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Chen D, Chen Q, Qin X, Tong P, Peng L, Zhang T, Xia C. Development and evolution of human glutaminyl cyclase inhibitors (QCIs): an alternative promising approach for disease-modifying treatment of Alzheimer's disease. Front Aging Neurosci 2023; 15:1209863. [PMID: 37600512 PMCID: PMC10435661 DOI: 10.3389/fnagi.2023.1209863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/10/2023] [Indexed: 08/22/2023] Open
Abstract
Human glutaminyl cyclase (hQC) is drawing considerable attention and emerging as a potential druggable target for Alzheimer's disease (AD) due to its close involvement in the pathology of AD via the post-translational pyroglutamate modification of amyloid-β. A recent phase 2a study has shown promising early evidence of efficacy for AD with a competitive benzimidazole-based QC inhibitor, PQ912, which also demonstrated favorable safety profiles. This finding has sparked new hope for the treatment of AD. In this review, we briefly summarize the discovery and evolution of hQC inhibitors, with a particular interest in classic Zinc binding group (ZBG)-containing chemicals reported in recent years. Additionally, we highlight several high-potency inhibitors and discuss new trends and challenges in the development of QC inhibitors as an alternative and promising disease-modifying therapy for AD.
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Affiliation(s)
- Daoyuan Chen
- School of Bioengineering, Zunyi Medical University, Zhuhai, China
| | - Qingxiu Chen
- School of Bioengineering, Zunyi Medical University, Zhuhai, China
| | - Xiaofei Qin
- School of Bioengineering, Zunyi Medical University, Zhuhai, China
| | - Peipei Tong
- School of Bioengineering, Zunyi Medical University, Zhuhai, China
| | - Liping Peng
- School of Bioengineering, Zunyi Medical University, Zhuhai, China
| | - Tao Zhang
- Fujian Key Laboratory of Translational Research in Cancer and Neurodegenerative Diseases, School of Basic Medical Sciences, Institute of Basic Medicine, Fujian Medical University, Fuzhou, China
| | - Chunli Xia
- School of Bioengineering, Zunyi Medical University, Zhuhai, China
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2
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Xia Y, Li F, Zhang X, Balamkundu S, Tang F, Hu S, Lescar J, Tam JP, Liu CF. A Cascade Enzymatic Reaction Scheme for Irreversible Transpeptidative Protein Ligation. J Am Chem Soc 2023; 145:6838-6844. [PMID: 36924109 DOI: 10.1021/jacs.2c13628] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Enzymatic peptide ligation holds great promise in the study of protein functions and development of protein therapeutics. Owing to their high catalytic efficiency and a minimal tripeptide recognition motif, peptidyl asparaginyl ligases (PALs) are particularly useful tools for bioconjugation. However, as an inherent limitation of transpeptidases, PAL-mediated ligation is reversible, requiring a large excess of one of the ligation partners to shift the reaction equilibrium in the forward direction. Herein, we report a method to make PAL-mediated intermolecular ligation irreversible by coupling it to glutaminyl cyclase (QC)-catalyzed pyroglutamyl formation. In this method, the acyl donor substrate of PALs is designed to have glutamine at the P1' position of the Asn-P1'-P2' tripeptide PAL recognition motif. Upon ligation with an acyl acceptor substrate, the acyl donor substrate releases a leaving group in which the exposed N-terminal glutamine is cyclized by QC, quenching the Gln Nα-amine in a lactam. Using this method, PAL-mediated ligation can achieve near-quantitative yields even at an equal molar ratio between the two ligation partners. We have demonstrated this method for a wide range of applications, including protein-to-protein ligations. We anticipate that this cascade enzymatic reaction scheme will make PAL enzymes well suited for numerous new uses in biotechnology.
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Affiliation(s)
- Yiyin Xia
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Fupeng Li
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Xiaohong Zhang
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | | | - Fan Tang
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Side Hu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Julien Lescar
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - James P Tam
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Chuan-Fa Liu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
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3
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Tsai KC, Zhang YX, Kao HY, Fung KM, Tseng TS. Pharmacophore-driven identification of human glutaminyl cyclase inhibitors from foods, plants and herbs unveils the bioactive property and potential of Azaleatin in the treatment of Alzheimer's disease. Food Funct 2022; 13:12632-12647. [PMID: 36416361 DOI: 10.1039/d2fo02507h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Alzheimer's disease (AD) is the leading cause of disabilities in old age and a rapidly growing condition in the elderly population. AD brings significant burden and has a devastating impact on public health, society and the global economy. Thus, developing new therapeutics to combat AD is imperative. Human glutaminyl cyclase (hQC), which catalyzes the formation of neurotoxic pyroglutamate (pE)-modified β-amyloid (Aβ) peptides, is linked to the amyloidogenic process that leads to the initiation of AD. Hence, hQC is an essential target for developing anti-AD therapeutics. Here, we systematically screened and identified hQC inhibitors from natural products by pharmacophore-driven inhibitor screening coupled with biochemical and biophysical examinations. We employed receptor-ligand pharmacophore generation to build pharmacophore models and Phar-MERGE and Phar-SEN for inhibitor screening through ligand-pharmacophore mapping. About 11 and 24 hits identified from the Natural Product and Traditional Chinese Medicine databases, respectively, showed diverse hQC inhibitory abilities. Importantly, the inhibitors TCM1 (Azaleatin; IC50 = 1.1 μM) and TCM2 (Quercetin; IC50 = 4.3 μM) found in foods and plants exhibited strong inhibitory potency against hQC. Furthermore, the binding affinity and molecular interactions were analyzed by surface plasmon resonance (SPR) and molecular modeling/simulations to explore the possible modes of action of Azaleatin and Quercetin. Our study successfully screened and characterized the foundational biochemical and biophysical properties of Azaleatin and Quercetin toward targeting hQC, unveiling their bioactive potential in the treatment of AD.
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Affiliation(s)
- Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan. .,Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Yi-Xuan Zhang
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
| | - Hsiang-Yun Kao
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
| | - Kit-Man Fung
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan. .,Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
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4
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Zhang Y, Wang Y, Zhao Z, Peng W, Wang P, Xu X, Zhao C. Glutaminyl cyclases, the potential targets of cancer and neurodegenerative diseases. Eur J Pharmacol 2022; 931:175178. [DOI: 10.1016/j.ejphar.2022.175178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 11/03/2022]
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5
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Functional Analysis of the GPI Transamidase Complex by Screening for Amino Acid Mutations in Each Subunit. Molecules 2021; 26:molecules26185462. [PMID: 34576938 PMCID: PMC8465894 DOI: 10.3390/molecules26185462] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 12/20/2022] Open
Abstract
Glycosylphosphatidylinositol (GPI) anchor modification is a posttranslational modification of proteins that has been conserved in eukaryotes. The biosynthesis and transfer of GPI to proteins are carried out in the endoplasmic reticulum. Attachment of GPI to proteins is mediated by the GPI-transamidase (GPI-TA) complex, which recognizes and cleaves the C-terminal GPI attachment signal of precursor proteins. Then, GPI is transferred to the newly exposed C-terminus of the proteins. GPI-TA consists of five subunits: PIGK, GPAA1, PIGT, PIGS, and PIGU, and the absence of any subunit leads to the loss of activity. Here, we analyzed functionally important residues of the five subunits of GPI-TA by comparing conserved sequences among homologous proteins. In addition, we optimized the purification method for analyzing the structure of GPI-TA. Using purified GPI-TA, preliminary single particle images were obtained. Our results provide guidance for the structural and functional analysis of GPI-TA.
