1
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Khamrui S, Dodatko T, Wu R, Leandro J, Sabovic A, Violante S, Cross JR, Marsan E, Kumar K, DeVita RJ, Lazarus MB, Houten SM. Characterization, structure and inhibition of the human succinyl-CoA:glutarate-CoA transferase, a genetic modifier of glutaric aciduria type 1. bioRxiv 2024:2024.02.07.578422. [PMID: 38370847 PMCID: PMC10871334 DOI: 10.1101/2024.02.07.578422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Glutaric Aciduria Type 1 (GA1) is a serious inborn error of metabolism with no pharmacological treatments. A novel strategy to treat this disease is to divert the toxic biochemical intermediates to less toxic or non-toxic metabolites. Here, we report a novel target, SUGCT, which we hypothesize suppresses the GA1 metabolic phenotype through decreasing glutaryl-CoA. We report the structure of SUGCT, the first eukaryotic structure of a type III CoA transferase, develop a high-throughput enzyme assay and a cell-based assay, and identify valsartan and losartan carboxylic acid as inhibitors of the enzyme validating the screening approach. These results may form the basis for future development of new pharmacological intervention to treat GA1.
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Affiliation(s)
- Susmita Khamrui
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ruoxi Wu
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Amanda Sabovic
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sara Violante
- The Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Justin R Cross
- The Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Eric Marsan
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kunal Kumar
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Robert J DeVita
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael B Lazarus
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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2
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Houten SM, Dodatko T, Dwyer W, Violante S, Chen H, Stauffer B, DeVita RJ, Vaz FM, Cross JR, Yu C, Leandro J. Acyl-CoA dehydrogenase substrate promiscuity: Challenges and opportunities for development of substrate reduction therapy in disorders of valine and isoleucine metabolism. J Inherit Metab Dis 2023; 46:931-942. [PMID: 37309295 PMCID: PMC10526699 DOI: 10.1002/jimd.12642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/04/2023] [Accepted: 06/07/2023] [Indexed: 06/14/2023]
Abstract
Toxicity of accumulating substrates is a significant problem in several disorders of valine and isoleucine degradation notably short-chain enoyl-CoA hydratase (ECHS1 or crotonase) deficiency, 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) deficiency, propionic acidemia (PA), and methylmalonic aciduria (MMA). Isobutyryl-CoA dehydrogenase (ACAD8) and short/branched-chain acyl-CoA dehydrogenase (SBCAD, ACADSB) function in the valine and isoleucine degradation pathways, respectively. Deficiencies of these acyl-CoA dehydrogenase (ACAD) enzymes are considered biochemical abnormalities with limited or no clinical consequences. We investigated whether substrate reduction therapy through inhibition of ACAD8 and SBCAD can limit the accumulation of toxic metabolic intermediates in disorders of valine and isoleucine metabolism. Using analysis of acylcarnitine isomers, we show that 2-methylenecyclopropaneacetic acid (MCPA) inhibited SBCAD, isovaleryl-CoA dehydrogenase, short-chain acyl-CoA dehydrogenase and medium-chain acyl-CoA dehydrogenase, but not ACAD8. MCPA treatment of wild-type and PA HEK-293 cells caused a pronounced decrease in C3-carnitine. Furthermore, deletion of ACADSB in HEK-293 cells led to an equally strong decrease in C3-carnitine when compared to wild-type cells. Deletion of ECHS1 in HEK-293 cells caused a defect in lipoylation of the E2 component of the pyruvate dehydrogenase complex, which was not rescued by ACAD8 deletion. MCPA was able to rescue lipoylation in ECHS1 KO cells, but only in cells with prior ACAD8 deletion. SBCAD was not the sole ACAD responsible for this compensation, which indicates substantial promiscuity of ACADs in HEK-293 cells for the isobutyryl-CoA substrate. Substrate promiscuity appeared less prominent for 2-methylbutyryl-CoA at least in HEK-293 cells. We suggest that pharmacological inhibition of SBCAD to treat PA should be investigated further.
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Affiliation(s)
- Sander M. Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - William Dwyer
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sara Violante
- The Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Hongjie Chen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Brandon Stauffer
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Pathology, Molecular and Cell Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Robert J. DeVita
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Frédéric M. Vaz
- Amsterdam UMC location University of Amsterdam, Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children’s Hospital, Meibergdreef 9, Amsterdam, The Netherlands
- Amsterdam Gastroenterology Endocrinology Metabolism, Inborn errors of metabolism, Amsterdam, The Netherlands
- Core Facility Metabolomics, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
| | - Justin R. Cross
- The Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Pathology, Molecular and Cell Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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3
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Leandro P, Lino PR, Lopes R, Leandro J, Amaro MP, Sousa P, Vicente JB, Almeida AJ. Isothermal denaturation fluorimetry vs Differential scanning fluorimetry as tools for screening of stabilizers for protein freeze-drying: human phenylalanine hydroxylase as the case study. Eur J Pharm Biopharm 2023; 187:1-11. [PMID: 37011788 DOI: 10.1016/j.ejpb.2023.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/24/2023] [Accepted: 03/25/2023] [Indexed: 04/03/2023]
Abstract
The structural maintenance of therapeutic proteins during formulation and/or storage is a critical aspect, particularly for multi-domain and/or multimeric proteins which usually exhibit intrinsic structural dynamics leading to aggregation with concomitant loss-of-function. Protein freeze-drying is a widely used technique to preserve protein structure and function during storage. To minimize chemical/physical stresses occurring during this process, protein stabilizers are usually included, their effect being strongly dependent on the target protein. Therefore, they should be screened for on a time-consuming case-by-case basis. Herein, differential scanning fluorimetry (DSF) and isothermal denaturation fluorimetry (ITDF) were employed to screen, among different classes of freeze-drying additives, for the most effective stabilizer of the model protein human phenylalanine hydroxylase (hPAH). Correlation studies among retrieved DSF and ITDF parameters with recovered enzyme amount and activity indicated ITDF as the most appropriate screening method. Biochemical and biophysical characterization of hPAH freeze-dried with ITDF-selected stabilizers and a long-term storage study (12 months, 5 ± 3 °C) showed that the selected compounds prevented protein aggregation and preserved hPAH structural and functional properties throughout time storage. Our results provide a solid basis towards the choice of ITDF as a high-throughput screening step for the identification of protein freeze-drying protectors.
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Affiliation(s)
- Paula Leandro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.
| | - Paulo R Lino
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Raquel Lopes
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - João Leandro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Mariana P Amaro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Paulo Sousa
- Sofarimex, Indústria Química e Farmacêutica SA, Av. das Indústrias, Alto de Colaride, 2735-521 Agualva, Portugal
| | - João B Vicente
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República 2780-157 Oeiras, Portugal
| | - António J Almeida
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.
