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Albisetti A, Hälg S, Zoltner M, Mäser P, Wiedemar N. Suramin action in African trypanosomes involves a RuvB-like DNA helicase. Int J Parasitol Drugs Drug Resist 2023; 23:44-53. [PMID: 37757728 PMCID: PMC10520940 DOI: 10.1016/j.ijpddr.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/15/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023]
Abstract
Suramin is one of the oldest drugs in use today. It is still the treatment of choice for the hemolymphatic stage of African sleeping sickness caused by Trypanosoma brucei rhodesiense, and it is also used for surra in camels caused by Trypanosoma evansi. Yet despite one hundred years of use, suramin's mode of action is not fully understood. Suramin is a polypharmacological molecule that inhibits diverse proteins. Here we demonstrate that a DNA helicase of the pontin/ruvB-like 1 family, termed T. brucei RuvBL1, is involved in suramin resistance in African trypanosomes. Bloodstream-form T. b. rhodesiense under long-term selection for suramin resistance acquired a homozygous point mutation, isoleucine-312 to valine, close to the ATP binding site of T. brucei RuvBL1. The introduction of this missense mutation, by reverse genetics, into drug-sensitive trypanosomes significantly decreased their sensitivity to suramin. Intriguingly, the corresponding residue of T. evansi RuvBL1 was found mutated in a suramin-resistant field isolate, in that case to a leucine. RuvBL1 (Tb927.4.1270) is predicted to build a heterohexameric complex with RuvBL2 (Tb927.4.2000). RNAi-mediated silencing of gene expression of either T. brucei RuvBL1 or RuvBL2 caused cell death within 72 h. At 36 h after induction of RNAi, bloodstream-form trypanosomes exhibited a cytokinesis defect resulting in the accumulation of cells with two nuclei and two or more kinetoplasts. Taken together, these data indicate that RuvBL1 DNA helicase is involved in suramin action in African trypanosomes.
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Affiliation(s)
- Anna Albisetti
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland; University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Silvan Hälg
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland; University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Martin Zoltner
- Department of Parasitology, Faculty of Science, Charles University in Prague, Biocev, Vestec, Czech Republic
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland; University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Natalie Wiedemar
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland; University of Basel, Petersplatz 1, 4001, Basel, Switzerland.
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2
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Hulme J. COVID-19 and Diarylamidines: The Parasitic Connection. Int J Mol Sci 2023; 24:6583. [PMID: 37047556 PMCID: PMC10094973 DOI: 10.3390/ijms24076583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
As emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants (Omicron) continue to outpace and negate combinatorial vaccines and monoclonal antibody therapies targeting the spike protein (S) receptor binding domain (RBD), the appetite for developing similar COVID-19 treatments has significantly diminished, with the attention of the scientific community switching to long COVID treatments. However, treatments that reduce the risk of "post-COVID-19 syndrome" and associated sequelae remain in their infancy, particularly as no established criteria for diagnosis currently exist. Thus, alternative therapies that reduce infection and prevent the broad range of symptoms associated with 'post-COVID-19 syndrome' require investigation. This review begins with an overview of the parasitic-diarylamidine connection, followed by the renin-angiotensin system (RAS) and associated angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSSR2) involved in SARS-CoV-2 infection. Subsequently, the ability of diarylamidines to inhibit S-protein binding and various membrane serine proteases associated with SARS-CoV-2 and parasitic infections are discussed. Finally, the roles of diarylamidines (primarily DIZE) in vaccine efficacy, epigenetics, and the potential amelioration of long COVID sequelae are highlighted.
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Affiliation(s)
- John Hulme
- Department of Bionano Technology, Gachon Bionano Research Institute, Gachon University, 1342 Sungnam-daero, Sujung-gu, Seongnam-si 461-701, Republic of Korea
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3
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Mehner C, Hockla A, Coban M, Madden B, Estrada R, Radisky DC, Radisky ES. Activity-based protein profiling reveals active serine proteases that drive malignancy of human ovarian clear cell carcinoma. J Biol Chem 2022; 298:102146. [PMID: 35716777 PMCID: PMC9304776 DOI: 10.1016/j.jbc.2022.102146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 12/14/2022] Open
Abstract
Ovarian clear cell carcinoma (OCCC) is an understudied poor prognosis subtype of ovarian cancer lacking in effective targeted therapies. Efforts to define molecular drivers of OCCC malignancy may lead to new therapeutic targets and approaches. Among potential targets are secreted proteases, enzymes which in many cancers serve as key drivers of malignant progression. Here, we found that inhibitors of trypsin-like serine proteases suppressed malignant phenotypes of OCCC cell lines. To identify the proteases responsible for malignancy in OCCC, we employed activity-based protein profiling to directly analyze enzyme activity. We developed an activity-based probe featuring an arginine diphenylphosphonate warhead to detect active serine proteases of trypsin-like specificity and a biotin handle to facilitate affinity purification of labeled proteases. Using this probe, we identified active trypsin-like serine proteases within the complex proteomes secreted by OCCC cell lines, including two proteases in common, tissue plasminogen activator and urokinase-type plasminogen activator. Further interrogation of these proteases showed that both were involved in cancer cell invasion and proliferation of OCCC cells and were also detected in in vivo models of OCCC. We conclude the detection of tissue plasminogen activator and urokinase-type plasminogen activator as catalytically active proteases and significant drivers of the malignant phenotype may point to these enzymes as targets for new therapeutic strategies in OCCC. Our activity-based probe and profiling methodology will also serve as a valuable tool for detection of active trypsin-like serine proteases in models of other cancers and other diseases.
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Affiliation(s)
- Christine Mehner
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, Minnesota, USA,Department of Cancer Biology, Mayo Clinic, Jacksonville, Florida, USA
| | - Alexandra Hockla
- Department of Cancer Biology, Mayo Clinic, Jacksonville, Florida, USA
| | - Mathew Coban
- Department of Cancer Biology, Mayo Clinic, Jacksonville, Florida, USA
| | - Benjamin Madden
- Medical Genome Facility Proteomics Core, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Derek C. Radisky
- Department of Cancer Biology, Mayo Clinic, Jacksonville, Florida, USA
| | - Evette S. Radisky
- Department of Cancer Biology, Mayo Clinic, Jacksonville, Florida, USA,For correspondence: Evette S. Radisky
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4
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Eyssen LEA, Coetzer TH. Validation of ligands targeting metacaspase-2 (MCA2) from Trypanosoma brucei brucei and their application to MCA5 from T. congolense as possible trypanocides. J Mol Graph Model 2020; 97:107579. [PMID: 32197135 DOI: 10.1016/j.jmgm.2020.107579] [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: 11/19/2019] [Revised: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 11/29/2022]
Abstract
Metacaspases (MCAs) are ideal drug and diagnostic targets for animal and human African trypanosomiasis, as these cysteine peptidases are absent from the metazoan kingdom and have been implicated in the parasite cell cycle and cell death. Tsetse fly-transmitted trypanosomes that live free in the bloodstream and/or cerebrospinal fluid of the mammalian host cause animal and human African trypanosomiasis (nagana or sleeping sickness respectively). Chemotherapy and chemoprophylaxis are the main forms of control, but in contrast to human trypanocides, the veterinary drugs are old and drug resistance is on the increase. A peptidomimetic library targeting the MCA2 from Trypanosoma brucei brucei has ligands with low IC50 values, some of which were antiparasitic. This study validates the inhibitory activity of these ligands using the protein structure solved by X-ray diffraction after the ligand library was published. Water molecules were shown to be important in substrate binding and strategies to improve the efficacy of these ligands are highlighted. These ligands appear to be pan-specific as they were docked into the active site of the homology modelled MCA5 of animal infective Trypanosoma congolense with similar binding energies and conformations.
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Affiliation(s)
- L E-A Eyssen
- Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg Campus), Private Bag X01, Scottsville, 3209, South Africa
| | - Theresa Ht Coetzer
- Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg Campus), Private Bag X01, Scottsville, 3209, South Africa.
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5
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Abstract
Suramin is 100 years old and is still being used to treat the first stage of acute human sleeping sickness, caused by Trypanosoma brucei rhodesiense Suramin is a multifunctional molecule with a wide array of potential applications, from parasitic and viral diseases to cancer, snakebite, and autism. Suramin is also an enigmatic molecule: What are its targets? How does it get into cells in the first place? Here, we provide an overview of the many different candidate targets of suramin and discuss its modes of action and routes of cellular uptake. We reason that, once the polypharmacology of suramin is understood at the molecular level, new, more specific, and less toxic molecules can be identified for the numerous potential applications of suramin.
