1
|
Mahanta PJ, Lhouvum K. Plasmodium falciparum proteases as new drug targets with special focus on metalloproteases. Mol Biochem Parasitol 2024; 258:111617. [PMID: 38554736 DOI: 10.1016/j.molbiopara.2024.111617] [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: 10/17/2023] [Revised: 02/15/2024] [Accepted: 03/10/2024] [Indexed: 04/02/2024]
Abstract
Malaria poses a significant global health threat particularly due to the prevalence of Plasmodium falciparum infection. With the emergence of parasite resistance to existing drugs including the recently discovered artemisinin, ongoing research seeks novel therapeutic avenues within the malaria parasite. Proteases are promising drug targets due to their essential roles in parasite biology, including hemoglobin digestion, merozoite invasion, and egress. While exploring the genomic landscape of Plasmodium falciparum, it has been revealed that there are 92 predicted proteases, with only approximately 14 of them having been characterized. These proteases are further distributed among 26 families grouped into five clans: aspartic proteases, cysteine proteases, metalloproteases, serine proteases, and threonine proteases. Focus on metalloprotease class shows further role in organelle processing for mitochondria and apicoplasts suggesting the potential of metalloproteases as viable drug targets. Holistic understanding of the parasite intricate life cycle and identification of potential drug targets are essential for developing effective therapeutic strategies against malaria and mitigating its devastating global impact.
Collapse
Affiliation(s)
| | - Kimjolly Lhouvum
- Department of Biotechnology, National Institute of Technology, Arunachal Pradesh, India.
| |
Collapse
|
2
|
Mansouri M, Daware K, Webb CT, McGowan S. Understanding the structure and function of Plasmodium aminopeptidases to facilitate drug discovery. Curr Opin Struct Biol 2023; 82:102693. [PMID: 37657352 DOI: 10.1016/j.sbi.2023.102693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 09/03/2023]
Abstract
Malaria continues to be the most widespread parasitic disease affecting humans globally. As parasites develop drug resistance at an alarming pace, it has become crucial to identify novel drug targets. Over the last decade, the metalloaminopeptidases have gained importance as potential targets for new antimalarials. These enzymes are responsible for removing the N-terminal amino acids from proteins and peptides, and their restricted specificities suggest that many perform unique and essential roles within the malaria parasite. This mini-review focuses on the recent progress in structure and functional data relating to the Plasmodium metalloaminopeptidases that have been validated or shown promise as new antimalarial drug targets.
Collapse
Affiliation(s)
- Mahta Mansouri
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia; Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia. https://twitter.com/Mahta__Mansouri
| | - Kajal Daware
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia; Centre to Impact AMR, Monash University, Clayton, 3800, Victoria Australia
| | - Chaille T Webb
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia; Centre to Impact AMR, Monash University, Clayton, 3800, Victoria Australia
| | - Sheena McGowan
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, 3800, Australia; Centre to Impact AMR, Monash University, Clayton, 3800, Victoria Australia.
| |
Collapse
|
3
|
Pinheiro ADS, Kazura JW, Pinheiro AA, Schmaier AH. Is there a role for bradykinin in cerebral malaria pathogenesis? Front Cell Infect Microbiol 2023; 13:1184896. [PMID: 37637466 PMCID: PMC10448822 DOI: 10.3389/fcimb.2023.1184896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023] Open
Abstract
Malaria is a parasitic disease of global health significance and a leading cause of death in children living in endemic regions. Although various Plasmodium species are responsible for the disease, Plasmodium falciparum infection accounts for most severe cases of the disease in humans. The mechanisms of cerebral malaria pathogenesis have been studied extensively in humans and animal malaria models; however, it is far from being fully understood. Recent discoveries indicate a potential role of bradykinin and the kallikrein kinin system in the pathogenesis of cerebral malaria. The aim of this review is to highlight how bradykinin is formed in cerebral malaria and how it may impact cerebral blood-brain barrier function. Areas of interest in this context include Plasmodium parasite enzymes that directly generate bradykinin from plasma protein precursors, cytoadhesion of P. falciparum infected red blood cells to brain endothelial cells, and endothelial cell blood-brain barrier disruption.
