1
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Uzawa H, Kohno D, Koga T, Sasaki T, Fukunaka A, Okuno T, Jo-Watanabe A, Kazuno S, Miyatsuka T, Kitamura T, Fujitani Y, Watada H, Saeki K, Yokomizo T. Leukotriene A 4 hydrolase deficiency protects mice from diet-induced obesity by increasing energy expenditure through neuroendocrine axis. FASEB J 2020; 34:13949-13958. [PMID: 32844470 DOI: 10.1096/fj.202001148r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 12/20/2022]
Abstract
Obesity is a health problem worldwide, and brown adipose tissue (BAT) is important for energy expenditure. Here, we explored the role of leukotriene A4 hydrolase (LTA4 H), a key enzyme in the synthesis of the lipid mediator leukotriene B4 (LTB4 ), in diet-induced obesity. LTA4 H-deficient (LTA4 H-KO) mice fed a high-fat diet (HFD) showed a lean phenotype, and bone-marrow transplantation studies revealed that LTA4 H-deficiency in non-hematopoietic cells was responsible for this lean phenotype. LTA4 H-KO mice exhibited greater energy expenditure, but similar food intake and fecal energy loss. LTA4 H-KO BAT showed higher expression of thermogenesis-related genes. In addition, the plasma thyroid-stimulating hormone and thyroid hormone concentrations, as well as HFD-induced catecholamine secretion, were higher in LTA4 H-KO mice. In contrast, LTB4 receptor (BLT1)-deficient mice did not show a lean phenotype, implying that the phenotype of LTA4 H-KO mice is independent of the LTB4 /BLT1 axis. These results indicate that LTA4 H mediates the diet-induced obesity by reducing catecholamine and thyroid hormone secretion.
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Affiliation(s)
- Hirotsugu Uzawa
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan.,Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Daisuke Kohno
- Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Tomoaki Koga
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan.,Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Tsutomu Sasaki
- Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan.,Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Ayako Fukunaka
- Laboratory of Developmental Biology and Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Toshiaki Okuno
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan
| | - Airi Jo-Watanabe
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan
| | - Saiko Kazuno
- Laboratory of Proteomics and Biomolecular Science, Research Support Center, Juntendo University School of Medicine, Tokyo, Japan
| | - Takeshi Miyatsuka
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Tadahiro Kitamura
- Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Yoshio Fujitani
- Laboratory of Developmental Biology and Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Hirotaka Watada
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kazuko Saeki
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan
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2
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Saeki K, Yokomizo T. Identification, signaling, and functions of LTB 4 receptors. Semin Immunol 2018; 33:30-36. [PMID: 29042026 DOI: 10.1016/j.smim.2017.07.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 05/02/2017] [Accepted: 07/26/2017] [Indexed: 10/18/2022]
Abstract
Leukotriene B4 (LTB4), a lipid mediator produced from arachidonic acid, is a chemoattractant for inflammatory leukocytes. We identified two receptors for LTB4, the high-affinity receptor BLT1 and the low-affinity receptor BLT2. BLT1 is expressed in various subsets of leukocytes, and analyses of BLT1-deficient mice revealed that the LTB4/BLT1 axis enhances leukocyte recruitment to infected sites, and is involved in the elimination of pathogens. Hyperactivation of the LTB4/BLT1 axis induces acute and chronic inflammation, resulting in various inflammatory diseases. BLT2 was originally identified as a low-affinity receptor for LTB4, and we later identified 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (12-HHT) as a high-affinity ligand for BLT2. BLT2 is highly expressed in epithelial cells in various tissues including intestine and skin. Large quantities of 12-HHT are produced by activated platelets during skin injury, and activation of BLT2 on epidermal keratinocytes accelerates skin wound healing by enhancing cell migration. BLT2 signaling also enhances cell-cell junctions, protectes against transepidermal water loss, and preventes entry of environmental substances into the body.
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Affiliation(s)
- Kazuko Saeki
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan.
