed unique structural and functional features, which clearly established the differences between G6PD::6PGL protein from G. lamblia and the human G6PD enzyme, proving that the model can be used for the design of new drugs with antigiardiasic activity. These results broaden the perspective for future studies of the function of the protein and its effect on the metabolism of this parasite as a potential pharmacological target.
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Alvarez GM, Casiró S, Gutnisky C, Dalvit GC, Sutton-McDowall ML, Thompson JG, Cetica PD. Implications of glycolytic and pentose phosphate pathways on the oxidative status and active mitochondria of the porcine oocyte during IVM. Theriogenology 2016; 86:2096-2106. [DOI: 10.1016/j.theriogenology.2015.11.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 11/24/2022]
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Ibrahim MA, Ghazy AHM, Salem AMH, Ghazy MA, Abdel-Monsef MM. Biochemical characterization of buffalo liver glucose-6-phosphate dehydrogenase isoforms. Protein J 2016; 34:193-204. [PMID: 25980795 DOI: 10.1007/s10930-015-9615-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) is a key regulatory enzyme involved in the pentose phosphate pathway. This works represents purification of two buffalo liver glucose-6-phosphate dehydrogenases (BLG6PD1 and BLG6PD2) using combination of ammonium sulfate precipitation and several chromatographic columns. Both enzymes (BLG6PD1 and BLG6PD2) were homogenous on both native PAGE as well as 12% SDS PAGE with molecular weights of 28 and 66 kDa. The molecular weight of BLG6PD1 and BLG6PD2 native forms were determined to be 28 and 66 kDa by gel filtration; indicating monomeric proteins. The K(m) values for BLG6PD1 and BLG6PD2 estimated to be 0.059 and 0.06 mM of β-nicotinamide adenine dinucleotide phosphate. The optimum activity of BLG6PD1 and BLG6PD2 were displayed at pH 8.0 and 8.2 with an isoelectric point (pI) of pH 7.7-7.9 and 5.7-5.9. The divalent cations MgCl2, and CoCl2 act as activators, on the other hand, FeCl2, CuCl2 and ZnCl2 are potent inhibitors of BLG6PD1 and BLG6PD2 activity. NADPH inhibited both isoenzymes competitively with Ki values of 0.012 and 0.030 mM. This study describes a reproducible purification scheme of G6PD from the liver of buffalo as a rich source.
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Affiliation(s)
- Mahmoud A Ibrahim
- Molecular Biology Department, National Research Centre, El-Tahrir St., Dokki, Cairo, 12311, Egypt,
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9
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Saeed H, Ismaeil M, Embaby A, Ataya F, Malik A, Shalaby M, El-Banna S, Ali AAM, Bassiouny K. Overexpression, purification and enzymatic characterization of a recombinant Arabian camel Camelus dromedarius glucose-6-phosphate dehydrogenase. Protein Expr Purif 2015; 142:88-94. [PMID: 26363117 DOI: 10.1016/j.pep.2015.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Revised: 08/27/2015] [Accepted: 09/03/2015] [Indexed: 11/29/2022]
Abstract
In a previous study the full-length open reading frame of the Arabian camel, Camelus dromedarius liver cytosolic glucose-6-phosphate dehydrogenase (G6PD) cDNA was determined using reverse transcription polymerase chain reaction. The C. dromedarius cDNA was found to be 1545 nucleotides (accession number JN098421) that encodes a protein of 515 amino acids residues. In the present study, C. dromedarius recombinant G6PD was heterologously overexpressed in Escherichia coli BL21 (DE3) pLysS and purified by immobilized metal affinity fast protein liquid chromatography (FPLC) in a single step. The purity and molecular weight of the enzyme were analyzed on SDS-PAGE and the purified enzyme showed a single band on the gel with a molecular weight of 63.0 KDa. The specific activity was determined to be 2000 EU/mg protein. The optimum temperature and pH were found to be 60 °C and 7.4, respectively. The isoelectric point (pI) for the purified G6PD was determined to be 6.4. The apparent Km values for the two substrates NADP+ and G6P were found to be 23.2 μM and 66.7 μM, respectively. The far-UV circular dichroism (CD) spectra of G6PD showed that it has two minima at 208 and 222 nm as well as maxima at 193 nm which is characteristic of high content of α-helix. Moreover, the far-UV CD spectra of the G6PD in the presence or absence of NADP+ were nearly identical.
