scholarly journals Trypanosomatid cysteine protease activity may be enhanced by a kininogen-like moiety from host serum

1995 ◽  
Vol 305 (2) ◽  
pp. 549-556 ◽  
Author(s):  
J D Lonsdale-Eccles ◽  
G W N Mpimbaza ◽  
Z R M Nkhungulu ◽  
J Olobo ◽  
L Smith ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Leishmania Donovani ◽  
Leishmania Major ◽  
Cysteine Proteases ◽  
Cysteine Protease Inhibitor ◽  
Cysteine Protease Inhibitors ◽  
African Trypanosomes

African trypanosomes contain cysteine proteases (trypanopains) the activity of which can be measured by in vitro digestion of fibrinogen, after electrophoresis in fibrinogen-containing SDS/polyacrylamide gels. When assessed by this procedure, trypanopain from Trypanosoma brucei (trypanopain-Tb) is estimated to have a molecular mass of 28 kDa. However, two additional bands of trypanopain activity (87 kDa and 105 kDa) are observed if serum is added to the trypanopain before electrophoresis. Formation of the 87 and 105 kDa bands is frequently accompanied by a reduction in the intensity of the 28 kDa activity which suggests that the extra bands are complexes of the 28 kDa trypanopain-Tb and a molecule from rat serum called rat trypanopain moledulator (rTM). The rTM-induced activation of cysteine proteases is not restricted to T. brucei as it is also observed with proteases from other protozoan parasites such as bloodstream forms of Trypanosoma congolense and the mammalian-infective in vitro-derived promastigote forms of Leishmania donovani and Leishmania major. The physical properties of rTM resemble those of the kininogen family of cysteine protease inhibitors. rTM is an acidic (pI 4.7) heat-stable 68 kDa glycoprotein with 15 kDa protease-susceptible domains. This resemblance between rTM and kininogens was confirmed by the positive, albeit weak, immunoreactivity between anti-(human low-molecular-mass kininogen) antibody and rTM as well as anti-rTM antibody and human low-molecular-mass kininogen. Furthermore, commercial preparations of human-low-molecular-mass kininogen and chicken egg white cystatin mimicked rTM by forming extra bands of proteolytic activity in the presence of trypanopain-Tb. In some instances, low-molecular-mass kininogen was also observed to increase the rate of hydrolysis of 7-(benzyloxycarbonyl-phenylalanyl-arginyl-amido)-4- methylcoumarin by live T. brucei. Although this effect was rather erratic, in no instance was significant inhibition observed when this putative cysteine protease inhibitor was used under these conditions. The activation of parasite cysteine proteases by commonly accepted cysteine protease inhibitors is unexpected and may have important pathological repercussions.

scholarly journals Studies of Inhibitory Mechanisms of Propeptide-Like Cysteine Protease Inhibitors

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Bui T. T. Nga ◽  
Yuki Takeshita ◽  
Misa Yamamoto ◽  
Yoshimi Yamamoto
Keyword(s):  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Cathepsin L ◽  
Cysteine Residue ◽  
Cysteine Protease Inhibitor ◽  
Inhibition Mechanism ◽  
Cysteine Protease Inhibitors ◽  
Inhibitory Potency ◽  
Inhibitory Mechanisms

Mouse cytotoxic T-lymphocyte antigen-2α (CTLA-2α), Drosophila CTLA-2-like protein (crammer), and Bombyx cysteine protease inhibitor (BCPI) belong to a novel family of cysteine protease inhibitors (I29). Their inhibitory mechanisms were studied comparatively. CTLA-2α contains a cysteine residue (C75), which is essential for its inhibitory potency. The CTLA-2α monomer was converted to a disulfide-bonded dimer in vitro and in vivo. The dimer was fully inhibitory, but the monomer, which possessed a free thiol residue, was not. A disulfide-bonded CTLA-2α/cathepsin L complex was isolated, and a cathepsin L subunit with a molecular weight of 24,000 was identified as the interactive enzyme protein. Crammer also contains a cysteine residue (C72). Both dimeric and monomeric forms of crammer were inhibitory. A crammer mutant with Cys72 to alanine (C72A) was fully inhibitory, while the replacement of Gly73 with alanine (G73A) caused a significant loss in inhibitory potency, which suggests a different inhibition mechanism from CTLA-2α. BCPI does not contain cysteine residue. C-terminal region (L77-R80) of BCPI was essential for its inhibitory potency. CTLA-2α was inhibitory in the acidic pH condition but stabilized cathepsin L under neutral pH conditions. The different inhibition mechanisms and functional considerations of these inhibitors are discussed.

scholarly journals A Phytophthora palmivora Extracellular Cystatin-Like Protease Inhibitor Targets Papain to Contribute to Virulence on Papaya

2018 ◽  
Vol 31 (3) ◽  
pp. 363-373 ◽  
Author(s):  
Rebecca Gumtow ◽  
Dongliang Wu ◽  
Janice Uchida ◽  
Miaoying Tian
Keyword(s):  
Protease Inhibitor ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Gene Editing ◽  
Sequence Data ◽  
Cysteine Protease Inhibitor ◽  
Phytophthora Palmivora ◽  
Cysteine Protease Inhibitors ◽  
Successful Infection