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Motta FN, Azevedo CDS, Neves BP, Araújo CND, Grellier P, Santana JMD, Bastos IMD. Oligopeptidase B, a missing enzyme in mammals and a potential drug target for trypanosomatid diseases. Biochimie 2019; 167:207-216. [DOI: 10.1016/j.biochi.2019.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/15/2019] [Indexed: 12/21/2022]
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Leishmanicidal therapy targeted to parasite proteases. Life Sci 2019; 219:163-181. [PMID: 30641084 DOI: 10.1016/j.lfs.2019.01.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 12/31/2022]
Abstract
Leishmaniasis is considered a serious public health problem and the current available therapy has several disadvantages, which makes the search for new therapeutic targets and alternative treatments extremely necessary. In this context, this review focuses on the importance of parasite proteases as target drugs against Leishmania parasites, as a chemotherapy approach. Initially, we discuss about the current scenario for the treatment of leishmaniasis, highlighting the main drugs used and the problems related to their use. Subsequently, we describe the inhibitors of major proteases of Leishmania already discovered, such as Compound s9 (aziridine-2,3-dicarboxylate), Compound 1c (benzophenone derivative), Au2Phen (gold complex), AubipyC (gold complex), MDL 28170 (dipeptidyl aldehyde), K11777, Hirudin, diazo-acetyl norleucine methyl ester, Nelfinavir, Saquinavir, Nelfinavir, Saquinavir, Indinavir, Saquinavir, GNF5343 (azabenzoxazole), GNF6702 (azabenzoxazole), Benzamidine and TPCK. Next, we discuss the importance of the protease gene to parasite survival and the aspects of the validation of proteases as target drugs, with emphasis on gene disruption. Then, we describe novel important strategies that can be used to support the research of new antiparasitic drugs, such as molecular modeling and nanotechnology, whose main targets are parasitic proteases. And finally, we discuss possible perspectives to improve drug development. Based on all findings, proteases could be considered potential targets against leishmaniasis.
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8
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Kayode O, Huang Z, Soares AS, Caulfield TR, Dong Z, Bode AM, Radisky ES. Small molecule inhibitors of mesotrypsin from a structure-based docking screen. PLoS One 2017; 12:e0176694. [PMID: 28463992 PMCID: PMC5413004 DOI: 10.1371/journal.pone.0176694] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/16/2017] [Indexed: 01/18/2023] Open
Abstract
PRSS3/mesotrypsin is an atypical isoform of trypsin, the upregulation of which has been implicated in promoting tumor progression. To date there are no mesotrypsin-selective pharmacological inhibitors which could serve as tools for deciphering the pathological role of this enzyme, and could potentially form the basis for novel therapeutic strategies targeting mesotrypsin. A virtual screen of the Natural Product Database (NPD) and Food and Drug Administration (FDA) approved Drug Database was conducted by high-throughput molecular docking utilizing crystal structures of mesotrypsin. Twelve high-scoring compounds were selected for testing based on lowest free energy docking scores, interaction with key mesotrypsin active site residues, and commercial availability. Diminazene (CID22956468), along with two similar compounds presenting the bis-benzamidine substructure, was validated as a competitive inhibitor of mesotrypsin and other human trypsin isoforms. Diminazene is the most potent small molecule inhibitor of mesotrypsin reported to date with an inhibitory constant (Ki) of 3.6±0.3 μM. Diminazene was subsequently co-crystalized with mesotrypsin and the crystal structure was solved and refined to 1.25 Å resolution. This high resolution crystal structure can now offer a foundation for structure-guided efforts to develop novel and potentially more selective mesotrypsin inhibitors based on similar molecular substructures.
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Affiliation(s)
- Olumide Kayode
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Jacksonville, Florida, United States of America
| | - Zunnan Huang
- The Hormel Institute, University of Minnesota, Austin, Minnesota, United States of America
| | - Alexei S. Soares
- Photon Sciences Directorate, Brookhaven National Laboratory, Upton, New York, United States of America
| | - Thomas R. Caulfield
- Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, Florida, United States of America
| | - Zigang Dong
- The Hormel Institute, University of Minnesota, Austin, Minnesota, United States of America
| | - Ann M. Bode
- The Hormel Institute, University of Minnesota, Austin, Minnesota, United States of America
| | - Evette S. Radisky
- Department of Cancer Biology, Mayo Clinic Comprehensive Cancer Center, Jacksonville, Florida, United States of America
- * E-mail:
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9
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Inhibition of Wnt signalling and breast tumour growth by the multi-purpose drug suramin through suppression of heterotrimeric G proteins and Wnt endocytosis. Biochem J 2016; 473:371-81. [DOI: 10.1042/bj20150913] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/24/2015] [Indexed: 11/17/2022]
Abstract
Multi-purpose drug suramin is found to be active against cancer-related Wnt signalling. As a consequence of heterotrimeric G proteins suppression, suramin inhibits Wnt ligand internalization, which renders the drug active against triple-negative breast cancer (TNBC).
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10
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Jin H, Zhu J, Dong Y, Han W. Exploring the different ligand escape pathways in acylaminoacyl peptidase by random acceleration and steered molecular dynamics simulations. RSC Adv 2016. [DOI: 10.1039/c5ra24952j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Acylaminoacyl peptidase (APH, EC 3.4.19.1) is a novel class of serine-type protease belonging to the prolyl oligopeptidase (POP) family.
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Affiliation(s)
- Hanyong Jin
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education
- School of Life Science
- Jilin University
- Changchun 130012
- China
| | - Jingxuan Zhu
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education
- School of Life Science
- Jilin University
- Changchun 130012
- China
| | - Yang Dong
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education
- School of Life Science
- Jilin University
- Changchun 130012
- China
| | - Weiwei Han
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education
- School of Life Science
- Jilin University
- Changchun 130012
- China
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11
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Huang TL, Mayence A, Vanden Eynde JJ. Some non-conventional biomolecular targets for diamidines. A short survey. Bioorg Med Chem 2014; 22:1983-92. [DOI: 10.1016/j.bmc.2014.02.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/19/2014] [Accepted: 02/24/2014] [Indexed: 12/24/2022]
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12
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Bastos IMD, Motta FN, Grellier P, Santana JM. Parasite prolyl oligopeptidases and the challenge of designing chemotherapeuticals for Chagas disease, leishmaniasis and African trypanosomiasis. Curr Med Chem 2014; 20:3103-15. [PMID: 23514419 PMCID: PMC3778648 DOI: 10.2174/0929867311320250006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 10/16/2012] [Indexed: 11/22/2022]
Abstract
The trypanosomatids Trypanosoma cruzi, Leishmania spp. and Trypanosoma brucei spp. cause Chagas disease, leishmaniasis and human African trypanosomiasis, respectively. It is estimated that over 10 million people worldwide suffer from these neglected diseases, posing enormous social and economic problems in endemic areas. There are no vaccines to prevent these infections and chemotherapies are not adequate. This picture indicates that new chemotherapeutic agents must be developed to treat these illnesses. For this purpose, understanding the biology of the pathogenic trypanosomatid-host cell interface is fundamental for molecular and functional characterization of virulence factors that may be used as targets for the development of inhibitors to be used for effective chemotherapy. In this context, it is well known that proteases have crucial functions for both metabolism and infectivity of pathogens and are thus potential drug targets. In this regard, prolyl oligopeptidase and oligopeptidase B, both members of the S9 serine protease family, have been shown to play important roles in the interactions of pathogenic protozoa with their mammalian hosts and may thus be considered targets for drug design. This review aims to discuss structural and functional properties of these intriguing enzymes and their potential as targets for the development of drugs against Chagas disease, leishmaniasis and African trypanosomiasis.
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Affiliation(s)
- I M D Bastos
- Pathogen-Host Interface Laboratory, Department of Cell Biology, The University of Brasília, Brasília, Brazil
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Fukumoto J, Ismail NIM, Kubo M, Kinoshita K, Inoue M, Yuasa K, Nishimoto M, Matsuki H, Tsuji A. Possible role of inter-domain salt bridges in oligopeptidase B from Trypanosoma brucei: critical role of Glu172 of non-catalytic -propeller domain in catalytic activity and Glu490 of catalytic domain in stability of OPB. J Biochem 2013; 154:465-73. [PMID: 23946505 DOI: 10.1093/jb/mvt077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Junki Fukumoto
- Department of Biological Science and Technology, The University of Tokushima Graduate School, 2-1 Minamijosanjima, Tokushima 770-8506, Japan; Faculty of Science, Universiti Tunku Abdul Rahman, Jalam Universiti, Bandar Barat, 31900 Kampar, Perak D.R., Malaysia; and Department of Parasitology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
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14
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Abrahão RQ, Franciosi AC, Andrade D, Juliano L, Juliano MA, Giorgi R, Dale CS. Oligopeptidases B from Trypanossoma cruzi and Trypanossoma brucei Inhibit Inflammatory Pain in Mice by Targeting Serotoninergic Receptors. Inflammation 2013; 36:705-12. [DOI: 10.1007/s10753-013-9595-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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15
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Kangethe RT, Boulangé AF, Coustou V, Baltz T, Coetzer TH. Trypanosoma brucei brucei oligopeptidase B null mutants display increased prolyl oligopeptidase-like activity. Mol Biochem Parasitol 2012; 182:7-16. [DOI: 10.1016/j.molbiopara.2011.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 10/07/2011] [Accepted: 11/14/2011] [Indexed: 01/08/2023]
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16
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Motta FN, Bastos IMD, Faudry E, Ebel C, Lima MM, Neves D, Ragno M, Barbosa JARG, de Freitas SM, Santana JM. The Trypanosoma cruzi virulence factor oligopeptidase B (OPBTc) assembles into an active and stable dimer. PLoS One 2012; 7:e30431. [PMID: 22276197 PMCID: PMC3261901 DOI: 10.1371/journal.pone.0030431] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 12/20/2011] [Indexed: 01/31/2023] Open
Abstract
Oligopeptidase B, a processing enzyme of the prolyl oligopeptidase family, is considered as an important virulence factor in trypanosomiasis. Trypanosoma cruzi oligopeptidase B (OPBTc) is involved in host cell invasion by generating a Ca(2+)-agonist necessary for recruitment and fusion of host lysosomes at the site of parasite attachment. The underlying mechanism remains unknown and further structural and functional characterization of OPBTc may help clarify its physiological function and lead to the development of new therapeutic molecules to treat Chagas disease. In the present work, size exclusion chromatography and analytical ultracentrifugation experiments demonstrate that OPBTc is a dimer in solution, an association salt and pH-resistant and independent of intermolecular disulfide bonds. The enzyme retains its dimeric structure and is fully active up to 42°C. OPBTc is inactivated and its tertiary, but not secondary, structure is disrupted at higher temperatures, as monitored by circular dichroism and fluorescence spectroscopy. It has a highly stable secondary structure over a broad range of pH, undergoes subtle tertiary structure changes at low pH and is less stable under moderate ionic strength conditions. These results bring new insights into the structural properties of OPBTc, contributing to future studies on the rational design of OPBTc inhibitors as a promising strategy for Chagas disease chemotherapy.