Collapse
Affiliation(s)
- Alessandro de Sa Pinheiro
- Department of Medicine, Hematology and Oncology, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH, United States
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - James W. Kazura
- Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - Ana Acacia Pinheiro
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Alvin H. Schmaier
- Department of Medicine, Hematology and Oncology, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH, United States
| |
Collapse
|
4
|
Aguado ME, Izquierdo M, González-Matos M, Varela AC, Méndez Y, Del Rivero MA, Rivera DG, González-Bacerio J. Parasite Metalo-aminopeptidases as Targets in Human Infectious Diseases. Curr Drug Targets 2023; 24:416-461. [PMID: 36825701 DOI: 10.2174/1389450124666230224140724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/25/2022] [Accepted: 01/02/2023] [Indexed: 02/25/2023]
Abstract
BACKGROUND Parasitic human infectious diseases are a worldwide health problem due to the increased resistance to conventional drugs. For this reason, the identification of novel molecular targets and the discovery of new chemotherapeutic agents are urgently required. Metalo- aminopeptidases are promising targets in parasitic infections. They participate in crucial processes for parasite growth and pathogenesis. OBJECTIVE In this review, we describe the structural, functional and kinetic properties, and inhibitors, of several parasite metalo-aminopeptidases, for their use as targets in parasitic diseases. CONCLUSION Plasmodium falciparum M1 and M17 aminopeptidases are essential enzymes for parasite development, and M18 aminopeptidase could be involved in hemoglobin digestion and erythrocyte invasion and egression. Trypanosoma cruzi, T. brucei and Leishmania major acidic M17 aminopeptidases can play a nutritional role. T. brucei basic M17 aminopeptidase down-regulation delays the cytokinesis. The inhibition of Leishmania basic M17 aminopeptidase could affect parasite viability. L. donovani methionyl aminopeptidase inhibition prevents apoptosis but not the parasite death. Decrease in Acanthamoeba castellanii M17 aminopeptidase activity produces cell wall structural modifications and encystation inhibition. Inhibition of Babesia bovis growth is probably related to the inhibition of the parasite M17 aminopeptidase, probably involved in host hemoglobin degradation. Schistosoma mansoni M17 aminopeptidases inhibition may affect parasite development, since they could participate in hemoglobin degradation, surface membrane remodeling and eggs hatching. Toxoplasma gondii M17 aminopeptidase inhibition could attenuate parasite virulence, since it is apparently involved in the hydrolysis of cathepsin Cs- or proteasome-produced dipeptides and/or cell attachment/invasion processes. These data are relevant to validate these enzymes as targets.
Collapse
Affiliation(s)
- Mirtha E Aguado
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Maikel Izquierdo
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Maikel González-Matos
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Ana C Varela
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Yanira Méndez
- Center for Natural Products Research, Faculty of Chemistry, University of Havana, Zapata y G, 10400, La Habana, Cuba
| | - Maday A Del Rivero
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
| | - Daniel G Rivera
- Center for Natural Products Research, Faculty of Chemistry, University of Havana, Zapata y G, 10400, La Habana, Cuba
| | - Jorge González-Bacerio
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, 10400, Vedado, La Habana, Cuba
- Department of Biochemistry, Faculty of Biology, University of Havana, calle 25 #455 entre I y J, 10400, Vedado, La Habana, Cuba
| |
Collapse
|
5
|
Mills B, Isaac RE, Foster R. Metalloaminopeptidases of the Protozoan Parasite Plasmodium falciparum as Targets for the Discovery of Novel Antimalarial Drugs. J Med Chem 2021; 64:1763-1785. [PMID: 33534577 DOI: 10.1021/acs.jmedchem.0c01721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Malaria poses a significant threat to approximately half of the world's population with an annual death toll close to half a million. The emergence of resistance to front-line antimalarials in the most lethal human parasite species, Plasmodium falciparum (Pf), threatens progress made in malaria control. The prospect of losing the efficacy of antimalarial drugs is driving the search for small molecules with new modes of action. Asexual reproduction of the parasite is critically dependent on the recycling of amino acids through catabolism of hemoglobin (Hb), which makes metalloaminopeptidases (MAPs) attractive targets for the development of new drugs. The Pf genome encodes eight MAPs, some of which have been found to be essential for parasite survival. In this article, we discuss the biological structure and function of each MAP within the Pf genome, along with the drug discovery efforts that have been undertaken to identify novel antimalarial candidates of therapeutic value.