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Affiliation(s)
- Hesham Saeed
- Department of Biotechnology, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt.
| | - Mohammad Ismaeil
- Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Protein Research Chair, Biochemistry Department, College of Science King Saud University, Bld. 5, P.O. Box 2454, Riyadh, Saudi Arabia
| | - Amira Embaby
- Department of Biotechnology, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt
| | - Farid Ataya
- Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Molecular Biology Department, Genetic Engineering Division, National Research Centre, 33 El-Bohouth St. (former El-Tahrir St.), P.O. 12622, Dokki, Giza, Egypt
| | - Ajamaluddin Malik
- Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Protein Research Chair, Biochemistry Department, College of Science King Saud University, Bld. 5, P.O. Box 2454, Riyadh, Saudi Arabia
| | - Manal Shalaby
- Genetic Engineering and Biotechnology Research Institute (GEBRI), City for Scientific Research and Technology Applications, New Borg Alarab City, Alexandria, Egypt
| | - Sabah El-Banna
- Department of Environmental Studies, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt
| | - Ahmed Abdelrahim Mohamed Ali
- Food and Agricultural Science, Plant Production Department, Biotechnology Laboratory, King Saud University, P.O. Box 2454, Riyadh, Saudi Arabia
| | - Khalid Bassiouny
- Molecular Biology Department, Genetic Engineering and Biotechnology Institute, University of Sadat City, Egypt
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10
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Gutnisky C, Dalvit GC, Thompson JG, Cetica PD. Pentose phosphate pathway activity: effect on in vitro maturation and oxidative status of bovine oocytes. Reprod Fertil Dev 2015; 26:931-42. [PMID: 23859479 DOI: 10.1071/rd12397] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 06/11/2013] [Indexed: 11/23/2022] Open
Abstract
The relationship between pentose phosphate pathway (PPP) activity in cumulus-oocyte complexes (COCs) and oxidative and mitochondrial activity in bovine oocytes was evaluated with the aim of analysing the impact of two inhibitors (NADPH and 6-aminonicotinamide (6-AN)) and a stimulator (NADP) of the key enzymes of the PPP on the maturation rate, oxidative and mitochondrial activity and the mitochondrial distribution in oocytes. The proportion of COCs with measurable PPP activity (assessed using brilliant cresyl blue staining), glucose uptake, lactate production and meiotic maturation rate diminished when 6-AN (0.1, 1, 5 and 10mM for 22h) was added to the maturation medium (P<0.05). The addition of NADPH did not modify glucose uptake or lactate production, but reduced PPP activity in COCs and meiotic maturation rates (P<0.05). The presence of NADP (0.0125, 0.125, 1.25 and 12.5mM for 22h of culture) in the maturation medium had no effect on PPP activity in COCs, glucose uptake, lactate production and meiotic maturation rate. However, in the absence of gonadotropin supplementation, NADP stimulated both glucose uptake and lactate production at 12.5mM (the highest concentration tested; P<0.05). NADP did not modify cleavage rate, but decreased blastocyst production (P<0.05). During IVM, oocyte oxidative and mitochondrial activity was observed to increase at 15 and 22h maturation, which was also related to progressive mitochondrial migration. Inhibiting the PPP with 6-AN or NADPH led to reduced oxidative and mitochondrial activity compared with the respective control groups and inhibition of mitochondrial migration (P<0.05). Stimulation of the PPP with NADP increased oxidative and mitochondrial activity at 9h maturation (P<0.05) and delayed mitochondrial migration. The present study shows the significance of altering PPP activity during bovine oocyte IVM, revealing that there is a link between the activity of the PPP and the oxidative status of the oocyte.