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4
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Leandro J, Khamrui S, Suebsuwong C, Chen PJ, Secor C, Dodatko T, Yu C, Sanchez R, DeVita RJ, Houten SM, Lazarus MB. Characterization and structure of the human lysine-2-oxoglutarate reductase domain, a novel therapeutic target for treatment of glutaric aciduria type 1. Open Biol 2022; 12:220179. [PMID: 36128717 PMCID: PMC9490328 DOI: 10.1098/rsob.220179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/30/2022] [Indexed: 12/26/2022] Open
Abstract
In humans, a single enzyme 2-aminoadipic semialdehyde synthase (AASS) catalyses the initial two critical reactions in the lysine degradation pathway. This enzyme evolved to be a bifunctional enzyme with both lysine-2-oxoglutarate reductase (LOR) and saccharopine dehydrogenase domains (SDH). Moreover, AASS is a unique drug target for inborn errors of metabolism such as glutaric aciduria type 1 that arise from deficiencies downstream in the lysine degradation pathway. While work has been done to elucidate the SDH domain structurally and to develop inhibitors, neither has been done for the LOR domain. Here, we purify and characterize LOR and show that it is activated by alkylation of cysteine 414 by N-ethylmaleimide. We also provide evidence that AASS is rate-limiting upon high lysine exposure of mice. Finally, we present the crystal structure of the human LOR domain. Our combined work should enable future efforts to identify inhibitors of this novel drug target.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Susmita Khamrui
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chalada Suebsuwong
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Peng-Jen Chen
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Cody Secor
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Mount Sinai Genomics, Inc, Stamford, CT 06902, USA
| | - Roberto Sanchez
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Robert J. DeVita
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sander M. Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael B. Lazarus
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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5
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Leandro J, Dodatko T, Aten J, Nemeria NS, Zhang X, Jordan F, Hendrickson RC, Sanchez R, Yu C, DeVita RJ, Houten SM. DHTKD1 and OGDH display substrate overlap in cultured cells and form a hybrid 2-oxo acid dehydrogenase complex in vivo. Hum Mol Genet 2021; 29:1168-1179. [PMID: 32160276 DOI: 10.1093/hmg/ddaa037] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/27/2020] [Accepted: 03/04/2020] [Indexed: 11/14/2022] Open
Abstract
Glutaric aciduria type 1 (GA1) is an inborn error of lysine degradation characterized by a specific encephalopathy that is caused by toxic accumulation of lysine degradation intermediates. Substrate reduction through inhibition of DHTKD1, an enzyme upstream of the defective glutaryl-CoA dehydrogenase, has been investigated as a potential therapy, but revealed the existence of an alternative enzymatic source of glutaryl-CoA. Here, we show that loss of DHTKD1 in glutaryl-CoA dehydrogenase-deficient HEK-293 cells leads to a 2-fold decrease in the established GA1 clinical biomarker glutarylcarnitine and demonstrate that oxoglutarate dehydrogenase (OGDH) is responsible for this remaining glutarylcarnitine production. We furthermore show that DHTKD1 interacts with OGDH, dihydrolipoyl succinyltransferase and dihydrolipoamide dehydrogenase to form a hybrid 2-oxoglutaric and 2-oxoadipic acid dehydrogenase complex. In summary, 2-oxoadipic acid is a substrate for DHTKD1, but also for OGDH in a cell model system. The classical 2-oxoglutaric dehydrogenase complex can exist as a previously undiscovered hybrid containing DHTKD1 displaying improved kinetics towards 2-oxoadipic acid.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jan Aten
- Department of Pathology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, 1105 AZ The Netherlands
| | - Natalia S Nemeria
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA
| | - Xu Zhang
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA
| | - Frank Jordan
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, NJ 07102, USA
| | - Ronald C Hendrickson
- Microchemistry and Proteomics Core, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Roberto Sanchez
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Mount Sinai Genomics, Inc., Stamford, CT 06902, USA
| | - Robert J DeVita
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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6
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Lino PR, Leandro J, Figueiredo L, Amaro MP, Gonçalves LMD, Leandro P, Almeida AJ. Systematic Modification and Evaluation of Enzyme-Loaded Chitosan Nanoparticles. Int J Mol Sci 2021; 22:ijms22157987. [PMID: 34360752 PMCID: PMC8348744 DOI: 10.3390/ijms22157987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 11/29/2022] Open
Abstract
Polymeric-based nano drug delivery systems have been widely exploited to overcome protein instability during formulation. Presently, a diverse range of polymeric agents can be used, among which polysaccharides, such as chitosan (CS), hyaluronic acid (HA) and cyclodextrins (CDs), are included. Due to its unique biological and physicochemical properties, CS is one of the most used polysaccharides for development of protein delivery systems. However, CS has been described as potentially immunogenic. By envisaging a biosafe cytocompatible and haemocompatible profile, this paper reports the systematic development of a delivery system based on CS and derived with HA and CDs to nanoencapsulate the model human phenylalanine hydroxylase (hPAH) through ionotropic gelation with tripolyphosphate (TPP), while maintaining protein stability and enzyme activity. By merging the combined set of biopolymers, we were able to effectively entrap hPAH within CS nanoparticles with improvements in hPAH stability and the maintenance of functional activity, while simultaneously achieving strict control of the formulation process. Detailed characterization of the developed nanoparticulate systems showed that the lead formulations were internalized by hepatocytes (HepG2 cell line), did not reveal cell toxicity and presented a safe haemocompatible profile.
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7
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Lopes RR, Tomé CS, Russo R, Paterna R, Leandro J, Candeias NR, Gonçalves LMD, Teixeira M, Sousa PMF, Guedes RC, Vicente JB, Gois PMP, Leandro P. Modulation of Human Phenylalanine Hydroxylase by 3-Hydroxyquinolin-2(1H)-One Derivatives. Biomolecules 2021; 11:biom11030462. [PMID: 33808760 PMCID: PMC8003416 DOI: 10.3390/biom11030462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/08/2021] [Accepted: 03/13/2021] [Indexed: 01/14/2023] Open
Abstract
Phenylketonuria (PKU) is a genetic disease caused by deficient activity of human phenylalanine hydroxylase (hPAH) that, when untreated, can lead to severe psychomotor impairment. Protein misfolding is recognized as the main underlying pathogenic mechanism of PKU. Therefore, the use of stabilizers of protein structure and/or activity is an attractive therapeutic strategy for this condition. Here, we report that 3-hydroxyquinolin-2(1H)-one derivatives can act as protectors of hPAH enzyme activity. Electron paramagnetic resonance spectroscopy demonstrated that the 3-hydroxyquinolin-2(1H)-one compounds affect the coordination of the non-heme ferric center at the enzyme active-site. Moreover, surface plasmon resonance studies showed that these stabilizing compounds can be outcompeted by the natural substrate l-phenylalanine. Two of the designed compounds functionally stabilized hPAH by maintaining protein activity. This effect was observed on the recombinant purified protein and in a cellular model. Besides interacting with the catalytic iron, one of the compounds also binds to the N-terminal regulatory domain, although to a different location from the allosteric l-Phe binding site, as supported by the solution structures obtained by small-angle X-ray scattering.
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Affiliation(s)
- Raquel R. Lopes
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
| | - Catarina S. Tomé
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal;
- Instituto de Biologia Experimental e Tecnológica, Quinta do Marquês, 2780-155 Oeiras, Portugal;
| | - Roberto Russo
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
| | - Roberta Paterna
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
| | - João Leandro
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
| | - Nuno R. Candeias
- Faculty of Engineering and Natural Sciences, Tampere University, Korkeakoulunkatu 8, 33101 Tampere, Finland;
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Lídia M. D. Gonçalves
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
| | - Miguel Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal;
| | - Pedro M. F. Sousa
- Instituto de Biologia Experimental e Tecnológica, Quinta do Marquês, 2780-155 Oeiras, Portugal;
| | - Rita C. Guedes
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
| | - João B. Vicente
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal;
- Correspondence: (J.B.V.); (P.M.P.G.); (P.L.); Tel.: +351-217946400 (P.L.)
| | - Pedro M. P. Gois
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
- Correspondence: (J.B.V.); (P.M.P.G.); (P.L.); Tel.: +351-217946400 (P.L.)
| | - Paula Leandro
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (R.R.L.); (C.S.T.); (R.R.); (R.P.); (J.L.); (L.M.D.G.); (R.C.G.)
- Correspondence: (J.B.V.); (P.M.P.G.); (P.L.); Tel.: +351-217946400 (P.L.)
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8
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Lino PR, Leandro J, Amaro M, Gonçalves LMD, Leandro P, Almeida AJ. In Silico and In Vitro Tailoring of a Chitosan Nanoformulation of a Human Metabolic Enzyme. Pharmaceutics 2021; 13:pharmaceutics13030329. [PMID: 33806405 PMCID: PMC8000282 DOI: 10.3390/pharmaceutics13030329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/23/2021] [Accepted: 02/27/2021] [Indexed: 01/10/2023] Open
Abstract
Enzyme nanoencapsulation holds an enormous potential to develop new therapeutic approaches to a large set of human pathologies including cancer, infectious diseases and inherited metabolic disorders. However, enzyme formulation has been limited by the need to maintain the catalytic function, which is governed by protein conformation. Herein we report the rational design of a delivery system based on chitosan for effective encapsulation of a functionally and structurally complex human metabolic enzyme through ionic gelation with tripolyphosphate. The rationale was to use a mild methodology to entrap the multimeric multidomain 200 kDa human phenylalanine hydroxylase (hPAH) in a polyol-like matrix that would allow an efficient maintenance of protein structure and function, avoiding formulation stress conditions. Through an in silico and in vitro based development, the particulate system was optimized with modulation of nanomaterials protonation status, polymer, counterion and protein ratios, taking into account particle size, polydispersity index, surface charge, particle yield production, protein free energy of folding, electrostatic surface potential, charge, encapsulation efficiency, loading capacity and transmission electron microscopy morphology. Evaluation of the thermal stability, substrate binding profile, relative enzymatic activity, and substrate activation ratio of the encapsulated hPAH suggests that the formulation procedure does not affect protein stability, allowing an effective maintenance of hPAH biological function. Hence, this study provides an important framework for an enzyme formulation process.