Collapse
Affiliation(s)
- Belinda Mills
- School of Chemistry, University of Leeds, Leeds, U.K., LS2 9JT
| | - R Elwyn Isaac
- School of Biology, University of Leeds, Leeds, U.K., LS2 9JT
| | - Richard Foster
- School of Chemistry, University of Leeds, Leeds, U.K., LS2 9JT
| |
Collapse
|
6
|
Nasamu AS, Polino AJ, Istvan ES, Goldberg DE. Malaria parasite plasmepsins: More than just plain old degradative pepsins. J Biol Chem 2020; 295:8425-8441. [PMID: 32366462 PMCID: PMC7307202 DOI: 10.1074/jbc.rev120.009309] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Plasmepsins are a group of diverse aspartic proteases in the malaria parasite Plasmodium Their functions are strikingly multifaceted, ranging from hemoglobin degradation to secretory organelle protein processing for egress, invasion, and effector export. Some, particularly the digestive vacuole plasmepsins, have been extensively characterized, whereas others, such as the transmission-stage plasmepsins, are minimally understood. Some (e.g. plasmepsin V) have exquisite cleavage sequence specificity; others are fairly promiscuous. Some have canonical pepsin-like aspartic protease features, whereas others have unusual attributes, including the nepenthesin loop of plasmepsin V and a histidine in place of a catalytic aspartate in plasmepsin III. We have learned much about the functioning of these enzymes, but more remains to be discovered about their cellular roles and even their mechanisms of action. Their importance in many key aspects of parasite biology makes them intriguing targets for antimalarial chemotherapy. Further consideration of their characteristics suggests that some are more viable drug targets than others. Indeed, inhibitors of invasion and egress offer hope for a desperately needed new drug to combat this nefarious organism.
Collapse
Affiliation(s)
- Armiyaw S Nasamu
- Division of Infectious Diseases, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Alexander J Polino
- Division of Infectious Diseases, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Eva S Istvan
- Division of Infectious Diseases, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Daniel E Goldberg
- Division of Infectious Diseases, Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| |
Collapse
|
7
|
Evidence for Regulation of Hemoglobin Metabolism and Intracellular Ionic Flux by the Plasmodium falciparum Chloroquine Resistance Transporter. Sci Rep 2018; 8:13578. [PMID: 30206341 PMCID: PMC6134138 DOI: 10.1038/s41598-018-31715-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 08/22/2018] [Indexed: 11/30/2022] Open
Abstract
Plasmodium falciparum multidrug resistance constitutes a major obstacle to the global malaria elimination campaign. Specific mutations in the Plasmodium falciparum chloroquine resistance transporter (PfCRT) mediate resistance to the 4-aminoquinoline drug chloroquine and impact parasite susceptibility to several partner agents used in current artemisinin-based combination therapies, including amodiaquine. By examining gene-edited parasites, we report that the ability of the wide-spread Dd2 PfCRT isoform to mediate chloroquine and amodiaquine resistance is substantially reduced by the addition of the PfCRT L272F mutation, which arose under blasticidin selection. We also provide evidence that L272F confers a significant fitness cost to asexual blood stage parasites. Studies with amino acid-restricted media identify this mutant as a methionine auxotroph. Metabolomic analysis also reveals an accumulation of short, hemoglobin-derived peptides in the Dd2 + L272F and Dd2 isoforms, compared with parasites expressing wild-type PfCRT. Physiologic studies with the ionophores monensin and nigericin support an impact of PfCRT isoforms on Ca2+ release, with substantially reduced Ca2+ levels observed in Dd2 + L272F parasites. Our data reveal a central role for PfCRT in regulating hemoglobin catabolism, amino acid availability, and ionic balance in P. falciparum, in addition to its role in determining parasite susceptibility to heme-binding 4-aminoquinoline drugs.
