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Abstract
Pyroglutamate (pE) modification, catalyzed mainly by glutaminyl cyclase (QC), is prevalent throughout nature and is particularly important in mammals including humans for the maturation of hormones, peptides, and proteins. In humans, the upregulation of QC is involved in multiple diseases and conditions including Alzheimer's disease, Huntington's disease, melanomas, thyroid carcinomas, accelerated atherosclerosis, septic arthritics, etc. This upregulation catalyzes the generation of modified mediators such as pE-amyloid beta (Aß) and pE-chemokine ligand 2 (CCL2) peptides. Not surprisingly, QC has emerged as a reasonable target for the development of therapeutics to combat these diseases and conditions. In this manuscript the deleterious effects of upregulated QC resulting in disease manifestation are reviewed, along with progress on the development of QC inhibitors.
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Affiliation(s)
- Chenshu Xu
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen 518060, China
| | - Yi-Nan Wang
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen 518060, China
| | - Haiqiang Wu
- School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen 518060, China
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Wang X, Wang L, Yu X, Li Y, Liu Z, Zou Y, Zheng Y, He Z, Wu H. Glutaminyl cyclase inhibitor exhibits anti-inflammatory effects in both AD and LPS-induced inflammatory model mice. Int Immunopharmacol 2019; 75:105770. [DOI: 10.1016/j.intimp.2019.105770] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/13/2019] [Accepted: 07/18/2019] [Indexed: 01/08/2023]
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Khan RAW, Chen J, Shen J, Li Z, Wang M, Wen Z, Song Z, Li W, Xu Y, Shi Y, Yi Q, Ji W. Common variants in QPCT gene confer risk of schizophrenia in the Han Chinese population. Am J Med Genet B Neuropsychiatr Genet 2016; 171B:237-42. [PMID: 26492838 DOI: 10.1002/ajmg.b.32397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/14/2015] [Indexed: 11/11/2022]
Abstract
Schizophrenia (SCZ) is a common and severe mental disorder, its etiology has not been elucidated completely. In one previous genome-wide association study (GWAS) of SCZ in the Caucasian population, the QPCT has been reported as susceptible gene for SCZ. The QPCT gene encodes Glutaminyl cyclase (QC), an enzyme which is involved in the post translational modification by converting N-terminal glutamate of protein to pyroglutamate, which is resistant to protease degradation, more hydrophobic, and prone to aggregation and neurotoxic. To further investigate the role of this gene in the pathogenesis of schizophrenia in the Han Chinese population, we conducted this study in 1,248 (Mean age ± S.D, 36.44 years ± 9.0) SCZ cases, 1,248 (Mean age ± S.D, 30.62 years ± 11.35) healthy control samples for a case control study. We genotyped six SNPs in this study, including one positive SNP of the previous study, using the Sequenom MassARRAY platform. We found that rs2373000 was significantly associated with SCZ before correction [rs2373000: P allele = 0.016, χ(2) = 5.784, OR [95%CI] = 0.861 [0.762-0.972], P genotype = 0.018, χ(2) = 0.069]. After permutation correction for multiple testing, rs2373000 [rs2373000: P Allele corrected = 0.063, P genotype corrected = 0.069] showed marginal association with SCZ. Additionally, one pathogenic haplotype (TGT) containing rs2373000 was also significantly associated with SCZ. Our results are consistent with the findings of previous study and the genetic risk of QPCT gene for SCZ also exists in the Han Chinese population.
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Affiliation(s)
- Raja Amjad Waheed Khan
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China.,University of Azad Jammu and Kashmir, Department of Chemistry, Muzaffarabad, 13100, Pakistan
| | - Jianhua Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jiawei Shen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Zhiqiang Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Meng Wang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Zujia Wen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Zhijian Song
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Wenjin Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Yifeng Xu
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Yongyong Shi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China.,Shanghai Changning Mental Health Center, Shanghai, People's Republic of China.,Institute of Neuropsychiatric Science and Systems Biological Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Qizhong Yi
- Department of Psychiatry, First Teaching Hospital of Xinjiang Medical University, Urumqi, People's Republic of China
| | - Weidong Ji
- Shanghai Changning Mental Health Center, Shanghai, People's Republic of China.,Institute of Neuropsychiatric Science and Systems Biological Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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Nemoto TK, Ohara-Nemoto Y, Bezerra GA, Shimoyama Y, Kimura S. A Porphyromonas gingivalis Periplasmic Novel Exopeptidase, Acylpeptidyl Oligopeptidase, Releases N-Acylated Di- and Tripeptides from Oligopeptides. J Biol Chem 2016; 291:5913-5925. [PMID: 26733202 DOI: 10.1074/jbc.m115.687566] [Citation(s) in RCA: 13] [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: 08/23/2015] [Indexed: 01/01/2023] Open
Abstract
Exopeptidases, including dipeptidyl- and tripeptidylpeptidase, are crucial for the growth of Porphyromonas gingivalis, a periodontopathic asaccharolytic bacterium that incorporates amino acids mainly as di- and tripeptides. In this study, we identified a novel exopeptidase, designated acylpeptidyl oligopeptidase (AOP), composed of 759 amino acid residues with active Ser(615) and encoded by PGN_1349 in P. gingivalis ATCC 33277. AOP is currently listed as an unassigned S9 family peptidase or prolyl oligopeptidase. Recombinant AOP did not hydrolyze a Pro-Xaa bond. In addition, although sequence similarities to human and archaea-type acylaminoacyl peptidase sequences were observed, its enzymatic properties were apparently distinct from those, because AOP scarcely released an N-acyl-amino acid as compared with di- and tripeptides, especially with N-terminal modification. The kcat/Km value against benzyloxycarbonyl-Val-Lys-Met-4-methycoumaryl-7-amide, the most potent substrate, was 123.3 ± 17.3 μm(-1) s(-1), optimal pH was 7-8.5, and the activity was decreased with increased NaCl concentrations. AOP existed predominantly in the periplasmic fraction as a monomer, whereas equilibrium between monomers and oligomers was observed with a recombinant molecule, suggesting a tendency of oligomerization mediated by the N-terminal region (Met(16)-Glu(101)). Three-dimensional modeling revealed the three domain structures (residues Met(16)-Ala(126), which has no similar homologue with known structure; residues Leu(127)-Met(495) (β-propeller domain); and residues Ala(496)-Phe(736) (α/β-hydrolase domain)) and further indicated the hydrophobic S1 site of AOP in accord with its hydrophobic P1 preference. AOP orthologues are widely distributed in bacteria, archaea, and eukaryotes, suggesting its importance for processing of nutritional and/or bioactive oligopeptides.
