1
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Xin Y, Xiong S, Zhou L, Lin X. Activation of leukotriene B 4 receptor 1 is a prerequisite for complement receptor 3-mediated antifungal responses of neutrophils. Cell Mol Immunol 2024; 21:245-259. [PMID: 38297112 PMCID: PMC10901876 DOI: 10.1038/s41423-024-01130-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 12/31/2023] [Indexed: 02/02/2024] Open
Abstract
Invasive fungal infections are life-threatening, and neutrophils are vital cells of the innate immune system that defend against them. The role of LTA4H-LTB4-BLT1 axis in regulation of neutrophil responses to fungal infection remains poorly understood. Here, we demonstrated that the LTA4H-LTB4-BLT1 axis protects the host against Candida albicans and Aspergillus fumigatus, but not Cryptococcus neoformans infection, by regulating the antifungal activity of neutrophils. Our results show that deleting Lta4h or Blt1 substantially impairs the fungal-specific phagocytic capacity of neutrophils. Moreover, defective activation of the spleen tyrosine kinase (Syk) and extracellular signal-related kinase (ERK1/2) pathways in neutrophils accompanies this impairment. Mechanistically, BLT1 regulates CR3-mediated, β-1,3-glucan-induced neutrophil phagocytosis, while a physical interaction with CR3 with slight influence on its dynamics is observed. Our findings thus demonstrate that the LTA4H-LTB4-BLT1 axis is essential for the phagocytic function of neutrophils in host antifungal immune response against Candida albicans and Aspergillus fumigatus.
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Affiliation(s)
- Yan Xin
- Institute for Immunology and School of Medicine, Tsinghua University, 100084, Beijing, China
- Tsinghua University-Peking University Center for Life Sciences, 100084, Beijing, China
| | - Sihan Xiong
- Institute for Immunology and School of Medicine, Tsinghua University, 100084, Beijing, China
| | - Linghong Zhou
- Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Xin Lin
- Institute for Immunology and School of Medicine, Tsinghua University, 100084, Beijing, China.
- Tsinghua University-Peking University Center for Life Sciences, 100084, Beijing, China.
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2
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Kalsi KK, Jackson S, Baines DL. Lipoxin receptor agonist and inhibition of LTA4 hydrolase prevent tight junction disruption caused by P. aeruginosa filtrate in airway epithelial cells. PLoS One 2023; 18:e0287183. [PMID: 37406028 PMCID: PMC10321624 DOI: 10.1371/journal.pone.0287183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 05/31/2023] [Indexed: 07/07/2023] Open
Abstract
Airway diseases can disrupt tight junction proteins, compromising the epithelial barrier and making it more permeable to pathogens. In people with pulmonary disease who are prone to infection with Pseudomonas aeruginosa, pro-inflammatory leukotrienes are increased and anti-inflammatory lipoxins are decreased. Upregulation of lipoxins is effective in counteracting inflammation and infection. However, whether combining a lipoxin receptor agonist with a specific leukotriene A4 hydrolase (LTA4H) inhibitor could enhance these protective effects has not to our knowledge been investigated. Therefore, we explored the effect of lipoxin receptor agonist BML-111 and JNJ26993135 a specific LTA4H inhibitor that prevents the production of pro-inflammatory LTB4 on tight junction proteins disrupted by P. aeruginosa filtrate (PAF) in human airway epithelial cell lines H441 and 16HBE-14o. Pre-treatment with BML-111 prevented an increase in epithelial permeability induced by PAF and conserved ZO-1 and claudin-1 at the cell junctions. JNJ26993135 similarly prevented the increased permeability induced by PAF, restored ZO-1 and E-cadherin and reduced IL-8 but not IL-6. Cells pre-treated with BML-111 plus JNJ26993135 restored TEER and permeability, ZO-1 and claudin-1 to the cell junctions. Taken together, these data indicate that the combination of a lipoxin receptor agonist with a LTA4H inhibitor could provide a more potent therapy.
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Affiliation(s)
- Kameljit K. Kalsi
- Institute for Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Sonya Jackson
- Translational Science and Experimental Medicine Research and Early Development, Respiratory, Inflammation & Autoimmune (RIA), Biopharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Deborah L. Baines
- Institute for Infection and Immunity, St George’s University of London, London, United Kingdom
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3
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Lee KH, Ali NF, Lee SH, Zhang Z, Burdick M, Beaulac ZJ, Petruncio G, Li L, Xiang J, Chung EM, Foreman KW, Noble SM, Shim YM, Paige M. Substrate-dependent modulation of the leukotriene A 4 hydrolase aminopeptidase activity and effect in a murine model of acute lung inflammation. Sci Rep 2022; 12:9443. [PMID: 35676292 PMCID: PMC9177663 DOI: 10.1038/s41598-022-13238-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 04/12/2022] [Indexed: 11/09/2022] Open
Abstract
The aminopeptidase activity (AP) of the leukotriene A4 hydrolase (LTA4H) enzyme has emerged as a therapeutic target to modulate host immunity. Initial reports focused on the benefits of augmenting the LTA4H AP activity and clearing its putative pro-inflammatory substrate Pro-Gly-Pro (PGP). However, recent reports have introduced substantial complexity disconnecting the LTA4H modulator 4-methoxydiphenylmethane (4MDM) from PGP as follows: (1) 4MDM inhibits PGP hydrolysis and subsequently inhibition of LTA4H AP activity, and (2) 4MDM activates the same enzyme target in the presence of alternative substrates. Differential modulation of LTA4H by 4MDM was probed in a murine model of acute lung inflammation, which showed that 4MDM modulates the host neutrophilic response independent of clearing PGP. X-ray crystallography showed that 4MDM and PGP bind at the zinc binding pocket and no allosteric binding was observed. We then determined that 4MDM modulation is not dependent on the allosteric binding of the ligand, but on the N-terminal side chain of the peptide. In conclusion, our study revealed that a peptidase therapeutic target can interact with its substrate and ligand in complex biochemical mechanisms. This raises an important consideration when ligands are designed to explain some of the unpredictable outcomes observed in therapeutic discovery targeting LTA4H.