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Affiliation(s)
- Flávia Nader Motta
- Pathogen-Host Interface Laboratory, Department of Cell Biology, The University of Brasília, Brasília, Brazil
| | - Izabela M. D. Bastos
- Pathogen-Host Interface Laboratory, Department of Cell Biology, The University of Brasília, Brasília, Brazil
- Faculty of Ceilândia, The University of Brasília, Brasília, Brazil
| | - Eric Faudry
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble, France
- CNRS, ERL 5261, Bacterial Pathogenesis and Cellular Responses, Grenoble, France
- UJF-Grenoble 1, Biology of Cancer and Infection, Grenoble, France
- CEA, DSV/iRTSV, Biology of Cancer and Infection, Grenoble, France
| | - Christine Ebel
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
- CNRS, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
- Université Joseph Fourier – Grenoble 1, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
| | - Meire M. Lima
- Pathogen-Host Interface Laboratory, Department of Cell Biology, The University of Brasília, Brasília, Brazil
| | - David Neves
- Pathogen-Host Interface Laboratory, Department of Cell Biology, The University of Brasília, Brasília, Brazil
| | - Michel Ragno
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble, France
- CNRS, ERL 5261, Bacterial Pathogenesis and Cellular Responses, Grenoble, France
- UJF-Grenoble 1, Biology of Cancer and Infection, Grenoble, France
- CEA, DSV/iRTSV, Biology of Cancer and Infection, Grenoble, France
| | - João Alexandre R. G. Barbosa
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil
| | - Sônia Maria de Freitas
- Laboratory of Biophysics, Department of Cell Biology, The University of Brasília, Brasília, Brazil
| | - Jaime Martins Santana
- Pathogen-Host Interface Laboratory, Department of Cell Biology, The University of Brasília, Brasília, Brazil
- * E-mail:
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17
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In vitro efficacy of dicationic compounds and mefloquine enantiomers against Echinococcus multilocularis metacestodes. Antimicrob Agents Chemother 2011; 55:4866-72. [PMID: 21768518 DOI: 10.1128/aac.00478-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The current chemotherapy of alveolar echinococcosis (AE) is based on benzimidazoles such as albendazole and has been shown to be parasitostatic rather than parasiticidal, requiring lifelong duration. Thus, new and more efficient treatment options are urgently needed. By employing a recently validated assay based on the release of functional phosphoglucose isomerase (PGI) from dying parasites, the activities of 26 dicationic compounds and of the (+)- and (-)-erythro-enantiomers of mefloquine were investigated. Initial screening of compounds was performed at 40 μM, and those compounds exhibiting considerable antiparasitic activities were also assessed at lower concentrations. Of the dicationic drugs, DB1127 (a diguanidino compound) with activities comparable to nitazoxanide was further studied. The activity of DB1127 was dose dependent and led to severe structural alterations, as visualized by electron microscopy. The (+)- and (-)-erythro-enantiomers of mefloquine showed similar dose-dependent effects, although higher concentrations of these compounds than of DB1127 were required for metacestode damage. In conclusion, of the drugs investigated here, the diguanidino compound DB1127 represents the most promising compound for further study in appropriate in vivo models for Echinococcus multilocularis infection.
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Alvarez VE, Niemirowicz GT, Cazzulo JJ. The peptidases of Trypanosoma cruzi: digestive enzymes, virulence factors, and mediators of autophagy and programmed cell death. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1824:195-206. [PMID: 21621652 DOI: 10.1016/j.bbapap.2011.05.011] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 05/11/2011] [Accepted: 05/12/2011] [Indexed: 02/06/2023]
Abstract
Trypanosoma cruzi, the agent of the American Trypanosomiasis, Chagas disease, contains cysteine, serine, threonine, aspartyl and metallo peptidases. The most abundant among these enzymes is cruzipain, a cysteine proteinase expressed as a mixture of isoforms, some of them membrane-bound. The enzyme is an immunodominant antigen in human chronic Chagas disease and seems to be important in the host/parasite relationship. Inhibitors of cruzipain kill the parasite and cure infected mice, thus validating the enzyme as a very promising target for the development of new drugs against the disease. In addition, a 30kDa cathepsin B-like enzyme, two metacaspases and two autophagins have been described. Serine peptidases described in the parasite include oligopeptidase B, a member of the prolyl oligopeptidase family involved in Ca(2+)-signaling during mammalian cell invasion; a prolyl endopeptidase (Tc80), against which inhibitors are being developed, and a lysosomal serine carboxypeptidase. Metallopeptidases homologous to the gp63 of Leishmania spp. are present, as well as two metallocarboxypeptidases belonging to the M32 family, previously found only in prokaryotes. The proteasome has properties similar to those of other eukaryotes, and its inhibition by lactacystin blocks some differentiation steps in the life cycle of the parasite. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome.
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Affiliation(s)
- Vanina E Alvarez
- Instituto de Investigaciones Biotecnológicas (IIB-INTECH, Universidad Nacional de San Martín-CONICET), Buenos Aires, Argentina
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McLuskey K, Paterson NG, Bland ND, Isaacs NW, Mottram JC. Crystal structure of Leishmania major oligopeptidase B gives insight into the enzymatic properties of a trypanosomatid virulence factor. J Biol Chem 2010; 285:39249-59. [PMID: 20926390 PMCID: PMC2998157 DOI: 10.1074/jbc.m110.156679] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 09/20/2010] [Indexed: 11/06/2022] Open
Abstract
Oligopeptidase B (OPB) is a serine peptidase with dibasic substrate specificity. It is found in bacteria, plants, and trypanosomatid pathogens, where it has been identified as a virulence factor and potential drug target. In this study we expressed active recombinant Leishmania major OPB and provide the first structure of an oligopeptidase B at high resolution. The crystallographic study reveals that OPB comprises two domains, a catalytic and a propeller domain, linked together by a hinge region. The structure has been determined in complex with the oligopeptide, protease-inhibitor antipain, giving detailed information on the enzyme active site and extended substrate binding pockets. It shows that Glu-621 plays a critical role in the S1 binding pocket and, along with Phe-603, is largely responsible for the enzyme substrate specificity in P1. In the S2 binding pocket, Tyr-499 was shown to be important for substrate stability. The structure also allowed an investigation into the function of residues highlighted in other studies including Glu-623, which was predicted to be involved in the S1 binding pocket but is found forming an inter-domain hydrogen bond. Additional important salt bridges/hydrogen bonds between the two domains were observed, highlighting the significance of the domain interface in OPB. This work provides a foundation for the study of the role of OPBs as virulence factors in trypanosomatids. It could facilitate the development of specific OPB inhibitors with therapeutic potential by exploiting its unique substrate recognition properties as well as providing a model for OPBs in general.
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Affiliation(s)
- Karen McLuskey
- Westchem School of Chemistry, University of Glasgow, Glasgow G12 8TA, Scotland, United Kingdom.
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Swenerton RK, Zhang S, Sajid M, Medzihradszky KF, Craik CS, Kelly BL, McKerrow JH. The oligopeptidase B of Leishmania regulates parasite enolase and immune evasion. J Biol Chem 2010; 286:429-40. [PMID: 20961853 DOI: 10.1074/jbc.m110.138313] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proteases are a ubiquitous group of enzymes that play key roles in the life cycle of parasites, in the host-parasite relationship, and in the pathogenesis of parasitic diseases. Furthermore, proteases are targets for the development of new anti-parasitic therapy. Protozoan parasites like Leishmania predominantly express Clan CA cysteine proteases for key life cycle functions. It was therefore unexpected to find a high level of serine protease activity expressed by Leishmania donovani. Purification of this activity followed by mass spectrometry identified oligopeptidase B (OPB; Clan SC, family S9A) as the responsible enzyme. This was confirmed by gene knock-out of OPB, which resulted in the disappearance of the detected serine protease activity of Leishmania extracts. To delineate the specific role of OPB in parasite physiology, proteomic analysis was carried out on OPB(-/-) versus wild type parasites. Four protein species were significantly elevated in OPB(-/-) parasites, and all four were identified by mass spectrometry as enolase. This increased enolase was enzymatically inactive and associated with the parasite membrane. Aside from its classic role in carbohydrate metabolism, enolase was recently found to localize to membranes, where it binds host plasminogen and functions as a virulence factor for several pathogens. As expected, there was a striking alteration in macrophage responses to Leishmania when OPB was deleted. Whereas wild type parasites elicited little, if any, response from infected macrophages, OPB(-/-) parasites induced a massive up-regulation in gene transcription. Additionally, these OPB(-/-) parasites displayed decreased virulence in the murine footpad infection model.