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Xu C, Zou H, Yu X, Xie Y, Cai J, Shang Q, Ouyang N, Wang Y, Xu P, He Z, Wu H. Repurposing FDA-Approved Compounds for the Discovery of Glutaminyl Cyclase Inhibitors as Drugs Against Alzheimer's Disease. ChemistryOpen 2021; 10:877-881. [PMID: 33377311 PMCID: PMC8409088 DOI: 10.1002/open.202000235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/07/2020] [Indexed: 12/01/2022] Open
Abstract
Alzheimer's disease (AD) is one of the most common neurodegenerative causes of dementia, the pathology of which is still not much clear. It's challenging to discover the disease modifying agents for the prevention and treatment of AD over the years. Emerging evidence has been accumulated to reveal the crucial role of up-regulated glutaminyl cyclase (QC) in the initiation of AD. In the current study, the QC inhibitory potency of a library consisting of 1621 FDA-approved compounds was assessed. A total of 54 hits, 3.33 % of the pool, exhibited QC inhibitory activities. The Ki of the top 5 compounds with the highest QC inhibitory activities were measured. Among these selected hits, compounds affecting neuronal signaling pathways and other mechanisms were recognized. Moreover, several polyphenol derivatives with QC inhibitory activities were also identified. Frameworks and subsets contained in these hits were analyzed. Taken together, our results may contribute to the discovery and development of novel QC inhibitors as potential anti-AD agents.
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Affiliation(s)
- Chenshu Xu
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Haoman Zou
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Xi Yu
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Yazhou Xie
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Jiaxin Cai
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Qi Shang
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Na Ouyang
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Yinan Wang
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Pan Xu
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Zhendan He
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
| | - Haiqiang Wu
- School of Pharmaceutical Sciences Health Science CenterShenzhen University3688 Nanhai RoadShenzhen518055China
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7
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Xu C, Wang YN, Wu H. Glutaminyl Cyclase, Diseases, and Development of Glutaminyl Cyclase Inhibitors. J Med Chem 2021; 64:6549-6565. [PMID: 34000808 DOI: 10.1021/acs.jmedchem.1c00325] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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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8
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Ding H, Wang B, Han Y, Li S. The pivotal function of dehydroascorbate reductase in glutathione homeostasis in plants. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3405-3416. [PMID: 32107543 DOI: 10.1093/jxb/eraa107] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 02/25/2020] [Indexed: 05/20/2023]
Abstract
Under natural conditions, plants are exposed to various abiotic and biotic stresses that trigger rapid changes in the production and removal of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). The ascorbate-glutathione pathway has been recognized to be a key player in H2O2 metabolism, in which reduced glutathione (GSH) regenerates ascorbate by reducing dehydroascorbate (DHA), either chemically or via DHA reductase (DHAR), an enzyme belonging to the glutathione S-transferase (GST) superfamily. Thus, DHAR has been considered to be important in maintaining the ascorbate pool and its redox state. Although some GSTs and peroxiredoxins may contribute to GSH oxidation, analysis of Arabidopsis dhar mutants has identified the key role of DHAR in coupling H2O2 to GSH oxidation. The reaction of DHAR has been proposed to proceed by a ping-pong mechanism, in which binding of DHA to the free reduced form of the enzyme is followed by binding of GSH. Information from crystal structures has shed light on the formation of sulfenic acid at the catalytic cysteine of DHAR that occurs with the reduction of DHA. In this review, we discuss the molecular properties of DHAR and its importance in coupling the ascorbate and glutathione pools with H2O2 metabolism, together with its functions in plant defense, growth, and development.
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Affiliation(s)
- Haiyan Ding
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Bipeng Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Yi Han
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, China
- Engineering Research Center of Bio-process, Ministry of Education, Hefei University of Technology, Hefei, China
| | - Shengchun Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
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Lin W, Zheng X, Fang D, Zhou S, Wu W, Zheng K. Identifying hQC Inhibitors of Alzheimer's Disease by Effective Customized Pharmacophore-Based Virtual Screening, Molecular Dynamic Simulation, and Binding Free Energy Analysis. Appl Biochem Biotechnol 2018; 187:1173-1192. [PMID: 30187344 DOI: 10.1007/s12010-018-2780-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/06/2018] [Indexed: 01/14/2023]
Abstract
Human glutaminyl cyclase (hQC) appeared as a promising new target with its inhibitors attracted much attention for the treatment of Alzheimer's disease (AD) in recent years. But so far, only a few compounds have been reported as hQC inhibitors. To find novel and potent hQC inhibitors, a high-specificity ZBG (zinc-binding groups)-based pharmacophore model comprising customized ZBG feature was first generated using HipHop algorithm in Discovery Studio software for screening out hQC inhibitors from the SPECS database. After purification by docking studies and drug-like ADMET properties filters, four potential hit compounds were retrieved. Subsequently, these hit compounds were subjected to 30-ns molecular dynamic (MD) simulations to explore their binding modes at the active side of hQC. MD simulations demonstrated that these hit compounds formed a chelating interaction with the zinc ion, which was consistent with the finding that the electrostatic interaction was the major driving force for binding to hQC confirmed with MMPBSA energy decomposition. Higher binding affinities of these compounds were also verified by the binding free energy calculations comparing with the references. Thus, these identified compounds might be potential hQC candidates and could be used for further investigation.
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Affiliation(s)
- Weicong Lin
- Department of Physical Chemistry, College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Xiaojie Zheng
- Department of Physical Chemistry, College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Danqing Fang
- Department of Cardiothoracic Surgery, Affiliated Second Hospital of Guangzhou Medical University, Guangzhou, 510260, China
| | - Shengfu Zhou
- Department of Physical Chemistry, College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Wenjuan Wu
- Department of Physical Chemistry, College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
| | - Kangcheng Zheng
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, China
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10
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Schulze A, Wermann M, Demuth HU, Yoshimoto T, Ramsbeck D, Schlenzig D, Schilling S. Continuous assays for meprin alpha and beta using prolyl tripeptidyl aminopeptidase (PtP) from Porphyromonas gingivalis. Anal Biochem 2018; 559:11-16. [PMID: 30098994 DOI: 10.1016/j.ab.2018.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/03/2018] [Accepted: 08/04/2018] [Indexed: 01/17/2023]
Abstract
Common assays for endoprotease activity of meprin α and β are based on cleavage of internally quenched substrates. Although direct and convenient, for meprins these assays bear disadvantages such as, e.g., significant substrate inhibition or potential fluorescence quenching by compounds applied in inhibitor analysis. Here, we present a novel continuous assay by introducing an auxiliary enzyme, prolyl tripeptidyl aminopeptidase (PtP) and the chromogenic substrate KKGYVADAP-p-nitroanilide. We provide a quick strategy for expression and one-step-purification of the auxiliary enzyme. The enzyme kinetic data for meprin α and β suggest hyperbolic v/S-characteristics, the kinetic parameters of substrate conversion by meprin β were Km = 184 ± 32 μM and kcat = 20 ± 4 s-1. We also present conditions for the use of the fluorogenic substrate KKGYVADAP-AMC to assess meprin β activity. The assays were applied for determination of inhibitory parameters of the natural inhibitor actinonin and two recently published hydroxamates. Hence, we present two novel methods, which can be applied to assess inhibitory mechanism and potency with the attractive current drug targets meprin α and β. Furthermore, the assay might also provide implications for analysis of other endoproteases as well as their inhibitors.
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Affiliation(s)
- Anja Schulze
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation (IZI-MWT), Halle (Saale), Germany
| | - Michael Wermann
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation (IZI-MWT), Halle (Saale), Germany
| | - Hans-Ulrich Demuth
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation (IZI-MWT), Halle (Saale), Germany
| | | | - Daniel Ramsbeck
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation (IZI-MWT), Halle (Saale), Germany
| | - Dagmar Schlenzig
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation (IZI-MWT), Halle (Saale), Germany
| | - Stephan Schilling
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation (IZI-MWT), Halle (Saale), Germany.
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Antonyan A, Schlenzig D, Schilling S, Naumann M, Sharoyan S, Mardanyan S, Demuth HU. Concerted action of dipeptidyl peptidase IV and glutaminyl cyclase results in formation of pyroglutamate-modified amyloid peptides in vitro. Neurochem Int 2017; 113:112-119. [PMID: 29224965 DOI: 10.1016/j.neuint.2017.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/29/2017] [Accepted: 12/04/2017] [Indexed: 11/18/2022]
Abstract
Compelling evidence suggests a crucial role of amyloid beta peptides (Aβ(1-40/42)) in the etiology of Alzheimer's disease (AD). The N-terminal truncation of Aβ(1-40/42) and their modification, e.g. by glutaminyl cyclase (QC), is expected to enhance the amyloid toxicity. In this work, the MALDI-TOF mass spectrometry application proved N-terminal cleavage of Aβ(1-40/42) by purified dipeptidyl peptidase IV (DPPIV) in vitro observed earlier. The subsequent transformation of resulted Aβ(3-40/42) to pE-Aβ(3-40/42) in QC catalyzed glutamate cyclization was manifested. Hence, consecutive conversion of Aβ(1-40/42) by DPPIV and QC can be assumed as a potential mechanism of formation of non-degrading pyroglutamated pE-Aβ(3-40/42), which might accumulate and contribute to AD progression. The in vitro acceleration of Aβ(1-40) aggregation in the simultaneous presence of DPPIV and QC was shown also.