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Affiliation(s)
- Kyung Hyeon Lee
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA
| | - Nadia Fazal Ali
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
| | - Soo Hyeon Lee
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA
| | - Zhimin Zhang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, PO Box 800546, Charlottesville, VA, 22908, USA
| | - Marie Burdick
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, PO Box 800546, Charlottesville, VA, 22908, USA
| | - Zachary J Beaulac
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
| | - Greg Petruncio
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
| | - Linxia Li
- Department of Obstetrics and Gynecology, Seventh People's Hospital of Shanghai University of Traditional Chinese Medicine, 358 Datong Road, Shanghai, 200137, China
| | - Jiangdong Xiang
- Department of Obstetrics and Gynecology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China
| | - Ezra M Chung
- STCube Pharmaceutical, Inc., 401 Professional Dr, Gaithersburg, MD, 20879, USA
| | - Kenneth W Foreman
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA
| | - Schroeder M Noble
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA.
| | - Yun M Shim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, PO Box 800546, Charlottesville, VA, 22908, USA.
| | - Mikell Paige
- Department of Chemistry & Biochemistry, George Mason University, 10920 George Mason Circle, Manassas, VA, 20110, USA.
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4
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The Potential of Proteolytic Chimeras as Pharmacological Tools and Therapeutic Agents. Molecules 2020; 25:molecules25245956. [PMID: 33339292 PMCID: PMC7766482 DOI: 10.3390/molecules25245956] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/09/2020] [Accepted: 12/14/2020] [Indexed: 02/07/2023] Open
Abstract
The induction of protein degradation in a highly selective and efficient way by means of druggable molecules is known as targeted protein degradation (TPD). TPD emerged in the literature as a revolutionary idea: a heterobifunctional chimera with the capacity of creating an interaction between a protein of interest (POI) and a E3 ubiquitin ligase will induce a process of events in the POI, including ubiquitination, targeting to the proteasome, proteolysis and functional silencing, acting as a sort of degradative knockdown. With this programmed protein degradation, toxic and disease-causing proteins could be depleted from cells with potentially effective low drug doses. The proof-of-principle validation of this hypothesis in many studies has made the TPD strategy become a new attractive paradigm for the development of therapies for the treatment of multiple unmet diseases. Indeed, since the initial protacs (Proteolysis targeting chimeras) were posited in the 2000s, the TPD field has expanded extraordinarily, developing innovative chemistry and exploiting multiple degradation approaches. In this article, we review the breakthroughs and recent novel concepts in this highly active discipline.
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5
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Ma TT, Cao MD, Yu RL, Shi HY, Yan WJ, Liu JG, Pan C, Sun J, Wei QY, Wang DY, Wei JF, Wang XY, Yin JS. Leukotriene A 4 Hydrolase Is a Candidate Predictive Biomarker for Successful Allergen Immunotherapy. Front Immunol 2020; 11:559746. [PMID: 33329520 PMCID: PMC7732448 DOI: 10.3389/fimmu.2020.559746] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 10/22/2020] [Indexed: 12/19/2022] Open
Abstract
Background Allergic rhinitis is a common disorder that affects 10% to 40% of the population worldwide. Allergen immunotherapy (AIT) represents the only therapy that has the potential to resolve clinical symptoms of allergic rhinitis. However, up to 30% of patients do not respond to AIT. Biomarkers predicting the clinical efficacy of AIT as early as possible would significantly improve the patient selection and reduce unnecessary societal costs. Methods Artemisia pollen allergic patients who received at least 1-year AIT were enrolled. Clinical responses before and after 1-year AIT were evaluated to determine AIT responders. Artemisia specific IgE and IgG4 levels were measured by using ImmunoCAP and enzyme-linked immunosorbent assay (ELISA) separately. Stepwise regression analysis was performed to identify which rhinitis-relevant parameters explained the most variability in AIT results. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics was applied to identify the potential candidate biomarkers in the sera of responders and non-responders collected before and after 1-year therapy. The diagnostic performance of the potential biomarkers was then assessed using enzyme-linked immunosorbent assay (ELISA) in 30 responders and 15 non-responders. Results Artemisia specific IgE and IgG4 levels were elevated only in the responders. Regression analysis of allergic rhinitis-relevant parameters provided a robust model that included two most significant variables (sneeze and nasal congestion). Thirteen candidate biomarkers were identified for predicting AIT outcomes. Based on their association with allergy and protein fold change (more than 1.1 or less than 0.9), four proteins were identified to be potential biomarkers for predicting effective AIT. However, further ELISA revealed that only leukotriene A4 hydrolase (LTA4H) was consistent with the proteomics data. The LTA4H level in responders increased significantly (P < 0.001) after 1-year therapy, while that of non-responders remained unchanged. Assessment of LTA4H generated area under curve (AUC) value of 0.844 (95% confidence interval: 0.727 to 0.962; P < 0.05) in distinguishing responders from the non-responders, suggesting that serum LTA4H might be a potential biomarker for predicting the efficiency of AIT. Conclusion Serum LTA4H may be a potential biomarker for early prediction of an effective AIT.