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Affiliation(s)
- Cynthia Gutnisky
- Area of Biochemistry, Institute of Research and Technology on Animal Reproduction, School of Veterinary Sciences, University of Buenos Aires, Chorroarín 280, Buenos Aires C1427CWO, Argentina
| | - Gabriel C Dalvit
- Area of Biochemistry, Institute of Research and Technology on Animal Reproduction, School of Veterinary Sciences, University of Buenos Aires, Chorroarín 280, Buenos Aires C1427CWO, Argentina
| | - Jeremy G Thompson
- Research Centre for Reproductive Health, The Robinson Institute, School of Paediatrics and Reproductive Health, The University of Adelaide, 2nd Floor, Medical School South, Adelaide, SA 5005, Australia
| | - Pablo D Cetica
- Area of Biochemistry, Institute of Research and Technology on Animal Reproduction, School of Veterinary Sciences, University of Buenos Aires, Chorroarín 280, Buenos Aires C1427CWO, Argentina
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Ibrahim MA, Ghazy AHM, Salem AMH, Ghazy MA, Abdel-Monsef MM. Purification and characterization of glucose-6-phosphate dehydrogenase from camel liver. Enzyme Res 2014; 2014:714054. [PMID: 25610637 PMCID: PMC4290037 DOI: 10.1155/2014/714054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/23/2014] [Indexed: 12/02/2022] Open
Abstract
Glucose-6-phosphate dehydrogenase from camel liver was purified to homogeneity by ammonium sulfate precipitation and a combination of DEAE-cellulose, Sephacryl S-300 gel filtration, and 2', 5' ADP Sepharose 4B affinity chromatography columns. The specific activity of camel liver G6PD is increased to 1.80438 units/mg proteins with 63-fold purification. It turned out to be homogenous on both native PAGE and 12% SDS PAGE, with a molecular weight of 64 kDa. The molecular weight of the native form of camel liver G6PD was determined to be 194 kDa by gel filtration indicating a trimeric protein. The K m value was found to be 0.081 mM of NADP(+). Camel liver G6PD displayed its optimum activity at pH 7.8 with an isoelectric point (pI) of pH 6.6-6.8. The divalent cations MgCl2, MnCl2, and CoCl2 act as activators; on the other hand, CaCl2 and NiCl2 act as moderate inhibitors, while FeCl2, CuCl2, and ZnCl2 are potent inhibitors of camel liver G6PD activity. NADPH inhibited camel liver G6PD competitively with K i value of 0.035 mM. One binding site was deduced for NADPH on the enzyme molecule. This study presents a simple and reproducible purification procedure of G6PD from the camel liver.
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Affiliation(s)
- Mahmoud A. Ibrahim
- Molecular Biology Department, National Research Center, Dokki, Cairo 12311, Egypt
| | - Abdel-Hady M. Ghazy
- Molecular Biology Department, National Research Center, Dokki, Cairo 12311, Egypt
| | - Ahmed M. H. Salem
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo 11566, Egypt
| | - Mohamed A. Ghazy
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo 11566, Egypt
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12
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Hu W, Zhi L, Zhuo MQ, Zhu QL, Zheng JL, Chen QL, Gong Y, Liu CX. Purification and characterization of glucose 6-phosphate dehydrogenase (G6PD) from grass carp (Ctenopharyngodon idella) and inhibition effects of several metal ions on G6PD activity in vitro. FISH PHYSIOLOGY AND BIOCHEMISTRY 2013; 39:637-647. [PMID: 23053609 DOI: 10.1007/s10695-012-9726-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 09/24/2012] [Indexed: 06/01/2023]
Abstract