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Affiliation(s)
- Ryan K Swenerton
- Department of Pathology, Sandler Center for Drug Discovery, University of California, San Francisco, California 94158, USA
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Munday JC, McLuskey K, Brown E, Coombs GH, Mottram JC. Oligopeptidase B deficient mutants of Leishmania major. Mol Biochem Parasitol 2010; 175:49-57. [PMID: 20883728 DOI: 10.1016/j.molbiopara.2010.09.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 08/27/2010] [Accepted: 09/11/2010] [Indexed: 01/02/2023]
Abstract
Oligopeptidase B is a clan SC, family S9 serine peptidase found in gram positive bacteria, plants and trypanosomatids. Evidence suggests it is a virulence factor and thus therapeutic target in both Trypanosoma cruzi and T. brucei, but little is known about its function in Leishmania. In this study L. major OPB-deficient mutants (Δopb) were created. These grew normally as promastigotes, had a small deficiency in their ability to undergo differentiation to metacyclic promastigotes, were significantly less able to infect and survive within macrophages in vitro, but were virulent to mice. These data suggest that L. major OPB itself is not an important virulence factor, indicating functional differences between trypanosomes and Leishmania in their interaction with the mammalian host. The possibility that an OPB-like enzyme (designated OPB2) in L. major might compensate for the loss of OPB in Δopb was investigated via by mapping its sequence onto the 1.6Å structure of L. major OPB. This suggested that the residues involved in the S1 and S2 subsites of OPB2 are identical to OPB and hence the substrate specificity would be similar. Consequently there may be redundancy between the two enzymes.
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Affiliation(s)
- Jane C Munday
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland, UK
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da Silva-López RE, dos Santos TR, Morgado-Díaz JA, Tanaka MN, de Simone SG. Serine protease activities in Leishmania (Leishmania) chagasi promastigotes. Parasitol Res 2010; 107:1151-62. [PMID: 20668879 DOI: 10.1007/s00436-010-1983-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 07/13/2010] [Indexed: 10/19/2022]
Abstract
The present work reports the isolation, biochemical characterization, and subcellular location of serine proteases from aqueous, detergent soluble, and culture supernatant of Leishmania chagasi promastigote extracts, respectively, LCSII, LCSI, and LCSIII. The active enzyme molecular masses of LCSII were about 105, 66, and 60 kDa; of LCSI, 60 and 58 kDa; and of LCSIII, approximately 76 and 68 kDa. Optimal pH for the enzymes was 7.0 for LCSI and LCSIII and 8.5 for LCSII, and the optimal temperature for all enzymes was 37°C, using α-N-ρ-tosyl-L: -arginine methyl ester as substrate. Assay of thermal stability indicated that LCSIII is the more stable enzyme. Hemoglobin, bovine serum albumin, and ovalbumin were hydrolyzed by LCSII and LCSI but not by LCSIII. Inhibition studies suggested that enzymes belong to the serine protease class modulated by divalent cations. Rabbit antiserum against 56-kDa serine protease of Leishmania amazonensis identified proteins in all extracts of L. chagasi. Furthermore, immunocytochemistry demonstrated that serine proteases are located in flagellar pocket region and cytoplasmic vesicles of L. chagasi promastigotes. These findings indicate that L. chagasi serine proteases differ from L. amazonensis proteases and all known flagellate proteases, but display some similarities with serine proteases from other Leishmania species, suggesting a conservation of this enzymatic activity in the genus.
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Affiliation(s)
- Raquel Elisa da Silva-López
- Laboratório de Bioquímica de Proteínas e Peptídeos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Rio de Janeiro, Brazil.
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Structural binding evidence of the trypanocidal drugs berenil and pentacarinate active principles to a serine protease model. Int J Biol Macromol 2010; 46:502-11. [PMID: 20356563 DOI: 10.1016/j.ijbiomac.2010.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Revised: 03/12/2010] [Accepted: 03/16/2010] [Indexed: 11/22/2022]
Abstract
Bovine trypsin is a model system for the serine protease class of enzymes, which is an important target for contemporary medicinal chemistry. Some structural and thermodynamic reports are available on its interaction with benzamidine-based compounds but no structural information is available so far on its binding modes to the active principles of the trypanocidal drugs Pentacarinate (pentamidine) and Berenil (diminazene). The crystallographic structures of bovine beta-trypsin in complex with the ligands were determined to a resolution of 1.57 A (diminazene) and 1.70 A (diminazene and pentamidine). The second benzamidine moieties in these inhibitors are bound to the enzyme in different hot spots and only few hydrogen bonds mediate these interactions. Thermodynamic parameters for the association of pentamidine with beta-trypsin reveal that this inhibitor has about 1.3-fold lower affinity than diminazene. Moreover its binding mode resembles other benzamidine-based compounds that assess the aryl binding pocket of the enzyme; however, with almost 2.5-fold higher affinity. This is the first structural evidence of the binding of Berenil and Pentacarinate active principles trypanocidal drugs to serine proteases.
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Mohd Ismail NI, Yuasa T, Yuasa K, Nambu Y, Nisimoto M, Goto M, Matsuki H, Inoue M, Nagahama M, Tsuji A. A critical role for highly conserved Glu(610) residue of oligopeptidase B from Trypanosoma brucei in thermal stability. J Biochem 2009; 147:201-11. [PMID: 19819899 DOI: 10.1093/jb/mvp156] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Oligopeptidase B from Trypanosoma brucei (Tb OPB) is a virulence factor and therapeutic target in African sleeping sickness. Three glutamic acid residues at positions 607, 609 and 610 of the catalytic domain are highly conserved in the OPB subfamily. In this study, the roles of Glu(607), Glu(609) and Glu(610) in Tb OPB were investigated by site-directed mutagenesis. A striking effect on k(cat)/K(m) was obtained following mutation of Glu(607) to glutamine. In contrast, the heat stability of Tb OPB decreased markedly following the single mutation of Glu(610) to glutamine, although this mutation had significantly less effect on catalytic properties compared with the Glu(607) mutation. Although no differences were found in the tertiary and secondary structures between wild-type (WT) OPB and the E610Q mutant prior to heat treatment, the E610Q mutant is inactivated more rapidly than WT OPB following heat treatment in a manner correlating with its attendant structural changes. Trypsin digestion showed that the boundary regions between the beta-propeller and catalytic domain of the E610Q mutant are unfolded with heat treatment. It is concluded that Glu(607) is essential for the catalytic activity of Tb OPB and that Glu(610) plays a critical role in stabilization rather than catalytic activity despite their close proximity.
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Affiliation(s)
- Nor Ismaliza Mohd Ismail
- Department of Biological Science and Technology, University of Tokushima Graduate School, 2-1 Minamijosanjima, Tokushima 770-8506, Japan
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25
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Host cells participate in the in vitro effects of novel diamidine analogues against tachyzoites of the intracellular apicomplexan parasites Neospora caninum and Toxoplasma gondii. Antimicrob Agents Chemother 2008; 52:1999-2008. [PMID: 18362190 DOI: 10.1128/aac.01236-07] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The in vitro effects of 19 dicationic diamidine derivatives against the proliferative tachyzoite stages of the apicomplexan parasites Neospora caninum and Toxoplasma gondii were investigated. Four compounds (DB811, DB786, DB750, and DB766) with similar structural properties exhibited profound inhibition of tachyzoite proliferation. The lowest 50% inhibitory concentrations were found for DB786 (0.21 microM against Neospora and 0.22 microM against Toxoplasma) and DB750 (0.23 microM against Neospora and 0.16 microM against Toxoplasma), with complete proliferation inhibition at 1.7 microM for both drugs against both species. DB750 and DB786 were chosen for further studies. Electron microscopy of N. caninum-infected human foreskin fibroblast (HFF) cultures revealed distinct alterations and damage of parasite ultrastructure upon drug treatment, while host cells remained unaffected. For true parasiticidal efficacy against N. caninum, a treatment duration of 3 h at 1.7 microM was sufficient for DB750, while a longer treatment period (24 h) was necessary for DB786. Pretreatment of tachyzoites for 1 h prior to host cell exposure had no effect on infectivity. However, pretreatment of uninfected host cells had a significant adverse effect on N. caninum proliferation: exposure of HFFs to 1.7 microM DB750 for 6, 12, or 24 h, followed by infection with N. caninum tachyzoites and subsequent culture in the absence of DB750, resulted in significantly delayed parasite proliferation. This suggests that either (i) these compounds or their respective active metabolites were still present after the removal of the drugs or (ii) the drug treatments reversibly impaired some functional activities in HFFs that were essential for parasite proliferation and/or survival.