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Affiliation(s)
- Ting-Ting Ma
- Department of Allergy, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Meng-Da Cao
- Research Division of Clinical Pharmacology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Rui-Li Yu
- Department of Allergy, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Hai-Yun Shi
- Department of Allergy, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Wei-Jun Yan
- Department of Allergy, Duolun People's Hospital, Duolun, China
| | - Jian-Guo Liu
- Department of Allergy, Duolun People's Hospital, Duolun, China
| | - Chen Pan
- Research Division of Clinical Pharmacology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.,School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jinlyu Sun
- Department of Allergy, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing Key Laboratory of Precision Medicine for Diagnosis and Treatment on Allergic Diseases, Beijing, China
| | - Qing-Yu Wei
- Department of Allergy, General Hospital of Northern Theater Command, Shenyang, China
| | - De-Yun Wang
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Ji-Fu Wei
- Research Division of Clinical Pharmacology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xue-Yan Wang
- Department of Allergy, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Jin-Shu Yin
- Department of Allergy, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
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6
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Lee KH, Petruncio G, Shim A, Burdick M, Zhang Z, Shim YM, Noble SM, Paige M. Effect of Modifier Structure on the Activation of Leukotriene A 4 Hydrolase Aminopeptidase Activity. J Med Chem 2019; 62:10605-10616. [PMID: 31751136 DOI: 10.1021/acs.jmedchem.9b00663] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Activation of the leukotriene A4 hydrolase (LTA4H) aminopeptidase (AP) activity with 4-methoxydiphenylmethane (4MDM) promoted resolution of neutrophil infiltration in a murine cigarette smoke-induced model for emphysematous chronic obstructive pulmonary disease. Recently, 4-(4-benzylphenyl)thiazol-2-amine (ARM1) was published as a ligand for LTA4H with potential anti-inflammatory properties. To investigate the effect of modifier structure on enzyme kinetics of LTA4H, a series of analogues bearing structural features of ARM1 and 4MDM were synthesized using trifluoroborate Suzuki coupling reactions. Following, the 2.8 Å X-ray crystal structure of LTA4H complexed with 4-OMe-ARM1, a 4MDM-ARM1 hybrid molecule, was determined. Kinetic analysis showed that ARM1 and related analogues lowered affinity for the enzyme-substrate complex, resulting in a change of mechanism from hyperbolic mixed predominately catalytic activation (HMx(Sp < Ca)A) as observed for 4MDM to a predominately specific activation (HMx(Sp > Ca)A) mechanism. 4-OMe-ARM1 was then shown to dose responsively reduce LTB4 production in human neutrophils.
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Affiliation(s)
- Kyung Hyeon Lee
- Department of Chemistry & Biochemistry , George Mason University , 10920 George Mason Circle , Manassas , Virginia 20110 , United States
- Bacterial Diseases Branch, Wound Infections Department , Walter Reed Army Institute of Research , 503 Robert Grant Ave , Silver Spring , Maryland 20910 , United States
| | - Greg Petruncio
- Department of Chemistry & Biochemistry , George Mason University , 10920 George Mason Circle , Manassas , Virginia 20110 , United States
| | - Amanda Shim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine , University of Virginia , P.O. Box 800546, Charlottesville , Virginia 22908 , United States
| | - Marie Burdick
- Division of Pulmonary and Critical Care Medicine, Department of Medicine , University of Virginia , P.O. Box 800546, Charlottesville , Virginia 22908 , United States
| | - Zhimin Zhang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine , University of Virginia , P.O. Box 800546, Charlottesville , Virginia 22908 , United States
| | - Yun M Shim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine , University of Virginia , P.O. Box 800546, Charlottesville , Virginia 22908 , United States
| | - Schroeder M Noble
- Bacterial Diseases Branch, Wound Infections Department , Walter Reed Army Institute of Research , 503 Robert Grant Ave , Silver Spring , Maryland 20910 , United States
| | - Mikell Paige
- Department of Chemistry & Biochemistry , George Mason University , 10920 George Mason Circle , Manassas , Virginia 20110 , United States
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7
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Mu X, Xu D. QM/MM Molecular Dynamics Investigations of the Substrate Binding of Leucotriene A4 Hydrolase: Implication for the Catalytic Mechanism. J Phys Chem B 2018; 122:7253-7263. [PMID: 29965770 DOI: 10.1021/acs.jpcb.8b04203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
LTA4H is a monozinc bifunctional enzyme which exhibits both aminopeptidase and epoxide hydrolase activities. Its dual functions in anti- and pro-inflammatory roles have attracted wide attention to the inhibitor design. In this work, we tried to construct Michaelis complexes of LTA4H with both a native peptide substrate and LTA4 molecule using combined quantum mechanics and molecular mechanics molecular dynamics simulations. First of all, the zinc ion is coordinated by H295, H299, and E318. For its aminopeptidase activity, similar to conventional peptidases, the fourth ligand to the zinc ion is suggested to be an active site water, which is further hydrogen bonded with a downstream glutamic acid, E296. For the epoxide hydrolase activity, the fourth ligand to the zinc ion is found to be an epoxy oxygen atom. The potential of mean force calculation indicates about an 8.5 kcal/mol activation barrier height for the ring-opening reaction, which will generate a metastable carbenium intermediate. Subsequent frontier molecular orbital analyses suggest that the next step would be the nucleophilic attacking reaction at the C12 atom by a water molecule activated by D375. Our simulations also analyzed functions of several important residues like R563, K565, E271, Y383, and Y378 in the binding of peptide and LTA4.