Collapse
|
8
|
Arreola R, Villalpando JL, Puente-Rivera J, Morales-Montor J, Rudiño-Piñera E, Alvarez-Sánchez ME. Trichomonas vaginalis metalloproteinase TvMP50 is a monomeric Aminopeptidase P-like enzyme. Mol Biotechnol 2018; 60:563-575. [PMID: 29936696 DOI: 10.1007/s12033-018-0097-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Previously, metalloproteinase was isolated and identified from Trichomonas vaginalis, belonging to the aminopeptidase P-like metalloproteinase subfamily A/B, family M24 of clan MG, named TvMP50. The native and recombinant TvMP50 showed proteolytic activity, determined by gelatin zymogram, and a 50 kDa band, suggesting that TvMP50 is a monomeric active enzyme. This was an unexpected finding since other Xaa-Pro aminopeptidases/prolidases are active as a biological unit formed by dimers/tetramers. In this study, the evolutionary history of TvMP50 and the preliminary crystal structure of the recombinant enzyme determined at 3.4 Å resolution is reported. TvMP50 was shown to be a type of putative, eukaryotic, monomeric aminopeptidase P, and the crystallographic coordinates showed a monomer on a "pseudo-homodimer" array on the asymmetric unit that resembles the quaternary structure of the M24B dimeric family and suggests a homodimeric aminopeptidase P-like enzyme as a likely ancestor. Interestingly, TvMP50 had a modified N-terminal region compared with other Xaa-Pro aminopeptidases/prolidases with three-dimensional structures; however, the formation of the standard dimer is structurally unstable in aqueous solution, and a comparably reduced number of hydrogen bridges and lack of saline bridges were found between subunits A/B, which could explain why TvMP50 portrays monomeric functionality. Additionally, we found that the Parabasalia group contains two protein lineages with a "pita bread" fold; the ancestral monomeric group 1 was probably derived from an ancestral dimeric aminopeptidase P-type enzyme, and group 2 has a probable dimeric kind of ancestral eukaryotic prolidase lineage. The implications of such hypotheses are also presented.
Collapse
Affiliation(s)
- Rodrigo Arreola
- Psychiatric Genetics Department, Clinical Research Branch, National Institute of Psychiatry, Ramón de la Fuente, Calzada México-Xochimilco 101, Colonia San Lorenzo Huipulco, Tlalpan, 14370, Mexico City, DF, Mexico
| | - José Luis Villalpando
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México (UACM), San Lorenzo # 290, Colonia Del Valle, CP 0310, Mexico City, Mexico
| | - Jonathan Puente-Rivera
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México (UACM), San Lorenzo # 290, Colonia Del Valle, CP 0310, Mexico City, Mexico
| | - Jorge Morales-Montor
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ap 70228, CP 04510, Mexico City, Mexico
| | - Enrique Rudiño-Piñera
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, 62210, Cuernavaca, MOR, Mexico
| | - María Elizbeth Alvarez-Sánchez
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México (UACM), San Lorenzo # 290, Colonia Del Valle, CP 0310, Mexico City, Mexico.
| |
Collapse
|
9
|
Structure and substrate fingerprint of aminopeptidase P from Plasmodium falciparum. Biochem J 2016; 473:3189-204. [DOI: 10.1042/bcj20160550] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 07/26/2016] [Indexed: 12/18/2022]
Abstract
Malaria is one of the world's most prevalent parasitic diseases, with over 200 million cases annually. Alarmingly, the spread of drug-resistant parasites threatens the effectiveness of current antimalarials and has made the development of novel therapeutic strategies a global health priority. Malaria parasites have a complicated lifecycle, involving an asymptomatic ‘liver stage’ and a symptomatic ‘blood stage’. During the blood stage, the parasites utilise a proteolytic cascade to digest host hemoglobin, which produces free amino acids absolutely necessary for parasite growth and reproduction. The enzymes required for hemoglobin digestion are therefore attractive therapeutic targets. The final step of the cascade is catalyzed by several metalloaminopeptidases, including aminopeptidase P (APP). We developed a novel platform to examine the substrate fingerprint of APP from Plasmodium falciparum (PfAPP) and to show that it can catalyze the removal of any residue immediately prior to a proline. Further, we have determined the crystal structure of PfAPP and present the first examination of the 3D structure of this essential malarial enzyme. Together, these analyses provide insights into potential mechanisms of inhibition that could be used to develop novel antimalarial therapeutics.
Collapse
|
10
|
Abstract
SUMMARYIn the present study, a recombinant aminopeptidase P (rTgAPP) from Toxoplasma gondii was expressed in Escherichia coli to evaluate its enzyme parameters. The rTgAPP showed strong activity against a synthetic substrate for aminopeptidase P at pH 8·0 with a Km value of 0·255 µm and a kcat value of 35·6 s−1. The overall catalytic efficiency (kcat/Km) of the rTgAPP was 139·6 × 105 M−1 s−1. The activity of rTgAPP was enhanced by the addition of divalent cations and inhibited by bestatin. Deletion of TgAPP gene in the parasite through a CRISPR/Cas9 system resulted in inhibition of growth indicating the importance of TgAPP. Thus our findings reveal that TgAPP is an active enzyme in T. gondii and provide an insight into the function of TgAPP.