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9
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Leandro J, Bender A, Dodatko T, Argmann C, Yu C, Houten SM. Glutaric aciduria type 3 is a naturally occurring biochemical trait in inbred mice of 129 substrains. Mol Genet Metab 2021; 132:139-145. [PMID: 33483254 DOI: 10.1016/j.ymgme.2021.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 11/24/2022]
Abstract
The glutaric acidurias are a group of inborn errors of metabolism with different etiologies. Glutaric aciduria type 3 (GA3) is a biochemical phenotype with uncertain clinical relevance caused by a deficiency of succinyl-CoA:glutarate-CoA transferase (SUGCT). SUGCT catalyzes the succinyl-CoA-dependent conversion of glutaric acid into glutaryl-CoA preventing urinary loss of the organic acid. Here, we describe the presence of a GA3 trait in mice of 129 substrains due to SUGCT deficiency, which was identified by screening of urine organic acid profiles obtained from different inbred mouse strains including 129S2/SvPasCrl. Molecular and biochemical analyses in an F2 population of the parental C57BL/6J and 129S2/SvPasCrl strains (B6129F2) confirmed that the GA3 trait occurred in Sugct129/129 animals. We evaluated the impact of SUGCT deficiency on metabolite accumulation in the glutaric aciduria type 1 (GA1) mouse model. We found that GA1 mice with SUGCT deficiency have decreased excretion of urine 3-hydroxyglutaric acid and decreased levels glutarylcarnitine in urine, plasma and kidney. Our work demonstrates that SUGCT contributes to the production of glutaryl-CoA under conditions of low and pathologically high glutaric acid levels. Our work also highlights the notion that unexpected biochemical phenotypes can occur in widely used inbred animal lines.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Aaron Bender
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Carmen Argmann
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Mount Sinai Genomics, Inc, Stamford, CT 06902, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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10
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Leandro J, Dodatko T, DeVita RJ, Chen H, Stauffer B, Yu C, Houten SM. Deletion of 2-aminoadipic semialdehyde synthase limits metabolite accumulation in cell and mouse models for glutaric aciduria type 1. J Inherit Metab Dis 2020; 43:1154-1164. [PMID: 32567100 DOI: 10.1002/jimd.12276] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/04/2020] [Accepted: 06/17/2020] [Indexed: 11/10/2022]
Abstract
Glutaric aciduria type 1 (GA1) is an inborn error of lysine degradation characterized by acute encephalopathy that is caused by toxic accumulation of lysine degradation intermediates. We investigated the efficacy of substrate reduction through inhibition of 2-aminoadipic semialdehyde synthase (AASS), an enzyme upstream of the defective glutaryl-CoA dehydrogenase (GCDH), in a cell line and mouse model of GA1. We show that loss of AASS function in GCDH-deficient HEK-293 cells leads to an approximately fivefold reduction in the established GA1 clinical biomarker glutarylcarnitine. In the GA1 mouse model, deletion of Aass leads to a 4.3-, 3.8-, and 3.2-fold decrease in the glutaric acid levels in urine, brain, and liver, respectively. Parallel decreases were observed in urine and brain 3-hydroxyglutaric acid levels, and plasma, urine, and brain glutarylcarnitine levels. These in vivo data demonstrate that the saccharopine pathway is the main source of glutaric acid production in the brain and periphery of a mouse model for GA1, and support the notion that pharmacological inhibition of AASS may represent an attractive strategy to treat GA1.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Robert J DeVita
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai New York, New York, USA
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hongjie Chen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mount Sinai Genomics, Inc., Stamford, Connecticut, USA
| | - Brandon Stauffer
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mount Sinai Genomics, Inc., Stamford, Connecticut, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mount Sinai Genomics, Inc., Stamford, Connecticut, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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11
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Leandro J, Houten SM. The lysine degradation pathway: Subcellular compartmentalization and enzyme deficiencies. Mol Genet Metab 2020; 131:14-22. [PMID: 32768327 DOI: 10.1016/j.ymgme.2020.07.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/24/2020] [Accepted: 07/25/2020] [Indexed: 02/07/2023]
Abstract
Lysine degradation via formation of saccharopine is a pathway confined to the mitochondria. The second pathway for lysine degradation, the pipecolic acid pathway, is not yet fully elucidated and known enzymes are localized in the mitochondria, cytosol and peroxisome. The tissue-specific roles of these two pathways are still under investigation. The lysine degradation pathway is clinically relevant due to the occurrence of two severe neurometabolic disorders, pyridoxine-dependent epilepsy (PDE) and glutaric aciduria type 1 (GA1). The existence of three other disorders affecting lysine degradation without apparent clinical consequences opens up the possibility to find alternative therapeutic strategies for PDE and GA1 through pathway modulation. A better understanding of the mechanisms, compartmentalization and interplay between the different enzymes and metabolites involved in lysine degradation is of utmost importance.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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12
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Leandro J, Khamrui S, Wang H, Suebsuwong C, Nemeria NS, Huynh K, Moustakim M, Secor C, Wang M, Dodatko T, Stauffer B, Wilson CG, Yu C, Arkin MR, Jordan F, Sanchez R, DeVita RJ, Lazarus MB, Houten SM. Inhibition and Crystal Structure of the Human DHTKD1-Thiamin Diphosphate Complex. ACS Chem Biol 2020; 15:2041-2047. [PMID: 32633484 DOI: 10.1021/acschembio.0c00114] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
DHTKD1 is the E1 component of the 2-oxoadipate dehydrogenase complex, which is an enzyme involved in the catabolism of (hydroxy-)lysine and tryptophan. Mutations in DHTKD1 have been associated with 2-aminoadipic and 2-oxoadipic aciduria, Charcot-Marie-Tooth disease type 2Q and eosinophilic esophagitis, but the pathophysiology of these clinically distinct disorders remains elusive. Here, we report the identification of adipoylphosphonic acid and tenatoprazole as DHTKD1 inhibitors using targeted and high throughput screening, respectively. We furthermore elucidate the DHTKD1 crystal structure with thiamin diphosphate bound at 2.25 Å. We also report the impact of 10 disease-associated missense mutations on DHTKD1. Whereas the majority of the DHTKD1 variants displayed impaired folding or reduced thermal stability in combination with absent or reduced enzyme activity, three variants showed no abnormalities. Our work provides chemical and structural tools for further understanding of the function of DHTKD1 and its role in several human pathologies.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Susmita Khamrui
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Hui Wang
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Chalada Suebsuwong
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Natalia S. Nemeria
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102, United States
| | - Khoi Huynh
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Moses Moustakim
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Cody Secor
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - May Wang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Brandon Stauffer
- Mount Sinai Genomics, Inc, Stamford, Connecticut 06902, United States
| | - Christopher G. Wilson
- Small Molecule Discovery Center and Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, United States
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Mount Sinai Genomics, Inc, Stamford, Connecticut 06902, United States
| | - Michelle R. Arkin
- Small Molecule Discovery Center and Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, United States
| | - Frank Jordan
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102, United States
| | - Roberto Sanchez
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Robert J. DeVita
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Drug Discovery Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Michael B. Lazarus
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Sander M. Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
- Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
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13
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Zhang X, Nemeria NS, Leandro J, Houten S, Lazarus M, Gerfen G, Ozohanics O, Ambrus A, Nagy B, Brukh R, Jordan F. Structure-function analyses of the G729R 2-oxoadipate dehydrogenase genetic variant associated with a disorder of l-lysine metabolism. J Biol Chem 2020; 295:8078-8095. [PMID: 32303640 PMCID: PMC7278340 DOI: 10.1074/jbc.ra120.012761] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/16/2020] [Indexed: 12/13/2022] Open
Abstract
2-Oxoadipate dehydrogenase (E1a, also known as DHTKD1, dehydrogenase E1, and transketolase domain-containing protein 1) is a thiamin diphosphate-dependent enzyme and part of the 2-oxoadipate dehydrogenase complex (OADHc) in l-lysine catabolism. Genetic findings have linked mutations in the DHTKD1 gene to several metabolic disorders. These include α-aminoadipic and α-ketoadipic aciduria (AMOXAD), a rare disorder of l-lysine, l-hydroxylysine, and l-tryptophan catabolism, associated with clinical presentations such as developmental delay, mild-to-severe intellectual disability, ataxia, epilepsy, and behavioral disorders that cannot currently be managed by available treatments. A heterozygous missense mutation, c.2185G→A (p.G729R), in DHTKD1 has been identified in most AMOXAD cases. Here, we report that the G729R E1a variant when assembled into OADHc in vitro displays a 50-fold decrease in catalytic efficiency for NADH production and a significantly reduced rate of glutaryl-CoA production by dihydrolipoamide succinyl-transferase (E2o). However, the G729R E1a substitution did not affect any of the three side-reactions associated solely with G729R E1a, prompting us to determine the structure-function effects of this mutation. A multipronged systematic analysis of the reaction rates in the OADHc pathway, supplemented with results from chemical cross-linking and hydrogen-deuterium exchange MS, revealed that the c.2185G→A DHTKD1 mutation affects E1a-E2o assembly, leading to impaired channeling of OADHc intermediates. Cross-linking between the C-terminal region of both E1a and G729R E1a with the E2o lipoyl and core domains suggested that correct positioning of the C-terminal E1a region is essential for the intermediate channeling. These findings may inform the development of interventions to counter the effects of pathogenic DHTKD1 mutations.