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Affiliation(s)
- Xia Mu
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry , Sichuan University , Chengdu , Sichuan , People's Republic of China 610064
| | - Dingguo Xu
- MOE Key Laboratory of Green Chemistry and Technology, College of Chemistry , Sichuan University , Chengdu , Sichuan , People's Republic of China 610064
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8
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Byzia A, Haeggström JZ, Salvesen GS, Drag M. A remarkable activity of human leukotriene A4 hydrolase (LTA4H) toward unnatural amino acids. Amino Acids 2014; 46:1313-20. [PMID: 24573245 PMCID: PMC3984412 DOI: 10.1007/s00726-014-1694-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 02/06/2014] [Indexed: 12/01/2022]
Abstract
Leukotriene A4 hydrolase (LTA4H––EC 3.3.2.6) is a bifunctional zinc metalloenzyme, which processes LTA4 through an epoxide hydrolase activity and is also able to trim one amino acid at a time from N-terminal peptidic substrates via its aminopeptidase activity. In this report, we have utilized a library of 130 individual proteinogenic and unnatural amino acid fluorogenic substrates to determine the aminopeptidase specificity of this enzyme. We have found that the best proteinogenic amino acid recognized by LTA4H is arginine. However, we have also observed several unnatural amino acids, which were significantly better in terms of cleavage rate (kcat/Km values). Among them, the benzyl ester of aspartic acid exhibited a kcat/Km value that was more than two orders of magnitude higher (1.75 × 105 M−1 s−1) as compared to l-Arg (1.5 × 103 M−1 s−1). This information can be used for design of potent inhibitors of this enzyme, but may also suggest yet undiscovered functions or specificities of LTA4H.
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Affiliation(s)
- Anna Byzia
- Division of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370, Wrocław, Poland
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9
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Komatsu T, Hanaoka K, Adibekian A, Yoshioka K, Terai T, Ueno T, Kawaguchi M, Cravatt BF, Nagano T. Diced electrophoresis gel assay for screening enzymes with specified activities. J Am Chem Soc 2013; 135:6002-5. [PMID: 23581642 DOI: 10.1021/ja401792d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have established the diced electrophoresis gel (DEG) assay as a proteome-wide screening tool to identify enzymes with activities of interest using turnover-based fluorescent substrates. The method utilizes the combination of native polyacrylamide gel electrophoresis (PAGE) with a multiwell-plate-based fluorometric assay to find protein spots with the specified activity. By developing fluorescent substrates that mimic the structure of neutrophil chemoattractants, we could identify enzymes involved in metabolic inactivation of the chemoattractants.
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Affiliation(s)
- Toru Komatsu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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10
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Çalışkan B, Banoglu E. Overview of recent drug discovery approaches for new generation leukotriene A4 hydrolase inhibitors. Expert Opin Drug Discov 2012; 8:49-63. [DOI: 10.1517/17460441.2013.735228] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Burcu Çalışkan
- Gazi University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry,
Taç Sok. No:3 Yenimahalle, 06330 Ankara, Turkey
| | - Erden Banoglu
- Gazi University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry,
Taç Sok. No:3 Yenimahalle, 06330 Ankara, Turkey ; ;
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11
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Snelgrove RJ, Jackson PL, Hardison MT, Noerager BD, Kinloch A, Gaggar A, Shastry S, Rowe SM, Shim YM, Hussell T, Blalock JE. A critical role for LTA4H in limiting chronic pulmonary neutrophilic inflammation. Science 2010; 330:90-4. [PMID: 20813919 PMCID: PMC3072752 DOI: 10.1126/science.1190594] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Leukotriene A(4) hydrolase (LTA(4)H) is a proinflammatory enzyme that generates the inflammatory mediator leukotriene B(4) (LTB(4)). LTA(4)H also possesses aminopeptidase activity with unknown substrate and physiological importance; we identified the neutrophil chemoattractant proline-glycine-proline (PGP) as this physiological substrate. PGP is a biomarker for chronic obstructive pulmonary disease (COPD) and is implicated in neutrophil persistence in the lung. In acute neutrophil-driven inflammation, PGP was degraded by LTA(4)H, which facilitated the resolution of inflammation. In contrast, cigarette smoke, a major risk factor for the development of COPD, selectively inhibited LTA(4)H aminopeptidase activity, which led to the accumulation of PGP and neutrophils. These studies imply that therapeutic strategies inhibiting LTA(4)H to prevent LTB(4) generation may not reduce neutrophil recruitment because of elevated levels of PGP.
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Affiliation(s)
- Robert J Snelgrove
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham Lung Health Center, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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12
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Jiang X, Zhou L, Wei D, Meng H, Liu Y, Lai L. Activation and inhibition of leukotriene A4 hydrolase aminopeptidase activity by diphenyl ether and derivatives. Bioorg Med Chem Lett 2008; 18:6549-52. [DOI: 10.1016/j.bmcl.2008.10.044] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 09/24/2008] [Accepted: 10/10/2008] [Indexed: 10/21/2022]
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13
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Haeggström JZ, Tholander F, Wetterholm A. Structure and catalytic mechanisms of leukotriene A4 hydrolase. Prostaglandins Other Lipid Mediat 2007; 83:198-202. [PMID: 17481555 DOI: 10.1016/j.prostaglandins.2007.01.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Leukotriene A4 hydrolase catalyzes the final and committed step in the biosynthesis of leukotriene B4, a potent chemotactic agent for neutrophils, eosinophils, monocytes, and T-cells that play key roles in the innate immune response. Recent data strongly implicates leukotriene B4 in the pathogenesis of cardiovascular diseases, in particular arteriosclerosis, myocardial infarction and stroke. Here, we highlight the most salient features of leukotriene A4 hydrolase with emphasis on its biochemistry and structure biology.