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Affiliation(s)
- Takayuki K Nemoto
- From the Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan
| | - Yuko Ohara-Nemoto
- From the Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan
| | - Gustavo Arruda Bezerra
- the Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria, and.
| | - Yu Shimoyama
- the Division of Molecular Microbiology, Iwate Medical University, Iwate 028-3694, Japan
| | - Shigenobu Kimura
- the Division of Molecular Microbiology, Iwate Medical University, Iwate 028-3694, Japan
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Todd K, Ghiso J, Rostagno A. Oxidative stress and mitochondria-mediated cell death mechanisms triggered by the familial Danish dementia ADan amyloid. Neurobiol Dis 2015; 85:130-143. [PMID: 26459115 DOI: 10.1016/j.nbd.2015.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [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: 01/08/2015] [Revised: 09/14/2015] [Accepted: 10/08/2015] [Indexed: 12/16/2022] Open
Abstract
Familial Danish Dementia (FDD), an early-onset non-amyloid-β (Aβ) cerebral amyloidosis, is neuropathologically characterized by widespread cerebral amyloid angiopathy, parenchymal amyloid and preamyloid deposits, as well as neurofibrillary degeneration indistinguishable to that seen in Alzheimer's disease (AD). The main amyloid subunit composing FDD lesions, a 34-amino acid de-novo generated peptide ADan, is the direct result of a genetic defect at the 3'-end of the BRI2 gene and the physiologic action of furin-like proteolytic processing at the C-terminal region of the ADan precursor protein. We aimed to study the impact of the FDD mutation, the additional formation of the pyroglutamate (pE) posttranslational modification as well as the relevance of C-terminal truncations -all major components of the heterogeneous FDD deposits- on the structural and neurotoxic properties of the molecule. Our data indicates that whereas the mutation generated a β-sheet-rich hydrophobic ADan subunit of high oligomerization/fibrillization propensity and the pE modification further enhanced these properties, C-terminal truncations had the opposite effect mostly abolishing these features. The potentiation of pro-amyloidogenic properties correlated with the initiation of neuronal cell death mechanisms involving oxidative stress, perturbation of mitochondrial membrane potential, release of mitochondrial cytochrome c, and downstream activation of caspase-mediated apoptotic pathways. The amyloid-induced toxicity was inhibited by targeting specific components of these detrimental cellular pathways, using reactive oxygen scavengers and monoclonal antibodies recognizing the pathological amyloid subunit. Taken together, the data indicate that the FDD mutation and the pE posttranslational modification are both primary elements driving intact ADan into an amyloidogenic/neurotoxic pathway while truncations at the C-terminus eliminate the pro-amyloidogenic characteristics of the molecule, likely reflecting effect of physiologic clearance mechanisms.
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Affiliation(s)
- Krysti Todd
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Jorge Ghiso
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA; Department of Psychiatry, New York University School of Medicine, New York, NY 10016, USA.
| | - Agueda Rostagno
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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Höfling C, Indrischek H, Höpcke T, Waniek A, Cynis H, Koch B, Schilling S, Morawski M, Demuth HU, Roßner S, Hartlage-Rübsamen M. Mouse strain and brain region-specific expression of the glutaminyl cyclases QC and isoQC. Int J Dev Neurosci 2014; 36:64-73. [PMID: 24886834 DOI: 10.1016/j.ijdevneu.2014.05.008] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 05/20/2014] [Indexed: 11/25/2022] Open
Abstract
Glutaminyl cyclases (QCs) catalyze the formation of pyroglutamate (pGlu) from glutamine precursors at the N-terminus of a number of peptide hormones, neuropeptides and chemokines. This post-translational modification stabilizes these peptides, protects them from proteolytical degradation or is important for their biological activity. However, QC is also involved in a pathogenic pGlu modification of peptides accumulating in protein aggregation disorders such as Alzheimer's disease and familial Danish and familial British dementia. Its isoenzyme (isoQC) was shown to contribute to aspects of inflammation by pGlu-modifying and thereby stabilizing the monocyte chemoattractant protein CCL2. For the generation of respective animal models and for pharmacological treatment studies the characterization of the mouse strain and brain region-specific expression of QC and isoQC is indispensible. In order to address this issue, we used enzymatic activity assays and specific antibodies to detect both QC variants by immunohistochemistry in nine different mouse strains. Comparing different brain regions, the highest enzymatic QC/isoQC activity was detected in ventral brain, followed by cortex and hippocampus. Immunohistochemical stainings revealed that QC/isoQC activity in cortex mostly arises from isoQC expression. For most brain regions, the highest QC/isoQC activity was detected in C3H and FVB mice, whereas low QC/isoQC activity was present in CD1, SJL and C57 mice. Quantification of QC- and isoQC-immunoreactive cells by unbiased stereology revealed a higher abundance of isoQC- than of QC-immunoreactive neurons in Edinger-Westphal nucleus and in substantia nigra. In the locus coeruleus, however, there were comparable densities of QC- and of isoQC-immunoreactive neurons. These observations are of considerable importance with regard to the selection of appropriate mouse strains for the study of QC/isoQC relevance in mouse models of neurodegeneration and neuroinflammation and for the testing of therapeutical interventions in these models.
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Affiliation(s)
- Corinna Höfling
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Henrike Indrischek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Theodor Höpcke
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Alexander Waniek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Holger Cynis
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT, Halle, Germany
| | - Birgit Koch
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT, Halle, Germany
| | - Stephan Schilling
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT, Halle, Germany
| | - Markus Morawski
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Hans-Ulrich Demuth
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT, Halle, Germany.
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany.
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Shih YP, Chou CC, Chen YL, Huang KF, Wang AHJ. Linked production of pyroglutamate-modified proteins via self-cleavage of fusion tags with TEV protease and autonomous N-terminal cyclization with glutaminyl cyclase in vivo. PLoS One 2014; 9:e94812. [PMID: 24733552 PMCID: PMC3986218 DOI: 10.1371/journal.pone.0094812] [Citation(s) in RCA: 20] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 03/19/2014] [Indexed: 12/28/2022] Open
Abstract
Overproduction of N-terminal pyroglutamate (pGlu)-modified proteins utilizing Escherichia coli or eukaryotic cells is a challenging work owing to the fact that the recombinant proteins need to be recovered by proteolytic removal of fusion tags to expose the N-terminal glutaminyl or glutamyl residue, which is then converted into pGlu catalyzed by the enzyme glutaminyl cyclase. Herein we describe a new method for production of N-terminal pGlu-containing proteins in vivo via intracellular self-cleavage of fusion tags by tobacco etch virus (TEV) protease and then immediate N-terminal cyclization of passenger target proteins by a bacterial glutaminyl cyclase. To combine with the sticky-end PCR cloning strategy, this design allows the gene of target proteins to be efficiently inserted into the expression vector using two unique cloning sites (i.e., SnaB I and Xho I), and the soluble and N-terminal pGlu-containing proteins are then produced in vivo. Our method has been successfully applied to the production of pGlu-modified enhanced green fluorescence protein and monocyte chemoattractant proteins. This design will facilitate the production of protein drugs and drug target proteins that possess an N-terminal pGlu residue required for their physiological activities.