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Affiliation(s)
- Xu Zhang
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Natalia S Nemeria
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - João Leandro
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Sander Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Michael Lazarus
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Gary Gerfen
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10641-2304
| | - Oliver Ozohanics
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - Attila Ambrus
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - Balint Nagy
- Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest H-1094, Hungary
| | - Roman Brukh
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
| | - Frank Jordan
- Department of Chemistry, Rutgers, The State University of New Jersey, Newark, New Jersey 07102
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14
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Tomé CS, Lopes RR, Sousa PMF, Amaro MP, Leandro J, Mertens HDT, Leandro P, Vicente JB. Author Correction: Structure of full-length wild-type human phenylalanine hydroxylase by small angle X-ray scattering reveals substrate-induced conformational stability. Sci Rep 2019; 9:17513. [PMID: 31745241 PMCID: PMC6863894 DOI: 10.1038/s41598-019-54425-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Affiliation(s)
- Catarina S Tomé
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.,Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Raquel R Lopes
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro M F Sousa
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Mariana P Amaro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal.,Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - João Leandro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal.,Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Paula Leandro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal.
| | - João B Vicente
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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15
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Tomé CS, Lopes RR, Sousa PMF, Amaro MP, Leandro J, Mertens HDT, Leandro P, Vicente JB. Structure of full-length wild-type human phenylalanine hydroxylase by small angle X-ray scattering reveals substrate-induced conformational stability. Sci Rep 2019; 9:13615. [PMID: 31541188 PMCID: PMC6754429 DOI: 10.1038/s41598-019-49944-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/03/2019] [Indexed: 01/30/2023] Open
Abstract
Human phenylalanine hydroxylase (hPAH) hydroxylates L-phenylalanine (L-Phe) to L-tyrosine, a precursor for neurotransmitter biosynthesis. Phenylketonuria (PKU), caused by mutations in PAH that impair PAH function, leads to neurological impairment when untreated. Understanding the hPAH structural and regulatory properties is essential to outline PKU pathophysiological mechanisms. Each hPAH monomer comprises an N-terminal regulatory, a central catalytic and a C-terminal oligomerisation domain. To maintain physiological L-Phe levels, hPAH employs complex regulatory mechanisms. Resting PAH adopts an auto-inhibited conformation where regulatory domains block access to the active site. L-Phe-mediated allosteric activation induces a repositioning of the regulatory domains. Since a structure of activated wild-type hPAH is lacking, we addressed hPAH L-Phe-mediated conformational changes and report the first solution structure of the allosterically activated state. Our solution structures obtained by small-angle X-ray scattering support a tetramer with distorted P222 symmetry, where catalytic and oligomerisation domains form a core from which regulatory domains protrude, positioning themselves close to the active site entrance in the absence of L-Phe. Binding of L-Phe induces a large movement and dimerisation of regulatory domains, exposing the active site. Activated hPAH is more resistant to proteolytic cleavage and thermal denaturation, suggesting that the association of regulatory domains stabilises hPAH.
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Affiliation(s)
- Catarina S Tomé
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Raquel R Lopes
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro M F Sousa
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Mariana P Amaro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
- Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - João Leandro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
- Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Paula Leandro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal.
| | - João B Vicente
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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16
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Leandro J, Violante S, Argmann CA, Hagen J, Dodatko T, Bender A, Zhang W, Williams EG, Bachmann AM, Auwerx J, Yu C, Houten SM. Mild inborn errors of metabolism in commonly used inbred mouse strains. Mol Genet Metab 2019; 126:388-396. [PMID: 30709776 PMCID: PMC6535113 DOI: 10.1016/j.ymgme.2019.01.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 10/27/2022]
Abstract
Inbred mouse strains are a cornerstone of translational research but paradoxically many strains carry mild inborn errors of metabolism. For example, α-aminoadipic acidemia and branched-chain ketoacid dehydrogenase deficiency are known in C57BL/6J mice. Using RNA sequencing, we now reveal the causal variants in Dhtkd1 and Bckdhb, and the molecular mechanism underlying these metabolic defects. C57BL/6J mice have decreased Dhtkd1 mRNA expression due to a solitary long terminal repeat (LTR) in intron 4 of Dhtkd1. This LTR harbors an alternate splice donor site leading to a partial splicing defect and as a consequence decreased total and functional Dhtkd1 mRNA, decreased DHTKD1 protein and α-aminoadipic acidemia. Similarly, C57BL/6J mice have decreased Bckdhb mRNA expression due to an LTR retrotransposon in intron 1 of Bckdhb. This transposable element encodes an alternative exon 1 causing aberrant splicing, decreased total and functional Bckdhb mRNA and decreased BCKDHB protein. Using a targeted metabolomics screen, we also reveal elevated plasma C5-carnitine in 129 substrains. This biochemical phenotype resembles isovaleric acidemia and is caused by an exonic splice mutation in Ivd leading to partial skipping of exon 10 and IVD protein deficiency. In summary, this study identifies three causal variants underlying mild inborn errors of metabolism in commonly used inbred mouse strains.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| | - Sara Violante
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA; Mount Sinai Genomics, Inc, One Gustave L Levy Place #1497, New York, NY 10029, USA
| | - Carmen A Argmann
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| | - Jacob Hagen
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| | - Aaron Bender
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| | - Wei Zhang
- Mount Sinai Genomics, Inc, One Gustave L Levy Place #1497, New York, NY 10029, USA
| | - Evan G Williams
- Department of Biology, Institute of Molecular Systems Biology, ETH Zürich, Zürich CH-8093, Switzerland
| | - Alexis M Bachmann
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA; Mount Sinai Genomics, Inc, One Gustave L Levy Place #1497, New York, NY 10029, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA.
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Abstract
Leandro and Houten highlight new work from Zhou et al. exploring the disease relevance and toxicity of lysine metabolites in mitochondria. Saccharopine, a nonproteinogenic amino acid originally isolated from the yeast Saccharomyces cerevisiae, is an intermediate in lysine metabolism. In this issue, Zhou et al. (2019. J. Cell Biol.https://doi.org./10.1083/jcb.201807204) show that abnormal accumulation of saccharopine results in defective mitochondrial dynamics and function in worm and mouse models.