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Affiliation(s)
- Jesper Z Haeggström
- Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, S-171 77 Stockholm, Sweden.
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14
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Brock TG, Lee YJ, Maydanski E, Marburger TL, Luo M, Paine R, Peters-Golden M. Nuclear localization of leukotriene A4 hydrolase in type II alveolar epithelial cells in normal and fibrotic lung. Am J Physiol Lung Cell Mol Physiol 2005; 289:L224-32. [PMID: 15805137 DOI: 10.1152/ajplung.00423.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leukotriene A4 (LTA4) hydrolase catalyzes the final step in leukotriene B4 (LTB4) synthesis. In addition to its role in LTB4 synthesis, the enzyme possesses aminopeptidase activity. In this study, we sought to define the subcellular distribution of LTA4 hydrolase in alveolar epithelial cells, which lack 5-lipoxygenase and do not synthesize LTA4. Immunohistochemical staining localized LTA4 hydrolase in the nucleus of type II but not type I alveolar epithelial cells of normal mouse, human, and rat lungs. Nuclear localization of LTA4 hydrolase was also demonstrated in proliferating type II-like A549 cells. The apparent redistribution of LTA4 hydrolase from the nucleus to the cytoplasm during type II-to-type I cell differentiation in vivo was recapitulated in vitro. Surprisingly, this change in localization of LTA4 hydrolase did not affect the capacity of isolated cells to convert LTA4 to LTB4. However, proliferation of A549 cells was inhibited by the aminopeptidase inhibitor bestatin. Nuclear accumulation of LTA4 hydrolase was also conspicuous in epithelial cells during alveolar repair following bleomycin-induced acute lung injury in mice, as well as in hyperplastic type II cells associated with fibrotic lung tissues from patients with idiopathic pulmonary fibrosis. These results show for the first time that LTA4 hydrolase can be accumulated in the nucleus of type II alveolar epithelial cells and that redistribution of the enzyme to the cytoplasm occurs with differentiation to the type I phenotype. Furthermore, the aminopeptidase activity of LTA4 hydrolase within the nucleus may play a role in promoting epithelial cell growth.
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Affiliation(s)
- Thomas G Brock
- Dept. of Internal Medicine, Univ. of Michigan, 6301 MSRB III, Ann Arbor, MI 48109-0642, USA.
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15
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Cadel S, Gouzy-Darmon C, Petres S, Piesse C, Pham VL, Beinfeld MC, Cohen P, Foulon T. Expression and purification of rat recombinant aminopeptidase B secreted from baculovirus-infected insect cells. Protein Expr Purif 2004; 36:19-30. [PMID: 15177280 DOI: 10.1016/j.pep.2004.03.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2003] [Revised: 03/16/2004] [Indexed: 11/17/2022]
Abstract
Aminopeptidase B (Ap-B) is a ubiquitous enzyme and its physiological function still remains an open question. This Zn2+ -exopeptidase catalyzes the amino-terminal cleavage of basic residues of peptide or protein substrates, indicating a role in precursor processing. In addition, the enzyme exhibits a residual capacity to hydrolyze leukotriene A4 (LTA4) into the pro-inflammatory lipid mediator leukotriene B4 (LTB4) in vitro. This potential bi-functional nature of Ap-B is supported by a close structural relationship with LTA4 hydrolase, which hydrolyzes LTA4 into LTB4, in vivo, and exhibits an aminopeptidase activity, in vitro. Structural studies are necessary for the detailed understanding of the bi-functional enzymatic mechanism of Ap-B. In this study, we report cDNA cloning, baculovirus expression, and purification of the rat Ap-B (rAp-B). The Ap-B cDNA was constructed from extracted rat testes total RNA and introduced into the pBAC1 baculovirus transfer vector to generate recombinant baculoviruses. rAp-B expression, with or without COOH-hexahistidine tag, was tested in two different insect cell hosts (Sf9 and H5). The enzyme is secreted into the insect cell culture medium, which allowed a rapid purification of the protein. The His-tagged rAp-B was purified using metal affinity resin while the native recombinant rAp-B was partially purified using a single step DEAE Trisacryl ion exchange column. Although the recombinant rAp-B exhibits biochemical properties equivalent to those of the rat testes purified protein, the presence of the histidine-tag seems to partially inhibit the exopeptidase activity. However, this report shows that baculovirus-infected cells are a useful system to produce rat Ap-B for use in studying enzymatic mechanisms in vitro and 3D structure.
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Affiliation(s)
- Sandrine Cadel
- Laboratoire de Biochimie des Signaux Régulateurs Cellulaires et Moléculaires, FRE 2621, Université Pierre et Marie Curie--Centre National de la Recherche Scientifique, 96 Boulevard Raspail, 75006 Paris, France
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16
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Haeggström JZ, Kull F, Rudberg PC, Tholander F, Thunnissen MMGM. Leukotriene A4 hydrolase. Prostaglandins Other Lipid Mediat 2002; 68-69:495-510. [PMID: 12432939 DOI: 10.1016/s0090-6980(02)00051-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The leukotrienes (LTs) are a family of lipid mediators involved in inflammation and allergy. Leukotriene B4 is a classical chemoattractant, which triggers adherence and aggregation of leukocytes to the endothelium at only nanomolar concentrations. In addition, leukotriene B4 modulates immune responses, participates in the host-defense against infections, and is a key mediator of PAF-induced lethal shock. Because of these powerful biological effects, leukotriene B4 is implicated in a variety of acute and chronic inflammatory diseases, e.g. nephritis, arthritis, dermatitis, and chronic obstructive pulmonary disease. The final step in the biosynthesis of leukotriene B4 is catalyzed by leukotriene A4 hydrolase, a unique bi-functional zinc metalloenzyme with an anion-dependent aminopeptidase activity. Here we describe the most recent developments regarding our understanding of the structure, function, and catalytic mechanisms of leukotriene A4 hydrolase.