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3
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Tholander F, Muroya A, Roques BP, Fournié-Zaluski MC, Thunnissen MMGM, Haeggström JZ. Structure-based dissection of the active site chemistry of leukotriene A4 hydrolase: implications for M1 aminopeptidases and inhibitor design. ACTA ACUST UNITED AC 2008; 15:920-9. [PMID: 18804029 DOI: 10.1016/j.chembiol.2008.07.018] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 07/26/2008] [Accepted: 07/31/2008] [Indexed: 11/29/2022]
Abstract
M1 aminopeptidases comprise a large family of biologically important zinc enzymes. We show that peptide turnover by the M1 prototype, leukotriene A4 hydrolase/aminopeptidase, involves a shift in substrate position associated with exchange of zinc coordinating groups, while maintaining the overall coordination geometry. The transition state is stabilized by residues conserved among M1 members and in the final reaction step, Glu-296 of the canonical zinc binding HEXXH motif shuffles a proton from the hydrolytic water to the leaving group. Tripeptide substrates bind along the conserved GXMEN motif, precisely occupying the distance between Glu-271 and Arg-563, whereas the Arg specificity is governed by a narrow S1 pocket capped with Asp-375. Our data provide detailed insights to the active site chemistry of M1 aminopeptidases and will aid in the development of novel enzyme inhibitors.
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Affiliation(s)
- Fredrik Tholander
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institute, Stockholm, Sweden
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4
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Haeggström JZ, Tholander F, Wetterholm A. Structure and catalytic mechanisms of leukotriene A4 hydrolase. Prostaglandins Other Lipid Mediat 2007; 83:198-202. [PMID: 17481555 DOI: 10.1016/j.prostaglandins.2007.01.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Leukotriene A4 hydrolase catalyzes the final and committed step in the biosynthesis of leukotriene B4, a potent chemotactic agent for neutrophils, eosinophils, monocytes, and T-cells that play key roles in the innate immune response. Recent data strongly implicates leukotriene B4 in the pathogenesis of cardiovascular diseases, in particular arteriosclerosis, myocardial infarction and stroke. Here, we highlight the most salient features of leukotriene A4 hydrolase with emphasis on its biochemistry and structure biology.
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Affiliation(s)
- Jesper Z Haeggström
- Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, S-171 77 Stockholm, Sweden.
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5
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Haeggström JZ. Leukotriene A4 hydrolase/aminopeptidase, the gatekeeper of chemotactic leukotriene B4 biosynthesis. J Biol Chem 2004; 279:50639-42. [PMID: 15339917 DOI: 10.1074/jbc.r400027200] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Jesper Z Haeggström
- Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, S-171 77 Stockholm, Sweden.
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6
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Haeggström JZ, Kull F, Rudberg PC, Tholander F, Thunnissen MMGM. Leukotriene A4 hydrolase. Prostaglandins Other Lipid Mediat 2002; 68-69:495-510. [PMID: 12432939 DOI: 10.1016/s0090-6980(02)00051-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The leukotrienes (LTs) are a family of lipid mediators involved in inflammation and allergy. Leukotriene B4 is a classical chemoattractant, which triggers adherence and aggregation of leukocytes to the endothelium at only nanomolar concentrations. In addition, leukotriene B4 modulates immune responses, participates in the host-defense against infections, and is a key mediator of PAF-induced lethal shock. Because of these powerful biological effects, leukotriene B4 is implicated in a variety of acute and chronic inflammatory diseases, e.g. nephritis, arthritis, dermatitis, and chronic obstructive pulmonary disease. The final step in the biosynthesis of leukotriene B4 is catalyzed by leukotriene A4 hydrolase, a unique bi-functional zinc metalloenzyme with an anion-dependent aminopeptidase activity. Here we describe the most recent developments regarding our understanding of the structure, function, and catalytic mechanisms of leukotriene A4 hydrolase.
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Affiliation(s)
- Jesper Z Haeggström
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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7
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Haeggström JZ, Wetterholm A. Leukotriene-A4 hydrolase: probing the active sites and catalytic mechanisms by site-directed mutagenesis. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2000:85-96. [PMID: 10943329 DOI: 10.1007/978-3-662-04047-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J Z Haeggström
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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8
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Rasmussen TE, Pedraza-Díaz S, Hardré R, Laustsen PG, Carríon AG, Kristensen T. Structure of the human oxytocinase/insulin-regulated aminopeptidase gene and localization to chromosome 5q21. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:2297-306. [PMID: 10759854 DOI: 10.1046/j.1432-1327.2000.01234.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The human oxytocinase/insulin-regulated aminopeptidase (OTase/IRAP) is a 1024 amino acid type II integral membrane protein that is expressed mainly in fat, muscle and placenta tissues. It has been thought to be involved mainly in the control of onset of labour but recently rat OTase/IRAP was shown to participate in the regulation of glucose transporter isoform 4 vesicle trafficking in adipocytes as well. To approach an understanding of OTase/IRAP gene regulation the organization of the human gene was determined. Accordingly, three overlapping genomic clones were isolated and characterized. The human OTase/IRAP gene (OTASE) was found to span approximately 75 kb containing 18 exons and 17 introns. The gluzincin aminopeptidase motif: GAMEN-(31 amino acids)-HELAH-(18 amino acids)-E associated with Zn2+-binding, substrate binding and catalysis is encoded by exons 6 and 7. A major and a minor transcriptional initiation site in OTASE were identified by primer extension 514 bp and 551 bp, respectively, upstream of the translation start codon. Chloroamphenicol acetyltransferase-reporter assays revealed a functional CpG-rich promoter/enhancer region located between nucleotide -621 and the major transcriptional initiation site. Human OTASE was assigned to chromosome 5 by hybridization to genomic DNA from characterized somatic cell hybrids. Finally, the OTASE and the human aminopeptidase A gene were subchromosomally localized to 5q21 and 4q25, respectively, by in situ hybridization.