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Affiliation(s)
- Alvard Antonyan
- H. Buniatian Institute of Biochemistry of Armenian NAS, Yerevan 0014, Armenia.
| | - Dagmar Schlenzig
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, Halle, Germany
| | - Stephan Schilling
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, Halle, Germany
| | - Marcel Naumann
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, Halle, Germany
| | - Svetlana Sharoyan
- H. Buniatian Institute of Biochemistry of Armenian NAS, Yerevan 0014, Armenia
| | - Sona Mardanyan
- H. Buniatian Institute of Biochemistry of Armenian NAS, Yerevan 0014, Armenia
| | - Hans-Ulrich Demuth
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, Halle, Germany
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12
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Chang HY, Lin ST, Ko TP, Wu SM, Lin TH, Chang YC, Huang KF, Lee TM. Enzymatic characterization and crystal structure analysis of Chlamydomonas reinhardtii dehydroascorbate reductase and their implications for oxidative stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 120:144-155. [PMID: 29028546 DOI: 10.1016/j.plaphy.2017.09.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/21/2017] [Accepted: 09/29/2017] [Indexed: 06/07/2023]
Abstract
Dehydroascorbate reductase (DHAR) is a key enzyme for glutathione (GSH)-dependent reduction of dehydroascorbate (DHA) to recycled ascorbate (AsA) in plants, and plays a major role against the toxicity of reactive oxygen species (ROS). Previously, we proposed that the increase of AsA regeneration via enhanced DHAR activity modulates the ascorbate-glutathione cycle activity against photooxidative stress in Chlamydomonas reinhardtii. In the present work, we use site-directed mutagenesis and crystal structure analysis to elucidate the molecular basis of how C. reinhardtii DHAR (CrDHAR1) is involved in the detoxification mechanisms. Mutagenesis data show that the D21A, D21N and C22A mutations result in severe loss of the enzyme's function, suggesting crucial roles of Asp-21 and Cys-22 in substrate binding and catalysis. The mutant K11A also exhibits reduced redox activity (∼50%). The crystal structure of apo CrDHAR1 further provides insights into the proposed mechanism centering on the strictly conserved Cys-22, which is suggested to initiate the redox reactions of DHA and GSH. Furthermore, in vitro oxidation of the recombinant CrDHAR1 in the presence of 1 mM H2O2 has minor effects on the Km for the substrates but significantly reduces the kcat. The enzyme's activity and its mRNA abundance in the C. reinhardtii cells are increased by treatment with 0.2-1 mM H2O2 but decreased when H2O2 is ≥ 1.5 mM. The latter decrease is accompanied by oxidative damage and lower AsA concentrations. These biochemical and physiological data provide new insights into the catalytic mechanism of CrDHAR1, which protects the C. reinhardtii cells from oxidative stress-induced toxicity.
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Affiliation(s)
- Hsin-Yang Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
| | - Shu-Tseng Lin
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Shu-Mei Wu
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Tsen-Hung Lin
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Yu-Ching Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Kai-Fa Huang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Tse-Min Lee
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung 80424, Taiwan; Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
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13
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Li M, Dong Y, Yu X, Li Y, Zou Y, Zheng Y, He Z, Liu Z, Quan J, Bu X, Wu H. Synthesis and Evaluation of Diphenyl Conjugated Imidazole Derivatives as Potential Glutaminyl Cyclase Inhibitors for Treatment of Alzheimer's Disease. J Med Chem 2017; 60:6664-6677. [PMID: 28700245 DOI: 10.1021/acs.jmedchem.7b00648] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
High expression of glutaminyl cyclase (QC) contributes to the initiation of Alzheimer's disease (AD) by catalyzing the generation of neurotoxic pyroglutamate (pE)-modified β-amyloid (Aβ) peptides. Preventing the generation of pE-Aβs by QC inhibition has been suggested as a novel approach to a disease-modifying therapy for AD. In this work, a series of diphenyl conjugated imidazole derivatives (DPCIs) was rationally designed and synthesized. Analogues with this scaffold exhibited potent inhibitory activity against human QC (hQC) and good in vitro blood-brain barrier (BBB) permeability. Further assessments corroborated that the selected hQC inhibitor 28 inhibits the activity of hQC, dramatically reduces the generation of pE-Aβs in cultured cells and in vivo, and improves the behavior of AD mice.
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Affiliation(s)
- Manman Li
- Department of Pharmacy, School of Medicine, Shenzhen University , Shenzhen 518060, China.,College of Life Sciences and Oceanography, Shenzhen University , Shenzhen 518060, China
| | - Yao Dong
- Department of Pharmacy, School of Medicine, Shenzhen University , Shenzhen 518060, China.,College of Life Sciences and Oceanography, Shenzhen University , Shenzhen 518060, China
| | - Xi Yu
- Department of Pharmacy, School of Medicine, Shenzhen University , Shenzhen 518060, China.,College of Life Sciences and Oceanography, Shenzhen University , Shenzhen 518060, China
| | - Yue Li
- Department of Pharmacy, School of Medicine, Shenzhen University , Shenzhen 518060, China
| | - Yongdong Zou
- College of Life Sciences and Oceanography, Shenzhen University , Shenzhen 518060, China
| | - Yizhi Zheng
- College of Life Sciences and Oceanography, Shenzhen University , Shenzhen 518060, China
| | - Zhendan He
- Department of Pharmacy, School of Medicine, Shenzhen University , Shenzhen 518060, China
| | - Zhigang Liu
- School of Medicine, Shenzhen University , Shenzhen 518060, China
| | - Junmin Quan
- Key Laboratory of Structural Biology, School of Chemical Biology & Biotechnology, Peking University, Shenzhen Graduate School , Shenzhen 518055, China
| | - Xianzhang Bu
- School of Pharmaceutical Science, Sun Yat-sen University , Guangzhou, 510006, China
| | - Haiqiang Wu
- Department of Pharmacy, School of Medicine, Shenzhen University , Shenzhen 518060, China.,College of Life Sciences and Oceanography, Shenzhen University , Shenzhen 518060, China.,Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, United States
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14
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Spahn C, Wermann M, Eichentopf R, Hause G, Schlenzig D, Schilling S. Purification of recombinant Aβ(1-42) and pGlu-Aβ(3-42) using preparative SDS-PAGE. Electrophoresis 2017; 38:2042-2049. [PMID: 28510356 DOI: 10.1002/elps.201700154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/11/2017] [Accepted: 05/11/2017] [Indexed: 11/10/2022]
Abstract
Recombinant expression and purification of amyloid peptides represents a common basis for investigating the molecular mechanisms of amyloid formation and toxicity. However, the isolation of the recombinant peptides is hampered by inefficient separation from contaminants such as the fusion protein required for efficient expression in E. coli. Here, we present a new approach for the isolation of highly purified Aβ(1-42) and pGlu-Aβ(3-42), which is based on a separation using preparative SDS-PAGE. The method relies on the purification of the Aβ fusion protein by affinity chromatography followed by preparative SDS-PAGE under reducing conditions and subsequent removal of detergents by precipitation. The application of preparative SDS-PAGE represents the key step to isolate highly pure recombinant Aβ, which has been applied for characterization of aggregation and toxicity. Thereby, the yield of the purification strategy was >60%. To the best of our knowledge, this is the first description of an electrophoresis-based method for purification of a recombinant Aβ peptide. Therefore, the method might be of interest for isolation of other amyloid peptides, which are critical for conventional purification strategies due to their aggregation propensity.