Glucose 6-phosphate dehydrogenase (G6PD) is a key enzyme catalyzing the first step of the pentose phosphate pathway which generates NADPH for anabolic pathways and protection systems in various organisms, including fish. In the present study, G6PD was purified from grass carp (Ctenopharyngodon idella) hepatopancreas using the methods of 2',5'-ADP-Sepharose 4B affinity chromatography followed by DEAE Sepharose Fast Flow ion exchange chromatography. The characterization of G6PD and inhibition effects of several metal ions on G6PD activity in vitro were also determined. Grass carp hepatopancreas G6PD, with a specific activity of 18 U/mg protein, was purified 1,066-fold with a yield of 19.5 % and Mr of 71.85 kDa. The enzyme had a temperature optimum of 42 °C, pH optimum of 7.5 and 9.0. The K(m) values for G6-P and NADP(+) were determined to be 0.026, 0.0068 mM, respectively. The V(max) values for G6-P and NADP(+) were 2.20 and 2.27 μM min(-1) mg protein(-1), respectively. The catalytic efficiency for G6-P and NADP as the substrates was 0.085 and 0.334 × 10(-6) min(-1) mg protein(-1), respectively. Inhibition effects of metal ions on the purified G6PD activity indicated that IC50 values of Zn(+2), Mn(+2), Al(+3), Cu(+2), and Cd(+2) were 0.42, 0.54, 0.94, 1.20, and 4.17 mM, respectively. The Ki constants of Zn(+2), Al(+3), Cu(+2), and Cd(+2) were 0.52, 1.12, 0.26, and 4.8 mM, respectively. Zn(+2), Al(+3), and Cd(+2) showed competitive inhibition, while Cu(+2) inhibited the G6PD in a noncompetitive inhibition manner. Our study provided important information about the control of the grass carp liver PPP, the biosynthesis of several important related biomolecules, and the status of detoxification systems in grass carp liver in relation to metabolism.
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Affiliation(s)
- Wei Hu
- Fishery College, Huazhong Agricultural University, Wuhan 430070, China
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13
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Comakli V, Akkemik E, Ciftci M, Kufrevioglu OI. Purification and characterization of glucose 6-phosphate dehydrogenase enzyme from rainbow trout (Oncorhynchus mykiss) liver and investigation of the effects of some metal ions on enzyme activity. Toxicol Ind Health 2013; 31:403-11. [DOI: 10.1177/0748233713475514] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glucose 6-phosphate dehydrogenase (d-glucose 6-phosphate: NADP+ oxidoreductase, EC 1.1.1.49; G6PD) is a key enzyme that is localized in all mammal tissues, especially in cytoplasmic sections and that catalyzes the first step of pentose phosphate metabolic pathway. In this study, G6PD enzyme was purified 1444-fold with a yield of 77% from rainbow trout liver using 2′,5′-ADP-sepharose-4B affinity chromatography. Moreover, a purity check of the enzyme was performed with sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Some characteristic features like optimal pH, stable pH, optimal temperature and optimal ionic strength were determined for the purified enzyme. In addition to this, in vitro effects of ions like silver nitrate (Ag+), thallium sulphate (TI+), cobalt (II) nitrate (Co2+) and arsenic (V) oxide (As5+) on enzyme activity were researched. Half-maximal inhibitory concentration (IC50) values of Ag+, Co2+ and As5+ metal ions, which showed an inhibitory effect, were found to be 0.0044, 0.084 and 4.058 mM, respectively; and their inhibition constants ( Ki) were found to be 0.0052 ± 0.00042, 0.087 ± 0.015700 and 4.833 ± 1.753207 mM, respectively. Tl+ not exhibited inhibitory effect on the enzyme activity.