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Affiliation(s)
- João Leandro
- Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Sander M Houten
- Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY
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Leandro J, Stokka AJ, Teigen K, Andersen OA, Flatmark T. Substituting Tyr 138 in the active site loop of human phenylalanine hydroxylase affects catalysis and substrate activation. FEBS Open Bio 2017; 7:1026-1036. [PMID: 28680815 PMCID: PMC5494296 DOI: 10.1002/2211-5463.12243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/27/2017] [Accepted: 05/10/2017] [Indexed: 11/22/2022] Open
Abstract
Mammalian phenylalanine hydroxylase (PAH) is a key enzyme in l‐phenylalanine (l‐Phe) metabolism and is active as a homotetramer. Biochemical and biophysical work has demonstrated that it cycles between two states with a variably low and a high activity, and that the substrate l‐Phe is the key player in this transition. X‐ray structures of the catalytic domain have shown mobility of a partially intrinsically disordered Tyr138‐loop to the active site in the presence of l‐Phe. The mechanism by which the loop dynamics are coupled to substrate binding at the active site in tetrameric PAH is not fully understood. We have here conducted functional studies of four Tyr138 point mutants. A high linear correlation (r2 = 0.99) was observed between their effects on the catalytic efficiency of the catalytic domain dimers and the corresponding effect on the catalytic efficiency of substrate‐activated full‐length tetramers. In the tetramers, a correlation (r2 = 0.96) was also observed between the increase in catalytic efficiency (activation) and the global conformational change (surface plasmon resonance signal response) at the same l‐Phe concentration. The new data support a similar functional importance of the Tyr138‐loop in the catalytic domain and the full‐length enzyme homotetramer.
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Affiliation(s)
- João Leandro
- Department of Biomedicine University of Bergen Norway.,Metabolism and Genetics Group Research Institute for Medicines (iMed.ULisboa) Faculty of Pharmacy University of Lisbon Portugal.,Present address: Department of Genetics and Genomic Sciences Icahn School of Medicine at Mount Sinai 1425 Madison Avenue, Box 1498 New York NY 10029 USA
| | - Anne J Stokka
- Department of Biomedicine University of Bergen Norway.,The Biotechnology Centre of Oslo University of Oslo Norway
| | - Knut Teigen
- Department of Biomedicine University of Bergen Norway
| | - Ole A Andersen
- Department of Biomedicine University of Bergen Norway.,Evotec (UK) Ltd .Abingdon UK
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19
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Cantante C, Lourenço S, Morais M, Leandro J, Gano L, Silva N, Leandro P, Serrano M, Henriques AO, Andre A, Cunha-Santos C, Fontes C, Correia JDG, Aires-da-Silva F, Goncalves J. Albumin-binding domain from Streptococcus zooepidemicus protein Zag as a novel strategy to improve the half-life of therapeutic proteins. J Biotechnol 2017; 253:23-33. [PMID: 28549690 DOI: 10.1016/j.jbiotec.2017.05.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/20/2017] [Accepted: 05/22/2017] [Indexed: 11/28/2022]
Abstract
Recombinant antibody fragments belong to the promising class of biopharmaceuticals with high potential for future therapeutic applications. However, due to their small size they are rapidly cleared from circulation. Binding to serum proteins can be an effective approach to improve pharmacokinetic properties of short half-life molecules. Herein, we have investigated the Zag albumin-binding domain (ABD) derived from Streptococcus zooepidemicus as a novel strategy to improve the pharmacokinetic properties of therapeutic molecules. To validate our approach, the Zag ABD was fused with an anti-TNFα single-domain antibody (sdAb). Our results demonstrated that the sdAb-Zag fusion protein was highly expressed and specifically recognizes human, rat and mouse serum albumins with affinities in the nanomolar range. Moreover, data also demonstrated that the sdAb activity against the therapeutic target (TNFα) was not affected when fused with Zag ABD. Importantly, the Zag ABD increased the sdAb half-life ∼39-fold (47min for sdAb versus 31h for sdAb-Zag). These findings demonstrate that the Zag ABD fusion is a promising approach to increase the half-life of small recombinant antibodies molecules without affecting their therapeutic efficacy. Moreover, the present study strongly suggests that the Zag ABD fusion strategy can be potentially used as a universal method to improve the pharmokinetics properties of many others therapeutics proteins and peptides in order to improve their dosing schedule and clinical effects.
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Affiliation(s)
- Cátia Cantante
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | | | - Maurício Morais
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - João Leandro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Lurdes Gano
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Nuno Silva
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Paula Leandro
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Mónica Serrano
- Instituto de Tecnologia Química e Biológica (ITQB), Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Adriano O Henriques
- Instituto de Tecnologia Química e Biológica (ITQB), Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Ana Andre
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa,1300-477 Lisbon, Portugal
| | - Catarina Cunha-Santos
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Carlos Fontes
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa,1300-477 Lisbon, Portugal
| | - João D G Correia
- Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Frederico Aires-da-Silva
- Technophage, SA, 1649-028 Lisbon, Portugal; CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa,1300-477 Lisbon, Portugal.
| | - Joao Goncalves
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal.
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20
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Leandro J, Saraste J, Leandro P, Flatmark T. PKU mutation p.G46S prevents the stereospecific binding of l-phenylalanine to the dimer of human phenylalanine hydroxylase regulatory domain. FEBS Open Bio 2017; 7:195-203. [PMID: 28174686 PMCID: PMC5292662 DOI: 10.1002/2211-5463.12175] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/01/2016] [Accepted: 12/03/2016] [Indexed: 11/23/2022] Open
Abstract
Mammalian phenylalanine hydroxylase (PAH) has a potential allosteric regulatory binding site for l‐phenylalanine (l‐Phe), in addition to its catalytic site. This arrangement is supported by a crystal structure of a homodimeric truncated form of the regulatory domain of human PAH (hPAH‐RD1–118/19–118) [Patel D et al. (2016) Sci Rep doi: 10.1038/srep23748]. In this study, a fusion protein of the domain (MBP‐(pepXa)‐hPAH‐RD1–120) was overexpressed and recovered in a metastable and soluble state, which allowed the isolation of a dimeric and a monomeric fusion protein. When cleaved from MBP, hPAH‐RD forms aggregates which are stereospecifically inhibited by l‐Phe (> 95%) at low physiological concentrations. Aggregation of the cleaved dimer of the mutant form hPAH‐G46S‐RD was not inhibited by l‐Phe, which is compatible with structurally/conformationally changed βαββαβ ACT domain folds in the mutant.
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Affiliation(s)
- João Leandro
- Department of Biomedicine University of Bergen Norway; Metabolism and Genetics Group Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) Faculty of Pharmacy University of Lisbon Portugal
| | | | - Paula Leandro
- Metabolism and Genetics Group Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) Faculty of Pharmacy University of Lisbon Portugal
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21
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Bonito CA, Nunes J, Leandro J, Louro F, Leandro P, Ventura FV, Guedes RC. Unveiling the Pathogenic Molecular Mechanisms of the Most Common Variant (p.K329E) in Medium-Chain Acyl-CoA Dehydrogenase Deficiency by in Vitro and in Silico Approaches. Biochemistry 2016; 55:7086-7098. [PMID: 27976856 DOI: 10.1021/acs.biochem.6b00759] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most common genetic disorder affecting the mitochondrial fatty acid β-oxidation pathway. The mature and functional form of human MCAD (hMCAD) is a homotetramer assembled as a dimer of dimers (monomers A/B and C/D). Each monomer binds a FAD cofactor, necessary for the enzyme's activity. The most frequent mutation in MCADD results from the substitution of a lysine with a glutamate in position 304 of mature hMCAD (p.K329E in the precursor protein). Here, we combined in vitro and in silico approaches to assess the impact of the p.K329E mutation on the protein's structure and function. Our in silico results demonstrated for the first time that the p.K329E mutation, despite lying at the dimer-dimer interface and being deeply buried inside the tetrameric core, seems to affect the tetramer surface, especially the β-domain that forms part of the catalytic pocket wall. Additionally, the molecular dynamics data indicate a stronger impact of the mutation on the protein's motions in dimer A/B, while dimer C/D remains similar to the wild type. For dimer A/B, severe disruptions in the architecture of the pockets and in the FAD and octanoyl-CoA binding affinities were also observed. The presence of unaffected pockets (C/D) in the in silico studies may explain the decreased enzymatic activity determined for the variant protein (46% residual activity). Moreover, the in silico structural changes observed for the p.K329E variant protein provide an explanation for the structural instability observed experimentally, namely, the disturbed oligomeric profile, thermal stability, and conformational flexibility, with respect to the wild-type.