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26
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Oligopeptidase B: A processing peptidase involved in pathogenesis. Biochimie 2008; 90:336-44. [DOI: 10.1016/j.biochi.2007.10.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2007] [Accepted: 10/25/2007] [Indexed: 11/20/2022]
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27
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Yu WY, Yang LX, Xie JS, Zhou L, Jiang XY, Zhu DX, Muramatsu M, Wang MW. Derivatives of aryl-4-guanidinomethylbenzoate and N-aryl-4-guanidinomethylbenzamide as new antibacterial agents: synthesis and bioactivity. Acta Pharmacol Sin 2008; 29:267-77. [PMID: 18215358 DOI: 10.1111/j.1745-7254.2008.00720.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
AIM The aim of the present study was to design, synthesize, and evaluate novel antibacterial agents, derivatives of aryl-4-guanidinomethylbenzoate and N-aryl-4-guanidinomethylbenzamide. METHODS A total of 44 derivatives of aryl-4-guanidin-omethylbenzoate (series A) and N-aryl-4-guanidinomethylbenzamide (series B) were synthesized and their antibacterial activities were assessed in vitro against a variety of Gram-positive and Gram-negative bacteria by an agar dilution method. RESULTS Twelve compounds showed potent bactericidal effects against a panel of Gram-positive germs, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), vancomycin-intermediate Staphylococcus aureus (VISA), and methicillin-resistant coagulase-negative staphylococci (MRCNS), with minimum inhibitory concentrations (MIC) ranging between 0.5 and 8 microg/mL, which were comparable to the MIC values of several marketed antibiotics. They exhibited weak or no activity on the Gram-negative bacteria tested. In addition, these compounds displayed high inhibitory activities towards oligopeptidase B of bacterial origin. CONCLUSION In comparison with the previously reported MIC values of several known antibiotics, the derivatives of aryl-4-guanidinomethylbenzoate and N-aryl-4-guanidinomethylbenzamide showed comparable in vitro bactericidal activities against VRE and VISA as linezolid. Their growth inhibitory effects on MRSA were similar to vancomycin, but were less potent than linezolid and vancomycin against MRCNS. This class of compounds may have the potential to be developed into narrow spectrum antibacterial agents against certain drug-resistant strains of bacteria.
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Affiliation(s)
- Wen-yuan Yu
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
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28
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Oligopeptidase B from Leishmania amazonensis: molecular cloning, gene expression analysis and molecular model. Parasitol Res 2008; 101:865-75. [PMID: 18074461 DOI: 10.1007/s00436-007-0630-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Serine oligopeptidases of trypanosomatids are emerging as important virulence factors and therapeutic targets in trypanosome infections. A complete open reading frame of oligopeptidase B from Leishmania amazonensis was amplified with polymerase chain reaction with gradient annealing temperatures using primers designed for the oligopeptidase B gene from L. major. The 2,196-bp fragment coded for a protein of 731 amino acids with a predicted molecular mass of 83.49 KDa. The encoded protein (La_OpB) shares a 90% identity with oligopeptidases of L. major and L. infantum, 84% with L. braziliensis, and approximately 62% identity with Trypanosoma peptidases. The oligopeptidase B gene is expressed in all cycle stages of L. amazonensis. The three dimensional model of La_OpB was obtained by homology modeling based on the structure of prolyl oligopeptidases. We mapped a La_OpB model that presents a greater negative charge than prolyl oligopeptidases; our results suggest a difference in the S2 subsite when compared to oligopeptidases B from Trypanosoma and bacterial oligopeptidases B. The La_OpB model serves as a starting point for its exploration as a potential target source for a rational chemotherapy.
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29
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Soeiro MDNC, Souza EMD, Boykin DW. Antiparasitic activity of aromatic diamidines and their patented literature. Expert Opin Ther Pat 2007. [DOI: 10.1517/13543776.17.8.927] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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30
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de Matos Guedes HL, Carneiro MPD, Gomes DCDO, Rossi-Bergmanmn B, Giovanni de Simone S. Oligopeptidase B from L. amazonensis: molecular cloning, gene expression analysis and molecular model. Parasitol Res 2007; 101:853-63. [PMID: 17530480 DOI: 10.1007/s00436-007-0552-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 04/17/2007] [Indexed: 11/25/2022]
Abstract
Serine oligopeptidases of trypanosomatids are emerging as important virulence factors and therapeutic targets in trypanosome infections. A complete open reading frame of oligopeptidase B from Leishmania amazonensis was amplified with polymerase chain reaction with gradient annealing temperatures using primers designed for the oligopeptidase B gene from L. major. The 2,196-bp fragment coded for a protein of 731 amino acids with a predicted molecular mass of 83.49 KDa. The encoded protein (La_OpB) shares a 90% identity with oligopeptidases of L. major and L. infantum, 84% with L. braziliensis, and approximately 62 identity with Trypanosoma peptidases. The oligopeptidase B gene is expressed in all cycle stages of L. amazonensis. The three dimensional model of La_OpB was obtained by homology modeling based on the structure of prolyl oligopeptidases. We mapped a La_OpB model that presents a greater negative charge than prolyl oligopeptidases; our results suggest a difference in the S2 subsite when compared to oligopeptidases B from Trypanosoma and bacterial oligopeptidases B. The La_OpB model serves as a starting point for its exploration as a potential target source for a rational chemotherapy.
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Affiliation(s)
- Herbert Leonel de Matos Guedes
- Laboratório de Bioquímica de Proteínas e Peptídeos, Departamento de Bioquímica e Biologia Molecular, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
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31
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Rea D, Hazell C, Andrews NW, Morty RE, Fülöp V. Expression, purification and preliminary crystallographic analysis of oligopeptidase B from Trypanosoma brucei. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:808-10. [PMID: 16880564 PMCID: PMC2242912 DOI: 10.1107/s1744309106027874] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 07/18/2006] [Indexed: 11/22/2022]
Abstract
Recombinant oligopeptidase B from T. brucei has been prepared and crystallized. Data were collected to 2.7 Å. Heavy-atom soaks and preparation of selenomethionine-substituted protein are in progress for structure determination by MAD or MIR. African sleeping sickness, also called trypanosomiasis, is a significant cause of morbidity and mortality in sub-Saharan Africa. Peptidases from Trypanosoma brucei, the causative agent, include the serine peptidase oligopeptidase B, a documented virulence factor and therapeutic target. Determination of the three-dimensional structure of oligopeptidase B is desirable to facilitate the development of novel inhibitors. Oligopeptidase B was overexpressed in Escherichia coli as an N-terminally hexahistidine-tagged fusion protein, purified using metal-affinity chromatography and crystallized using the hanging-drop vapour-diffusion technique in 7%(w/v) polyethylene glycol 6000, 1 M LiCl, 0.1 M bis-tris propane pH 7.5. Diffraction data to 2.7 Å resolution were collected using synchrotron radiation. The crystals belong to space group P3121 or P3221, with unit-cell parameters a = b = 124.5, c = 249.9 Å. A complete data set to 2.7 Å was collected using synchrotron radiation.
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Affiliation(s)
- Dean Rea
- Department of Biological Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, England
| | - Carole Hazell
- Department of Biological Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, England
| | - Norma W. Andrews
- Section of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA
| | - Rory E. Morty
- Department of Internal Medicine, University of Giessen Medical Centre, Aulweg 123 (Room 6-11), D-35392 Giessen, Germany
| | - Vilmos Fülöp
- Department of Biological Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, England
- Correspondence e-mail:
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Brigotti M, Alfieri RR, Petronini PG, Carnicelli D. Inhibition by suramin of protein synthesis in vitro. Ribosomes as the target of the drug. Biochimie 2006; 88:497-503. [PMID: 16386828 DOI: 10.1016/j.biochi.2005.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Revised: 10/17/2005] [Accepted: 10/24/2005] [Indexed: 11/18/2022]
Abstract
Suramin, a drug widely used both as a therapeutic agent and in research, inhibits translation in eukaryotic cell-free systems from rabbit reticulocyte lysate (IC(50)=142-241 microM). Suramin affects both initiation (block of 43S pre-initiation complex formation) and elongation (impairment of poly(U) translation). The drug induces an increase in the pools of ribosomal subunits and the formation of high molecular weight ribosomal complexes, thus causing the disappearance of polysomes. Ribosomes isolated from suramin-treated translating mixtures are inactivated. [(3)H]Suramin binds to ribosomes and to isolated 60S and 40S ribosomal subunits (116, 106 and 3 binding sites, respectively) showing higher affinity for the small subunit (K(d)=2 microM).
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Affiliation(s)
- Maurizio Brigotti
- Dipartimento di Patologia Sperimentale, Università di Bologna, Via San Giacomo 14, 40126 Bologna, Italy.
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Tsuji A, Yoshimoto T, Yuasa K, Matsuda Y. Protamine: a unique and potent inhibitor of oligopeptidase B. J Pept Sci 2006; 12:65-71. [PMID: 15948139 DOI: 10.1002/psc.683] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Oligopeptidase B is a serine endopeptidase found in prokaryotes, unicellular eukaryotes and higher plants. The enzyme has been shown recently to play a central role in the pathogenesis of several parasitic diseases such as African trypanosomiasis, and to be a potential therapeutic target. This study reports that protamine, a basic peptide rich in arginine, is a potent inhibitor at the nanomolar level of oligopeptidase B from E. coli and wheat. Protamines 1B, 2C, 3A and TP17 displayed similar inhibitory activities and were capable of binding strongly to oligopeptidase B without proteolytic cleavage. The concentration of protamine needed for 50% inhibition (IC50) of oligopeptidase B was 10(4)-fold lower than the IC50 of trypsin. Oligopeptidase B was highly sensitive to inhibition by protamines even in the presence of serum (IC50, 1 microM). These data indicate that protamines might provide information useful for the design of more specific synthetic oligopeptidase B inhibitors.