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Affiliation(s)
- Claudia Spahn
- Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation (IZI-MWT), Halle, Germany
| | - Michael Wermann
- Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation (IZI-MWT), Halle, Germany
| | - Rico Eichentopf
- Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation (IZI-MWT), Halle, Germany
| | - Gerd Hause
- Martin-Luther University Halle-Wittenberg, Halle, Germany
| | - Dagmar Schlenzig
- Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation (IZI-MWT), Halle, Germany
| | - Stephan Schilling
- Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation (IZI-MWT), Halle, Germany
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15
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Gamerith C, Vastano M, Ghorbanpour SM, Zitzenbacher S, Ribitsch D, Zumstein MT, Sander M, Herrero Acero E, Pellis A, Guebitz GM. Enzymatic Degradation of Aromatic and Aliphatic Polyesters by P. pastoris Expressed Cutinase 1 from Thermobifida cellulosilytica. Front Microbiol 2017; 8:938. [PMID: 28596765 PMCID: PMC5443175 DOI: 10.3389/fmicb.2017.00938] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/09/2017] [Indexed: 11/13/2022] Open
Abstract
To study hydrolysis of aromatic and aliphatic polyesters cutinase 1 from Thermobifida cellulosilytica (Thc_Cut1) was expressed in P. pastoris. No significant differences between the expression of native Thc_Cut1 and of two glycosylation site knock out mutants (Thc_Cut1_koAsn and Thc_Cut1_koST) concerning the total extracellular protein concentration and volumetric activity were observed. Hydrolysis of poly(ethylene terephthalate) (PET) was shown for all three enzymes based on quantification of released products by HPLC and similar concentrations of released terephthalic acid (TPA) and mono(2-hydroxyethyl) terephthalate (MHET) were detected for all enzymes. Both tested aliphatic polyesters poly(butylene succinate) (PBS) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were hydrolyzed by Thc_Cut1 and Thc_Cut1_koST, although PBS was hydrolyzed to significantly higher extent than PHBV. These findings were also confirmed via quartz crystal microbalance (QCM) analysis; for PHBV only a small mass change was observed while the mass of PBS thin films decreased by 93% upon enzymatic hydrolysis with Thc_Cut1. Although both enzymes led to similar concentrations of released products upon hydrolysis of PET and PHBV, Thc_Cut1_koST was found to be significantly more active on PBS than the native Thc_Cut1. Hydrolysis of PBS films by Thc_Cut1 and Thc_Cut1_koST was followed by weight loss and scanning electron microscopy (SEM). Within 96 h of hydrolysis up to 92 and 41% of weight loss were detected with Thc_Cut1_koST and Thc_Cut1, respectively. Furthermore, SEM characterization of PBS films clearly showed that enzyme tretment resulted in morphological changes of the film surface.
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Affiliation(s)
| | - Marco Vastano
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences ViennaTulln, Austria.,Dipartimento di Scienze Chimiche, Universita degli Studi di Napoli Federico IINaples, Italy
| | - Sahar M Ghorbanpour
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences ViennaTulln, Austria
| | | | - Doris Ribitsch
- Austrian Centre of Industrial BiotechnologyTulln, Austria.,Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences ViennaTulln, Austria
| | - Michael T Zumstein
- Institute of Biogeochemistry and Pollutant Dynamics, ETH ZurichZurich, Switzerland
| | - Michael Sander
- Institute of Biogeochemistry and Pollutant Dynamics, ETH ZurichZurich, Switzerland
| | | | - Alessandro Pellis
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences ViennaTulln, Austria
| | - Georg M Guebitz
- Austrian Centre of Industrial BiotechnologyTulln, Austria.,Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences ViennaTulln, Austria
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16
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Hoffmann T, Meyer A, Heiser U, Kurat S, Böhme L, Kleinschmidt M, Bühring KU, Hutter-Paier B, Farcher M, Demuth HU, Lues I, Schilling S. Glutaminyl Cyclase Inhibitor PQ912 Improves Cognition in Mouse Models of Alzheimer's Disease-Studies on Relation to Effective Target Occupancy. J Pharmacol Exp Ther 2017; 362:119-130. [PMID: 28446518 DOI: 10.1124/jpet.117.240614] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/24/2017] [Indexed: 12/22/2022] Open
Abstract
Numerous studies suggest that the majority of amyloid-β (Aβ) peptides deposited in Alzheimer's disease (AD) are truncated and post-translationally modified at the N terminus. Among these modified species, pyroglutamyl-Aβ (pE-Aβ, including N3pE-Aβ40/42 and N11pE-Aβ40/42) has been identified as particularly neurotoxic. The N-terminal modification renders the peptide hydrophobic, accelerates formation of oligomers, and reduces degradation by peptidases, leading ultimately to the accumulation of the peptide and progression of AD. It has been shown that the formation of pyroglutamyl residues is catalyzed by glutaminyl cyclase (QC). Here, we present data about the pharmacological in vitro and in vivo efficacy of the QC inhibitor (S)-1-(1H-benzo[d]imidazol-5-yl)-5-(4-propoxyphenyl)imidazolidin-2-one (PQ912), the first-in-class compound that is in clinical development. PQ912 inhibits human, rat, and mouse QC activity, with Ki values ranging between 20 and 65 nM. Chronic oral treatment of hAPPSLxhQC double-transgenic mice with approximately 200 mg/kg/day via chow shows a significant reduction of pE-Aβ levels and concomitant improvement of spatial learning in a Morris water maze test paradigm. This dose results in a brain and cerebrospinal fluid concentration of PQ912 which relates to a QC target occupancy of about 60%. Thus, we conclude that >50% inhibition of QC activity in the brain leads to robust treatment effects. Secondary pharmacology experiments in mice indicate a fairly large potency difference for Aβ cyclization compared with cyclization of physiologic substrates, suggesting a robust therapeutic window in humans. This information constitutes an important translational guidance for predicting the therapeutic dose range in clinical studies with PQ912.
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Affiliation(s)
- Torsten Hoffmann
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Antje Meyer
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Ulrich Heiser
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Stephan Kurat
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Livia Böhme
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Martin Kleinschmidt
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Karl-Ulrich Bühring
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Birgit Hutter-Paier
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Martina Farcher
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Hans-Ulrich Demuth
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Inge Lues
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Stephan Schilling
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
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17
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Hielscher-Michael S, Griehl C, Buchholz M, Demuth HU, Arnold N, Wessjohann LA. Natural Products from Microalgae with Potential against Alzheimer's Disease: Sulfolipids Are Potent Glutaminyl Cyclase Inhibitors. Mar Drugs 2016; 14:md14110203. [PMID: 27827845 PMCID: PMC5128746 DOI: 10.3390/md14110203] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/20/2016] [Accepted: 10/25/2016] [Indexed: 12/30/2022] Open
Abstract
In recent years, many new enzymes, like glutaminyl cyclase (QC), could be associated with pathophysiological processes and represent targets for many diseases, so that enzyme-inhibiting properties of natural substances are becoming increasingly important. In different studies, the pathophysiology connection of QC to various diseases including Alzheimer's disease (AD) was described. Algae are known for the ability to synthesize complex and highly-diverse compounds with specific enzyme inhibition properties. Therefore, we screened different algae species for the presence of QC inhibiting metabolites using a new "Reverse Metabolomics" technique including an Activity-correlation Analysis (AcorA), which is based on the correlation of bioactivities to mass spectral data with the aid of mathematic informatics deconvolution. Thus, three QC inhibiting compounds from microalgae belonging to the family of sulfolipids were identified. The compounds showed a QC inhibition of 81% and 76% at concentrations of 0.25 mg/mL and 0.025 mg/mL, respectively. Thus, for the first time, sulfolipids are identified as QC inhibiting compounds and possess substructures with the required pharmacophore qualities. They represent a new lead structure for QC inhibitors.
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Affiliation(s)
- Stephanie Hielscher-Michael
- Group Algae Biotechnology, Department of Applied Biosciences and Process Technology, Anhalt University of Applied Sciences, 06366 Köthen, Germany.