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Affiliation(s)
- T E Rasmussen
- Department of Molecular and Structural Biology, University of Aarhus, Denmark
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9
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Andberg M, Hamberg M, Haeggström JZ. Evidence for a carbocation intermediate in the enzymatic transformation of leukotriene A4 into leukotriene B4. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 469:319-25. [PMID: 10667348 DOI: 10.1007/978-1-4615-4793-8_47] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Affiliation(s)
- M Andberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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10
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Penning TD, Chandrakumar NS, Chen BB, Chen HY, Desai BN, Djuric SW, Docter SH, Gasiecki AF, Haack RA, Miyashiro JM, Russell MA, Yu SS, Corley DG, Durley RC, Kilpatrick BF, Parnas BL, Askonas LJ, Gierse JK, Harding EI, Highkin MK, Kachur JF, Kim SH, Krivi GG, Villani-Price D, Pyla EY, Smith WG. Structure-activity relationship studies on 1-[2-(4-Phenylphenoxy)ethyl]pyrrolidine (SC-22716), a potent inhibitor of leukotriene A(4) (LTA(4)) hydrolase. J Med Chem 2000; 43:721-35. [PMID: 10691697 DOI: 10.1021/jm990496z] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Leukotriene B(4) (LTB(4)) is a pro-inflammatory mediator that has been implicated in the pathogenesis of a number of diseases including inflammatory bowel disease (IBD) and psoriasis. Since the action of LTA(4) hydrolase is the rate-limiting step for LTB(4) production, this enzyme represents an attractive pharmacological target for the suppression of LTB(4) production. From an in-house screening program, SC-22716 (1, 1-[2-(4-phenylphenoxy)ethyl]pyrrolidine) was identified as a potent inhibitor of LTA(4) hydrolase. Structure-activity relationship (SAR) studies around this structural class resulted in the identification of a number of novel, potent inhibitors of LTA(4) hydrolase, several of which demonstrated good oral activity in a mouse ex vivo whole blood assay.
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Affiliation(s)
- T D Penning
- Departments of Medicinal Chemistry, Structure-Activity Screening Program, Inflammatory Diseases Research, and Molecular Pharmacology, Searle Research and Development, Monsanto Company, Skokie, Illinois 60077, USA.
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11
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Affiliation(s)
- J Z Haeggström
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, Stockholm, Sweden.