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Affiliation(s)
- Yan-Ping Shih
- Institute of Biological Chemistry and Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan
| | - Chi-Chi Chou
- Institute of Biological Chemistry and Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan
| | - Yi-Ling Chen
- Institute of Biological Chemistry and Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan
| | - Kai-Fa Huang
- Institute of Biological Chemistry and Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan
- * E-mail: (AHJW); (KFH)
| | - Andrew H.- J. Wang
- Institute of Biological Chemistry and Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan
- * E-mail: (AHJW); (KFH)
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Tran PT, Hoang VH, Thorat SA, Kim SE, Ann J, Chang YJ, Nam DW, Song H, Mook-Jung I, Lee J, Lee J. Structure–activity relationship of human glutaminyl cyclase inhibitors having an N-(5-methyl-1H-imidazol-1-yl)propyl thiourea template. Bioorg Med Chem 2013; 21:3821-30. [DOI: 10.1016/j.bmc.2013.04.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 04/06/2013] [Accepted: 04/08/2013] [Indexed: 12/31/2022]
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Saul A, Lashley T, Revesz T, Holton J, Ghiso JA, Coomaraswamy J, Wirths O. Abundant pyroglutamate-modified ABri and ADan peptides in extracellular and vascular amyloid deposits in familial British and Danish dementias. Neurobiol Aging 2012; 34:1416-25. [PMID: 23261769 DOI: 10.1016/j.neurobiolaging.2012.11.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 09/17/2012] [Accepted: 11/22/2012] [Indexed: 11/15/2022]
Abstract
Familial British and familial Danish dementia (FDD) are progressive neurodegenerative disorders characterized by cerebral deposition of the amyloidogenic peptides ABri and ADan, respectively. These amyloid peptides start with an N-terminal glutamate residue, which can be posttranslationally converted into a pyroglutamate (pGlu) modified form, a mechanism which has been extensively described to be relevant for amyloid-beta (Aβ) peptides in Alzheimer's disease. Like pGlu-Aβ peptides, pGlu-ABri peptides have an increased aggregation propensity and show higher toxicity on human neuroblastoma cells as their nonmodified counterparts. We have generated novel N-terminal specific antibodies detecting the pGlu-modified forms of ABri and ADan peptides. With these antibodies we were able to identify abundant extracellular amyloid plaques, vascular, and parenchymal deposits in human familial British dementia and FDD brain tissue, and in a mouse model for FDD. Double-stainings using C-terminal specific antibodies in human samples revealed that highly aggregated pGlu-ABri and pGlu-ADan peptides are mainly present in plaque cores and central vascular deposits, leading to the assumption that these peptides have seeding properties. Furthermore, in an FDD-mouse model ADan peptides were detected in presynaptic terminals of the hippocampus where they might contribute to impaired synaptic transmission. These similarities of ABri and ADan to Aβ in Alzheimer's disease suggest that the posttranslational pGlu-modification of amyloid peptides might represent a general pathological mechanism leading to increased aggregation and toxicity in these forms of degenerative dementias.
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Affiliation(s)
- Anika Saul
- Division of Molecular Psychiatry, Georg-August-University Goettingen, University Medicine Goettingen, Germany
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Kumar V, Gupta MK, Singh G, Prabhakar YS. CP-MLR/PLS directed QSAR study on the glutaminyl cyclase inhibitory activity of imidazoles: rationales to advance the understanding of activity profile. J Enzyme Inhib Med Chem 2012; 28:515-22. [DOI: 10.3109/14756366.2011.654111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Viney Kumar
- Molecular Modelling and Pharmacoinformatics Lab, Department of Pharmaceutical Chemistry, ISF College of Pharmacy,
Moga, India
| | - Manish K. Gupta
- Molecular Modelling and Pharmacoinformatics Lab, Department of Pharmaceutical Chemistry, ISF College of Pharmacy,
Moga, India
| | - Gagandip Singh
- Molecular Modelling and Pharmacoinformatics Lab, Department of Pharmaceutical Chemistry, ISF College of Pharmacy,
Moga, India
| | - Yenamandra S. Prabhakar
- Medicinal and Process Chemistry Division, Central Drug Research Institute,
CSIR, Lucknow, India
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11
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Abstract
Senile plaques (SP) are characteristic histopathological manifestations of Alzheimer's disease (AD), but are also found in normal aging (NA). Recent studies have demonstrated that beta amyloid (Aβ) proteins that have been truncated at the N-terminal position 3 (AβpN3) are the predominant component of SP in AD, but not in NA. The present study revealed that AβpN3 was deposited in an age-dependent manner in canine brains. Moreover, AβpN3 was the main component of the SP that developed in very old dogs. The deposition of AβpN3 increased in accordance with the number of SP, but that of N-terminally intact Aβ (AβN1) did not. In addition, AβpN3 was also deposited in the SP of a Japanese macaque and an American black bear, but not in a feline brain. Focal microvascular cerebral amyloid angiopathy was also observed in the deep cortices and the white matter of the dogs and a woodpecker. Those were always composed of both AβpN3 and AβN1. In conclusion, though non-human animals do not develop full pathology of AD of the human type, AβpN3 is widely deposited in the brains of senescent vertebrates.
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Affiliation(s)
- James K Chambers
- Department of Veterinary Pathology, Graduate School of Agricultural and Life Science, The University of Tokyo, Bunkyo-ku, Japan
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12
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Huang KF, Liaw SS, Huang WL, Chia CY, Lo YC, Chen YL, Wang AHJ. Structures of human Golgi-resident glutaminyl cyclase and its complexes with inhibitors reveal a large loop movement upon inhibitor binding. J Biol Chem 2011; 286:12439-49. [PMID: 21288892 DOI: 10.1074/jbc.m110.208595] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Aberrant pyroglutamate formation at the N terminus of certain peptides and proteins, catalyzed by glutaminyl cyclases (QCs), is linked to some pathological conditions, such as Alzheimer disease. Recently, a glutaminyl cyclase (QC) inhibitor, PBD150, was shown to be able to reduce the deposition of pyroglutamate-modified amyloid-β peptides in brain of transgenic mouse models of Alzheimer disease, leading to a significant improvement of learning and memory in those transgenic animals. Here, we report the 1.05-1.40 Å resolution structures, solved by the sulfur single-wavelength anomalous dispersion phasing method, of the Golgi-luminal catalytic domain of the recently identified Golgi-resident QC (gQC) and its complex with PBD150. We also describe the high-resolution structures of secretory QC (sQC)-PBD150 complex and two other gQC-inhibitor complexes. gQC structure has a scaffold similar to that of sQC but with a relatively wider and negatively charged active site, suggesting a distinct substrate specificity from sQC. Upon binding to PBD150, a large loop movement in gQC allows the inhibitor to be tightly held in its active site primarily by hydrophobic interactions. Further comparisons of the inhibitor-bound structures revealed distinct interactions of the inhibitors with gQC and sQC, which are consistent with the results from our inhibitor assays reported here. Because gQC and sQC may play different biological roles in vivo, the different inhibitor binding modes allow the design of specific inhibitors toward gQC and sQC.
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Affiliation(s)
- Kai-Fa Huang
- Institute of Biological Chemistry, Core Facility for Protein Production and X-ray Structural Analysis, Academia Sinica, Taipei, Taiwan
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13
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Huang WL, Wang YR, Ko TP, Chia CY, Huang KF, Wang AHJ. Crystal Structure and Functional Analysis of the Glutaminyl Cyclase from Xanthomonas campestris. J Mol Biol 2010; 401:374-88. [DOI: 10.1016/j.jmb.2010.06.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 05/31/2010] [Accepted: 06/05/2010] [Indexed: 01/14/2023]
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Hartlage‐Rübsamen M, Staffa K, Waniek A, Wermann M, Hoffmann T, Cynis H, Schilling S, Demuth H, Roßner S. Developmental expression and subcellular localization of glutaminyl cyclase in mouse brain. Int J Dev Neurosci 2009; 27:825-35. [DOI: 10.1016/j.ijdevneu.2009.08.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 08/07/2009] [Accepted: 08/15/2009] [Indexed: 11/27/2022] Open
Affiliation(s)
| | - Katharina Staffa
- Paul Flechsig Institute for Brain ResearchUniversity of LeipzigLeipzigGermany
| | - Alexander Waniek
- Paul Flechsig Institute for Brain ResearchUniversity of LeipzigLeipzigGermany
| | | | | | | | | | | | - Steffen Roßner
- Paul Flechsig Institute for Brain ResearchUniversity of LeipzigLeipzigGermany
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15
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McColl G, Roberts BR, Gunn AP, Perez KA, Tew DJ, Masters CL, Barnham KJ, Cherny RA, Bush AI. The Caenorhabditis elegans A beta 1-42 model of Alzheimer disease predominantly expresses A beta 3-42. J Biol Chem 2009; 284:22697-702. [PMID: 19574211 DOI: 10.1074/jbc.c109.028514] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Transgenic expression of human amyloid beta (A beta) peptide in body wall muscle cells of Caenorhabditis elegans has been used to better understand aspects of Alzheimer disease (AD). In human aging and AD, A beta undergoes post-translational changes including covalent modifications, truncations, and oligomerization. Amino truncated A beta is increasingly recognized as potentially contributing to AD pathogenesis. Here we describe surface-enhanced laser desorption ionization-time of flight mass spectrometry mass spectrometry of A beta peptide in established transgenic C. elegans lines. Surprisingly, the A beta being expressed is not full-length 1-42 (amino acids) as expected but rather a 3-42 truncation product. In vitro analysis demonstrates that A beta(3-42) self-aggregates like A beta(1-42), but more rapidly, and forms fibrillar structures. Similarly, A beta(3-42) is also the more potent initiator of A beta(1-40) aggregation. Seeded aggregation via A beta(3-42) is further enhanced via co-incubation with the transition metal Cu(II). Although unexpected, the C. elegans model of A beta expression can now be co-opted to study the proteotoxic effects and processing of A beta(3-42).