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Affiliation(s)
- Jesper Z Haeggström
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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17
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Haeggström JZ, Wetterholm A. Leukotriene-A4 hydrolase: probing the active sites and catalytic mechanisms by site-directed mutagenesis. ERNST SCHERING RESEARCH FOUNDATION WORKSHOP 2000:85-96. [PMID: 10943329 DOI: 10.1007/978-3-662-04047-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J Z Haeggström
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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18
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Affiliation(s)
- J Z Haeggström
- Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, Stockholm, Sweden.
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Haeggström JZ. Leukotriene A4 hydrolase and the committed step in leukotriene B4 biosynthesis. Clin Rev Allergy Immunol 1999; 17:111-31. [PMID: 10436862 DOI: 10.1007/bf02737600] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- J Z Haeggström
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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20
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Orning L, Fitzpatrick FA. Modification of leukotriene A(4) hydrolase/aminopeptidase by sulfhydryl-blocking reagents: differential effects on dual enzyme activities by methyl-methane thiosulfonate. Arch Biochem Biophys 1999; 368:131-8. [PMID: 10415120 DOI: 10.1006/abbi.1999.1289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The presence of a cysteine residue at or near the active site of leukotriene A(4) hydrolase (EC 3.3.2.6) was suggested by inactivation of the enzyme with sulfhydryl-blocking reagents and by protection against inactivation afforded by substrates and competitive inhibitors. The aminopeptidase activity was more susceptible to inactivation than the epoxide hydrolase activity. The sulfhydryl-modifying reagent methyl-methane thiosulfonate reacted with one thiol as judged by kinetic data and titration with 5, 5'-dithiobis-2-nitrobenzoate. Inactivation was a time- and dose-dependent process of apparent pseudo-first-order and maximal at 80-85%. The inactivation rate was nonsaturable and strongly influenced by ion strength. The second-order rate constant increased from 0.9 to 4.3 M(-1) s(-1) in the presence of 0.2 M NaCl. Albumin, a stimulator of the aminopeptidase activity, increased apparent inactivation rates by shifting pK(a) for the modification from 8.2 to 7.8. The inactivated enzyme partially regained activity upon treatment with beta-mercaptoethanol. Peptide substrates and competitive inhibitors protected against inactivation. Bestatin, a competitive inhibitor, afforded complete protection with a K(D) = 0.15 microM, similar to K(i) = 0.17 microM for inhibition of peptidase activity. Treated enzyme had an unchanged K(m) but a reduced V(max). The epoxide hydrolase activity was only weakly affected by methyl-methane thiosulfonate with a maximal inactivation of 15-20% after prolonged treatment. Pretreatment of leukotriene A(4) hydrolase with the reagent did not protect against mechanism-based inactivation by its lipid substrate, leukotriene A(4). On the other hand, leukotriene B(4) was a competitive inhibitor of aminopeptidase activity and protected against modification by methyl-methane thiosulfonate. Our results suggest the presence of a cysteine at or close to subsite S'(1) of the active site of leukotriene A(4) hydrolase and that modification of this residue interferes with the function of the aminopeptidase activity, but not the epoxide hydrolase activity. This is the first report to distinguish the two catalytic activities of leukotriene A(4) hydrolase by chemical means.
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Affiliation(s)
- L Orning
- Axis Biochemicals ASA, Oslo, Norway.
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21
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Baset HA, Ford-Hutchinson AW, O'Neill GP. Molecular cloning and functional expression of a Caenorhabditis elegans aminopeptidase structurally related to mammalian leukotriene A4 hydrolases. J Biol Chem 1998; 273:27978-87. [PMID: 9774412 DOI: 10.1074/jbc.273.43.27978] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In a search of the Caenorhabditis elegans DNA data base, an expressed sequence tag of 327 base pairs (termed cm01c7) with strong homology to the human leukotriene A4 (LTA4) hydrolase was found. The use of cm01c7 as a probe, together with conventional hybridization screening and anchored polymerase chain reaction techniques resulted in the cloning of the full-length 2.1 kilobase pair C. elegans LTA4 hydrolase-like homologue, termed aminopeptidase-1 (AP-1). The AP-1 cDNA was expressed transiently as an epitope-tagged recombinant protein in COS-7 mammalian cells, purified using an anti-epitope antibody affinity resin, and tested for LTA4 hydrolase and aminopeptidase activities. Despite the strong homology between the human LTA4 hydrolase and C. elegans AP-1(63% similarity and 45% identity at the amino acid level), reverse-phase high pressure liquid chromatography and radioimmunoassay for LTB4 production revealed the inability of the C. elegans AP-1 to use LTA4 as a substrate. In contrast, the C. elegans AP-1 was an efficient aminopeptidase, as demonstrated by its ability to hydrolyze a variety of amino acid p-nitroanilide derivatives. The aminopeptidase activity of C. elegans AP-1 resembled that of the human LTA4 hydrolase/aminopeptidase enzyme with a preference for arginyl-p-nitroanilide as a substrate. Hydrolysis of the amide bond of arginyl-p-nitroanilide was inhibited by bestatin with an IC50 of 2.6 +/- 1.2 microM. The bifunctionality of the mammalian LTA4 hydrolase is still poorly understood, as the physiological substrate for its aminopeptidase activity is yet to be discovered. Our results support the idea that the enzyme originally functioned as an aminopeptidase in lower metazoa and then developed LTA4 hydrolase activity in more evolved organisms.