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12
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Haeggström JZ. Leukotriene A4 hydrolase and the committed step in leukotriene B4 biosynthesis. Clin Rev Allergy Immunol 1999; 17:111-31. [PMID: 10436862 DOI: 10.1007/bf02737600] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- J Z Haeggström
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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13
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Orning L, Fitzpatrick FA. Modification of leukotriene A(4) hydrolase/aminopeptidase by sulfhydryl-blocking reagents: differential effects on dual enzyme activities by methyl-methane thiosulfonate. Arch Biochem Biophys 1999; 368:131-8. [PMID: 10415120 DOI: 10.1006/abbi.1999.1289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The presence of a cysteine residue at or near the active site of leukotriene A(4) hydrolase (EC 3.3.2.6) was suggested by inactivation of the enzyme with sulfhydryl-blocking reagents and by protection against inactivation afforded by substrates and competitive inhibitors. The aminopeptidase activity was more susceptible to inactivation than the epoxide hydrolase activity. The sulfhydryl-modifying reagent methyl-methane thiosulfonate reacted with one thiol as judged by kinetic data and titration with 5, 5'-dithiobis-2-nitrobenzoate. Inactivation was a time- and dose-dependent process of apparent pseudo-first-order and maximal at 80-85%. The inactivation rate was nonsaturable and strongly influenced by ion strength. The second-order rate constant increased from 0.9 to 4.3 M(-1) s(-1) in the presence of 0.2 M NaCl. Albumin, a stimulator of the aminopeptidase activity, increased apparent inactivation rates by shifting pK(a) for the modification from 8.2 to 7.8. The inactivated enzyme partially regained activity upon treatment with beta-mercaptoethanol. Peptide substrates and competitive inhibitors protected against inactivation. Bestatin, a competitive inhibitor, afforded complete protection with a K(D) = 0.15 microM, similar to K(i) = 0.17 microM for inhibition of peptidase activity. Treated enzyme had an unchanged K(m) but a reduced V(max). The epoxide hydrolase activity was only weakly affected by methyl-methane thiosulfonate with a maximal inactivation of 15-20% after prolonged treatment. Pretreatment of leukotriene A(4) hydrolase with the reagent did not protect against mechanism-based inactivation by its lipid substrate, leukotriene A(4). On the other hand, leukotriene B(4) was a competitive inhibitor of aminopeptidase activity and protected against modification by methyl-methane thiosulfonate. Our results suggest the presence of a cysteine at or close to subsite S'(1) of the active site of leukotriene A(4) hydrolase and that modification of this residue interferes with the function of the aminopeptidase activity, but not the epoxide hydrolase activity. This is the first report to distinguish the two catalytic activities of leukotriene A(4) hydrolase by chemical means.
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Affiliation(s)
- L Orning
- Axis Biochemicals ASA, Oslo, Norway.
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14
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Barbirato F, Verdoes JC, de Bont JA, van der Werf MJ. The Rhodococcus erythropolis DCL14 limonene-1,2-epoxide hydrolase gene encodes an enzyme belonging to a novel class of epoxide hydrolases. FEBS Lett 1998; 438:293-6. [PMID: 9827564 DOI: 10.1016/s0014-5793(98)01322-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recently, we reported the purification of the novel enzyme limonene-1,2-epoxide hydrolase involved in limonene degradation by Rhodococcus erythropolis DCL14. The N-terminal amino acid sequence of the purified enzyme was used to design two degenerate primers at the beginning and the end of the 50 amino acids long stretch. Subsequently, the complete limonene-1,2-epoxide hydrolase gene (limA) was isolated from a genomic library of R. erythropolis DCL14 using a combination of PCR and colony hybridization. The limA gene encoded a 149-residue polypeptide with a deduced molecular mass of 16.5 kDa. It was functionally expressed in Escherichia coli. The amino acid sequence of limA contains neither any of the conserved regions of the alpha,beta-hydrolase fold enzymes, to which most of the previously reported epoxide hydrolases belong, nor any of the conserved motifs present in leukotriene A4 hydrolase. The structural data presented in this paper confirm previous physical and biochemical findings [van der Werf et al. (1998) J. Bacteriol. 180, 5052-5057] that limonene-1,2-epoxide hydrolase is the first member of a new class of epoxide hydrolases.
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Affiliation(s)
- F Barbirato
- Department of Food Technology and Nutritional Sciences, Wageningen University and Research Centre, The Netherlands
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15
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Mueller MJ, Andberg M, Haeggström JZ. Analysis of the molecular mechanism of substrate-mediated inactivation of leukotriene A4 hydrolase. J Biol Chem 1998; 273:11570-5. [PMID: 9565573 DOI: 10.1074/jbc.273.19.11570] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The bifunctional leukotriene A4 hydrolase catalyzes the final step in the biosynthesis of the proinflammatory leukotriene B4. During exposure to the substrate leukotriene A4, a labile allylic epoxide, the enzyme is gradually inactivated as a consequence of the covalent binding of leukotriene A4 to the active site. This phenomenon, commonly referred to as suicide inactivation, has previously been rationalized as a mechanism-based process in which the enzyme converts the substrate to a highly reactive intermediate within an activated enzyme-substrate complex that partitions between covalent bond formation (inactivation) and catalysis. To further explore the molecular mechanism of the self-inactivation of leukotriene A4 hydrolase by leukotriene A4, we prepared and analyzed mutated forms of the enzyme that were either catalytically incompetent or fully active but resistant toward substrate-mediated inactivation. These mutants were treated with leukotriene A4 and leukotriene A4 methyl and ethyl esters and subjected to differential peptide mapping and enzyme activity determinations, which showed that inactivation and/or covalent modification can be completely dissociated from catalysis. Our results, together with recent findings described in the literature, argue against a mechanism-based model for suicide inactivation. We conclude that the collected data on the substrate-mediated inactivation of leukotriene A4 hydrolase best conforms to an affinity-labeling mechanism.