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Affiliation(s)
- Gawain McColl
- Mental Health Research Institute, Parkville, Victoria 3052, Australia
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Schilling S, Zeitschel U, Hoffmann T, Heiser U, Francke M, Kehlen A, Holzer M, Hutter-Paier B, Prokesch M, Windisch M, Jagla W, Schlenzig D, Lindner C, Rudolph T, Reuter G, Cynis H, Montag D, Demuth HU, Rossner S. Glutaminyl cyclase inhibition attenuates pyroglutamate Abeta and Alzheimer's disease-like pathology. Nat Med 2008; 14:1106-11. [PMID: 18836460 DOI: 10.1038/nm.1872] [Citation(s) in RCA: 271] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 09/03/2008] [Indexed: 11/09/2022]
Abstract
Because of their abundance, resistance to proteolysis, rapid aggregation and neurotoxicity, N-terminally truncated and, in particular, pyroglutamate (pE)-modified Abeta peptides have been suggested as being important in the initiation of pathological cascades resulting in the development of Alzheimer's disease. We found that the N-terminal pE-formation is catalyzed by glutaminyl cyclase in vivo. Glutaminyl cyclase expression was upregulated in the cortices of individuals with Alzheimer's disease and correlated with the appearance of pE-modified Abeta. Oral application of a glutaminyl cyclase inhibitor resulted in reduced Abeta(3(pE)-42) burden in two different transgenic mouse models of Alzheimer's disease and in a new Drosophila model. Treatment of mice was accompanied by reductions in Abeta(x-40/42), diminished plaque formation and gliosis and improved performance in context memory and spatial learning tests. These observations are consistent with the hypothesis that Abeta(3(pE)-42) acts as a seed for Abeta aggregation by self-aggregation and co-aggregation with Abeta(1-40/42). Therefore, Abeta(3(pE)-40/42) peptides seem to represent Abeta forms with exceptional potency for disturbing neuronal function. The reduction of brain pE-Abeta by inhibition of glutaminyl cyclase offers a new therapeutic option for the treatment of Alzheimer's disease and provides implications for other amyloidoses, such as familial Danish dementia.
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Schilling S, Wasternack C, Demuth HU. Glutaminyl cyclases from animals and plants: a case of functionally convergent protein evolution. Biol Chem 2008. [DOI: 10.1515/bc.2008.111_bchm.just-accepted] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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18
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Schilling S, Wasternack C, Demuth HU. Glutaminyl cyclases from animals and plants: a case of functionally convergent protein evolution. Biol Chem 2008; 389:983-91. [DOI: 10.1515/bc.2008.111] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractSeveral mammalian peptide hormones and proteins from plant and animal origin contain an N-terminal pyroglutamic acid (pGlu) residue. Frequently, the moiety is important in exerting biological function in either mediating interaction with receptors or stabilizing against N-terminal degradation. Glutaminyl cyclases (QCs) were isolated from different plants and animals catalyzing pGlu formation. The recent resolution of the 3D structures ofCarica papayaand human QCs clearly supports different evolutionary origins of the proteins, which is also reflected by different enzymatic mechanisms. The broad substrate specificity is revealed by the heterogeneity of physiological substrates of plant and animal QCs, including cytokines, matrix proteins and pathogenesis-related proteins. Moreover, recent evidence also suggests human QC as a catalyst of pGlu formation at the N-terminus of amyloid peptides, which contribute to Alzheimer's disease. Obviously, owing to its biophysical properties, the function of pGlu in plant and animal proteins is very similar in terms of stabilizing or mediating protein and peptide structure. It is possible that the requirement for catalysis of pGlu formation under physiological conditions may have triggered separate evolution of QCs in plants and animals.
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Cynis H, Rahfeld JU, Stephan A, Kehlen A, Koch B, Wermann M, Demuth HU, Schilling S. Isolation of an Isoenzyme of Human Glutaminyl Cyclase: Retention in the Golgi Complex Suggests Involvement in the Protein Maturation Machinery. J Mol Biol 2008; 379:966-80. [DOI: 10.1016/j.jmb.2008.03.078] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 03/12/2008] [Accepted: 03/31/2008] [Indexed: 11/25/2022]
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Gontsarova A, Kaufmann E, Tumani H, Dressel A, Mandel F, Wiesmüller KH, Kunert-Keil C, Brinkmeier H. Glutaminyl cyclase activity is a characteristic feature of human cerebrospinal fluid. Clin Chim Acta 2008; 389:152-9. [DOI: 10.1016/j.cca.2007.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2007] [Revised: 12/11/2007] [Accepted: 12/11/2007] [Indexed: 10/22/2022]
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Schilling S, Lindner C, Koch B, Wermann M, Rahfeld JU, von Bohlen A, Rudolph T, Reuter G, Demuth HU. Isolation and characterization of glutaminyl cyclases from Drosophila: evidence for enzyme forms with different subcellular localization. Biochemistry 2007; 46:10921-30. [PMID: 17722885 DOI: 10.1021/bi701043x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glutaminyl cyclases (QCs) present in plants and vertebrates catalyze the formation of pyroglutamic acid (pGlu) from N-terminal glutamine. Pyroglutamyl hormones also identified in invertebrates imply the involvement of QC activity during their posttranslational maturation. Database mining led to the identification of two genes in Drosophila, which putatively encode QCs, CG32412 (DromeQC) and CG5976 (isoDromeQC). Analysis of their primary structure suggests different subcellular localizations. While DromeQC appeared to be secreted due to an N-terminal signal peptide, isoDromeQC contains either an N-terminal mitochondrial targeting or a secretion signal due to generation of different transcripts from gene CG5976. According to the prediction, homologous expression of the corresponding cDNAs in S2 cells revealed either secreted protein in the medium or intracellular QC activity. Subcellular fractionation and immunochemistry support export of isoDromeQC into the mitochondrion. For enzymatic characterization, DromeQC and isoDromeQC were expressed heterologously in Pichia pastoris and Escherichia coli, respectively. Compared to mammalian QCs, the specificity constants were about 1 order of magnitude lower for most of the analyzed substrates. The pH dependence of the specificity constant was similar for both enzymes, indicating the necessity of an unprotonated substrate amino group and two protonated groups of the enzyme, resulting in an asymmetric bell-shaped characteristic. The determination of the metal content of DromeQC revealed equimolar protein-bound zinc. These results prove conserved enzymatic mechanisms between QCs from invertebrates and mammals. Drosophila is the first organism for which isoenzymes of glutaminyl cyclase have been isolated. The identification of a mitochondrial QC points toward yet undiscovered physiological functions of these enzymes.