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
| | - Carola Griehl
- Group Algae Biotechnology, Department of Applied Biosciences and Process Technology, Anhalt University of Applied Sciences, 06366 Köthen, Germany.
| | - Mirko Buchholz
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology IZI, 06120 Halle (Saale), Germany.
| | - Hans-Ulrich Demuth
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology IZI, 06120 Halle (Saale), Germany.
| | - Norbert Arnold
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology IZI, 06120 Halle (Saale), Germany.
| | - Ludger A Wessjohann
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
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18
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High level expression of a recombinant xylanase by Pichia pastoris cultured in a bioreactor with methanol as the sole carbon source: Purification and biochemical characterization of the enzyme. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2016.04.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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19
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Li M, Dong Y, Yu X, Zou Y, Zheng Y, Bu X, Quan J, He Z, Wu H. Inhibitory effect of flavonoids on human glutaminyl cyclase. Bioorg Med Chem 2016; 24:2280-6. [DOI: 10.1016/j.bmc.2016.03.064] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 03/30/2016] [Accepted: 03/30/2016] [Indexed: 10/22/2022]
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20
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Pérez de los Santos AI, Cayetano-Cruz M, Gutiérrez-Antón M, Santiago-Hernández A, Plascencia-Espinosa M, Farrés A, Hidalgo-Lara ME. Improvement of catalytical properties of two invertases highly tolerant to sucrose after expression in Pichia pastoris . Effect of glycosylation on enzyme properties. Enzyme Microb Technol 2016; 83:48-56. [DOI: 10.1016/j.enzmictec.2015.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 11/16/2022]
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21
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Common Polymorphisms Within QPCT Gene Are Associated with the Susceptibility of Schizophrenia in a Han Chinese Population. Mol Neurobiol 2015; 53:6362-6366. [DOI: 10.1007/s12035-015-9541-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 11/11/2015] [Indexed: 01/09/2023]
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22
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Boldrini-França J, Santos Rodrigues R, Santos-Silva LK, de Souza DLN, Gomes MSR, Cologna CT, de Pauw E, Quinton L, Henrique-Silva F, de Melo Rodrigues V, Arantes EC. Expression of a new serine protease from Crotalus durissus collilineatus venom in Pichia pastoris and functional comparison with the native enzyme. Appl Microbiol Biotechnol 2015; 99:9971-86. [PMID: 26227411 DOI: 10.1007/s00253-015-6836-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 07/07/2015] [Accepted: 07/11/2015] [Indexed: 11/28/2022]
Abstract
Snake venom serine proteases (SVSPs) act primarily on plasma proteins related to blood clotting and are considered promising for the treatment of several hemostatic disorders. We report the heterologous expression of a serine protease from Crotalus durissus collilineatus, named collinein-1, in Pichia pastoris, as well as the enzymatic comparative characterization of the toxin in native and recombinant forms. The complementary DNA (cDNA) encoding collinein-1 was amplified from cDNA library of C. d. collilineatus venom gland and cloned into the pPICZαA vector. The recombinant plasmid was used to transform cells of KM71H P. pastoris. Heterologous expression was induced by methanol and yielded 56 mg of recombinant collinein-1 (rCollinein-1) per liter of culture. The native collinein-1 was purified from C. d. collilineatus venom, and its identity was confirmed by amino acid sequencing. The native and recombinant enzymes showed similar effects upon bovine fibrinogen by releasing preferentially fibrinopeptide A. Although both enzymes have induced plasma coagulation, native Colinein-1 has shown higher coagulant activity. The serine proteases were able to hydrolyze the chromogenic substrates S-2222, S-2238, and S2302. Both enzymes showed high stability on different pH and temperature, and their esterase activities were inhibited in the presence of Zn2+ and Cu2+. The serine proteases showed similar k cat/K m values in enzyme kinetics assays, suggesting no significant differences in efficiency of these proteins to hydrolyze the substrate. These results demonstrated that rCollinein-1 was expressed with functional integrity on the evaluated parameters. The success in producing a functionally active recombinant SVSP may generate perspectives to their future therapeutic applications.
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Affiliation(s)
- Johara Boldrini-França
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Física e Química, Universidade de São Paulo, Av. do Café s/n, Monte Alegre, Ribeirão Preto, SP, 14040-903, Brazil
| | - Renata Santos Rodrigues
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil.,INCT, Instituto Nacional de Ciência e Tecnologia em Nano-Biofarmacêutica, Belo Horizonte, MG, Brazil
| | | | - Dayane Lorena Naves de Souza
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil.,INCT, Instituto Nacional de Ciência e Tecnologia em Nano-Biofarmacêutica, Belo Horizonte, MG, Brazil
| | - Mário Sérgio Rocha Gomes
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil.,INCT, Instituto Nacional de Ciência e Tecnologia em Nano-Biofarmacêutica, Belo Horizonte, MG, Brazil
| | | | - Edwin de Pauw
- Department of Chemistry, University of Liège, Liège, Belgium
| | - Loïc Quinton
- Department of Chemistry, University of Liège, Liège, Belgium
| | - Flávio Henrique-Silva
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Veridiana de Melo Rodrigues
- Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil.,INCT, Instituto Nacional de Ciência e Tecnologia em Nano-Biofarmacêutica, Belo Horizonte, MG, Brazil
| | - Eliane Candiani Arantes
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Física e Química, Universidade de São Paulo, Av. do Café s/n, Monte Alegre, Ribeirão Preto, SP, 14040-903, Brazil.
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23
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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] [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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24
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Huang KF, Hsu HL, Karim S, Wang AHJ. Structural and functional analyses of a glutaminyl cyclase from Ixodes scapularis reveal metal-independent catalysis and inhibitor binding. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:789-801. [PMID: 24598748 PMCID: PMC8494195 DOI: 10.1107/s1399004713033488] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/10/2013] [Indexed: 11/10/2022]
Abstract
Glutaminyl cyclases (QCs) from mammals and Drosophila are zinc-dependent enzymes that catalyze N-terminal pyroglutamate formation of numerous proteins and peptides. These enzymes have been found to be critical for the oviposition and embryogenesis of ticks, implying that they are possible physiological targets for tick control. Here, 1.10-1.15 Å resolution structures of a metal-independent QC from the black-legged tick Ixodes scapularis (Is-QC) are reported. The structures exhibit the typical scaffold of mammalian QCs but have two extra disulfide bridges that stabilize the central β-sheet, resulting in an increased thermal stability. Is-QC contains ~0.5 stoichiometric zinc ions, which could be removed by 1 mM EDTA. Compared with the Zn-bound form, apo-Is-QC has a nearly identical active-site structure and stability, but unexpectedly possesses significantly increased QC activities towards both synthetic and physiological substrates. Enzyme-kinetic analysis revealed that apo-Is-QC has a stronger substrate-binding affinity, suggesting that bound zinc interferes with substrate binding during catalysis. The structures of Is-QC bound to the inhibitor PBD150 revealed similar binding modes to both forms of Is-QC, with the exception of the inhibitor imidazole ring, which is consistent with the comparable inhibition activities of the inhibitor towards both forms of Is-QC. These findings have implications for the design of new QC inhibitors.
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Affiliation(s)
- Kai-Fa Huang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei 11529, Taiwan
| | - Hui-Ling Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei 11529, Taiwan
| | - Shahid Karim
- Department of Biological Sciences, The University of Southern Mississippi, 18 College Drive #5018, Hattiesburg, MS 39406, USA
| | - Andrew H.-J. Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
- Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei 11529, Taiwan
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25
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Ramsbeck D, Buchholz M, Koch B, Böhme L, Hoffmann T, Demuth HU, Heiser U. Structure–Activity Relationships of Benzimidazole-Based Glutaminyl Cyclase Inhibitors Featuring a Heteroaryl Scaffold. J Med Chem 2013; 56:6613-25. [DOI: 10.1021/jm4001709] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel Ramsbeck
- Department
of Medicinal Chemistry, ‡Department of Enzymology §Department of Preclinical Pharmacology, Probiodrug AG, Weinbergweg 22, 06120
Halle, Germany
| | - Mirko Buchholz
- Department
of Medicinal Chemistry, ‡Department of Enzymology §Department of Preclinical Pharmacology, Probiodrug AG, Weinbergweg 22, 06120
Halle, Germany
| | - Birgit Koch
- Department
of Medicinal Chemistry, ‡Department of Enzymology §Department of Preclinical Pharmacology, Probiodrug AG, Weinbergweg 22, 06120
Halle, Germany
| | - Livia Böhme
- Department
of Medicinal Chemistry, ‡Department of Enzymology §Department of Preclinical Pharmacology, Probiodrug AG, Weinbergweg 22, 06120
Halle, Germany
| | - Torsten Hoffmann
- Department
of Medicinal Chemistry, ‡Department of Enzymology §Department of Preclinical Pharmacology, Probiodrug AG, Weinbergweg 22, 06120
Halle, Germany
| | - Hans-Ulrich Demuth
- Department
of Medicinal Chemistry, ‡Department of Enzymology §Department of Preclinical Pharmacology, Probiodrug AG, Weinbergweg 22, 06120
Halle, Germany
| | - Ulrich Heiser
- Department
of Medicinal Chemistry, ‡Department of Enzymology §Department of Preclinical Pharmacology, Probiodrug AG, Weinbergweg 22, 06120
Halle, Germany
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Abstract
Recombinant human Glutaminyl Cyclase expressed in E. coli is produced as inclusion bodies. Lack of glycosylation is the main origin of its accumulation in insoluble aggregates. Mutation of single isolated hydrophobic amino acids into negative amino acids was not able to circumvent inclusion bodies formation. On the contrary, substitution with carboxyl-terminal residues of two or three aromatic residues belonging to extended hydrophobic patches on the protein surface provided soluble but still active forms of the protein. These mutants could be expressed in isotopically enriched forms for NMR studies and the maximal attainable concentration was sufficient for the acquisition of 1H-15N HSQC spectra that represent the starting point for future drug development projects targeting Alzheimer’s disease.