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Affiliation(s)
- M J Mueller
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, S-171 77 Stockholm, Sweden
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16
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Andberg M, Wetterholm A, Haeggström JZ. Mutation of Tyr-383 in leukotriene A4 hydrolase: effects on enzyme activities. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 433:149-52. [PMID: 9561123 DOI: 10.1007/978-1-4899-1810-9_30] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- M Andberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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17
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Sajid M, Isaac RE, Harrow ID. Purification and properties of a membrane aminopeptidase from Ascaris suum muscle that degrades neuropeptides AF1 and AF2. Mol Biochem Parasitol 1997; 89:225-34. [PMID: 9364967 DOI: 10.1016/s0166-6851(97)00119-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have identified on the membranes of the locomotory muscle of Ascaris suum an amastatin-sensitive aminopeptidase that hydrolyses the bioactive neuropeptides AF1 (KNEFIRF-NH2) and AF2 (KHEYLRF-NH2), by cleavage of the Lys1-Asn2 and Lys1-His2 peptide bonds, respectively. AF2 (1.2 nmol of HEYLRF-NH2 formed min[-1] (mg protein[-1])) was hydrolysed at a faster rate compared to AF1 (0.2 nmol of NEFIRF-NH2 formed min[-1] (mg protein[-1])). AF1 hydrolysis by the aminopeptidase was inhibited by the amastatin (IC50, 9.0 microM), leuhistin (IC50, 1.25 microM) but was insensitive to puromycin, indicating a similarity to mammalian aminopeptidase N. The enzyme was also inhibited by arphamenine B (IC50, 9.0 microM), (2S, 3R)-3-amino-2-hydroxy-4-(4-nitrophenyl)butanoyl-L-leucine (IC50, 8.0 microM), bestatin (IC50, 15.0 microM) and 1 mM 1-10 bis-phenanthroline. The detergent Triton X-100 solubilised enzyme had a pI of 5.0 and after 1000-fold purification by ion-exchange chromatography, appeared to have a Mr of around 240,000 by SDS-PAGE. The purified aminopeptidase had a Km of 534 microM for the hydrolysis of AF1 and cleaved Phe1 from FMRF-NH2, but was unable to hydrolyse DFMRF-NH2 or FDMRF-NH2. The aminopeptidase that we have described in this report might have a role in the extracellular metabolism and inactivation of neuropeptides acting on the locomotory muscle of A. suum.
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Affiliation(s)
- M Sajid
- Department of Pure and Applied Biology, University of Leeds, UK
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18
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Wetterholm A, Mueller MJ, Blomster M, Samuelsson B, Haeggström JZ. Studies on the active site of leukotriene A4 hydrolase. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 407:1-7. [PMID: 9321924 DOI: 10.1007/978-1-4899-1813-0_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- A Wetterholm
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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19
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Andberg MB, Hamberg M, Haeggström JZ. Mutation of tyrosine 383 in leukotriene A4 hydrolase allows conversion of leukotriene A4 into 5S,6S-dihydroxy-7,9-trans-11,14-cis-eicosatetraenoic acid. Implications for the epoxide hydrolase mechanism. J Biol Chem 1997; 272:23057-63. [PMID: 9287304 DOI: 10.1074/jbc.272.37.23057] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Leukotriene A4 hydrolase is a bifunctional zinc metalloenzyme that catalyzes the final step in the biosynthesis of the proinflammatory mediator leukotriene B4. In previous studies with site-directed mutagenesis on mouse leukotriene A4 hydrolase, we have identified Tyr-383 as a catalytic amino acid involved in the peptidase reaction. Further characterization of the mutants in position 383 revealed that [Y383H], [Y383F], and [Y383Q] leukotriene A4 hydrolases catalyzed hydrolysis of leukotriene A4 into a novel enzymatic metabolite. From analysis by high performance liquid chromatography, gas chromatography/mass spectrometry of material generated in the presence of H216O or H218O, steric analysis of the hydroxyl groups, treatment with soybean lipoxygenase, and comparison with a synthetic standard, the novel metabolite was assigned the structure 5S, 6S-dihydroxy-7,9-trans-11,14-cis-eicosatetraenoic acid (5S,6S-DHETE). The kinetic parameters for the formation of 5S,6S-DHETE and leukotriene B4 were found to be similar. Also, both activities were susceptible to suicide inactivation and were equally sensitive to inhibition by bestatin. Moreover, from the stereochemical configuration of the vicinal diol, it could be inferred that 5S, 6S-DHETE is formed via an SN1 mechanism involving a carbocation intermediate, which in turn indicates that enzymatic hydrolysis of leukotriene A4 into leukotriene B4 follows the same mechanism. Inasmuch as soluble epoxide hydrolase utilizes leukotriene A4 as substrate to produce 5S,6R-DHETE, our results also suggest a functional relationship between leukotriene A4 hydrolase and xenobiotic epoxide hydrolases.