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Abstract
Cyclization of the N-terminal glutamine residue to pyroglutamic acid in onconase, an anti-cancer chemotherapeutic agent, increases the activity and stability of the protein. Here, we examine the correlated effects of the folding/unfolding process and the formation of this N-terminal pyroglutamic acid. The results in this study indicate that cyclization of the N-terminal glutamine has no significant effect on the rate of either reductive unfolding or oxidative folding of the protein. Both the cyclized and uncyclized proteins seem to follow the same oxidative folding pathways; however, cyclization altered the relative flux of the protein in these two pathways by increasing the rate of formation of a kinetically trapped intermediate. Glutaminyl cyclase (QC) catalyzed the cyclization of the unfolded, reduced protein but had no effect on the disulfide-intact, uncyclized, folded protein. The structured intermediates of uncyclized onconase were also resistant to QC catalysis, consistent with their having a native-like fold. These observations suggest that, in vivo, cyclization takes place during the initial stages of oxidative folding, specifically, before the formation of structured intermediates. The competition between oxidative folding and QC-mediated cyclization suggests that QC-catalyzed cyclization of the N-terminal glutamine in onconase occurs in the endoplasmic reticulum, probably co-translationally.
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Affiliation(s)
- Ervin Welker
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy, H-6701, Szeged, Temesvári krt. 62. Hungary
- Institute of Enzymology of the Hungarian Academy, H-1114, Budapest, Karolina út 62. Hungary
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
| | - Laura Hathaway
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
| | - Guoqiang Xu
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
| | - Mahesh Narayan
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
| | - Lovy Pradeep
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
| | - Hang-Cheol Shin
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
| | - Harold A. Scheraga
- Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
- To whom correspondence should be addressed: Tel. (607) 255-4034; Fax (607) 254-4700; E-mail:
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Dick LW, Kim C, Qiu D, Cheng KC. Determination of the origin of the N-terminal pyro-glutamate variation in monoclonal antibodies using model peptides. Biotechnol Bioeng 2007; 97:544-53. [PMID: 17099914 DOI: 10.1002/bit.21260] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this work is to determine the cause of the cyclization of the N-terminal glutamine in recombinant proteins and monoclonal antibodies. This cyclization reaction commonly occurs on the N-terminal of light and/or heavy chains of antibodies and leads to heterogeneity of the final product. Two model peptides and an antibody containing an N-terminal glutamine were used to investigate the formation of N-terminal pyro- glutamic acid under various experimental conditions and different stages of the biosynthetic process. LC-MS analysis was used to separate and quantify the N-terminal variants. Experiments prove that the cyclization reaction is spontaneous and highly dependent on temperature and buffer composition and less dependent on pH. The conditions presented in most biopharmaceutical processes accelerate the formation of this variant. The majority of the near complete conversion (>95%) of N-terminal glutamine to pyro-glutamic acid commonly observed for antibodies appears to occur inside the bioreactor with only a small contribution from purification, formulation, and analytical preparation.
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Affiliation(s)
- Lawrence W Dick
- Analytical Development Department, Medarex, Inc., 519 Route 173 West, Bloomsbury, New Jersey 08804, USA
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24
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Cynis H, Schilling S, Bodnár M, Hoffmann T, Heiser U, Saido TC, Demuth HU. Inhibition of glutaminyl cyclase alters pyroglutamate formation in mammalian cells. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 2006; 1764:1618-25. [PMID: 17005457 DOI: 10.1016/j.bbapap.2006.08.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 07/29/2006] [Accepted: 08/11/2006] [Indexed: 11/19/2022]
Abstract
Mammalian cell lines were examined concerning their Glutaminyl Cyclase (QC) activity using a HPLC method. The enzyme activity was suppressed by a QC specific inhibitor in all homogenates. Aim of the study was to prove whether inhibition of QC modifies the posttranslational maturation of N-glutamine and N-glutamate peptide substrates. Therefore, the impact of QC-inhibition on amino-terminal pyroglutamate (pGlu) formation of the modified amyloid peptides Abeta(N3E-42) and Abeta(N3Q-42) was investigated. These amyloid-beta peptides were expressed as fusion proteins with either the pre-pro sequence of TRH, to be released by a prohormone convertase, or as engineered amyloid precursor protein for subsequent liberation of Abeta(N3Q-42) after beta- and gamma-secretase cleavage during posttranslational processing. Inhibition of QC leads in both expression systems to significantly reduced pGlu-formation of differently processed Abeta-peptides. This reveals the importance of QC-activity during cellular maturation of pGlu-containing peptides. Thus, QC-inhibition should impact bioactivity, stability or even toxicity of pyroglutamyl peptides preventing glutamine and glutamate cyclization.
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Affiliation(s)
- Holger Cynis
- Probiodrug AG, Weinbergweg 22, 06120 Halle/Saale, Germany
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25
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Gillis JS. Microarray evidence of glutaminyl cyclase gene expression in melanoma: implications for tumor antigen specific immunotherapy. J Transl Med 2006; 4:27. [PMID: 16820060 PMCID: PMC1557589 DOI: 10.1186/1479-5876-4-27] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Accepted: 07/04/2006] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND In recent years encouraging progress has been made in developing vaccine treatments for cancer, particularly with melanoma. However, the overall rate of clinically significant results has remained low. The present research used microarray datasets from previous investigations to examine gene expression patterns in cancer cell lines with the goal of better understanding the tumor microenvironment. METHODS Principal Components Analyses with Promax rotational transformations were carried out with 90 cancer cell lines from 3 microarray datasets, which had been made available on the internet as supplementary information from prior publications. RESULTS In each of the analyses a well defined melanoma component was identified that contained a gene coding for the enzyme, glutaminyl cyclase, which was as highly expressed as genes from a variety of well established biomarkers for melanoma, such as MAGE-3 and MART-1, which have frequently been used in clinical trials of melanoma vaccines. CONCLUSION Since glutaminyl cyclase converts glutamine and glutamic acid into a pyroglutamic form, it may interfere with the tumor destructive process of vaccines using peptides having glutamine or glutamic acid at their N-terminals. Finding ways of inhibiting the activity of glutaminyl cyclase in the tumor microenvironment may help to increase the effectiveness of some melanoma vaccines.
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Affiliation(s)
- John Stuart Gillis
- Science and Technology Studies, St, Thomas University, Fredericton, New Brunswick, Canada.
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26
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Abstract
Glutaminyl cyclase (QC) catalyzes N-terminal glutamine cyclization of many endocrine peptides and is typically abundant in brain tissue. As three-finger toxins in the venoms of colubrid snakes Boiga dendrophila and Boiga irregularis contain N-terminal pyroglutamate, we searched for QC in venom glands of both snakes. Here we report cDNA sequences of QC from brain and venom gland tissues of Boiga species. We propose that QC expressed in snake venom gland tissue plays a role in the N-terminal pyroglutamate formation of several snake venom toxins, indirectly contributing to venom potency.