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Affiliation(s)
- Akihiko Tsuji
- Department of Biological Science and Technology, The faculty of Engineering, The University of Tokushima, 2-1 Minamijosanjima, Tokushima 770-8506, Japan.
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34
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Soeiro MNC, De Souza EM, Stephens CE, Boykin DW. Aromatic diamidines as antiparasitic agents. Expert Opin Investig Drugs 2006; 14:957-72. [PMID: 16050790 DOI: 10.1517/13543784.14.8.957] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Parasitic infections are widespread in developing countries and frequently associated with immunocompromised patients in developed countries. Consequently, such infections are responsible for a significant amount of human mortality, morbidity and economic hardship. A growing consensus has identified the urgent need for the development of new antiparasitic compounds, mostly due to the large number of drug-resistant parasites and the fact that currently available drugs are expensive, highly toxic, require long treatment regimens and frequently exhibit significantly reduced activity towards certain parasite strains and evolutive stages. In this context, the activity of aromatic diamidines has been explored against a widespread range of micro-organisms, and the authors' present aim is to review the current status of chemotherapy with these compounds against human parasitic infections.
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Affiliation(s)
- M N C Soeiro
- Lab. Biologia Celular, DUBC, Instituto Oswaldo Cruz, FIOCRUZ, Avenida Brasil 4365, Manguinhos, 21045-900, Rio de Janeiro, RJ, Brazil.
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35
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Morty RE, Vadász I, Bulau P, Dive V, Oliveira V, Seeger W, Juliano L. Tropolysin, a New Oligopeptidase from African Trypanosomes†,‡. Biochemistry 2005; 44:14658-69. [PMID: 16262265 DOI: 10.1021/bi051035k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Oligopeptidases are emerging as important pathogenic factors and therapeutic targets in trypanosome infections. We describe here the purification, cloning, and biochemical analysis of a new oligopeptidase from two pathogenic African trypanosomes. This oligopeptidase, which we have called tropolysin (encoded by the trn gene), represents an evolutionarily distant member of the M3A subfamily of metallopeptidases, ancestral to thimet oligopeptidase, neurolysin, and saccharolysin. The trn gene was present as a single copy per haploid genome, was expressed in both the mammalian and insect stages of the parasite life cycle, and encoded an 84 kDa protein. Both purified and hyperexpressed tropolysin hydrolyzed bradykinin-derived fluorogenic peptide substrates at restricted sites, with an alkaline pH optimum, and were activated by dithiothreitol and reduced glutathione and by divalent metal cations, in the order Zn(2+) > Co(2+) > Mn(2+). Under oxidizing conditions, tropolysin reversibly formed inactive multimers. Tropolysin exhibited a preference for acidic amino acid side chains in P(4), hydrophobic side chains in P(3), and hydrophobic or large uncharged side chains in P(1), P(1)', and P(3)', while the S(2)' site was unselective. Highly charged residues were not tolerated in P(1)'. Tropolysin was responsible for the bulk of the kinin-degrading activity in trypanosome lysates, potently (k(cat) approximately 119 s(-)(1)) inactivated the vasoactive kinins bradykinin and kallidin, and generated angiotensin(1-7) from angiotensin I. This hydrolysis both abolished the capacity of bradykinin to stimulate the bradykinin B(2) receptor and abrogated bradykinin prohypotensive properties in vivo, raising the possibility that tropolysin may play a role in the dysregulated kinin metabolism observed in the plasma of trypanosome-infected hosts.
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Affiliation(s)
- Rory E Morty
- Department of Internal Medicine, University Hospital Giessen, Aulweg 123, D-35392 Giessen, Germany.
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36
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Morty RE, Shih AY, Fülöp V, Andrews NW. Identification of the reactive cysteine residues in oligopeptidase B from Trypanosoma brucei. FEBS Lett 2005; 579:2191-6. [PMID: 15811340 DOI: 10.1016/j.febslet.2005.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 03/07/2005] [Accepted: 03/07/2005] [Indexed: 11/28/2022]
Abstract
Oligopeptidase B (OpdB) from Trypanosoma brucei is a candidate therapeutic target in African trypanosomiasis. OpdB is an atypical serine peptidase, since activity is inhibited by thiol-blocking reagents and enhanced by reducing agents. We have identified C256 as the reactive cysteine residue that mediates OpdB inhibition by N-ethylmaleimide and iodoacetic acid. Modeling studies suggest that C256 adducts occlude the P(1) substrate-binding site, preventing substrate binding. We further demonstrate that C559 and C597 are responsible for the thiol-enhancement of OpdB activity. These studies may facilitate the development of specific OpdB inhibitors with therapeutic potential, by exploiting these unique properties of this enzyme.
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Affiliation(s)
- Rory E Morty
- Department of Internal Medicine, University of Giessen School of Medicine, Aulweg 123 (Room 6-11), D-35392 Giessen, Germany.
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37
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Mayence A, Vanden Eynde JJ, LeCour L, Walker LA, Tekwani BL, Huang TL. Piperazine-linked bisbenzamidines: a novel class of antileishmanial agents. Eur J Med Chem 2005; 39:547-53. [PMID: 15183913 DOI: 10.1016/j.ejmech.2004.01.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Revised: 01/05/2004] [Accepted: 01/14/2004] [Indexed: 11/24/2022]
Abstract
A series of 13 1,4-diarylpiperazines has been prepared, evaluated for antileishmanial activity and their binding affinity to DNA was measured. Among these compounds, 1,4-bis[4-(1H-benzimidazol-2-yl)phenyl]piperazine (14) emerged as the most active compound with an IC(50) value of 0.41 microM which is about sevenfold more potent than pentamidine.
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Affiliation(s)
- Annie Mayence
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, LA 70125, USA
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39
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da Silva-Lopez RE, Giovanni-De-Simone S. Leishmania (Leishmania) amazonensis: purification and characterization of a promastigote serine protease. Exp Parasitol 2004; 107:173-82. [PMID: 15363943 DOI: 10.1016/j.exppara.2004.05.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Revised: 05/04/2004] [Accepted: 05/19/2004] [Indexed: 11/16/2022]
Abstract
Pathogenic protozoan proteases play crucial roles in the host-parasite interaction, and its characterization contributes to the understanding of protozoan disease mechanisms. A Leishmania amazonensis promastigote protease was purified 36-fold, using aprotinin-agarose affinity chromatography and gel filtration high performance liquid chromatography, yielding a total recovery of 49%. The molecular mass of active enzyme obtained from native gel filtration HPLC and SDS-PAGE under conditions of reduction and non-reduction was 68 kDa, suggesting that the enzyme may exist as a monomer. The protease isoelectric point (pI) was around 4.45 and, as demonstrated by deglycosylation assay, it did not have any carbohydrate content. The optimal pH and temperature of the enzyme were 8.0 and 28 degrees C, respectively, determined using alpha-N-rho-tosyl-L-arginyl-methyl ester (L-TAME) as substrate. Assays of thermal stability indicated that 50% of the enzymatic activity was preserved after 4 min of pre-treatment at 42 degrees C and after 24 h of pre-treatment at 37 degrees C, both in the absence of substrate. Hemoglobin, bovine serum albumin (BSA), ovalbumin, and both gelatin and peptide substrates containing arginine in ester bound were hydrolyzed by 68 kDa protease. The insulin beta-chain was also hydrolyzed by the protease, and four peptidic bonds (L11-V12, E13-A14, L15-Y16, and Y16-L17) were susceptible to the 68-kDa protease action. Inhibition studies suggested that the enzyme belonged to a serine protease class inhibited by calcium ions and activated by manganese ions. These findings demonstrate that the L. amazonensis 68-kDa serine protease differs from those of other protozoan parasites.
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Affiliation(s)
- Raquel Elisa da Silva-Lopez
- Laboratório de Bioquímica de Proteínas e Peptídeos, Departamento de Bioquímica e Biologia Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, 21045-900, Rio de Janeiro, Brazil.
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40
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Mayence A, Vanden Eynde JJ, Krogstad FM, Krogstad DJ, Cushion MT, Huang TL. Parallel Solution-Phase Synthesis of Conformationally Restricted Congeners of Pentamidine and Evaluation of Their Antiplasmodial Activities. J Med Chem 2004; 47:2700-5. [PMID: 15115412 DOI: 10.1021/jm030545e] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Conformationally restricted bisbenzamidines and related congeners have been synthesized and evaluated for activity against two Plasmodium falciparum strains. The most active compounds, bisbenzamidines linked by a 1,4-piperazinediyl core, had IC(50) values between 3 and 18 nM against both chloroquine-susceptible and -resistant parasites and IC(50) values for cytotoxicity greater than 5 microM, using the A549 human lung epithelial cell line. DNA binding affinity, as estimated by DeltaT(m), did not correlate with either antiparasite effects or cytotoxicity. Each of the active bisbenzamidines interfered with the formation of hemozoin in cell-free systems.