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Affiliation(s)
- H A Baset
- Department of Pharmacology and Experimental Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
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22
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Strömberg-Kull F, Haeggström JZ. Purification and characterization of leukotriene A4 hydrolase from Xenopus laevis oocytes. FEBS Lett 1998; 433:219-22. [PMID: 9744798 DOI: 10.1016/s0014-5793(98)00918-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In mammals, leukotriene A4 hydrolase converts leukotriene A4 into the proinflammatory mediator leukotriene B4. We have purified and characterized a non-mammalian leukotriene A4 hydrolase from Xenopus laevis oocytes. This enzyme contains one zinc atom and catalyzes an anion-dependent peptidase activity, two key features of the mammalian enzymes. The amino acid sequence of an internal segment is 60% identical with human leukotriene A4 hydrolase but only 27% identical with rat aminopeptidase B. The Xenopus laevis enzyme is catalytically very efficient and, unlike the human enzyme, converts leukotriene A4 into two enzymatic metabolites, viz. leukotriene B4 and delta6-trans-delta8-cis-leukotriene B4.
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Affiliation(s)
- F Strömberg-Kull
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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23
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Wetterholm A, Mueller MJ, Blomster M, Samuelsson B, Haeggström JZ. Studies on the active site of leukotriene A4 hydrolase. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 407:1-7. [PMID: 9321924 DOI: 10.1007/978-1-4899-1813-0_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- A Wetterholm
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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24
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Schmidt JJ, Bostian KA. Endoproteinase activity of type A botulinum neurotoxin: substrate requirements and activation by serum albumin. JOURNAL OF PROTEIN CHEMISTRY 1997; 16:19-26. [PMID: 9055204 DOI: 10.1023/a:1026386710428] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Type A botulinum neurotoxin, a zinc-dependent endoproteinase that selectively cleaves the neuronal protein SNAP-25, can also cleave relatively short peptides. We found that bovine and other serum albumins stimulated the type A-catalyzed hydrolysis of synthetic peptide substrates, through a direct effect on the kinetic constants of the reaction. Furthermore, with bovine serum albumin in the assays, the optimum substrate size was 16 residues (11 on the amino-terminal side of the cleavage site and 5 on the carboxy-terminal side). To further investigate the catalytic requirements of the neurotoxin, peptides were synthesized with various amino acid substitutions at the P5 through P5' substrate sites. Changes at all of these locations affected values for both kcat and K(m). Substitutions at the P2, P1', and P2' sites had more pronounced effects on hydrolysis rates than did substitutions at the P1 site. Enzyme-substrate interactions at the P3' threonine probably involved the side-chain methyl group rather than the hydroxyl group. Replacing the P2' alanine with leucine eliminated detectable hydrolysis, but not binding, since this peptide was an inhibitor. A negatively charged residue was preferred at P5, but not at P4. The data indicate that type A botulinum neurotoxin has an extended substrate recognition region and a requirement for arginine as the P1' residue.
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Affiliation(s)
- J J Schmidt
- Toxinology Division, U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland 21702-5011, USA
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25
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Baker JR, Kylstra TA, Bigby TD. Effects of metalloproteinase inhibitors on leukotriene A4 hydrolase in human airway epithelial cells. Biochem Pharmacol 1995; 50:905-12. [PMID: 7575672 DOI: 10.1016/0006-2952(95)00210-q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Human neutrophil leukotriene A4 (LTA4) hydrolase is a zinc-containing metalloproteinase with aminopeptidase activity and can be inhibited by some metalloproteinase inhibitors. Human airway epithelial cells also contain an LTA4 hydrolase enzyme that has some novel properties, suggesting that this enzyme may be functionally and structurally unique. Thus, we questioned whether the epithelial cells were studied either intact or disrupted. Of the metalloproteinase inhibitors examined, only captopril, bestatin, and fosinoprilat had appreciable inhibitory activity for LTA4 hydrolase in disrupted epithelial cells. Concentration-inhibition curves to captopril, bestatin, and fosinoprilat revealed IC50 values of 430 microM, 7 microM, and 1 mM, respectively, for disrupted-cell LTA4 hydrolase activity. In contrast to its effects on neutrophils, 1,10-O-phenanthroline had no significant effect on disrupted epithelial cell hydrolase activity and had only minimal effects when this activity was partially purified (179-fold). LTA4 hydrolase concentration-inhibition curves examined in intact cells with captopril, bestatin, and 1,10-O-phenanthroline revealed IC50 values of 63, 70, and 920 microM, respectively. Aminopeptidase activity in disrupted epithelial cells was inhibited by amastatin, bestatin, and 1,10-O-phenanthroline (IC50 values of 500 nM, 1 microM, and 17 microM, respectively), but not by captopril at the highest concentration tested, 10 mM. These findings are in contrast to prior studies in neutrophils. When neutrophils were stimulated with A23187 after treatment with captopril, transcellular synthesis of LTB4 was inhibited more effectively than direct synthesis of leukotriene B4 (LTB4) (43.8 +/- 2.5 vs 18.5 +/- 4.7%; N = 8, P < 0.02). We conclude that LTA4 hydrolase activity of human airway epithelial cells is inhibited by some metalloproteinase inhibitors, but that the profile of inhibition is distinct from that for the neutrophil enzyme. These data provide additional information that LTA4 hydrolase in the epithelial cell is a novel enzyme, distinct from that found in the neutrophil.