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Affiliation(s)
- Joanna Pawlak
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Science Drive 4, Singapore 117543, Singapore
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27
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Ghiso J, Rostagno A, Tomidokoro Y, Lashley T, Bojsen-Møller M, Braendgaard H, Plant G, Holton J, Lal R, Revesz T, Frangione B. Genetic alterations of the BRI2 gene: familial British and Danish dementias. Brain Pathol 2006; 16:71-9. [PMID: 16612984 PMCID: PMC8095812 DOI: 10.1111/j.1750-3639.2006.tb00563.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Classic arguments sustaining the importance of amyloid in the pathogenesis of dementia are usually centered on amyloid beta (Abeta) and its role in neuronal loss characteristic of Alzheimer disease, the most common form of human cerebral amyloidosis. Two non-Abeta cerebral amyloidoses, familial British and Danish dementias, share many aspects of Alzheimer disease, including the presence of neurofibrillary tangles, parenchymal pre-amyloid and amyloid deposits, cerebral amyloid angiopathy, and a widespread inflammatory response. Both early-onset conditions are linked to specific mutations in the BRI2 gene, causing the generation of longer-than-normal protein products and the release of 2 de novo created peptides ABri and ADan, the main components of amyloid fibrils in these inherited dementias. Although the molecular mechanisms and signal transduction pathways elicited by the amyloid deposits and their relation to cognitive impairment remain to be clarified, new evidence indicates that, independent of the differences in their primary structures, Abeta, ABri, and ADan subunits are able to form morphologically compatible ion-channel-like structures and elicit single ion-channel currents in reconstituted lipid membranes. These findings reaffirm the notion that non-Abeta amyloidosis constitute suitable alternative models to study the role of amyloid deposition in the mechanism of neuronal cell death.
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Affiliation(s)
- J Ghiso
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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28
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Schilling S, Cynis H, von Bohlen A, Hoffmann T, Wermann M, Heiser U, Buchholz M, Zunkel K, Demuth HU. Isolation, Catalytic Properties, and Competitive Inhibitors of the Zinc-Dependent Murine Glutaminyl Cyclase. Biochemistry 2005; 44:13415-24. [PMID: 16201766 DOI: 10.1021/bi051142e] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Murine glutaminyl cyclase (mQC) was identified in the insulinoma cell line beta-TC 3 by determination of enzymatic activity and RT-PCR. The cloned cDNA was expressed in the secretory pathway of the methylotrophic yeast Pichia pastoris and purified after fermentation using a new three-step protocol. mQC converted a set of various substrates with very similar specificity to human QC, indicating a virtually identical catalytic competence. Furthermore, mQC was competitively inhibited by imidazole derivatives. A screen of thiol reagents revealed cysteamine as a competitive inhibitor of mQC bearing a Ki value of 42 +/-2 microM. Substitution of the thiol or the amino group resulted in a drastic loss of inhibitory potency. The pH dependence of catalysis and inhibition support that an uncharged nitrogen of the inhibitors and the substrate is necessary in order to bind to the active site of the enzyme. In contrast to imidazole and cysteamine, the heterocyclic chelators 1,10-phenanthroline, 2,6-dipicolinic acid, and 8-hydroxyquinoline inactivated mQC in a time-dependent manner. In addition, citric acid inactivated the enzyme at pH 5.5. Inhibition by citrate was abolished in the presence of zinc ions. A determination of the metal content by total reflection X-ray fluorescence spectrometry and atomic absorption spectroscopy in mQC revealed stoichiometric amounts of zinc bound to the protein. Metal ion depletion appeared to have no significant effect on protein structure as shown by fluorescence spectroscopy, suggesting a catalytic role of zinc. The results demonstrate that mQC and probably all animal QCs are zinc-dependent catalysts. Apparently, during evolution from an ancestral protease, a switch occurred in the catalytic mechanism which is mainly based on a loss of one metal binding site.
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Huang KF, Liu YL, Cheng WJ, Ko TP, Wang AHJ. Crystal structures of human glutaminyl cyclase, an enzyme responsible for protein N-terminal pyroglutamate formation. Proc Natl Acad Sci U S A 2005; 102:13117-22. [PMID: 16135565 PMCID: PMC1201592 DOI: 10.1073/pnas.0504184102] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2005] [Indexed: 11/18/2022] Open
Abstract
N-terminal pyroglutamate (pGlu) formation from its glutaminyl (or glutamyl) precursor is required in the maturation of numerous bioactive peptides. The aberrant formation of pGlu may be related to several pathological processes, such as osteoporosis and amyloidotic diseases. This N-terminal cyclization reaction, once thought to proceed spontaneously, is greatly facilitated by the enzyme glutaminyl cyclase (QC). To probe this important but poorly understood modification, we present here the structure of human QC in free form and bound to a substrate and three imidazole-derived inhibitors. The structure reveals an alpha/beta scaffold akin to that of two-zinc exopeptidases but with several insertions and deletions, particularly in the active-site region. The relatively closed active site displays alternate conformations due to the different indole orientations of Trp-207, resulting in two substrate (glutamine t-butyl ester)-binding modes. The single zinc ion in the active site is coordinated to three conserved residues and one water molecule, which is replaced by an imidazole nitrogen upon binding of the inhibitors. Together with structural and kinetic analyses of several active-site-mutant enzymes, a catalysis mechanism of the formation of protein N-terminal pGlu is proposed. Our results provide a structural basis for the rational design of inhibitors against QC-associated disorders.
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Affiliation(s)
- Kai-Fa Huang
- Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan
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Huang KF, Liu YL, Wang AHJ. Cloning, expression, characterization, and crystallization of a glutaminyl cyclase from human bone marrow: A single zinc metalloenzyme. Protein Expr Purif 2005; 43:65-72. [PMID: 16084398 DOI: 10.1016/j.pep.2005.02.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [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: 02/01/2005] [Revised: 02/22/2005] [Accepted: 02/22/2005] [Indexed: 11/19/2022]
Abstract
Glutaminyl cyclase (QC) catalyzes the N-terminal pyroglutamate formation of numerous hormones and peptides from their glutaminyl precursor. Pyroglutamate is a posttranslational or cotranslational modification important in many physiological and pathological processes. Here, we present the cloning of a QC cDNA from human bone marrow cDNA library. The protein was expressed in Escherichia coli system with the yields higher than approximately 10 mg/L bacterial culture, using a thioredoxin-tagged expression vector with several modifications. Based on high histidine content ( approximately 5%) of the protein, a convenient purification step by Ni-affinity chromatography was designed, leading to near homogeneity of the purified human QC. The identity of the recombinant human QC was confirmed by mass spectrometry and circular dichroism spectroscopy. The enzyme was active on both synthetic and physiological substrates, and the activity could be inhibited by several imidazole, triazole, and tetrazole derivatives. An atomic absorption analysis demonstrated that human QC contains one zinc ion per protein molecule. We also obtained the human QC crystals, which belong to cubic, tetragonal, and rhombohedral forms. Our works are useful to acquire new insights into human and animal QCs, particularly for future structural analysis and inhibitor designs.