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Affiliation(s)
- Veysel Comakli
- Agri Ibrahim Cecen University, Health Services Vocational School, Agri, Turkey
| | - Ebru Akkemik
- Department of Chemistry, Faculty of Science, Ataturk University, Erzurum, Turkey
| | - Mehmet Ciftci
- Department of Chemistry, Faculty of Science, Ataturk University, Erzurum, Turkey
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Bongard RD, Lindemer BJ, Krenz GS, Merker MP. Preferential utilization of NADPH as the endogenous electron donor for NAD(P)H:quinone oxidoreductase 1 (NQO1) in intact pulmonary arterial endothelial cells. Free Radic Biol Med 2009; 46:25-32. [PMID: 18848878 PMCID: PMC2638208 DOI: 10.1016/j.freeradbiomed.2008.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 09/05/2008] [Accepted: 09/10/2008] [Indexed: 11/23/2022]
Abstract
The goal was to determine whether endogenous cytosolic NAD(P)H:quinone oxidoreductase 1 (NQO1) preferentially uses NADPH or NADH in intact pulmonary arterial endothelial cells in culture. The approach was to manipulate the redox status of the NADH/NAD(+) and NADPH/NADP(+) redox pairs in the cytosolic compartment using treatment conditions targeting glycolysis and the pentose phosphate pathway alone or with lactate, and to evaluate the impact on the intact cell NQO1 activity. Cells were treated with 2-deoxyglucose, iodoacetate, or epiandrosterone in the absence or presence of lactate, NQO1 activity was measured in intact cells using duroquinone as the electron acceptor, and pyridine nucleotide redox status was measured in total cell KOH extracts by high-performance liquid chromatography. 2-Deoxyglucose decreased NADH/NAD(+) and NADPH/NADP(+) ratios by 59 and 50%, respectively, and intact cell NQO1 activity by 74%; lactate restored NADH/NAD(+), but not NADPH/NADP(+) or NQO1 activity. Iodoacetate decreased NADH/NAD(+) but had no detectable effect on NADPH/NADP(+) or NQO1 activity. Epiandrosterone decreased NQO1 activity by 67%, and although epiandrosterone alone did not alter the NADPH/NADP(+) or NADH/NAD(+) ratio, when the NQO1 electron acceptor duroquinone was also present, NADPH/NADP(+) decreased by 84% with no impact on NADH/NAD(+). Duroquinone alone also decreased NADPH/NADP(+) but not NADH/NAD(+). The results suggest that NQO1 activity is more tightly coupled to the redox status of the NADPH/NADP(+) than NADH/NAD(+) redox pair, and that NADPH is the endogenous NQO1 electron donor. Parallel studies of pulmonary endothelial transplasma membrane electron transport (TPMET), another redox process that draws reducing equivalents from the cytosol, confirmed previous observations of a correlation with the NADH/NAD(+) ratio.
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Affiliation(s)
- Robert D Bongard
- Department of Pulmonary Medicine, Medical College of Wisconsin, Milwaukee, USA
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15
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Sakiroğlu H, Oztürk AE, Pepe AE, Erat M. Some kinetic properties of polyphenol oxidase obtained from dill (Anethum graveolens). J Enzyme Inhib Med Chem 2008; 23:380-5. [PMID: 18569343 DOI: 10.1080/14756360701587201] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Polyphenol oxidase (PPO) was partially purified from dill by (NH4)(2)SO4 precipitation followed by dialysis and gel filtration chromatography. Polyphenol oxidase activity was measured spectrophotometrically at 420 nm using catechol, dopamine and chlorogenic acid as substrates. Optimum pH, temperature, and ionic strength were determined with three substrates. The best substrate of dill PPO was found to be chlorogenic acid. Some kinetic properties of the enzyme such as V(max,) K(M) and V(max)/K(M) were determined for all three substrates. The effects of various inhibitors on the reaction catalysed by the enzyme were tested and I(50) values calculated. The most effective inhibitor was L-cysteine. Activation energies, E(a), were determined from the Arrhenius equation. In addition, activation enthalpy, DeltaH(a), and Q(10) values of the enzyme were also calculated.
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Affiliation(s)
- Halis Sakiroğlu
- Department of Chemistry, Faculty of Arts and Sciences, Ataturk University, Erzurum, Turkey.