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Affiliation(s)
- M B Andberg
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, S-171 77 Stockholm, Sweden
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20
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Laustsen PG, Rasmussen TE, Petersen K, Pedraza-Diaz S, Moestrup SK, Gliemann J, Sottrup-Jensen L, Kristensen T. The complete amino acid sequence of human placental oxytocinase. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1352:1-7. [PMID: 9177475 DOI: 10.1016/s0167-4781(97)00036-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The complete amino acid sequence of human placental oxytocinase (placental leucine aminopeptidase) has been determined by cDNA cloning and sequencing. Oxytocinase is a type II integral membrane protein of 1025 amino acid residues, consisting of an acidic intracellular region of 110 amino acids followed by a hydrophobic transmembrane segment of 22 residues and 893 extracellular residues containing the characteristic Zn2+ coordination sequence element His-Glu-Xaa-Xaa-His-(18 residues)-Glu found in gluzincins. Two sets of cDNA clones with different 5'-ends were isolated and suggested to represent different spliced products of 3.6 kb (mature mRNA) and 12 kb, respectively. Oxytocinase mRNA is present in large amounts in placenta, heart and skeletal muscle and in small amounts in brain, kidney, liver and pancreas. A conserved sequence element, the GAMEN motif, which distinguishes the aminopeptidase family among gluzincins from other gluzincins, has been identified.
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Affiliation(s)
- P G Laustsen
- Department of Molecular and Structural Biology, Aarhus University, Denmark
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21
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Penning TD, Askonas LJ, Djuric SW, Haack RA, Yu SS, Michener ML, Krivi GG, Pyla E. Kelatorphan and related analogs: potent and selective inhibitors of leukotriene A4 hydrolase. Bioorg Med Chem Lett 1995. [DOI: 10.1016/0960-894x(95)00441-u] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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22
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Nissen JB, Iversen L, Kragballe K. Characterization of the aminopeptidase activity of epidermal leukotriene A4 hydrolase against the opioid dynorphin fragment 1-7. Br J Dermatol 1995; 133:742-9. [PMID: 8555027 DOI: 10.1111/j.1365-2133.1995.tb02749.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Leukotriene A4 hydrolase is a bifunctional cytosolic enzyme, which both hydrolyses leukotriene A4 (LTA4) into leukotriene B4 (LTB4) and exerts aminopeptidase activity against opioid peptides. In the present study we have investigated whether the peptides angiotensin I and II, bradykinin, kallidine, histamine, dynorphin fragment 1-7 and substance P can act as substrates for epidermal and neutrophil LTA4 hydrolase. Among the tested substrates, dynorphin fragment 1-7 was found to be the best substrate for the enzyme. The aminopeptidase activity of epidermal and neutrophil LTA4 hydrolase against dynorphin fragment 1-7 was further characterized. The enzyme was purified from human epidermis and human neutrophils by anion exchange chromatography (Q-Sepharose) and affinity chromatography on a column with the LTA4 hydrolase inhibitor bestatin coupled to AH-Sepharose. The incubation of the dynorphin fragment 1-7 with LTA4 hydrolase resulted in the formation of tyrosine. The presence of the N-terminal amino acid tyrosine is essential for the interaction of opioids with their receptors, and this finding indicates that the LTA4 hydrolase can inactivate dynorphin fragment 1-7. After the two purification steps no other aminopeptidases acting at the N-terminal tyrosine of dynorphin fragment 1-7 was present in the preparation. This was demonstrated by the abolishment of the degradation at the N-terminal end of dynorphin fragment 1-7 when preincubating the enzyme preparation with LTA4 before the incubation with the dynorphin fragment 1-7. The abolishment of the aminopeptidase activity shows that activation of the hydrolase part of the enzyme, with conversion of LTA4 into the potent proinflammatory compound LTB4, results in an inhibition of the aminopeptidase activity of the enzyme. As a result, the catabolism of dynorphin fragment 1-7 and probably of other opioid peptides is inhibited, resulting in sustained biological effects of these opioids. This phenomenon may be important for the maintenance of inflammation in skin conditions, such as psoriasis and atopic dermatitis, in which LTB4 is formed.