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27
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Koch B, Buchholz M, Wermann M, Heiser U, Schilling S, Demuth HU. Probing Secondary Glutaminyl Cyclase (QC) Inhibitor Interactions Applying an in silico-Modeling/Site-Directed Mutagenesis Approach: Implications for Drug Development. Chem Biol Drug Des 2012; 80:937-46. [DOI: 10.1111/cbdd.12046] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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28
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Koch B, Kolenko P, Buchholz M, Carrillo DR, Parthier C, Wermann M, Rahfeld JU, Reuter G, Schilling S, Stubbs MT, Demuth HU. Crystal structures of glutaminyl cyclases (QCs) from Drosophila melanogaster reveal active site conservation between insect and mammalian QCs. Biochemistry 2012; 51:7383-92. [PMID: 22897232 DOI: 10.1021/bi300687g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Glutaminyl cyclases (QCs), which catalyze the formation of pyroglutamic acid (pGlu) at the N-terminus of a variety of peptides and proteins, have attracted particular attention for their potential role in Alzheimer's disease. In a transgenic Drosophila melanogaster (Dm) fruit fly model, oral application of the potent competitive QC inhibitor PBD150 was shown to reduce the burden of pGlu-modified Aβ. In contrast to mammals such as humans and rodents, there are at least three DmQC species, one of which (isoDromeQC) is localized to mitochondria, whereas DromeQC and an isoDromeQC splice variant possess signal peptides for secretion. Here we present the recombinant expression, characterization, and crystal structure determination of mature DromeQC and isoDromeQC, revealing an overall fold similar to that of mammalian QCs. In the case of isoDromeQC, the putative extended substrate binding site might be affected by the proximity of the N-terminal residues. PBD150 inhibition of DromeQC is roughly 1 order of magnitude weaker than that of the human and murine QCs. The inhibitor binds to isoDromeQC in a fashion similar to that observed for human QCs, whereas it adopts alternative binding modes in a DromeQC variant lacking the conserved cysteines near the active center and shows a disordered dimethoxyphenyl moiety in wild-type DromeQC, providing an explanation for the lower affinity. Our biophysical and structural data suggest that isoDromeQC and human QC are similar with regard to functional aspects. The two Dm enzymes represent a suitable model for further in-depth analysis of the catalytic mechanism of animal QCs, and isoDromeQC might serve as a model system for the structure-based design of potential AD therapeutics.
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Affiliation(s)
- Birgit Koch
- Probiodrug AG, Weinbergweg 22, D-06120 Halle (Saale), Germany
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29
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Cynis H, Hoffmann T, Friedrich D, Kehlen A, Gans K, Kleinschmidt M, Rahfeld JU, Wolf R, Wermann M, Stephan A, Haegele M, Sedlmeier R, Graubner S, Jagla W, Müller A, Eichentopf R, Heiser U, Seifert F, Quax PHA, de Vries MR, Hesse I, Trautwein D, Wollert U, Berg S, Freyse EJ, Schilling S, Demuth HU. The isoenzyme of glutaminyl cyclase is an important regulator of monocyte infiltration under inflammatory conditions. EMBO Mol Med 2011; 3:545-58. [PMID: 21774078 PMCID: PMC3377097 DOI: 10.1002/emmm.201100158] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 06/01/2011] [Accepted: 06/08/2011] [Indexed: 02/06/2023] Open
Abstract
Acute and chronic inflammatory disorders are characterized by detrimental cytokine and chemokine expression. Frequently, the chemotactic activity of cytokines depends on a modified N-terminus of the polypeptide. Among those, the N-terminus of monocyte chemoattractant protein 1 (CCL2 and MCP-1) is modified to a pyroglutamate (pE-) residue protecting against degradation in vivo. Here, we show that the N-terminal pE-formation depends on glutaminyl cyclase activity. The pE-residue increases stability against N-terminal degradation by aminopeptidases and improves receptor activation and signal transduction in vitro. Genetic ablation of the glutaminyl cyclase iso-enzymes QC (QPCT) or isoQC (QPCTL) revealed a major role of isoQC for pE1-CCL2 formation and monocyte infiltration. Consistently, administration of QC-inhibitors in inflammatory models, such as thioglycollate-induced peritonitis reduced monocyte infiltration. The pharmacologic efficacy of QC/isoQC-inhibition was assessed in accelerated atherosclerosis in ApoE3*Leiden mice, showing attenuated atherosclerotic pathology following chronic oral treatment. Current strategies targeting CCL2 are mainly based on antibodies or spiegelmers. The application of small, orally available inhibitors of glutaminyl cyclases represents an alternative therapeutic strategy to treat CCL2-driven disorders such as atherosclerosis/restenosis and fibrosis.
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30
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Ruiz-Carrillo D, Koch B, Parthier C, Wermann M, Dambe T, Buchholz M, Ludwig HH, Heiser U, Rahfeld JU, Stubbs MT, Schilling S, Demuth HU. Structures of Glycosylated Mammalian Glutaminyl Cyclases Reveal Conformational Variability near the Active Center. Biochemistry 2011; 50:6280-8. [DOI: 10.1021/bi200249h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David Ruiz-Carrillo
- Probiodrug AG, Weinbergweg 22, D-06120 Halle (Saale), Germany
- Institut für Biochemie und Biotechnologie, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3, D-06120 Halle (Saale), Germany
| | - Birgit Koch
- Probiodrug AG, Weinbergweg 22, D-06120 Halle (Saale), Germany
| | - Christoph Parthier
- Institut für Biochemie und Biotechnologie, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3, D-06120 Halle (Saale), Germany
| | - Michael Wermann
- Probiodrug AG, Weinbergweg 22, D-06120 Halle (Saale), Germany
| | - Tresfore Dambe
- PSF AG, Robert-Roessle-Strasse 10, D-13092 Berlin, Germany
| | - Mirko Buchholz
- Probiodrug AG, Weinbergweg 22, D-06120 Halle (Saale), Germany
| | | | - Ulrich Heiser
- Probiodrug AG, Weinbergweg 22, D-06120 Halle (Saale), Germany
| | | | - Milton T. Stubbs
- Institut für Biochemie und Biotechnologie, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3, D-06120 Halle (Saale), Germany
- Mitteldeutsches Zentrum für Struktur und Dynamik der Proteine (MZP), Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle (Saale), Germany
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31
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Biodegradable poly(ethylene glycol) hydrogels based on a self-elimination degradation mechanism. Biomaterials 2010; 31:6675-84. [PMID: 20561680 DOI: 10.1016/j.biomaterials.2010.05.021] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Accepted: 05/07/2010] [Indexed: 01/16/2023]
Abstract
Two vinyl sulfone functionalized crosslinkers were developed for the purpose of preparing degradable poly(ethylene glycol) (PEG) hydrogels (EMXL and GABA-EMXL hydrogels). A self-elimination degradation mechanism in which an N-terminal residue of a glutamine is converted to pyroglutamic acid with subsequent release of diamino PEG (DAP) is proposed. The hydrogels were formed via Michael addition by mixing degradable or nondegradable crosslinkers and copolymer {4% w/v; poly[PEG-alt-poly(mercapto-succinic acid)]} at room temperature in phosphate buffer (PB, pH = 7.4). Hydrogel degradation was characterized by assessing diamino PEG release and examining morphological changes as well as the swelling and weight loss ratio under physiological conditions (37 degrees C). Degradation of EMXL and GABA-EMXL hydrogels occurred by surface erosion (confirmed by SEM). GABA-EMXL degradation was significantly faster (approximately 3-fold) than EMXL; however, the degradation of both hydrogels in mouse plasma was 12-times slower than in PBS. The slower degradation rate in plasma as compared to buffer is consistent with the presence of gamma-glutamyltransferase, gamma-glutamylcyclotransferase and/or glutaminyl cyclase (QC), which have been shown to suppress pyroglutamic acid formation. The current studies suggest that EMXL and GABA-EMXL hydrogels may have biomedical applications where 1-2 week degradation timeframes are optimal.