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16
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Rendón JL, Del Arenal IP, Guevara-Flores A, Mendoza-Hernández G, Pardo JP. Glucose 6-phosphate dehydrogenase from larval Taenia crassiceps (cysticerci): purification and properties. Parasitol Res 2008; 102:1351-7. [PMID: 18297308 DOI: 10.1007/s00436-008-0917-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Accepted: 01/29/2008] [Indexed: 11/26/2022]
Abstract
Glucose 6-phosphate dehydrogenase (EC 1.1.1.49) was purified to homogeneity from the soluble fraction of larval Taenia crassiceps (Eucestoda: Cyclophyllidea) by a three-step protocol. Specific activity of the pure enzyme was 33.8 +/- 2.1 U mg(-1) at 25 degrees C and pH 7.8 with D: -glucose 6-phosphate and NADP+ as substrates. The activity increases to 67.6 +/- 3.9 U mg(-1) at 39 degrees C, a more physiological temperature in the intermediary host. Enzyme activity was maximal between pH 6.7 and 7.8. Km values were 14 +/- 1.7 microM and 1.3 +/- 0.4 microM for glucose 6-phosphate and NADP+, respectively. The enzyme showed absolute specificity for its sugar substrate. NAD+ was also a substrate but with a low catalytic efficiency (207 M(-1) s(-1)). No essential requirement for Mg++ or Ca++ was observed. Relative molecular mass of the native enzyme was 134,000 +/- 17,200, while a value of 61,000 +/- 1,700 was obtained for the enzyme subunit. Thus, glucose 6-phosphate dehydrogenase from T. crassiceps exists as a dimeric protein. The enzyme's isoelectric point was 4.5. The enzyme's activity dependence on temperature was complex, resulting in a biphasic Arrhenius plot. Activation energies of 9.91 +/- 0.51 and 7.94 +/- 0.45 kcal mol(-1) were obtained. Initial velocity patterns complemented with inhibition studies by product and substrate's analogues support a random bi bi sequential mechanism in rapid equilibrium. The low Ki value of 1.95 microM found for NADPH suggests a potential regulatory role for this nucleotide.
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Affiliation(s)
- Juan L Rendón
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Apartado Postal No. 70-159, 04510 Mexico City, Mexico.
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17
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Continuous counter-current purification of glucose-6-phosphate dehydrogenase using liquid–liquid extraction by reverse micelles. Biochem Eng J 2007. [DOI: 10.1016/j.bej.2006.12.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Hasmann FA, Gurpilhares DB, Roberto IC, Converti A, Pessoa A. New combined kinetic and thermodynamic approach to model glucose-6-phosphate dehydrogenase activity and stability. Enzyme Microb Technol 2007. [DOI: 10.1016/j.enzmictec.2006.06.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Hasmann FA, de Borba Gurpilhares D, Roberto IC, Pessoa A. Response surface methodology for the evaluation of glucose-6-phosphate dehydrogenase enrichment process by soybean lecithin reversed micelles. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 847:262-6. [PMID: 17085082 DOI: 10.1016/j.jchromb.2006.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 08/18/2006] [Accepted: 10/11/2006] [Indexed: 12/01/2022]
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) present in Saccahromyces cerevisiae is an enzyme of the pentose pathway. An effective enrichment of this intracellular enzyme can be achieved with the reversed micellar methodology. In this work, this methodology was employed with soybean lecithin, a biocompatible surfactant. A factorial design was used to evaluate the influence of pH (A) and extraction runs (B) on the G6PD purification factor. After statistical analysis and process optimization, a mathematical model representing G6PD enrichment was obtained: Y=4.89-0.83A+0.092B+0.27AB-1.37B2 with an enzyme purification factor of about 5.2.
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Affiliation(s)
- Francislene Andréia Hasmann
- Department of Biotechnology/Engineering School of Lorena/University of São Paulo, Rod. Itajubá-Lorena, Km 74.5, 12.600 - 000, P.O. Box 116, Lorena/SP, Brazil.