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Affiliation(s)
- Annie Mayence
- College of Pharmacy, Division of Basic Pharmaceutical Sciences, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, Louisiana 70125, USA
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41
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Hemerly JP, Oliveira V, Del Nery E, Morty RE, Andrews NW, Juliano MA, Juliano L. Subsite specificity (S3, S2, S1', S2' and S3') of oligopeptidase B from Trypanosoma cruzi and Trypanosoma brucei using fluorescent quenched peptides: comparative study and identification of specific carboxypeptidase activity. Biochem J 2003; 373:933-9. [PMID: 12737623 PMCID: PMC1223545 DOI: 10.1042/bj20030342] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2003] [Revised: 05/02/2003] [Accepted: 05/09/2003] [Indexed: 11/17/2022]
Abstract
We characterized the extended substrate binding site of recombinant oligopeptidase B enzymes from Trypanosoma cruzi (Tc-OP) and Trypanosoma brucei (Tb-OP), evaluating the specificity of their S3, S2, S1', S2' and S3' subsites. Five series of internally quenched fluorescent peptides based on the substrate Abz-AGGRGAQ-EDDnp [where Abz is o -aminobenzoic acid and EDDnp is N -(2,4-dinitrophenyl)ethylenediamine] were designed to contain amino acid residues with side chains of a minimum size, and each residue position of this substrate was modified. Synthetic peptides of different lengths derived from the human kininogen sequence were also examined, and peptides of up to 17 amino acids were found to be hydrolysed by Tc-OP and Tb-OP. These two oligopeptidases were essentially arginyl hydrolases, since for all peptides examined the only cleavage site was the Arg-Xaa bond. We also demonstrated that Tc-OP and Tb-OP have a very specific carboxypeptidase activity for basic amino acids, which depends on the presence of at least of a pair of basic amino acids at the C-terminal end of the substrate. The peptide with triple Arg residues (Abz-AGRRRAQ-EDDnp) was an efficient substrate for Tc-OP and Tb-OP: the Arg-Ala peptide bond was cleaved first and then two C-terminal Arg residues were successively removed. The S1' subsite seems to be an important determinant of the specificity of both enzymes, showing a preference for Tyr, Ser, Thr and Gln as hydrogen donors. The presence of these amino acids at P1' resulted in substrates that were hydrolysed with K (m) values in the sub-micromolar range. Taken together, this work supports the view that oligopeptidase B is a specialized protein-processing enzyme with a specific carboxypeptidase activity. Excellent substrates were obtained for Tb-OP and Tc-OP (Abz-AMRRTISQ-EDDnp and Abz-AHKRYSHQ-EDDnp respectively), which were hydrolysed with remarkably high k (cat) and low K (m) values.
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Affiliation(s)
- Jefferson P Hemerly
- Department of Biophysics, Escola Paulista de Medicina, Rua Três de Maio 100, São Paulo SP 04044-020, Brazil
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42
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Morty RE, Morehead J. Cloning and characterization of a leucyl aminopeptidase from three pathogenic Leishmania species. J Biol Chem 2002; 277:26057-65. [PMID: 12006595 DOI: 10.1074/jbc.m202779200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aminopeptidases are emerging as exciting novel drug targets and vaccine candidates in parasitic infections. In this study, we describe for the first time an aminopeptidase from three highly pathogenic Leishmania species. Intronless genes encoding a leucyl aminopeptidase (lap) were cloned from Leishmania amazonensis, Leishmania donovani, and Leishmania major, which encoded 60-kDa proteins that displayed homology to leucyl aminopeptidases from Gram-negative bacteria, plants, and mammals. The lap genes were present as a single copy in each genome, and lap mRNA was detected by reverse transcription-PCR in all life-cycle stages of L. amazonensis. Lap assembled into catalytically competent 360-kDa hexamers and demonstrated potent amidolytic activity against synthetic aminopeptidase substrates containing leucine, methionine, and cysteine residues, representing the most restricted substrate specificity of any leucyl aminopeptidase described to date. Optimal activity was observed against L-leucyl-7-amido-4-methylcoumarin (k(cat)/K(m) approximately 63 s(-1) x mm(-1)) with a pH optimum of 8.5. Leishmania Lap activity was inhibited by metal ion chelators and enhanced by divalent manganese, cobalt, and nickel cations, although only zinc was detected in the purified Lap by inductively coupled plasma atomic emission spectroscopy, indicating that zinc is the natural Lap cofactor. Activity was potently inhibited by bestatin and apstatin in a slow binding competitive fashion, with K(i)* values of 3 and 44 nm, respectively. Actinonin was a tight binding competitive inhibitor (K(i) approximately 1 nm), whereas arphamenine A (K(i) approximately 70 microm) and L-leucinol (K(i) approximately 100 microm) were non-tight binding competitive inhibitors. Lap was not secreted by Leishmania in vitro and was localized to the parasite cytosol.
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Affiliation(s)
- Rory E Morty
- Section of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536, USA.
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43
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Morty RE, Fülöp V, Andrews NW. Substrate recognition properties of oligopeptidase B from Salmonella enterica serovar Typhimurium. J Bacteriol 2002; 184:3329-37. [PMID: 12029050 PMCID: PMC135088 DOI: 10.1128/jb.184.12.3329-3337.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2002] [Accepted: 03/26/2002] [Indexed: 01/27/2023] Open
Abstract
Oligopeptidase B (OpdB) is a serine peptidase broadly distributed among unicellular eukaryotes, gram-negative bacteria, and spirochetes which has emerged as an important virulence factor and potential therapeutic target in infectious diseases. We report here the cloning and expression of the opdB homologue from Salmonella enterica serovar Typhimurium and demonstrate that it exhibits amidolytic activity exclusively against substrates with basic residues in P(1). While similar to its eukaryotic homologues in terms of substrate specificity, Salmonella OpdB differs significantly in catalytic power and inhibition and activation properties. In addition to oligopeptide substrates, restricted proteolysis of histone proteins was observed, although no cleavage was seen at or near residues that had been posttranslationally modified or at defined secondary structures. This supports the idea that the catalytic site of OpdB may be accessible only to unstructured oligopeptides, similar to the closely related prolyl oligopeptidase (POP). Salmonella OpdB was employed as a model enzyme to define determinants of substrate specificity that distinguish OpdB from POP, which hydrolyzes substrates exclusively at proline residues. Using site-directed mutagenesis, nine acidic residues that are conserved in OpdBs but absent from POPs were converted to their corresponding residues in POP. In this manner, we identified a pair of glutamic acid residues, Glu(576) and Glu(578), that define P(1) specificity and direct OpdB cleavage C terminal to basic residues. We have also identified a second pair of residues, Asp(460) and Asp(462), that may be involved in defining P(2) specificity and thus direct preferential cleavage by OpdB after pairs of basic residues.
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Affiliation(s)
- Rory E Morty
- Section of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536, USA
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44
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Juhász T, Szeltner Z, Renner V, Polgár L. Role of the oxyanion binding site and subsites S1 and S2 in the catalysis of oligopeptidase B, a novel target for antimicrobial chemotherapy. Biochemistry 2002; 41:4096-106. [PMID: 11900553 DOI: 10.1021/bi016016z] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Oligopeptidase B is a member of a novel serine peptidase family, found in Gram-negative bacteria and trypanosomes. The enzyme is involved in host cell invasion, and thus, it is an important target for drug design. Oligopeptidase B is specific for substrates with a pair of basic residues at positions P1 and P2. The sensitivity of substrates to high ionic strength suggests that the arginines interact with the carboxylate ions of the enzyme. On the basis of a three-dimensional model, two carboxyl dyads (Asp460 and Asp462 and Glu576 and Glu578) can be assigned as binding sites for arginines P1 and P2, respectively. The dyads are involved in several events: (i) substrate binding, (ii) substrate inhibition at high substrate concentrations (different inhibitory mechanisms were demonstrated with substrates bearing one and two arginine residues), (iii) enzyme activation at millimolar CaCl2 concentrations with substrates having one arginine, and (iv) interaction of Ca2+ with the dyads which simplified the complex pH dependence curves. Titration with a product-like inhibitor revealed the pK(a) of the carboxyl group that perturbed the pH-kcat/Km profiles. The OH group of Tyr452 is part of the oxyanion binding site, which stabilizes the transition state of the reaction. Its role studied with the Tyr452Phe variant indicates that (i) the catalytic contribution of the OH group depends on the substrate and (ii) the catalysis is, unusually, an entropy-driven process at physiological temperature. The NH group of the scissile peptide bond accounts for the deviation of the reaction from the Eyring plot above 25 degrees C, and for abolishing potential nonproductive binding.
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Affiliation(s)
- Tünde Juhász
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 7, Budapest H-1518, Hungary
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45
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Brendle JJ, Outlaw A, Kumar A, Boykin DW, Patrick DA, Tidwell RR, Werbovetz KA. Antileishmanial activities of several classes of aromatic dications. Antimicrob Agents Chemother 2002; 46:797-807. [PMID: 11850264 PMCID: PMC127500 DOI: 10.1128/aac.46.3.797-807.2002] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aromatic dicationic molecules possess impressive activity against a broad spectrum of microbial pathogens, including Pneumocystis carinii, Cryptosporidium parvum, and Candida albicans. In this work, 58 aromatic cations were examined for inhibitory activity against axenic amastigote-like Leishmania donovani parasites. In general, the most potent of the compounds were substituted diphenyl furan and thiophene dications. 2,5-Bis-(4-amidinophenyl)thiophene was the most active compound. This agent displayed a 50% inhibitory concentration (IC50) of 0.42 +/- 0.08 microM against L. donovani and an in vitro antileishmanial potency 6.2-fold greater than that of the clinical antileishmanial dication pentamidine and was 155-fold more toxic to the parasites than to a mouse macrophage cell line. 2,4-Bis-(4-amidinopheny)furan was twice as active as pentamidine (IC50), 1.30 +/- 0.21 microM), while 2,5-bis-(4-amidinopheny)furan and pentamidine were essentially equipotent in our in vitro antileishmanial assay. Carbazoles, dibenzofurans, dibenzothiophenes, and benzimidazoles containing amidine or substituted amidine groups were generally less active than the diphenyl furans and thiophenes. In all cases, aromatic dications possessing strong antileishmanial activity were severalfold more toxic to the parasites than to a cultured mouse macrophage cell line. These structure-activity relationships demonstrate the potent antileishmanial activity of several aromatic dications and provide valuable information for the future design and synthesis of more potent antiparasitic agents.