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32
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Buchholz M, Hamann A, Aust S, Brandt W, Böhme L, Hoffmann T, Schilling S, Demuth HU, Heiser U. Inhibitors for Human Glutaminyl Cyclase by Structure Based Design and Bioisosteric Replacement. J Med Chem 2009; 52:7069-80. [DOI: 10.1021/jm900969p] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - Wolfgang Brandt
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle, Germany
| | | | | | | | - Hans-Ulrich Demuth
- Department of Medicinal Chemistry
- Department of Enzymology
- Department of Preclinical Pharmacology
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33
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Bioorganic synthesis of a recombinant HIV-1 fusion inhibitor, SC35EK, with an N-terminal pyroglutamate capping group. Bioorg Med Chem 2009; 17:7964-70. [PMID: 19864148 DOI: 10.1016/j.bmc.2009.10.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 10/07/2009] [Accepted: 10/08/2009] [Indexed: 01/30/2023]
Abstract
The bioorganic synthesis of an end-capped anti-HIV peptide from a recombinant protein was investigated. Cyanogen bromide-mediated cleavage of two Met-Gln sites across the target anti-HIV sequence generated an HIV-1 fusion inhibitor (SC35EK) analog bearing an N-terminal pyroglutamate (pGlu) residue and a C-terminal homoserine lactone (Hsl) residue. The end-capped peptide, pGlu-SC35EK-Hsl, had similar bioactivity and biophysical properties to the parent peptide, and an improved resistance to peptidase-mediated degradation was observed compared with the non-end-capped peptide obtained using standard recombinant technology.
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34
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Stephan A, Wermann M, von Bohlen A, Koch B, Cynis H, Demuth HU, Schilling S. Mammalian glutaminyl cyclases and their isoenzymes have identical enzymatic characteristics. FEBS J 2009; 276:6522-36. [DOI: 10.1111/j.1742-4658.2009.07337.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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35
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Skropeta D. The effect of individual N-glycans on enzyme activity. Bioorg Med Chem 2009; 17:2645-53. [PMID: 19285412 DOI: 10.1016/j.bmc.2009.02.037] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Revised: 02/11/2009] [Accepted: 02/13/2009] [Indexed: 01/08/2023]
Abstract
In a series of investigations, N-glycosylation has proven to be a key determinant of enzyme secretion, activity, binding affinity and substrate specificity, enabling a protein to fine-tune its activity. In the majority of cases elimination of all putative N-glycosylation sites of an enzyme results in significantly reduced protein secretion levels, while removal of individual N-glycosylation sites often leads to the expression of active enzymes showing markedly reduced catalytic activity, with the decreased activity often commensurate with the number of glycosylation sites available, and the fully deglycosylated enzymes showing only minimal activity relative to their glycosylated counterparts. On the other hand, several cases have also recently emerged where deglycosylation of an enzyme results in significantly increased catalytic activity, binding affinity and altered substrate specificity, highlighting the very unique and diverse roles that individual N-glycans play in regulating enzyme function.
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Affiliation(s)
- Danielle Skropeta
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia.
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36
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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37
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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] [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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38
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Cynis H, Scheel E, Saido TC, Schilling S, Demuth HU. Amyloidogenic processing of amyloid precursor protein: evidence of a pivotal role of glutaminyl cyclase in generation of pyroglutamate-modified amyloid-beta. Biochemistry 2008; 47:7405-13. [PMID: 18570439 DOI: 10.1021/bi800250p] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Compelling evidence suggests that N-terminally truncated and pyroglutamyl-modified amyloid-beta (Abeta) peptides play a major role in the development of Alzheimer's disease. Posttranslational formation of pyroglutamic acid (pGlu) at position 3 or 11 of Abeta implies cyclization of an N-terminal glutamate residue rendering the modified peptide degradation resistant, more hydrophobic, and prone to aggregation. Previous studies using artificial peptide substrates suggested the potential involvement of the enzyme glutaminyl cyclase in generation of pGlu-Abeta. Here we show that glutaminyl cyclase (QC) catalyzes the formation of Abeta 3(pE)-40/42 after amyloidogenic processing of APP in two different cell lines, applying specific ELISAs and Western blotting based on urea-PAGE. Inhibition of QC by the imidazole derivative PBD150 led to a blockage of Abeta 3(pE)-42 formation. Apparently, the QC-catalyzed formation of N-terminal pGlu is favored in the acidic environment of secretory compartments, which is also supported by double-immunofluorescence labeling of QC and APP revealing partial colocalization. Finally, initial investigations focusing on the molecular pathway leading to the generation of truncated Abeta peptides imply an important role of the amino acid sequence near the beta-secretase cleavage site. Introduction of a single-point mutation, resulting in an amino acid substitution, APP(E599Q), i.e., at position 3 of Abeta, resulted in significant formation of Abeta 3(pE)-40/42. Introduction of the APP KM595/596NL "Swedish" mutation causing overproduction of Abeta, however, surprisingly diminished the concentration of Abeta 3(pE)-40/42. The study provides new cell-based assays for the profiling of small molecule inhibitors of QC and points to conspicuous differences in processing of APP depending on sequence at the beta-secretase cleavage site.
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Affiliation(s)
- Holger Cynis
- Probiodrug AG, Weinbergweg 22, 06120 Halle/Saale, Germany
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39
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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] [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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40
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update covering the period 2001-2002. MASS SPECTROMETRY REVIEWS 2008; 27:125-201. [PMID: 18247413 DOI: 10.1002/mas.20157] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This review is the second update of the original review on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates that was published in 1999. It covers fundamental aspects of the technique as applied to carbohydrates, fragmentation of carbohydrates, studies of specific carbohydrate types such as those from plant cell walls and those attached to proteins and lipids, studies of glycosyl-transferases and glycosidases, and studies where MALDI has been used to monitor products of chemical synthesis. Use of the technique shows a steady annual increase at the expense of older techniques such as FAB. There is an increasing emphasis on its use for examination of biological systems rather than on studies of fundamental aspects and method development and this is reflected by much of the work on applications appearing in tabular form.
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Affiliation(s)
- David J Harvey
- Department of Biochemistry, Oxford Glycobiology Institute, South Parks Road, Oxford OX1 3QU, UK.
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41
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Huang QY, Kung AWC. The association of common polymorphisms in the QPCT gene with bone mineral density in the Chinese population. J Hum Genet 2007; 52:757-762. [PMID: 17687619 DOI: 10.1007/s10038-007-0178-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Accepted: 07/12/2007] [Indexed: 11/26/2022]
Abstract
Evidence of the linkage of chromosome 2p to bone mineral density (BMD) has previously been reported in multiple populations. However, the identification of the BMD quantitative trait loci (QTL) gene at chromosome 2p remains a challenge. We performed a gene-wide and tag single nucleotide polymorphism (SNP)-based association study of four positional and functional candidate genes (CALM2, CYP1B1, QPCT, and POMC) in a sample of 1,243 cases and matched controls. Thirteen HapMap tag SNPs were selected and genotyped by using the high-throughput Sequenom genotyping platform. Binary logistic regression analyses were performed to test for associations between each SNP genotype and BMD. Haplotype association analyses were performed by WHAP. The rs3770748 within the QPCT gene showed a significant association with spine BMD in both single-marker (P = 0.002) and haplotype association analyses (P = 0.0482 for the global test; P = 0.00092 for the haplotype-specific test). Subgroup analysis revealed that the effect was primarily driven by an association in the postmenopausal women, presumably suggesting that the rs3770748 affects postmenopausal bone loss rather than peak bone mass. Our results suggest that QPCT may be the QTL gene at chromosome 2p for spine BMD variation in the Chinese population.