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20
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Ramnanan CJ, Storey KB. Glucose-6-phosphate dehydrogenase regulation during hypometabolism. Biochem Biophys Res Commun 2005; 339:7-16. [PMID: 16256936 DOI: 10.1016/j.bbrc.2005.10.036] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 10/08/2005] [Indexed: 11/27/2022]
Abstract
Glucose-6-phosphate dehydrogenase (G6PDH) from hepatopancreas of the land snail, Otala lactea, shows distinct changes in properties between active and estivating (dormant) states, providing the first evidence of pentose phosphate cycle regulation during hypometabolism. Compared with active snails, G6PDH Vmax increased by 50%, Km for glucose-6-phosphate decreased by 50%, Ka Mg x citrate decreased by 35%, and activation energy (from Arrhenius plots) decreased by 35% during estivation. DEAE-Sephadex chromatography separated two peaks of activity and in vitro incubations stimulating protein kinases or phosphatases showed that peak I (low phosphate) G6PDH was higher in active snails (57% of activity) whereas peak II (high phosphate) G6PDH dominated during estivation (71% of total). Kinetic properties of peaks I and II forms mirrored the enzyme from active and estivated states, respectively. Peak II G6PDH also showed reduced sensitivity to urea inhibition of activity and greater stability to thermolysin protease treatment. The interconversion of G6PDH between active and estivating forms was linked to protein kinase G and protein phosphatase 1. Estivation-induced phosphorylation of G6PDH may enhance relative carbon flow through the pentose phosphate cycle, compared with glycolysis, to help maintain NADPH production for use in antioxidant defense.
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Affiliation(s)
- Christopher J Ramnanan
- Institute of Biochemistry and Department of Biology, College of Natural Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, Ont., Canada K1S 5B6
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21
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Ceyhan D, Danişan A, Oğüş IH, Ozer N. Purification and Kinetic Properties of 6-Phosphogluconate Dehydrogenase from Rat Small Intestine. Protein J 2005; 24:293-301. [PMID: 16284727 DOI: 10.1007/s10930-005-6750-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
6-Phosphogluconate dehydrogenase (6PG) was purified from rat small intestine with 36% yield and a specific activity of 15 U/mg. On SDS/PAGE, one band with a mass of 52 kDa was found. On native PAGE three protein and two activity bands were observed. The pH optimum was 7.35. Using Arrhenius plots, Ea, DeltaH, Q10 and Tm for 6PGD were found to be 7.52 kcal/mol, 6.90 kcal/mol, 1.49 and 49.4 degrees C, respectively. The enzyme obeyed "Rapid Equilibrium Random Bi Bi" kinetic model with Km values of 595 +/- 213 microM for 6PG and 53.03+/-1.99 microM for NADP. 1/Vm versus 1/6PG and 1/NADP plots gave a Vm value of 8.91+/-1.92 U/mg protein. NADPH is the competitive inhibitor with a Ki of 31.91+/-1.31 microM. The relatively small Ki for the 6PGD:NADPH complex indicates the importance of NADPH in the regulation of the pentose phosphate pathway through G6PD and 6PGD.
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Affiliation(s)
- Deniz Ceyhan
- Department of Biochemistrry, Faculty of Medicine, Hacettepe University, 06100, Ankara, Turkey
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22
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Danişan A, Ceyhan D, Oğüş IH, Ozer N. Purification and characterization of glucose-6-phosphate dehydrogenase from rat small intestine. Protein J 2005; 23:317-24. [PMID: 15328887 DOI: 10.1023/b:jopc.0000032651.99875.8c] [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] [Indexed: 11/12/2022]
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) was purified from rat small intestine with 19.2% yield and had a specific activity of 53.8 units per miligram protein. The pH optimum was determined to be 8.1. The purified rat small intestinal G6PD gave one activity, one protein band on native PAGE. The observation of one band on SDS/PAGE with an Mr of 48 kDa and a specific activity lower than expected may suggest the proteolytically affected enzyme or different form of G6PD in the rat small intestine. The activation energy, activation enthalpy, Q10, and optimum temperature from Arrhenius plot for the rat small intestinal G6PD were found to be 8.52 kcal/mol, 7.90 kcal/mol, 1.59, and 38 degrees C, respectively. The Km values for G6P and NADP+ were 70.1 +/- 20.8 and 23.2 +/- 7.6 microM, respectively. Double-reciprocal plots of 1/Vm versus 1/G6P (at constant [NADP+]) and of 1/Vm versus 1/NADP+ at constant [G6P]) intersected at the same point on the 1/Vm axis to give Vm = 53.8 U/mg protein.
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Affiliation(s)
- Ali Danişan
- Department of Biochemistry, Faculty of Medicine, Hacettepe University, 06100 Ankara, Turkey
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