Prolylisoxazoles: potent inhibitors of prolyloligopeptidase with antitrypanosomal activity

Bal, Gunther; Veken, Pieter Van der; Antonov, Dimitri; Lambeir, Anne‐Marie; Grellier, Philippe; Croft, Simon L.; Augustyns, Koen; Haemers, Achiel

doi:10.1016/s0960-894x(03)00579-1

“…Oligopeptidase B (OPB) 2 has been identified in other protozoa, including T. cruzi, Trypanosoma brucei, and Trypanosoma evansi (7-9). These enzymes represent a subfamily of potential chemotherapeutic targets (10) because their inhibitors have been shown to be trypanocidal (4,11,12). OPB of T. cruzi is involved in the invasion of host cells through the generation of an unknown signaling ligand that interacts with host cells in order to recruit lysosomes to their surface (7).…”

mentioning

confidence: 99%

The Oligopeptidase B of Leishmania Regulates Parasite Enolase and Immune Evasion

Swenerton¹,

Zhang²,

Sajid

³

et al. 2011

Journal of Biological Chemistry

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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 antiparasitic 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.Proteases are a ubiquitous group of enzymes functioning in nearly all biological phenomena. In protozoan parasites, proteases play key roles in life cycle transition, host invasion, parasite immune evasion, and the pathogenesis of parasitic diseases (1, 2). At least 50 cysteine proteases and twenty serine proteases are known to exist in the Leishmania genome (3-5).The molecular evolution of proteases shows a striking dichotomy between the predominant Clan CA cysteine proteases of protozoa and primitive metazoa and the dominant trypsin family (S1A) serine proteases of vertebrates (6). It was therefore unexpected to find that Leishmania donovani, Leishmania major, and Leishmania mexicana (but not the related kinetoplastid parasite, Trypanosoma cruzi) express high levels of serine protease activity, relative to cysteine protease activity in parasite extracts.To delineate the character of this serine protease activity, it was purified from Leishmania extracts and identified as Clan SC, family S9A oligopeptidase B by mass spectrometry. Oligopeptidase B (OPB) 2 has been identified in other protozoa, including T. cruzi, Trypanosoma brucei, and Trypanosoma evansi (7-9). These enzymes represent a subfamily of potential chemotherapeutic targets (10) because their inhibitors have been shown to be trypanocidal (4,11,12). OPB of T. cruzi is i...

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“…Our research has shown that Leishmania parasites contain an unusual subtilisin-like enzyme that governs the levels of key peroxidases in the trypanothione reductase system. This serine protease, therefore, represents a potential target for rational drug design (39,40).…”

Section: Discussionmentioning

confidence: 99%

Leishmania Subtilisin Is a Maturase for the Trypanothione Reductase System and Contributes to Disease Pathology

Swenerton

¹

,

Knudsen

²

,

Sajid

³

et al. 2010

Journal of Biological Chemistry

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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 druggable targets for the development of new antiparasitic therapy. The subtilisin protease (SUB; Clan SB, family S8) of Leishmania donovani was cloned and found to possess a unique catalytic triad. This gene was then deleted by gene knock-out, which resulted in reduced ability by the parasite to undergo promastigote to amastigote differentiation in vitro. Electron microscopy of SUB knock-out amastigotes revealed abnormal membrane structures, retained flagella, and increased binucleation. SUB-deficient Leishmania displayed reduced virulence in both hamster and murine infection models. Histology of spleens from SUB knock-out-infected hamsters revealed the absence of psammoma body calcifications indicative of the granulomatous lesions that occur during Leishmania infection. To delineate the specific role of SUB in parasite physiology, twodimensional gel electrophoresis was carried out on SUB ؊/؊ versus wild-type parasites. SUB knock-out parasites showed altered regulation of the terminal peroxidases of the trypanothione reductase system. Leishmania and other trypanosomatids lack glutathione reductase, and therefore rely on the novel trypanothione reductase system to detoxify reactive oxygen intermediates and to maintain redox homeostasis. The predominant tryparedoxin peroxidases were decreased in SUB ؊/؊ parasites, and higher molecular weight isoforms were present, indicating altered processing. In addition, knock-out parasites showed increased sensitivity to hydroperoxide. These data suggest that subtilisin is the maturase for tryparedoxin peroxidases and is necessary for full virulence.

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“…To evaluate the possible role of POPTc80 in infection by the parasite, several specific inhibitors have been developed and tested [54,[64][65][66][67][68]. It was observed that these molecules block host cell invasion by T. cruzi trypomastigotes in a dose-dependent manner with IC 50 values ranging from 12 M for the POPTc80 inhibitor, phenylpropylcarbonyl-L-Ticpyrrolidine (see section 4), to 250 M for Z-P-prolinal dimethylacetal, the prototype inhibitor of mammalian POPs.…”

Section: Popsmentioning

confidence: 99%

“…A significant selectivity toward POPTc80 versus human POP was observed, with an index of selectivity of approximately 60 for the best one (the index is defined as Ki human POP/Ki POPTc80). Two promising compounds demonstrated in vitro inhibitory activity on the growth of different kinetoplastids known to possess POPs (T. cruzi, L. donovani and T. b. rhodesiense) with ED 50 s in a range of 2-13 g/mL [38,68]. One of them showed no cytotoxicity in KB cells.…”

Section: Development Of Drugs Against Try-panosome Pops and Opbsmentioning

confidence: 99%

Parasite Prolyl Oligopeptidases and the Challenge of Designing Chemotherapeuticals for Chagas Disease, Leishmaniasis and African Trypanosomiasis

Bastos¹,

Motta²,

Grellier³

et al. 2013

CMC

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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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Prolylisoxazoles: potent inhibitors of prolyloligopeptidase with antitrypanosomal activity

Cited by 44 publications

References 32 publications

The Oligopeptidase B of Leishmania Regulates Parasite Enolase and Immune Evasion

The Oligopeptidase B of Leishmania Regulates Parasite Enolase and Immune Evasion

Leishmania Subtilisin Is a Maturase for the Trypanothione Reductase System and Contributes to Disease Pathology

Parasite Prolyl Oligopeptidases and the Challenge of Designing Chemotherapeuticals for Chagas Disease, Leishmaniasis and African Trypanosomiasis

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