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Affiliation(s)
- Cátia A Bonito
- Department of Biochemistry and Human Biology, §Medicinal Chemistry, Research Institute for Medicines, iMed.ULisboa, ‡Metabolism and Genetics Group, Research Institute for Medicines, iMed.ULisboa, and ∥Department of Pharmaceutical Chemistry and Therapeutics, Faculty of Pharmacy, Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Joana Nunes
- Department of Biochemistry and Human Biology, §Medicinal Chemistry, Research Institute for Medicines, iMed.ULisboa, ‡Metabolism and Genetics Group, Research Institute for Medicines, iMed.ULisboa, and ∥Department of Pharmaceutical Chemistry and Therapeutics, Faculty of Pharmacy, Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - João Leandro
- Department of Biochemistry and Human Biology, §Medicinal Chemistry, Research Institute for Medicines, iMed.ULisboa, ‡Metabolism and Genetics Group, Research Institute for Medicines, iMed.ULisboa, and ∥Department of Pharmaceutical Chemistry and Therapeutics, Faculty of Pharmacy, Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Filipa Louro
- Department of Biochemistry and Human Biology, §Medicinal Chemistry, Research Institute for Medicines, iMed.ULisboa, ‡Metabolism and Genetics Group, Research Institute for Medicines, iMed.ULisboa, and ∥Department of Pharmaceutical Chemistry and Therapeutics, Faculty of Pharmacy, Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Paula Leandro
- Department of Biochemistry and Human Biology, §Medicinal Chemistry, Research Institute for Medicines, iMed.ULisboa, ‡Metabolism and Genetics Group, Research Institute for Medicines, iMed.ULisboa, and ∥Department of Pharmaceutical Chemistry and Therapeutics, Faculty of Pharmacy, Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Fátima V Ventura
- Department of Biochemistry and Human Biology, §Medicinal Chemistry, Research Institute for Medicines, iMed.ULisboa, ‡Metabolism and Genetics Group, Research Institute for Medicines, iMed.ULisboa, and ∥Department of Pharmaceutical Chemistry and Therapeutics, Faculty of Pharmacy, Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Rita C Guedes
- Department of Biochemistry and Human Biology, §Medicinal Chemistry, Research Institute for Medicines, iMed.ULisboa, ‡Metabolism and Genetics Group, Research Institute for Medicines, iMed.ULisboa, and ∥Department of Pharmaceutical Chemistry and Therapeutics, Faculty of Pharmacy, Universidade de Lisboa , Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
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22
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Muntau AC, Leandro J, Staudigl M, Mayer F, Gersting SW. Innovative strategies to treat protein misfolding in inborn errors of metabolism: pharmacological chaperones and proteostasis regulators. J Inherit Metab Dis 2014; 37:505-23. [PMID: 24687294 DOI: 10.1007/s10545-014-9701-z] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 02/19/2014] [Accepted: 02/24/2014] [Indexed: 10/25/2022]
Abstract
To attain functionality, proteins must fold into their three-dimensional native state. The intracellular balance between protein synthesis, folding, and degradation is constantly challenged by genetic or environmental stress factors. In the last ten years, protein misfolding induced by missense mutations was demonstrated to be the seminal molecular mechanism in a constantly growing number of inborn errors of metabolism. In these cases, loss of protein function results from early degradation of missense-induced misfolded proteins. Increasing knowledge on the proteostasis network and the protein quality control system with distinct mechanisms in different compartments of the cell paved the way for the development of new treatment strategies for conformational diseases using small molecules. These comprise proteostasis regulators that enhance the capacity of the proteostasis network and pharmacological chaperones that specifically bind and rescue misfolded proteins by conformational stabilization. They can be used either alone or in combination, the latter to exploit synergistic effects. Many of these small molecule compounds currently undergo preclinical and clinical pharmaceutical development and two have been approved: saproterin dihydrochloride for the treatment of phenylketonuria and tafamidis for the treatment of transthyretin-related hereditary amyloidosis. Different technologies are exploited for the discovery of new small molecule compounds that belong to the still young class of pharmaceutical products discussed here. These compounds may in the near future improve existing treatment strategies or even offer a first-time treatment to patients suffering from nowadays-untreatable inborn errors of metabolism.
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Affiliation(s)
- Ania C Muntau
- Department of Molecular Pediatrics, Dr von Hauner Children's Hospital, Ludwig Maximilians University, Lindwurmstrasse 4, 80337, Munich, Germany,
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Montalbano F, Leandro J, Farias GDVF, Lino PR, Guedes RC, Vicente JB, Leandro P, Gois PMP. Phenylalanine iminoboronates as new phenylalanine hydroxylase modulators. RSC Adv 2014. [DOI: 10.1039/c4ra10306h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Herein we report the discovery of new modulators of human phenylalanine hydroxylase (hPAH) inspired by the structure of its substrate and regulator l-phenylalanine.
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Affiliation(s)
- Francesco Montalbano
- Research Institute for Medicines (iMed.ULisboa)
- Faculty of Pharmacy
- Universidade de Lisboa
- Lisboa, Portugal
| | - João Leandro
- Research Institute for Medicines (iMed.ULisboa)
- Faculty of Pharmacy
- Universidade de Lisboa
- Lisboa, Portugal
| | - Gonçalo D. V. F. Farias
- Research Institute for Medicines (iMed.ULisboa)
- Faculty of Pharmacy
- Universidade de Lisboa
- Lisboa, Portugal
| | - Paulo R. Lino
- Research Institute for Medicines (iMed.ULisboa)
- Faculty of Pharmacy
- Universidade de Lisboa
- Lisboa, Portugal
| | - Rita C. Guedes
- Research Institute for Medicines (iMed.ULisboa)
- Faculty of Pharmacy
- Universidade de Lisboa
- Lisboa, Portugal
| | - João B. Vicente
- Research Institute for Medicines (iMed.ULisboa)
- Faculty of Pharmacy
- Universidade de Lisboa
- Lisboa, Portugal
| | - Paula Leandro
- Research Institute for Medicines (iMed.ULisboa)
- Faculty of Pharmacy
- Universidade de Lisboa
- Lisboa, Portugal
| | - Pedro M. P. Gois
- Research Institute for Medicines (iMed.ULisboa)
- Faculty of Pharmacy
- Universidade de Lisboa
- Lisboa, Portugal
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Leandro J, Leandro P, Flatmark T. Heterotetrameric forms of human phenylalanine hydroxylase: Co-expression of wild-type and mutant forms in a bicistronic system. Biochim Biophys Acta Mol Basis Dis 2011; 1812:602-12. [DOI: 10.1016/j.bbadis.2011.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 01/19/2011] [Accepted: 02/03/2011] [Indexed: 11/28/2022]
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Leandro J, Saraste J, Leandro P, Flatmark T. The G46S-hPAH mutant protein: a model to study the rescue of aggregation-prone PKU mutations by chaperones. Mol Genet Metab 2011; 104 Suppl:S40-4. [PMID: 21871828 DOI: 10.1016/j.ymgme.2011.07.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 07/26/2011] [Indexed: 11/19/2022]
Abstract
Phenylketonuria (PKU), the most common inborn error of metabolism, is caused by dysfunction of the liver enzyme phenylalanine hydroxylase (PAH), with more than 550 PAH gene mutations identified to date. A large number of these mutations result in mutant forms of the enzyme displaying reduced stability, increased propensity to aggregate, and accelerated in cellulo degradation. Loss or reduction of human PAH activity results in hyperphenylalaninemia (HPA) which, if untreated, results in severe mental retardation and impaired cognitive development. Until now, strict low phenylalanine diet has been the most effective therapy, but as a protein misfolding disease PKU is a good candidate for treatment by natural/chemical/pharmacological chaperones. The natural cofactor of human PAH, (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH(4)), has already been approved for oral treatment of HPA, giving a positive response in mild forms of the disease showing considerable residual enzymatic activity. In the case of the most severe forms of PKU, ongoing studies with chemical and pharmacological chaperones to rescue misfolded mutant proteins from aggregation and degradation are providing promising results. The PKU mutation G46S is associated with a severe form of the disease, resulting in an aggregation-prone protein. The human PAH mutant G46S is rapidly degraded in the cellular environment and, in vitro (upon removal of its stabilizing fusion partner maltose binding protein (MBP)) self-associates to form higher-order oligomers/fibrils. Here, we present an in vitro experimental model system to study the modulation of G46S aggregation by chemical/pharmacological chaperones, which may represent a useful approach to study the rescue of other severe PKU mutations by chemical/pharmacological chaperones.