Collapse
|
11
|
Iyer S, La-Borde PJ, Payne KAP, Parsons MR, Turner AJ, Isaac RE, Acharya KR. Crystal structure of X-prolyl aminopeptidase from Caenorhabditis elegans: A cytosolic enzyme with a di-nuclear active site. FEBS Open Bio 2015; 5:292-302. [PMID: 25905034 PMCID: PMC4404410 DOI: 10.1016/j.fob.2015.03.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/28/2015] [Accepted: 03/30/2015] [Indexed: 01/22/2023] Open
Abstract
Eukaryotic aminopeptidase P1 (APP1), also known as X‐prolyl aminopeptidase (XPNPEP1) in human tissues, is a cytosolic exopeptidase that preferentially removes amino acids from the N‐terminus of peptides possessing a penultimate N‐terminal proline residue. The enzyme has an important role in the catabolism of proline containing peptides since peptide bonds adjacent to the imino acid proline are resistant to cleavage by most peptidases. We show that recombinant and catalytically activeCaenorhabditis elegans APP‐1 is a dimer that uses dinuclear zinc at the active site and, for the first time, we provide structural information for a eukaryotic APP‐1 in complex with the inhibitor, apstatin. Our analysis reveals thatC. elegans APP‐1 shares similar mode of substrate binding and a common catalytic mechanism with other known X‐prolyl aminopeptidases. We present the crystal structure ofC. elegans APP‐1 both in bound and unbound forms. We showC. elegans APP‐1 uses dinuclear zinc at the active site. We confirm thatC. elegans APP‐1 is biological dimer. Our analysis reveals thatC. elegans APP‐1 shares a common catalytic mechanism with other X‐prolyl aminopeptidases.
Collapse
Key Words
- APP1, aminopeptidase P1
- Apstatin
- CCP4, computational collaborative project 4
- Di-nuclear active site
- ICP-AES, inductively coupled plasma atomic emission spectroscopy
- ICP-MS, inductively coupled plasma mass spectrometry
- MAP, methionine aminopeptidase
- NMR, nuclear magnetic resonance
- PCR, polymerase chain reaction
- PEG3350, polyethylene glycol 3350
- Protease inhibitor
- X-prolyl aminopeptidase
- X-ray crystallography
- XPNPEP, X-prolyl aminopeptidase
- Zinc metalloprotease
- rmsd, root mean square deviation
Collapse
Affiliation(s)
- Shalini Iyer
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Penelope J La-Borde
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK ; School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Karl A P Payne
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK ; Faculty of Life Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Mark R Parsons
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK ; Sevenoaks School, Sevenoaks TN13 1HU, UK
| | - Anthony J Turner
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK
| | - R Elwyn Isaac
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK
| | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| |
Collapse
|
12
|
Aminopeptidase N1 (EtAPN1), an M1 metalloprotease of the apicomplexan parasite Eimeria tenella, participates in parasite development. EUKARYOTIC CELL 2014; 13:884-95. [PMID: 24839124 DOI: 10.1128/ec.00062-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Aminopeptidases N are metalloproteases of the M1 family that have been reported in numerous apicomplexan parasites, including Plasmodium, Toxoplasma, Cryptosporidium, and Eimeria. While investigating the potency of aminopeptidases as therapeutic targets against coccidiosis, one of the most important avian diseases caused by the genus Eimeria, we identified and characterized Eimeria tenella aminopeptidase N1 (EtAPN1). Its inhibition by bestatin and amastatin, as well as its reactivation by divalent ions, is typical of zinc-dependent metalloproteases. EtAPN1 shared a similar sequence, three-dimensional structure, and substrate specificity and similar kinetic parameters with A-M1 from Plasmodium falciparum (PfA-M1), a validated target in the treatment of malaria. EtAPN1 is synthesized as a 120-kDa precursor and cleaved into 96-, 68-, and 38-kDa forms during sporulation. Further, immunolocalization assays revealed that, similar to PfA-M1, EtAPN1 is present during the intracellular life cycle stages in both the parasite cytoplasm and the parasite nucleus. The present results support the hypothesis of a conserved role between the two aminopeptidases, and we suggest that EtAPN1 might be a valuable target for anticoccidiosis drugs.