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Affiliation(s)
- J R Baker
- Department of Veterans Affairs Medical Center, San Diego, CA 92161, USA
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26
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Cadel S, Pierotti AR, Foulon T, Créminon C, Barré N, Segrétain D, Cohen P. Aminopeptidase-B in the rat testes: isolation, functional properties and cellular localization in the seminiferous tubules. Mol Cell Endocrinol 1995; 110:149-60. [PMID: 7672445 DOI: 10.1016/0303-7207(95)03529-g] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An aminopeptidase of the B-type, with an apparent M(r) 72,000 and pI = 4.9, was isolated from rat testes and characterized. The enzyme was able to remove only Arg and/or Lys residues from L-amino acid beta-naphthylamide derivatives and from the N-terminus of several peptides. No cleavage occurred in the case of Arg-Pro bonds as found in bradykinin and substance P. The enzyme was sensitive to cysteinyl reagents and to aminopeptidase inhibitors, such as bestatin, amastatin and arphamenines A and B. The aminopeptidase activity, tested with L-Arg beta-naphthylamide and with Arg0-Met-enkephalin as substrates, was inhibited by o-phenanthroline, and restored by Zn2+ suggesting its metallopeptidase character. The partial characterization of an aminopeptidase-B activity in rat brain cortex identified a protein which is biochemically and immunologically related to the testis enzyme. By immunohistochemistry, the aminopeptidase-B was found to be particularly abundant in the seminiferous tubules at late stages of spermatogenesis and was clearly detected in a restricted area of elongated spermatids. Remarkably, the enzyme was observed to concentrate massively in the residual bodies. Since this aminopeptidase-B was able in vitro to trim out N-terminal Arg and/or Lys residues from peptides mimicking processing intermediates, it is proposed that this enzyme may be involved in propeptide and proprotein processing mechanisms in the course of spermatid differentiation.
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Affiliation(s)
- S Cadel
- Laboratoire de Biochimie des Signaux Régulateurs Cellulaires et Moléculaires, Université Pierre et Marie Curie, Unité de Recherches Associée au Centre National de la Recherche Scientifique 1682, Paris, France
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27
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Fitzpatrick FA, Lepley R, Orning L, Duffin K. Suicide inactivation of leukotriene A4 hydrolase/aminopeptidase. Ann N Y Acad Sci 1994; 744:31-8. [PMID: 7825854 DOI: 10.1111/j.1749-6632.1994.tb52721.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- F A Fitzpatrick
- University of Colorado Health Sciences Center, Department of Pharmacology, Denver 80262
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28
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Steinhilber D. 5-Lipoxygenase: enzyme expression and regulation of activity. PHARMACEUTICA ACTA HELVETIAE 1994; 69:3-14. [PMID: 7938075 DOI: 10.1016/0031-6865(94)90024-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
5-Lipoxygenase catalyzes the transformation of arachidonic acid to leukotriene A4. This unstable intermediate can be converted to leukotriene B4 by LTA4-hydrolase or to leukotriene C4 by LTC4-synthase. Leukotrienes are involved in host defense reactions and play an important role in inflammatory diseases like asthma, inflammatory bowel disease and arthritis. The capability to release leukotrienes is restricted to a few cell types. Under pathophysiological conditions, leukotrienes are released from granulocytes, mast cells or macrophages. During hematopoiesis the competence of these cells for leukotriene biosynthesis is supposed to be upregulated. In mature cells, 5-lipoxygenase activity is tightly regulated and seems to be under the control of additional cellular components. One cellular component, a membrane-bound peptide termed FLAP, which is necessary for 5-LO activity in intact cells has been recently identified. Inhibitors of FLAP function prevent translocation of 5-lipoxygenase from cytosol to the membrane and inhibit 5-LO activation. Thus, the understanding of the regulatory mechanisms of cellular leukotriene biosynthesis provides new concepts for the development of antiinflammatory drugs. This review focuses on the regulation of gene expression and activity of 5-lipoxygenase.
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Affiliation(s)
- D Steinhilber
- Dept. of Pharmaceutical Chemistry, University of Tübingen, Germany
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29
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Orning L, Gierse J, Fitzpatrick F. The bifunctional enzyme leukotriene-A4 hydrolase is an arginine aminopeptidase of high efficiency and specificity. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)78120-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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30
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Tanaka T, Ichishima E. Inactivation of chemotactic peptides by aminopeptidase Ey from hen's (Gallus gallus domesticus) egg yolk. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. BIOCHEMISTRY AND MOLECULAR BIOLOGY 1994; 107:533-8. [PMID: 8205380 DOI: 10.1016/0305-0491(94)90181-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Aminopeptidase Ey, purified from hen's (Gallus gallus domesticus) egg yolk, was studied for its specificity against N-blocked peptides. Only N-formylmethionyl peptides were hydrolyzed by the enzyme in the tested peptides. N-Formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe) lost its chemotactic activity toward human neutrophil after incubation with aminopeptidase Ey.
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Affiliation(s)
- T Tanaka
- Research Institute of Q.P. Corp., Tokyo, Japan
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31
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Orning L, Gierse J, Duffin K, Bild G, Krivi G, Fitzpatrick F. Mechanism-based inactivation of leukotriene A4 hydrolase/aminopeptidase by leukotriene A4. Mass spectrometric and kinetic characterization. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)50009-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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