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Affiliation(s)
- James J Brendle
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, USA
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46
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Stead AM, Bray PG, Edwards IG, DeKoning HP, Elford BC, Stocks PA, Ward SA. Diamidine compounds: selective uptake and targeting in Plasmodium falciparum. Mol Pharmacol 2001; 59:1298-306. [PMID: 11306715 DOI: 10.1124/mol.59.5.1298] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Extensive drug resistance in Plasmodium falciparum emphasizes the urgent requirement for novel antimalarial agents. Here we report potent antimalarial activity of a number of diamidine compounds. The lead compound pentamidine is concentrated 500-fold by erythrocytes infected with P. falciparum. Pentamidine accumulation can be blocked by inhibitors of hemoglobin digestion, suggesting that the drug binds to ferriprotoporphyrin IX (FPIX). All of the compounds bound to FPIX in vitro and inhibited the formation of hemozoin. Furthermore, inhibitors of hemoglobin digestion markedly antagonized the antimalarial activity of the diamidines, indicating that binding to FPIX is crucial for the activity of diamidine drugs. Pentamidine was not accumulated into uninfected erythrocytes. Pentamidine transport into infected cells exhibits an initial rapid phase, nonsaturable in the micromolar range and sensitive to inhibition by furosemide and glibenclamide. Changing the counter-ion in the order Cl(-) < Br(-) < NO(2)(-) < I(-) <SCN(-) markedly stimulated pentamidine transport. These data suggest that pentamidine is transported although a pore or ion channel with properties similar to those of the recently characterized 'induced permeability pathway' on the infected red cell membrane. In summary, the diamidines exhibit two levels of selectivity against P. falciparum. The route of entry and molecular target are both specific to malaria-infected cells and are distinct from targets in other protozoa. Drugs that target the hemoglobin degradation pathway of malaria parasites have a proven record of accomplishment. The employment of induced permeability pathways to access this target represents a novel approach to antiparasite chemotherapy and offers an additional level of selectivity.
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Affiliation(s)
- A M Stead
- Department of Pharmacology and Therapeutics, The University of Liverpool, Liverpool, United Kingdom
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47
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Morty RE, Lonsdale-Eccles JD, Mentele R, Auerswald EA, Coetzer TH. Trypanosome-derived oligopeptidase B is released into the plasma of infected rodents, where it persists and retains full catalytic activity. Infect Immun 2001; 69:2757-61. [PMID: 11254649 PMCID: PMC98221 DOI: 10.1128/iai.69.4.2757-2761.2001] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A trypsin-like serine peptidase activity, levels of which correlate with blood parasitemia levels, is present in the plasma of rats acutely infected with Trypanosoma brucei brucei. Antibodies to a trypanosome peptidase with a trypsin-like substrate specificity (oligopeptidase B [OP-Tb]) cross-reacted with a protein in the plasma of trypanosome-infected rats on a Western blot. These antibodies also abolished 80% of the activity in the plasma of trypanosome-infected rats, suggesting that the activity may be attributable to a parasite-derived peptidase. We purified the enzyme responsible for the bulk of this activity from parasite-free T. b. brucei-infected rat plasma and confirmed its identity by protein sequencing. We show that live trypanosomes do not release OP-Tb in vitro and propose that disrupted parasites release it into the host circulation, where it is unregulated and retains full catalytic activity and may thus play a role in the pathogenesis of African trypanosomiasis.
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Affiliation(s)
- R E Morty
- Department of Biochemistry, School of Molecular and Cellular Biosciences, University of Natal, Scottsville, South Africa.
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48
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Morty RE, Troeberg L, Powers JC, Ono S, Lonsdale-Eccles JD, Coetzer TH. Characterisation of the antitrypanosomal activity of peptidyl alpha-aminoalkyl phosphonate diphenyl esters. Biochem Pharmacol 2000; 60:1497-504. [PMID: 11020452 DOI: 10.1016/s0006-2952(00)00459-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two groups of irreversible serine peptidase inhibitors, peptidyl chloromethyl ketones and peptidyl phosphonate diphenyl esters, were examined for antitrypanosomal activity against the bloodstream form of Trypanosoma brucei brucei. Both peptidyl chloromethyl ketones and peptidyl phosphonate diphenyl esters inhibited trypsin-like peptidases of the parasites and exhibited antitrypanosomal activity at micromolar concentrations. In live T. b. brucei, labelled analogues of both of these groups of inhibitors primarily targeted an 80-kDa peptidase, possibly a serine oligopeptidase known as oligopeptidase B. In an in vivo mouse model of infection, one of these inhibitors, carbobenzyloxyglycyl-4-amidinophenylglycine phosphonate diphenyl ester, was curative at 5 mg kg(-1) day(-1) but appeared toxic at higher doses. There was no significant correlation between the inhibitory potency (as evaluated against purified T. b. brucei oligopeptidase B) and the in vitro antitrypanosomal efficacy of either group of inhibitors, suggesting that these inhibitors were acting on multiple targets within the parasites, or had different cell permeability properties. These findings suggest that serine peptidases may represent novel chemotherapeutic targets in African trypanosomes.
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Affiliation(s)
- R E Morty
- School of Molecular and Cellular Biosciences: Biochemistry, University of Natal, Scottsville, South Africa
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49
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Dhar S, Gullbo J, Csoka K, Eriksson E, Nilsson K, Nickel P, Larsson R, Nygren P. Antitumour activity of suramin analogues in human tumour cell lines and primary cultures of tumour cells from patients. Eur J Cancer 2000; 36:803-9. [PMID: 10762755 DOI: 10.1016/s0959-8049(00)00024-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Suramin has shown promising antitumour activity against several tumour types, both in vitro and in vivo, but the clinical utility of this compound is hampered by its unfavourable toxicity profile. In the present study, the semi-automated fluorometric microculture cytotoxicity assay (FMCA) was employed for evaluation of the cytotoxicity of seven suramin analogues in vitro in a panel of human tumour cell lines and in primary cultures of tumour cells from patients. Like suramin, the analogues showed little sensitivity to resistance mechanisms involving P-glycoprotein, topoisomerase II, multidrug resistance associated protein and glutathione-mediated drug resistance. In the cell line panel, NF067 and FCE 26644 showed activity comparable with suramin. All analogues were less potent than suramin in patient cells except for FCE 26644. Correlation to suramin activity patterns in the cell line panel was highest for NF037 and low to moderate for the remaining analogues. In patient cells, high correlation coefficients were obtained for FCE 26644, NF110, NF031 and NF037. The results indicate that the cytotoxic activity of suramin on patient tumour cells is shared by the analogues with FCE 26644 being the most active. The pharmacophore for cytotoxicity in patient cells may be different from that observed in the cell lines.
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Affiliation(s)
- S Dhar
- Division of Clinical Pharmacology, University Hospital, Uppsala University, S-751 85, Uppsala, Sweden.
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50
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Morty RE, Lonsdale-Eccles JD, Morehead J, Caler EV, Mentele R, Auerswald EA, Coetzer TH, Andrews NW, Burleigh BA. Oligopeptidase B from Trypanosoma brucei, a new member of an emerging subgroup of serine oligopeptidases. J Biol Chem 1999; 274:26149-56. [PMID: 10473566 DOI: 10.1074/jbc.274.37.26149] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma brucei contains a soluble serine oligopeptidase (OP-Tb) that is released into the host bloodstream during infection, where it has been postulated to participate in the pathogenesis of African trypanosomiasis. Here, we report the identification of a single copy gene encoding the T. brucei oligopeptidase and a homologue from the related trypanosomatid pathogen Leishmania major. The enzymes encoded by these genes belong to an emerging subgroup of the prolyl oligopeptidase family of serine hydrolases, referred to as oligopeptidase B. The trypanosomatid oligopeptidases share 70% amino acid sequence identity with oligopeptidase B from the intracellular pathogen Trypanosoma cruzi, which has a demonstrated role in mammalian host cell signaling and invasion. OP-Tb exhibited no activity toward the prolyl oligopeptidase substrate H-Gly-Pro-7-amido-4-methylcoumarin. Instead, it had activity toward substrates of trypsin-like enzymes, particularly those that have basic amino acids in both P(1) and P(2) (e.g. benzyloxycarbonyl-Arg-Arg-7-amido-4-methylcoumarin k(cat)/K(m) = 529 s(-1) microM(-1)). The activity of OP-Tb was enhanced by reducing agents and by polyamines, suggesting that these agents may act as in vivo regulators of OP-Tb activity. This study provides the basis of the characterization of a novel subgroup of serine oligopeptidases from kinetoplastid protozoa with potential roles in pathogenesis.
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Affiliation(s)
- R E Morty
- Department of Biochemistry, University of Natal, Private Bag X01, 3209 Scottsville, South Africa
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