Collapse
|
13
|
Trafficked Proteins-Druggable in Plasmodium falciparum? Int J Cell Biol 2013; 2013:435981. [PMID: 23710183 PMCID: PMC3655585 DOI: 10.1155/2013/435981] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 03/12/2013] [Indexed: 01/09/2023] Open
Abstract
Malaria is an infectious disease that results in serious health problems in the countries in which it is endemic. Annually this parasitic disease leads to more than half a million deaths; most of these are children in Africa. An effective vaccine is not available, and the treatment of the disease is solely dependent on chemotherapy. However, drug resistance is spreading, and the identification of new drug targets as well as the development of new antimalarials is urgently required. Attention has been drawn to a variety of essential plasmodial proteins, which are targeted to intra- or extracellular destinations, such as the digestive vacuole, the apicoplast, or into the host cell. Interfering with the action or the transport of these proteins will impede proliferation of the parasite. In this mini review, we will shed light on the present discovery of chemotherapeutics and potential drug targets involved in protein trafficking processes in the malaria parasite.
Collapse
|
14
|
Deponte M, Hoppe HC, Lee MC, Maier AG, Richard D, Rug M, Spielmann T, Przyborski JM. Wherever I may roam: Protein and membrane trafficking in P. falciparum-infected red blood cells. Mol Biochem Parasitol 2012; 186:95-116. [DOI: 10.1016/j.molbiopara.2012.09.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/21/2012] [Accepted: 09/24/2012] [Indexed: 11/27/2022]
|
15
|
Bagnaresi P, Barros NM, Assis DM, Melo PM, Fonseca RG, Juliano MA, Pesquero JB, Juliano L, Rosenthal PJ, Carmona AK, Gazarini ML. Intracellular proteolysis of kininogen by malaria parasites promotes release of active kinins. Malar J 2012; 11:156. [PMID: 22564457 PMCID: PMC3407703 DOI: 10.1186/1475-2875-11-156] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/07/2012] [Indexed: 01/22/2023] Open
Abstract
Background The malaria burden remains a major public health concern, especially in sub-Saharan Africa. The complex biology of Plasmodium, the apicomplexan parasite responsible for this disease, challenges efforts to develop new strategies to control the disease. Proteolysis is a fundamental process in the metabolism of malaria parasites, but roles for proteases in generating vasoactive peptides have not previously been explored. Results In the present work, it was demonstrated by mass spectrometry analysis that Plasmodium parasites (Plasmodium chabaudi and Plasmodium falciparum) internalize and process plasma kininogen, thereby releasing vasoactive kinins (Lys-BK, BK and des-Arg9-BK) that may mediate haemodynamic alterations during acute malaria. In addition, it was demonstrated that the P. falciparum cysteine proteases falcipain-2 and falcipain-3 generated kinins after incubation with human kininogen, suggesting that these enzymes have an important role in this process. The biologic activity of peptides released by Plasmodium parasites was observed by measuring ileum contraction and activation of kinin receptors (B1 and B2) in HUVEC cells; the peptides elicited an increase in intracellular calcium, measured by Fluo-3 AM fluorescence. This effect was suppressed by the specific receptor antagonists Des-Arg9[Leu8]-BK and HOE-140. Conclusions In previously undescribed means of modulating host physiology, it was demonstrated that malaria parasites can generate active kinins by proteolysis of plasma kininogen.
Collapse
Affiliation(s)
- Piero Bagnaresi
- Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo, 669 - 7 andar, 04039-032, São Paulo, Brazil
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Dalal S, Ragheb DRT, Klemba M. Engagement of the S1, S1' and S2' subsites drives efficient catalysis of peptide bond hydrolysis by the M1-family aminopeptidase from Plasmodium falciparum. Mol Biochem Parasitol 2012; 183:70-7. [PMID: 22348949 DOI: 10.1016/j.molbiopara.2012.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 02/02/2012] [Accepted: 02/06/2012] [Indexed: 12/19/2022]
Abstract
The M1-family aminopeptidase PfA-M1 catalyzes the last step in the catabolism of human hemoglobin to amino acids in the Plasmodium falciparum food vacuole. In this study, the structural features of the substrate that promote efficient PfA-M1-catalyzed peptide bond hydrolysis were analyzed. X-Ala and Ala-X dipeptide substrates were employed to characterize the specificities of the enzyme's S1 and S1' subsites. Both subsites exhibited a preference for basic and hydrophobic sidechains over polar and acidic sidechains. The relative specificity of the S1 subsite was similar over the pH range 5.5-7.5. Substrate P1 and P1' residues affected both K(m) and k(cat), revealing that sidechain-subsite interactions not only drive the formation of the Michaelis complex but also influence the rates of ensuing chemical steps. Only a small fraction of the available binding energy was exploited in interactions between substrate sidechains and the S1 and S1' subsites, which indicates a modest level of complementarity. There was no correlation between S1 and S1' specificities and amino acid abundance in hemoglobin. Interactions between PfA-M1 and the backbone atoms of the P1' and P2' residues as well as the P2' sidechain further contributed to the catalytic efficiency of substrate hydrolysis. By demonstrating the engagement of multiple, broad-specificity subsites in PfA-M1, these studies provide insight into how this enzyme is able to efficiently generate amino acids from highly sequence-diverse di- and oligopeptides in the food vacuole.