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Affiliation(s)
- João Leandro
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, N-5009 Bergen, Norway.
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Leandro J, Djordjević S, Chen AS, Savić DA, Stanić M. Calibration of a 1D/1D urban flood model using 1D/2D model results in the absence of field data. Water Sci Technol 2011; 64:1016-1024. [PMID: 22214046 DOI: 10.2166/wst.2011.467] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Recently increased flood events have been prompting researchers to improve existing coupled flood-models such as one-dimensional (1D)/1D and 1D/two-dimensional (2D) models. While 1D/1D models simulate sewer and surface networks using a one-dimensional approach, 1D/2D models represent the surface network by a two-dimensional surface grid. However their application raises two issues to urban flood modellers: (1) stormwater systems planning/emergency or risk analysis demands for fast models, and the 1D/2D computational time is prohibitive, (2) and the recognized lack of field data (e.g. Hunter et al. (2008)) causes difficulties for the calibration/validation of 1D/1D models. In this paper we propose to overcome these issues by calibrating a 1D/1D model with the results of a 1D/2D model. The flood-inundation results show that: (1) 1D/2D results can be used to calibrate faster 1D/1D models, (2) the 1D/1D model is able to map the 1D/2D flood maximum extent well, and the flooding limits satisfactorily in each time-step, (3) the 1D/1D model major differences are the instantaneous flow propagation and overestimation of the flood-depths within surface-ponds, (4) the agreement in the volume surcharged by both models is a necessary condition for the 1D surface-network validation and (5) the agreement of the manholes discharge shapes measures the fitness of the calibrated 1D surface-network.
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Affiliation(s)
- J Leandro
- Department of Civil Engineering, Faculty of Science and Technology, Rua Luis Reis Santos--Pólo II Univ. Coimbra, 3030-788 Coimbra, Portugal.
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Leandro J, Simonsen N, Saraste J, Leandro P, Flatmark T. Phenylketonuria as a protein misfolding disease: The mutation pG46S in phenylalanine hydroxylase promotes self-association and fibril formation. Biochim Biophys Acta Mol Basis Dis 2010; 1812:106-20. [PMID: 20937381 DOI: 10.1016/j.bbadis.2010.09.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/02/2010] [Accepted: 09/21/2010] [Indexed: 10/19/2022]
Abstract
The missense mutation pG46S in the regulatory (R) domain of human phenylalanine hydroxylase (hPAH), associated with a severe form of phenylketonuria, generates a misfolded protein which is rapidly degraded on expression in HEK293 cells. When overexpressed as a MBP-G46S fusion protein, soluble and fully active tetrameric/dimeric forms are assembled and recovered in a metastable conformational state. When MBP is cleaved off, G46S undergoes a conformational change and self-associates with a lag phase and an autocatalytic growth phase (tetramers≫dimers), as determined by light scattering. The self-association is controlled by pH, ionic strength, temperature, protein concentration and the phosphorylation state of Ser16; the net charge of the protein being a main modulator of the process. A superstoichiometric amount of WT dimers revealed a 2-fold enhancement of the rate of G46S dimer self-association. Electron microscopy demonstrates the formation of higher-order oligomers and linear polymers of variable length, partly as a branching network, and partly as individual long and twisted fibrils (diameter ~145-300Å). The heat-shock proteins Hsp70/Hsp40, Hsp90 and a proposed pharmacological PAH chaperone (3-amino-2-benzyl-7-nitro-4-(2-quinolyl)-1,2-dihydroisoquinolin-1-one) partly inhibit the self-association process. Our data indicate that the G46S mutation results in a N-terminal extension of α-helix 1 which perturbs the wild-type α-β sandwich motif in the R-domain and promotes new intermolecular contacts, self-association and non-amyloid fibril formation. The metastable conformational state of G46S as a MBP fusion protein, and its self-association propensity when released from MBP, may represent a model system for the study of other hPAH missense mutations characterized by misfolded proteins.
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Affiliation(s)
- João Leandro
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, N-5009 Bergen, Norway
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Abstract
Intense rainfall in urban areas often generates both pluvial flooding due to the limited capacity of drainage systems, as well as fluvial flooding caused by deluges from river channels. The concurrence of pluvial and fluvial flooding can aggravate their (individual) potential damages. To analyse the impact caused by individual and composite type of flooding, the SIPSON/UIM model, an integrated 1D sewer and 2D overland flow was applied to numerical modelling. An event matrix of possible pluvial scenarios was combined with hypothetic overtopping and breaching situations to estimate the surface flooding consequences in the Stockbridge area, Keighley (Bradford, UK). The modelling results identified different flooding drivers in different parts of the study area and showed that the worst scenarios resulted from synthesised events.
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Affiliation(s)
- A S Chen
- Centre for Water Systems, School of Engineering, Computing and Mathematics, University of Exeter, North Park Road, EX4 4QF Exeter, UK.
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Nascimento C, Leandro J, Lino PR, Ramos L, Almeida AJ, de Almeida IT, Leandro P. Polyol additives modulate the in vitro stability and activity of recombinant human phenylalanine hydroxylase. Appl Biochem Biotechnol 2009; 162:192-207. [PMID: 19937396 DOI: 10.1007/s12010-009-8862-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Accepted: 11/06/2009] [Indexed: 11/26/2022]
Abstract
Phenylketonuria (PKU; OMIM 261600), the most common disorder of amino acid metabolism, is caused by a deficient activity of human phenylalanine hydroxylase (hPAH). Although the dietetic treatment has proven to be effective in preventing the psycho-motor impairment, much effort has been made to develop new therapeutic approaches. Enzyme replacement therapy with hPAH could be regarded as a potential form of PKU treatment if the reported in vitro hPAH instability could be overcome. In this study, we investigated the effect of different polyol compounds, e.g. glycerol, mannitol and PEG-6000 on the in vitro stability of purified hPAH produced in a heterologous prokaryotic expression system. The recombinant human enzyme was stored in the presence of the studied stabilizing agents at different temperatures (4 and -20 degrees C) during a 1-month period. Protein content, degradation products, specific activity, oligomeric profile and conformational characteristics were assessed during storage. The obtained results showed that the use of 50% glycerol or 10% mannitol, at -20 degrees C, protected the enzyme from loss of its enzymatic activity. The determined DeltaG(0) and quenching parameters indicate the occurrence of conformational changes, which may be responsible for the observed increase in catalytic efficiency.
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Affiliation(s)
- Cátia Nascimento
- Metabolism and Genetics Group, iMed.UL, Faculdade Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
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Nascimento C, Leandro J, Tavares de Almeida I, Leandro P. Modulation of the activity of newly synthesized human phenylalanine hydroxylase mutant proteins by low-molecular-weight compounds. Protein J 2009; 27:392-400. [PMID: 18769885 DOI: 10.1007/s10930-008-9149-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Phenylketonuria, the most frequent disorder of amino acid metabolism, is caused by a deficient activity of human phenylalanine hydroxylase (hPAH). Rescue of the enzyme activity of several recombinant hPAH mutant forms (I65T, R261Q, R270K and V388M) by low molecular weight compounds namely glycerol, trimethylamine N-oxide (TMAO) and sodium 4-phenylbutyrate (4-PB) was investigated using a prokaryotic expression model. The studied compounds were added to the culture medium, in a concentration dependent manner, simultaneously to induction of protein expression. Among the tested molecules glycerol and TMAO were able to increase the enzyme activity of the studied mutant proteins. Furthermore, a decrease in aggregates and a recovery of the active tetrameric and dimeric forms were detected. Since the addition of the studied compounds to the medium did not change the expression level of E. Coli molecular chaperones we postulate that glycerol and TMAO rescue results from a direct stabilizing effect of the newly synthesized mutant hPAH enzymes.