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Affiliation(s)
- Kai-Fa Huang
- Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan
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31
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Tomidokoro Y, Lashley T, Rostagno A, Neubert TA, Bojsen-Møller M, Braendgaard H, Plant G, Holton J, Frangione B, Révész T, Ghiso J. Familial Danish dementia: co-existence of Danish and Alzheimer amyloid subunits (ADan AND A{beta}) in the absence of compact plaques. J Biol Chem 2005; 280:36883-94. [PMID: 16091362 DOI: 10.1074/jbc.m504038200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Familial Danish dementia is an early onset autosomal dominant neurodegenerative disorder linked to a genetic defect in the BRI2 gene and clinically characterized by dementia and ataxia. Cerebral amyloid and preamyloid deposits of two unrelated molecules (Danish amyloid (ADan) and beta-amyloid (Abeta)), the absence of compact plaques, and neurofibrillary degeneration indistinguishable from that observed in Alzheimer disease (AD) are the main neuropathological features of the disease. Biochemical analysis of extracted amyloid and preamyloid species indicates that as the solubility of the deposits decreases, the heterogeneity and complexity of the extracted peptides exponentially increase. Nonfibrillar deposits were mainly composed of intact ADan-(1-34) and its N-terminally modified (pyroglutamate) counterpart together with Abeta-(1-42) and Abeta-(4-42) in approximately 1:1 mixture. The post-translational modification, glutamate to pyroglutamate, was not present in soluble circulating ADan. In the amyloid fractions, ADan was heavily oligomerized and highly heterogeneous at the N and C terminus, and, when intact, its N terminus was post-translationally modified (pyroglutamate), whereas Abeta was mainly Abeta-(4-42). In all cases, the presence of Abeta-(X-40) was negligible, a surprising finding in view of the prevalence of Abeta40 in vascular deposits observed in sporadic and familial AD, Down syndrome, and normal aging. Whether the presence of the two amyloid subunits is imperative for the disease phenotype or just reflects a conformational mimicry remains to be elucidated; nonetheless, a specific interaction between ADan oligomers and Abeta molecules was demonstrated in vitro by ligand blot analysis using synthetic peptides. The absence of compact plaques in the presence of extensive neuro fibrillar degeneration strongly suggests that compact plaques, fundamental lesions for the diagnosis of AD, are not essential for the mechanism of dementia.
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Affiliation(s)
- Yasushi Tomidokoro
- Department of Pathology, New York University School of Medicine, New York, New York 10016, USA
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Azarkan M, Clantin B, Bompard C, Belrhali H, Baeyens-Volant D, Looze Y, Villeret V, Wintjens R. Crystallization and preliminary X-ray diffraction studies of the glutaminyl cyclase from Carica papaya latex. Acta Crystallogr Sect F Struct Biol Cryst Commun 2004; 61:59-61. [PMID: 16508091 PMCID: PMC1952388 DOI: 10.1107/s1744309104025904] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [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: 08/17/2004] [Accepted: 10/13/2004] [Indexed: 11/10/2022]
Abstract
In living systems, the intramolecular cyclization of N-terminal glutamine residues is accomplished by glutaminyl cyclase enzymes (EC 2.3.2.5). While in mammals these enzymes are involved in the synthesis of hormonal and neurotransmitter peptides, the physiological role played by the corresponding plant enzymes still remains to be unravelled. Papaya glutaminyl cyclase (PQC), a 33 kDa enzyme found in the latex of the tropical tree Carica papaya, displays an exceptional resistance to chemical and thermal denaturation as well as to proteolysis. In order to elucidate its enzymatic mechanism and to gain insights into the structural determinants underlying its remarkable stability, PQC was isolated from papaya latex, purified and crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 62.82, b = 81.23, c = 108.17 A and two molecules per asymmetric unit. Diffraction data have been collected at ESRF beamline BM14 and processed to a resolution of 1.7 A.
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Affiliation(s)
- Mohamed Azarkan
- Laboratoire de Chimie Générale I, Faculté de Médecine–ULB CP609, 808 Route de Lennik, B-1070 Brussels, Belgium
| | - Bernard Clantin
- CNRS–UMR 8525, Institut de Biologie de Lille, BP 477, 1 Rue du Professeur Calmette, F-59021 Lille, France
| | - Coralie Bompard
- CNRS–UMR 8525, Institut de Biologie de Lille, BP 477, 1 Rue du Professeur Calmette, F-59021 Lille, France
| | - Hassan Belrhali
- EMBL Grenoble Outstation, 6 Rue Jules Horowitz, BP 181, F-38042 Grenoble CEDEX 9, France
| | - Danielle Baeyens-Volant
- Laboratoire de Chimie Générale I, Faculté de Médecine–ULB CP609, 808 Route de Lennik, B-1070 Brussels, Belgium
| | - Yvan Looze
- Laboratoire de Chimie Générale, Institut de Pharmacie–ULB CP206/04, Boulevard du Triomphe, B-1050 Brussels, Belgium
| | - Vincent Villeret
- CNRS–UMR 8525, Institut de Biologie de Lille, BP 477, 1 Rue du Professeur Calmette, F-59021 Lille, France
- Correspondence e-mail: ,
| | - René Wintjens
- Laboratoire de Chimie Générale, Institut de Pharmacie–ULB CP206/04, Boulevard du Triomphe, B-1050 Brussels, Belgium
- Correspondence e-mail: ,
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Abstract
Glutaminyl cyclases (QC) catalyze the intramolecular cyclization of N-terminal glutamine residues of peptides and proteins. For a comparison of the substrate specificity of human and papaya QC enzymes, a novel continuous assay was established by adapting an existing discontinuous method. Specificity constants (kcat/Km) of dipeptides and dipeptide surrogates were higher for plant QC, whereas the selectivity for oligopeptides was similar for both enzymes. However, only the specificity constants of mammalian QC were dependent on size and composition of the substrates. Specificity constants of both enzymes were equally pH-dependent in the acidic pH-region, revealing a pKa value identical to the pKa of the substrate, suggesting similarities in the substrate conversion mode. Accordingly, both QCs converted the L-beta homoglutaminyl residue in the peptide H-beta homoGln-Phe-Lys-Arg-Leu-Ala-NH2 and the glutaminyl residues of the branched peptide H-Gln-Lys(Gln)-Arg-Leu-Ala-NH2 as well as the partially cyclized peptide H-Gln-cyclo(N epsilon-Lys-Arg-Pro-Ala-Gly-Phe). In contrast, only QC from C. papaya was able to cyclize a methylated glutamine residue, while this compound did not even inhibit human QC-catalysis, suggesting distinct substrate recognition pattern. The conversion of the potential physiological substrates [Gln1]-gastrin, [Gln1]-neurotensin and [Gln1]-fertilization promoting peptide indicates that human QC may play a key role in posttranslational modification of most if not all pGlu-containing hormones.
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Abstract
In recent years, 2 groups of hereditary neurodegenerative diseases have been recognized in which different genetic defects lead to the accumulation of proteins that contain a carboxyl-terminus that is abnormal in length and primary sequence. In this paper, we review the current knowledge on the molecular basis of diseases from these 2 groups. The first group includes familial British and Danish dementias, in which the molecular genetic defect resides in the BRI2 gene located on chromosome 13. In this group, carboxyl-terminal proteolytic products of the mutant BRI2 proteins aggregate in the extracellular space of the brain and in blood vessels. The second group includes 2 recently described ferritinopathies, in which the molecular genetic defect resides in the ferritin light polypeptide gene located on chromosome 19. In this group, full-length ferritin polypeptides aggregate intracellularly. The study of these conditions has led to the discovery of the BRI2 gene and to the finding of an unsuspected role for ferritin in neurodegeneration. These diseases provide new models in which to study the relationship between abnormal protein aggregation, neuronal cell death, and dementia.