Collapse
Affiliation(s)
- Seema Dalal
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | | | | |
Collapse
|
17
|
Bestatin-based chemical biology strategy reveals distinct roles for malaria M1- and M17-family aminopeptidases. Proc Natl Acad Sci U S A 2011; 108:E526-34. [PMID: 21844374 DOI: 10.1073/pnas.1105601108] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Malaria causes worldwide morbidity and mortality, and while chemotherapy remains an excellent means of malaria control, drug-resistant parasites necessitate the discovery of new antimalarials. Peptidases are a promising class of drug targets and perform several important roles during the Plasmodium falciparum erythrocytic life cycle. Herein, we report a multidisciplinary effort combining activity-based protein profiling, biochemical, and peptidomic approaches to functionally analyze two genetically essential P. falciparum metallo-aminopeptidases (MAPs), PfA-M1 and Pf-LAP. Through the synthesis of a suite of activity-based probes (ABPs) based on the general MAP inhibitor scaffold, bestatin, we generated specific ABPs for these two enzymes. Specific inhibition of PfA-M1 caused swelling of the parasite digestive vacuole and prevented proteolysis of hemoglobin (Hb)-derived oligopeptides, likely starving the parasite resulting in death. In contrast, inhibition of Pf-LAP was lethal to parasites early in the life cycle, prior to the onset of Hb degradation suggesting that Pf-LAP has an essential role outside of Hb digestion.
Collapse
|
18
|
Ragheb D, Dalal S, Bompiani KM, Ray WK, Klemba M. Distribution and biochemical properties of an M1-family aminopeptidase in Plasmodium falciparum indicate a role in vacuolar hemoglobin catabolism. J Biol Chem 2011; 286:27255-65. [PMID: 21659511 DOI: 10.1074/jbc.m111.225318] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Aminopeptidases catalyze N-terminal peptide bond hydrolysis and occupy many diverse roles across all domains of life. Here we present evidence that an M1-family aminopeptidase, PfA-M1, has been recruited to specialized roles in the human malaria parasite Plasmodium falciparum. PfA-M1 is abundant in two subcellular compartments in asexual intraerythrocytic parasites; that is, the food vacuole, where the catabolism of host hemoglobin takes place, and the nucleus. A unique N-terminal extension contributes to the observed dual targeting by providing a signal peptide and putative alternate translation initiation sites. PfA-M1 exists as two major isoforms, a nuclear 120-kDa species and a processed species consisting of a complex of 68- and 35-kDa fragments. PfA-M1 is both stable and active at the acidic pH of the food vacuole lumen. Determination of steady-state kinetic parameters for both aminoacyl-β-naphthylamide and unmodified dipeptide substrates over the pH range 5.0-8.5 reveals that k(cat) is relatively insensitive to pH, whereas K(m) increases at pH values below 6.5. At the pH of the food vacuole lumen (5.0-5.5), the catalytic efficiency of PfA-M1 remains high. Consistent with the kinetic data, the affinity of peptidic competitive inhibitors is diminished at acidic pH. Together, these results support a catalytic role for PfA-M1 in the food vacuole and indicate the importance of evaluating the potency of peptidic inhibitors at physiologically relevant pH values. They also suggest a second, distinct function for this enzyme in the parasite nucleus.