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Affiliation(s)
- J B Nissen
- Department of Dermatology, Marselisborg Hospital, University of Aarhus, Denmark
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23
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Yokomizo T, Uozumi N, Takahashi T, Kume K, Izumi T, Shimizu T. Leukotriene A4 hydrolase and leukotriene B4 metabolism. JOURNAL OF LIPID MEDIATORS AND CELL SIGNALLING 1995; 12:321-32. [PMID: 8777576 DOI: 10.1016/0929-7855(95)00041-n] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- T Yokomizo
- Department of Biochemistry, Faculty of Medicine, University of Tokyo, Japan
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24
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Minami M, Mutoh H, Ohishi N, Honda Z, Bito H, Shimizu T. Amino-acid sequence and tissue distribution of guinea-pig leukotriene A4 hydrolase. Gene 1995; 161:249-51. [PMID: 7665088 DOI: 10.1016/0378-1119(95)00179-a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The guinea-pig leukotriene A4 hydrolase (LTA4H)-encoding cDNA was isolated from a guinea-pig lung cDNA library by cross-hybridization using a human probe. The deduced amino acid (aa) sequence consists of 611 aa (68 756 Da) and contains all twelve internal peptide and N-terminal sequences determined from the purified enzyme from guinea-pig intestine. The aa identity of the guinea-pig enzyme with its human, mouse and rat counterparts was 92.9, 90.5 and 90.4%, respectively. The previously characterized zinc-binding motif and a putative active site were highly conserved, supporting the aminopeptidase activity described for this enzyme. RNA blot analysis demonstrated ubiquitous expression of the LTA4H mRNA.
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Affiliation(s)
- M Minami
- Department of Biochemistry, Faculty of Medicine, University of Tokyo, Japan
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25
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Blomster M, Wetterholm A, Mueller MJ, Haeggström JZ. Evidence for a catalytic role of tyrosine 383 in the peptidase reaction of leukotriene A4 hydrolase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1995; 231:528-34. [PMID: 7649151 DOI: 10.1111/j.1432-1033.1995.0528d.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Leukotriene A4 (LTA4) hydrolase is a bifunctional zinc metalloenzyme which catalyzes the final step in the biosynthesis of the proinflammatory leukotriene B4 and which also possesses a peptidase activity. From sequence comparisons with aminopeptidases, a tyrosine at position 383 in LTA4 hydrolase has been suggested as a possible catalytic amino acid. To explore the potential role of this amino acid in catalysis, we replaced the tyrosine residue with phenylalanine, histidine or glutamine residues by site-directed mutagenesis. The mutated cDNAs were expressed in Escherichia coli and the resulting recombinant proteins, named [Y383F]LTA4 hydrolase, [Y383H]LTA4 hydrolase and [Y383Q]LTA4 hydrolase, were purified to homogeneity to allow assays of both the epoxide hydrolase activity, i.e. the conversion of LTA4 into leukotriene B4, and the peptidase activity. None of the mutated proteins exhibited significant peptidase activities, all of them showing activities less than 0.3% that of the wild-type enzyme. The epoxide hydrolase activity was not affected to the same degree and corresponded to 11, 16 and 17% that of the unmutated enzyme for [Y383F]LTA4 hydrolase, [Y383H]LTA4 hydrolase and [Y383Q]LTA4 hydrolase, respectively. Kinetic analysis was performed with the mutant [Y383Q]LTA4 hydrolase, which revealed an approximately 10-fold increase in Km for leukotriene A4 compared to that for the unmutated enzyme. At high concentrations of substrate, the difference in enzyme velocity was only moderate, with Vmax values of 600 nmol.mg-1.min-1 and 1000 nmol.mg-1.min-1 for [Y383Q]LTA4 hydrolase and the wild-type enzyme, respectively. No such effect of substrate concentration could be observed on the peptidase activity. As a positive control, we exchanged a glycine residue in position 386 for an alanine residue, and the recombinant protein, [G386A]LTA4 hydrolase retained 19% and 77% of the peptidase and epoxide hydrolase activities, respectively. The results from this study are consistent with a role for Tyr383 in the peptidase reaction of LTA4 hydrolase, where it may act as a proton donor in a general base mechanism. However, our data do not allow a similar interpretation for the mechanism involved in the hydrolysis of LTA4 into LTB4.