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Affiliation(s)
- Ruben Vidal
- Indiana Alzheimer Disease Center and Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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Booth RE, Misquitta SA, Bateman RC. Human pituitary glutaminyl cyclase: expression in insect cells and dye affinity purification. Protein Expr Purif 2004; 32:141-6. [PMID: 14680951 DOI: 10.1016/s1046-5928(03)00226-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [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: 05/23/2003] [Revised: 07/15/2003] [Indexed: 11/30/2022]
Abstract
Human pituitary glutaminyl cyclase (hQC) was expressed in Drosophila S2 cells under the control of an inducible metallothionene promoter and fused to the Drosophila immunoglobulin-binding protein signal sequence to enable secretion into the culture media. Expression levels reached 50 microg/mL culture media after 7 days of induction. The enzyme was purified to homogeneity directly from culture media by affinity chromatography on Reactive Blue 4-agarose using a step pH elution. The identity of the expressed protein was confirmed by peptide mass mapping and Western blotting. Glutaminyl cyclase was expressed as a fully active 37 kDa enzyme with kcat/Km values of 14.3, 9.3, and 2.4 mM(-1)s(-1) for the substrates Gln-Gln, Gln-NH(2), and Gln-t-butyl ester, respectively. The two cysteines were disulfide bonded, and the lone predicted glycosylation site, asparagine 49, was shown by both enzymatic deglycosylation of the expressed enzyme and site-directed mutagenesis to be glycosylated.
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Affiliation(s)
- Rachell E Booth
- Department of Chemistry and Biochemistry, University of Southern Mississippi, P.O. Box 5043, Hattiesburg, MS 39406-5043, USA
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Affiliation(s)
- William C Wetsel
- Departments of Psychiatry and Behavioral Sciences, Medicine (Endocrinology), and Cell Biology, Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical Center, Durham, NC 27710, USA.
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Azarkan M, Amrani A, Zerhouni S, Oberg KA, Ruysschaert JM, Wintjens R, Looze Y. Evidence that thermodynamic stability of papaya glutamine cyclase is only marginal. Biopolymers 2002; 65:325-35. [PMID: 12389212 DOI: 10.1002/bip.10234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Papaya glutamine cyclase (PQC), a glycoprotein with a molecular mass of 32,980 Da, is a minor constituent of the papaya latex protein fraction. In neutral aqueous solutions, PQC adopts an all-beta conformation and exhibits high resistance to both proteolysis and denaturation. Complete unfolding of PQC requires a combination of an acidic medium and chemical denaturant such as urea or guanidine hydrochloride. The unfolding process takes place through formation of an intermediate A state that accumulates in the absence of chemical denaturants and displays all the features of a molten globule state. The different conformational states-N (native), A (acid-inactivated), and U (unfolded)-have been characterized by means of circular dichroism measurements, fluorescence spectroscopies, Stokes radii determinations, and 8-anilino-1-naphtalenesulfonic acid (ANS) binding characteristics. The unfolding pathways of the enzyme was further studied to estimate thermodynamic parameters characterizing both transitions N if A and A if U. In its A state, PQC is catalytically inefficient and highly susceptible to proteolysis. Also, its thermodynamic stability is decreased by some 3-5 kcal/mol. Conversion of the native to the A state involves digging up of five amino functions together with protonation of four to five acidic groups with pK(a)s, in the native state, around 2.7. It proceeds both cooperatively and reversibly although, in vitro, the refolding process is slow. Unfolding of the A state, on the other hand, occurs with a low degree of cooperativity. The intermediate A state thus seems to be only marginally more stable than the unfolded state. The role of suspected internal ion pairs in the stabilization of the native state of this enzyme is discussed.
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Affiliation(s)
- Mohamed Azarkan
- Protein Chemistry Department (CP 609), Faculty of Medicine, Free University of Brussels, Campus Erasme, 808 Route de Lennik, Belgium
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Abstract
The enzymatic conversion of one chromogenic substrate, l-glutamine-p-nitroanilide, and two fluorogenic substrates, l-glutaminyl-2-naphthylamide and l-glutaminyl-4-methylcoumarinylamide, into their respective pyroglutamic acid derivatives by glutaminyl cyclase (QC) was estimated by introducing a new coupled assay using pyroglutamyl aminopeptidase as the auxiliary enzyme. For the purified papaya QC, the kinetic parameters were found to be in the range of those previously reported for other glutaminyl peptides, such as Gln-Gln, Gln-Ala, or Gln-tert-butyl ester. The assay can be performed in the presence of ammonia up to a concentration of 50 mM. Increasing ionic strength, e.g., potassium chloride up to 300 mM, resulted in an increase in enzymatic activity of about 20%. This is the first report of a fast, continuous, and reliable determination of QC activity, even in the presence of ammonium ions, during the course of protein purification and enzymatic analysis.
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Affiliation(s)
- Stephan Schilling
- Laboratory of Biochemistry, probiodrug AG, Weinbergweg 22, 06120 Halle/Saale, Germany
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Abstract
Glutaminyl cyclase (QC, EC 2.3.2.5) catalyzes the formation of the pyroglutamyl residue present at the amino terminus of numerous secretory peptides and proteins. Treatment with diethyl pyrocarbonate inactivated recombinant human QC with the apparent modification of three essential histidine residues. Comparisons of the protein sequences of QC from a variety of eukaryotic species show four completely conserved histidine residues. Mutation of each of these residues to glutamine resulted in two mutant enzymes that were inactive (H140Q and H330Q), suggesting a role in catalysis, and two that exhibited increased Km values (H307Q and H319Q), suggesting a role in substrate binding. Consistent with these results is the prediction that QC possesses a zinc aminopeptidase domain in which the four histidines identified here are present in the active site. Mammalian glutaminyl cyclases may, therefore, have structural and catalytic similarities to a family of bacterial zinc aminopeptidases.
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Affiliation(s)
- R C Bateman
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, Mississippi 39406-5043, USA.
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Dahl SW, Slaughter C, Lauritzen C, Bateman RC, Connerton I, Pedersen J. Carica papaya glutamine cyclotransferase belongs to a novel plant enzyme subfamily: cloning and characterization of the recombinant enzyme. Protein Expr Purif 2000; 20:27-36. [PMID: 11035947 DOI: 10.1006/prep.2000.1273] [Citation(s) in RCA: 29] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A full-length cDNA encoding Carica papaya glutamine cyclotransferase was cloned by RT-PCR on the basis of results from amino acid sequencing of tryptic fragments of the native enzyme. The cDNA of 1036 nucleotides encodes a typical 22-residue signal peptide and a mature protein of 266 residues with a calculated molecular mass of 30,923 Da. Five plant ESTs encoding putative QCs highly homologous to PQC were identified and the numbers and locations of cysteines and N-glycosylation sites are conserved. The plant QC amino acid sequences are very different from the known mammalian QC sequences and no clear homology was observed. The PQC cDNA was expressed in Escherichia coli as either His-tagged PQC, with three different signal peptides and in fusions with thioredoxin, glutathione S-transferase, and (pre-) maltose-binding protein. In all cases, the expressed protein was either undetectable or insoluble. Expression in Pichia pastoris of PQC fused to the alpha-factor leader resulted in low levels of PQC activity. Extracellular expression of PQC in the insect cell/baculovirus system was successful and 15-50 mg/liter of active PQCs with three different secretion signals was expressed and purified. Further, PQC N-terminally fused to a combined secretion signal/His-tag peptide was correctly processed by the host signal peptidase and the His-tag could subsequently be removed with dipeptidyl peptidase I. The expressed products were characterized by activity assays, SDS-PAGE, N-terminal amino acid sequencing, MALDI-TOF mass spectroscopy, and peptide mass fingerprint analysis.
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Affiliation(s)
- S W Dahl
- Unizyme Laboratories A/S, Dr. Neergaards Vej 17, Horsholm, Denmark,
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