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Affiliation(s)
- Cátia Nascimento
- Metabolism and Genetics Group, iMed.UL, Faculdade Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal
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Leandro J, Nascimento C, de Almeida IT, Leandro P. Co-expression of different subunits of human phenylalanine hydroxylase: evidence of negative interallelic complementation. Biochim Biophys Acta Mol Basis Dis 2006; 1762:544-50. [PMID: 16545551 DOI: 10.1016/j.bbadis.2006.02.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 02/01/2006] [Accepted: 02/03/2006] [Indexed: 11/30/2022]
Abstract
To study the interaction between two different subunits of the heteromeric human phenylalanine hydroxylase (hPAH), present in hyperphenylalaninemic (HPA) compound heterozygous patients, heteroallelic hPAH enzymes were produced. A dual vector expression system was used (PRO Bacterial Expression System) in which each mutant subunit was expressed from a separate compatible vector, with different epitope tags, in a single bacterial host. Experimental conditions were selected in order that each plasmid produced equivalent levels of mutant subunits. In this study, we demonstrated that both subunits were expressed and that the purified heteroallelic enzymes, were catalytically active. As expected, the produced proteins displayed enzymatic activities levels lower than the predicted catalytic activity, calculated by averaging in vitro PAH activities from both alleles, and were strongly dependent on the proteins subunit composition. The obtained data suggest that interactions between the studied hPAH subunits, namely the I65T, R261Q, R270K and V388M, and the wild-type protein occurred. As postulated, this phenomenon could be a source of phenotypic variation in genetic diseases involving multimeric proteins.
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Affiliation(s)
- João Leandro
- Unidade de Biologia Molecular e Biopatologia Experimental, Centro de Patogénese Molecular, Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
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Abstract
Brucella endocarditis was diagnosed in two patients with acute renal failure. Both patients had major aortic insufficiency, congestive cardiac failure and clinical and laboratory signs of an active infection, although adequate antibacterial therapy had already been introduced. Replacement of the aortic valve, together with the aortic root in one of the cases, were carried out as emergency procedures, followed by antibacterial treatment with rifampicin, doxycycline and co-trimoxazole. Both patients left the hospital cured and are well 2.5 and 2 years after the surgery, respectively.
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Affiliation(s)
- J Leandro
- Cardiothoracic Surgery, University Hospital Coimbra, Portugal
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Leandro J, Elvas L, Cristovão J, Semedo L, Providéncia LA. [The pacemaker syndrome]. ACTA MEDICA PORT 1997; 10:81-5. [PMID: 9245183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- J Leandro
- Serviço de Cardiologia, Hospitais da Universidade de Coimbra
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Leandro J, Elvas L, Cristóvão J, Semedo L, Pontes N, Castro G, Andrade C, Correia FF, Providência LA. [Classical pacemaker syndrome. Report of 2 cases with severe clinical manifestations]. Rev Port Cardiol 1996; 15:425-30, 366. [PMID: 8763516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We report two cases of classic pacemaker syndrome. Both patients developed severe clinical manifestations after implantation of a VVI pacemaker. One patient presented syncopal episodes and the other one manifest cardiac heart failure. Additionally, we review the mechanisms responsible for this clinical entity.
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Affiliation(s)
- J Leandro
- Serviço de Cardilogia, Hospitais da Universidade de Coimbra
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Abstract
Despite a wealth of data documenting acute cardiac injury from anthracycline therapy and/or mediastinal radiotherapy used for childhood cancer, little information is available on the long-term consequence of these insults. Twenty-nine patients (mean age 15 +/- 4.3 years) from The Late Effects Follow-Up Clinic For Childhood Cancer study, who had been in continuous, complete remission and off chemotherapy for a minimum of 2 years (mean follow-up 7.2 +/- 3.2) were studied. All patients had normal ejection fractions before and during cancer therapy and all were in New York Heart Association class I at the time of study. Systolic and diastolic functions were assessed by 2-dimensional echocardiography, Doppler flow velocity, and radionuclide angiography, and results were compared with normal control subjects. Left ventricular mass and mass index were significantly reduced in the patient population. Fractional shortening was decreased overall and end-systolic wall stress was much higher in patients than in controls. However, contractility, as assessed by the relation of wall stress to rate-corrected velocity of shortening, was decreased by > or = 2 SDs in only 6 of 28 patients, and the force-mass relation was actually increased in the patient group as a whole. Mitral valve inflow velocities were significantly increased but the pattern was abnormal. These results suggest a pattern consistent with a thin-walled, complaint left ventricle with reduced muscle mass performing under above-normal levels of wall stress. Contractility measurements were normal or increased in the group, but some patients clearly demonstrated development of reduced contractile function.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Leandro
- Division of Cardiology, Hospital for Sick Children, University of Toronto, Ontario, Canada
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Leandro J, Dyck JD, Smallhorn JF. Intra-utero diagnosis of anomalous right ventricular muscle bundles in association with a ventricular septal defect: a case report. Pediatr Cardiol 1994; 15:246-8. [PMID: 7997430 DOI: 10.1007/bf00795736] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The morphology and natural history of anomalous right ventricular muscle bundles (ARVMB) have been described in a number of postnatal studies. Whether this is a congenital or acquired cardiac lesion remains obscure. A fetal echocardiogram performed in a 32-week gestation mother showed a large ventricular septal defect and anomalous right ventricular muscle bundles, which were easily appreciated at the ostium-infundibular level. The diagnosis was confirmed postnatally and at 6 months of age the child underwent surgical repair. This report documents the presence of ARVMB in a fetus, at a time when hemodynamics cannot explain the development of right ventricular muscle bundles. It suggests that at least, the morphologic substrate for this disease is congenital.
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Affiliation(s)
- J Leandro
- Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
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Leandro J, Smallhorn JF, Benson L, Musewe N, Balfe JW, Dyck JD, West L, Freedom R. Ambulatory blood pressure monitoring and left ventricular mass and function after successful surgical repair of coarctation of the aorta. J Am Coll Cardiol 1992; 20:197-204. [PMID: 1607525 DOI: 10.1016/0735-1097(92)90159-k] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Late cardiovascular morbidity and mortality remain significant despite apparently successful surgical repair of aortic coarctation. Alterations in cardiac function have been reported in normotensive patients who have had successful repair, the reasons for which remain unclear. This study addresses the relation between ambulatory blood pressure measurements and alterations in left ventricular performance in 20 patients with normotension at rest after successful repair of aortic coarctation. Exercise testing, ambulatory blood pressure monitoring and two-dimensional echocardiographic studies in 13 boys and 7 girls (mean age 14.2 +/- 2.31 and 14.7 +/- 3 years, respectively) who had no evidence of recoarctation were compared with the findings in 20 matched control subjects. No difference was found in systolic blood pressure at rest or peak exercise between patients and control subjects. Male patients developed a significant arm/leg gradient at peak exercise. Systolic ambulatory blood pressure was higher throughout the day in the male group. In the female group, systolic blood pressure was higher only during sleep. No difference was found in diastolic blood pressure or heart rate. The transverse aortic arch was smaller and the left ventricular mass greater in all patients. The relation of wall stress to rate-corrected velocity of shortening was 2 SD above normal in 8 of the 20 patients, suggesting that some have enhanced contractility. The E/A ratio on the atrial echocardiogram was significantly reduced in the patient group. Successfully treated patients who are normotensive at rest after operation are still at risk for developing end organ damage, which is probably explained by incipient mild hypertension documented by ambulatory blood pressure monitoring.
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Affiliation(s)
- J Leandro
- Division of Pediatric Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
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