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Affiliation(s)
- M Blomster
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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26
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Ollmann IR, Hogg JH, Muñoz B, Haeggström JZ, Samuelsson B, Wong CH. Investigation of the inhibition of leukotriene A4 hydrolase. Bioorg Med Chem 1995; 3:969-95. [PMID: 7582974 DOI: 10.1016/0968-0896(95)00078-u] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In an effort to better understand the favorable binding interactions between the reversible picomolar inhibitor 3-(4-benzyloxyphenyl)-2-(R)-amino-1- propanethiol (1) and leukotriene A4 (LTA4) hydrolase (EC 3.3.2.6), we prepared a number of derivatives of 1-L and other related structures, and assayed their inhibition of LTA4 hydrolase-catalyzed hydrolysis of L-alanine-p-nitroanilide. The inhibition data was analyzed using a weighted non-linear least-squares curve fitting computer program developed for this purpose to fit data derived under the non-Michaelis-Menten condition of [I]t < [E]t. The free thiol is necessary for sub-micromolar binding and the enzyme prefers the R enantiomer over the S enantiomer, in contrast to the stereoselectivity displayed towards bestatin, an inhibitor of somewhat similar structure. Substitution of acid moieties around the periphery of the benzyloxyphenyl portion of 1-L leads to substantially decreased binding, suggesting that this group resides within a large hydrophobic pocket when bound to the enzyme. Possible LTA4 binding modes in the active site of LTA4 hydrolase, including a possible direct role for the carboxylic acid of LTA4 in the enzyme-catalyzed hydrolysis of leukotriene A4, are discussed.
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Affiliation(s)
- I R Ollmann
- Department of Chemistry, Scripps Research Institute, La Jolla, CA 92037, USA
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27
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Orning L, Gierse J, Fitzpatrick F. The bifunctional enzyme leukotriene-A4 hydrolase is an arginine aminopeptidase of high efficiency and specificity. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)78120-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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28
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Pelletier JN, MacKenzie RE. Binding of the 2',5'-ADP subsite stimulates cyclohydrolase activity of human NADP(+)-dependent methylenetetrahydrofolate dehydrogenase/cyclohydrolase. Biochemistry 1994; 33:1900-6. [PMID: 8110794 DOI: 10.1021/bi00173a037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The bifunctional dehydrogenase/cyclohydrolase domain of the human trifunctional methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase/formyltetrahydrofolate synthetase catalyzes two sequential reactions with significant channeling of the intermediate, methenyltetrahydrofolate. Equilibrium dialysis established that a single, high-affinity NADP+ binding site exists per monomer of the dimeric enzyme. Kinetic characterization of NADP+ binding to the dehydrogenase using analogs as inhibitors demonstrated that affinity for this substrate is due almost exclusively to binding at the 2',5'-ADP subsite. The same structural specificities for binding are exhibited by these analogs in their effects on the cyclohydrolase. Both NADP+ and its 3-aminopyridine analog AADP partially inhibit the activity of the cyclohydrolase when assayed with added methenyltetrahydrofolate as substrate. However, under the same conditions, the cyclohydrolase is actually activated by 2',5'-ADP; activation requires the presence of the 5'-phosphate since 2'-AMP binds but does not activate. Nicotinamide ribose monophosphate (NMN) has no detectable effect either alone or in combination with 2',5'-ADP. The results are consistent with the existence of a shared dehydrogenase/cyclohydrolase active site proximal to the 2',5'-ADP subsite. NADP+ reduces the rate of the fully activated cyclohydrolase by 2-fold. Inhibition appears to be due to the loosely bound nicotinamide ring interacting with the common folate subsite, resulting in only partial inhibition by NADP+. The interaction of 2',5'-ADP with the cyclohydrolase suggests a potential role for this portion of the molecule in promoting the efficiency of the channeling of endogenously generated methenyltetrahydrofolate.
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Affiliation(s)
- J N Pelletier
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
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