Collapse
Affiliation(s)
- Daniel Ragheb
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | | | | | | | | |
Collapse
|
19
|
Deu E, Leyva MJ, Albrow VE, Rice MJ, Ellman JA, Bogyo M. Functional studies of Plasmodium falciparum dipeptidyl aminopeptidase I using small molecule inhibitors and active site probes. ACTA ACUST UNITED AC 2011; 17:808-19. [PMID: 20797610 DOI: 10.1016/j.chembiol.2010.06.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 06/20/2010] [Accepted: 06/25/2010] [Indexed: 11/26/2022]
Abstract
The widespread resistance of malaria parasites to all affordable drugs has made the identification of new targets urgent. Dipeptidyl aminopeptidases (DPAPs) represent potentially valuable new targets that are involved in hemoglobin degradation (DPAP1) and parasite egress (DPAP3). Here we use activity-based probes to demonstrate that specific inhibition of DPAP1 by a small molecule results in the formation of an immature trophozoite that leads to parasite death. Using computational methods, we designed stable, nonpeptidic covalent inhibitors that kill Plasmodium falciparum at low nanomolar concentrations. These compounds show signs of slowing parasite growth in a murine model of malaria, which suggests that DPAP1 might be a viable antimalarial target. Interestingly, we found that resynthesis and activation of DPAP1 after inhibition is rapid, suggesting that effective drugs would need to sustain DPAP1 inhibition for a period of 2-3 hr.
Collapse
Affiliation(s)
- Edgar Deu
- Department of Pathology, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
| | | | | | | | | | | |
Collapse
|
20
|
Identification of a mutant PfCRT-mediated chloroquine tolerance phenotype in Plasmodium falciparum. PLoS Pathog 2010; 6:e1000887. [PMID: 20485514 PMCID: PMC2869323 DOI: 10.1371/journal.ppat.1000887] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 04/01/2010] [Indexed: 11/20/2022] Open
Abstract
Mutant forms of the Plasmodium falciparum transporter PfCRT constitute the key determinant of parasite resistance to chloroquine (CQ), the former first-line antimalarial, and are ubiquitous to infections that fail CQ treatment. However, treatment can often be successful in individuals harboring mutant pfcrt alleles, raising questions about the role of host immunity or pharmacokinetics vs. the parasite genetic background in contributing to treatment outcomes. To examine whether the parasite genetic background dictates the degree of mutant pfcrt-mediated CQ resistance, we replaced the wild type pfcrt allele in three CQ-sensitive strains with mutant pfcrt of the 7G8 allelic type prevalent in South America, the Oceanic region and India. Recombinant clones exhibited strain-dependent CQ responses that ranged from high-level resistance to an incremental shift that did not meet CQ resistance criteria. Nonetheless, even in the most susceptible clones, 7G8 mutant pfcrt enabled parasites to tolerate CQ pressure and recrudesce in vitro after treatment with high concentrations of CQ. 7G8 mutant pfcrt was found to significantly impact parasite responses to other antimalarials used in artemisinin-based combination therapies, in a strain-dependent manner. We also report clinical isolates from French Guiana that harbor mutant pfcrt, identical or related to the 7G8 haplotype, and manifest a CQ tolerance phenotype. One isolate, H209, harbored a novel PfCRT C350R mutation and demonstrated reduced quinine and artemisinin susceptibility. Our data: 1) suggest that high-level CQR is a complex biological process dependent on the presence of mutant pfcrt; 2) implicate a role for variant pfcrt alleles in modulating parasite susceptibility to other clinically important antimalarials; and 3) uncover the existence of a phenotype of CQ tolerance in some strains harboring mutant pfcrt. Plasmodium falciparum resistance to the antimalarial drug chloroquine has been found to result primarily from point mutations in PfCRT, which provide a highly sensitive marker of in vivo treatment failure and in vitro resistance. Debate has nonetheless continued about the singular role of mutant PfCRT and the contribution of the parasite genetic background. To address this, we have generated recombinant P. falciparum lines expressing a mutant pfcrt allele, or the reference wild type allele, in three distinct chloroquine-sensitive strains. Their analysis reveals a spectrum of responses ranging from high-level resistance to a previously unrecognized tolerance phenotype. The latter is characterized by virtually unchanged chloroquine IC50 values, significantly elevated IC90 values, and the ability to recrudesce after exposure to drug concentrations that are lethal to chloroquine-sensitive parasites. This tolerance phenotype was also observed in an isolate from French Guiana, confirming its presence in malaria-endemic regions. Mutant PfCRT significantly affected parasite responses to other antimalarials, including ones used in artemisinin-based combination therapies, in a strain-dependent manner. Our data suggest that successful CQ treatment of drug-resistant parasites is dependent on both host immunity and the strain-dependent extent to which mutant pfcrt imparts resistance.
Collapse
|