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Affiliation(s)
- Qing-Yang Huang
- Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong.
| | - Annie W C Kung
- Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
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42
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Welker E, Hathaway L, Xu G, Narayan M, Pradeep L, Shin HC, Scheraga HA. Oxidative folding and N-terminal cyclization of onconase. Biochemistry 2007; 46:5485-93. [PMID: 17439243 PMCID: PMC2535829 DOI: 10.1021/bi602495a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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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43
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Schilling S, Stenzel I, von Bohlen A, Wermann M, Schulz K, Demuth HU, Wasternack C. Isolation and characterization of the glutaminyl cyclases from Solanum tuberosum and Arabidopsis thaliana: implications for physiological functions. Biol Chem 2007; 388:145-53. [PMID: 17261077 DOI: 10.1515/bc.2007.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Glutaminyl cyclases (QCs) catalyze the formation of pyroglutamic acid at the N-terminus of several peptides and proteins. On the basis of the amino acid sequence of Carica papaya QC, we identified cDNAs of the putative counterparts from Solanum tuberosum and Arabidopsis thaliana. Upon expression of the corresponding cDNAs from both plants via the secretory pathway of Pichia pastoris, two active QC proteins were isolated. The specificity of the purified proteins was assessed using various substrates with different amino acid composition and length. Highest specificities were observed with substrates possessing large hydrophobic residues adjacent to the N-terminal glutamine and for fluorogenic dipeptide surrogates. However, compared to Carica papaya QC, the specificity constants were approximately one order of magnitude lower for most of the QC substrates analyzed. The QCs also catalyzed the conversion of N-terminal glutamic acid to pyroglutamic acid, but with approximately 10(5)- to 10(6)-fold lower specificity. The ubiquitous distribution of plant QCs prompted a search for potential substrates in plants. Based on database entries, numerous proteins, e.g., pathogenesis-related proteins, were found that carry a pyroglutamate residue at the N-terminus, suggesting QC involvement. The putative relevance of QCs and pyroglutamic acid for plant defense reactions is discussed.
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Pawlak J, Manjunatha Kini R. Snake venom glutaminyl cyclase. Toxicon 2006; 48:278-86. [PMID: 16863655 DOI: 10.1016/j.toxicon.2006.05.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2006] [Revised: 05/24/2006] [Accepted: 05/30/2006] [Indexed: 10/24/2022]
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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Wintjens R, Belrhali H, Clantin B, Azarkan M, Bompard C, Baeyens-Volant D, Looze Y, Villeret V. Crystal Structure of Papaya Glutaminyl Cyclase, an Archetype for Plant and Bacterial Glutaminyl Cyclases. J Mol Biol 2006; 357:457-70. [PMID: 16438985 DOI: 10.1016/j.jmb.2005.12.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 12/08/2005] [Accepted: 12/09/2005] [Indexed: 10/25/2022]
Abstract
Glutaminyl cyclases (QCs) (EC 2.3.2.5) catalyze the intramolecular cyclization of protein N-terminal glutamine residues into pyroglutamic acid with the concomitant liberation of ammonia. QCs may be classified in two groups containing, respectively, the mammalian enzymes, and the enzymes from plants, bacteria, and parasites. The crystal structure of the QC from the latex of Carica papaya (PQC) has been determined at 1.7A resolution. The structure was solved by the single wavelength anomalous diffraction technique using sulfur and zinc as anomalous scatterers. The enzyme folds into a five-bladed beta-propeller, with two additional alpha-helices and one beta hairpin. The propeller closure is achieved via an original molecular velcro, which links the last two blades into a large eight stranded beta-sheet. The zinc ion present in the PQC is bound via an octahedral coordination into an elongated cavity located along the pseudo 5-fold axis of the beta-propeller fold. This zinc ion presumably plays a structural role and may contribute to the exceptional stability of PQC, along with an extended hydrophobic packing, the absence of long loops, the three-joint molecular velcro and the overall folding itself. Multiple sequence alignments combined with structural analyses have allowed us to tentatively locate the active site, which is filled in the crystal structure either by a Tris molecule or an acetate ion. These analyses are further supported by the experimental evidence that Tris is a competitive inhibitor of PQC. The active site is located at the C-terminal entrance of the PQC central tunnel. W83, W110, W169, Q24, E69, N155, K225, F22 and F67 are highly conserved residues in the C-terminal entrance, and their putative role in catalysis is discussed. The PQC structure is representative of the plants, bacterial and parasite enzymes and contrasts with that of mammalian enzymes, that may possibly share a conserved scaffold of the bacterial aminopeptidase.
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Affiliation(s)
- René Wintjens
- Laboratoire de Chimie Générale, Institut de Pharmacie-U.L.B. CP 206/04, Boulevard du Triomphe, B-1050 Brussels, Belgium
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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] [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] [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] [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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Schilling S, Manhart S, Hoffmann T, Ludwig HH, Wasternack C, Demuth HU. Substrate specificity of glutaminyl cyclases from plants and animals. Biol Chem 2004; 384:1583-92. [PMID: 14719800 DOI: 10.1515/bc.2003.175] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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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Ezura Y, Kajita M, Ishida R, Yoshida S, Yoshida H, Suzuki T, Hosoi T, Inoue S, Shiraki M, Orimo H, Emi M. Association of multiple nucleotide variations in the pituitary glutaminyl cyclase gene (QPCT) with low radial BMD in adult women. J Bone Miner Res 2004; 19:1296-301. [PMID: 15231017 DOI: 10.1359/jbmr.040324] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2003] [Revised: 02/27/2004] [Accepted: 03/29/2004] [Indexed: 11/18/2022]
Abstract
UNLABELLED Correlation between 13 genetic variations of the glutaminyl-peptide cyclotransferase gene and adjusted aBMD was tested among 384 adult women. Among 13 variations with strong linkage disequilibrium, R54W showed a prominent association (p = 0.0003), which was more striking when examined among 309 elder subjects (> or =50 years; p = 0.0001). Contribution for postmenopausal bone loss was suggested. INTRODUCTION Alterations in homeostatic regulation of estrogen through the hypothalamus-pituitary-gonadal axis (HPG axis) importantly affect the pathogenesis of osteoporosis. Osteoporosis-susceptibility genes have been proposed in this hormonal axis, such as estrogen receptor genes and the gonadotropin-releasing hormone gene (GnRH). Here we report another example of genes: glutaminyl-peptide cyclotransferase gene (QPCT), an essential modifier of pituitary peptide hormones, including GnRH. MATERIALS AND METHODS Analyses of association of 13 single nucleotide polymorphisms (SNPs) at the QPCT locus with adjusted areal BMD (adj-aBMD) were carried out among 384 adult women. Linkage disequilibrium (LD) was analyzed by haplotype estimation and calculation of D' and r2. Multiple regression analysis was applied for evaluating the combined effects of the variations. RESULTS AND CONCLUSIONS LD analysis indicated strong linkage disequilibrium within the entire 30-kb region of the QPCT gene. Significant correlations were observed between the genotypes of the six SNPs and the radial adj-aBMD, among which R54W (nt + 160C>T) presented the most prominent association (p = 0.0003). Striking association was observed for these SNPs among the 309 subjects >50 years of age (R54W, p = 0.0001; -1095T>C, p = 0.0002; -1844C>T, p = 0.0002). Multiple regression analyses indicated that multiple SNPs in the gene might act in combination to determine the radial adj-aBMD. These results indicate that genetic variations in QPCT are the important factors affecting the BMD of adult women that contribute to susceptibility for osteoporosis. The data should provide new insight into the etiology of the disease and may suggest a new target to be considered during treatment.
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Affiliation(s)
- Yoichi Ezura
- Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, Kawasaki, Japan
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