Papaya fruits, stems, and leaves are rich in papain, a cysteine protease that has been shown to mediate plant defense against pathogens and insects. Yet the oomycete Phytophthora palmivora is a destructive pathogen that infects all parts of papaya plants, suggesting that it has evolved cysteine protease inhibitors to inhibit papain to enable successful infection. Out of five putative extracellular cystatin-like cysteine protease inhibitors (PpalEPICs) from P. palmivora transcriptomic sequence data, PpalEPIC8 appeared to be unique to P. palmivora and was highly induced during infection of papaya. Purified recombinant PpalEPIC8 strongly inhibited papain enzyme activity, suggesting that it is a functional cysteine protease inhibitor. Homozygous PpalEPIC8 mutants were generated using CRISPR/Cas9-mediated gene editing via Agrobacterium-mediated transformation (AMT). Increased papain sensitivity of in-vitro growth and reduced pathogenicity during infection of papaya fruits were observed for the mutants compared with the wild-type strain, suggesting that PpalEPIC8, indeed, plays a role in P. palmivora virulence by inhibiting papain. This study provided genetic evidence demonstrating that plant-pathogenic oomycetes secrete cystatins as important weapons to invade plants. It also established an effective gene-editing system for P. palmivora by the combined use of CRISPR/Cas9 and AMT, which is expected to be applicable to other oomycetes.

scholarly journals Scrapie Protein Degradation by Cysteine Proteases in CD11c+ Dendritic Cells and GT1-1 Neuronal Cells

2004 ◽  
Vol 78 (9) ◽  
pp. 4776-4782 ◽  
Author(s):  
Katarina M. Luhr ◽  
Elin K. Nordström ◽  
Peter Löw ◽  
Hans-Gustaf Ljunggren ◽  
Albert Taraboulos ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Prion Proteins ◽  
Neuronal Cell ◽  
Cysteine Proteases ◽  
Proteinase K ◽  
Cysteine Protease Inhibitors

ABSTRACT Dendritic cells (DC) of the CD11c+ myeloid phenotype have been implicated in the spread of scrapie in the host. Previously, we have shown that CD11c+ DC can cause a rapid degradation of proteinase K-resistant prion proteins (PrPSc) in vitro, indicating a possible role of these cells in the clearance of PrPSc. To determine the mechanisms of PrPSc degradation, CD11c+ DC that had been exposed to PrPSc derived from a neuronal cell line (GT1-1) infected with scrapie (ScGT1-1) were treated with a battery of protease inhibitors. Following treatment with the cysteine protease inhibitors (2S,3S)-trans-epoxysuccinyl-l-leucylamido-3-methylbutane (E-64c), its ethyl ester (E-64d), and leupeptin, the degradation of PrPSc was inhibited, while inhibitors of serine and aspartic and metalloproteases (aprotinin, pepstatin, and phosphoramidon) had no effect. An endogenous degradation of PrPSc in ScGT1-1 cells was revealed by inhibiting the expression of cellular PrP (PrPC) by RNA interference, and this degradation could also be inhibited by the cysteine protease inhibitors. Our data show that PrPSc is proteolytically cleaved preferentially by cysteine proteases in both CD11c+ DC and ScGT1-1 cells and that the degradation of PrPSc by proteases is different from that of PrPC. Interference by protease inhibitors with DC-induced processing of PrPSc has the potential to modify prion spread, clearance, and immunization in a host.

scholarly journals Structure-Function of Falcipains: Malarial Cysteine Proteases

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Kailash C. Pandey ◽  
Rajnikant Dixit
Keyword(s):  
Functional Analysis ◽  
Drug Development ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Essential Role ◽  
Cysteine Proteases ◽  
Structural Studies ◽  
Cysteine Protease Inhibitors ◽  
Hemoglobin Binding ◽  
Structural Insight

Evidence indicates that cysteine proteases play essential role in malaria parasites; therefore an obvious area of investigation is the inhibition of these enzymes to treat malaria. Studies with cysteine protease inhibitors and manipulating cysteine proteases genes have suggested a role for cysteine proteases in hemoglobin hydrolysis. The best characterizedPlasmodiumcysteine proteases are falcipains, which are papain family enzymes. Falcipain-2 and falcipain-3 are major hemoglobinases ofP. falciparum. Structural and functional analysis of falcipains showed that they have unique domains including a refolding domain and a hemoglobin binding domain. Overall, the complexes of falcipain-2 and falcipain-3 with small and macromolecular inhibitors provide structural insight to facilitate the design or modification of effective drug treatment against malaria. Drug development targeting falcipains should be aided by a strong foundation of biochemical and structural studies.

Synthesis of quinoline derivatives as potential cysteine protease inhibitors

2020 ◽  
Author(s):  
Marina MS Andrade ◽  
Luan C Martins ◽  
Gabriel VL Marques ◽  
Carla A Silva ◽  
Gilson Faria ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Inhibitory Activity ◽  
Molecular Targets ◽  
Cysteine Proteases ◽  
Leishmania Species ◽  
Molecular Target ◽  
Quinoline Derivatives ◽  
Cysteine Protease Inhibitors

Aim: Cysteine proteases are important molecular targets involved in the replication, virulence and survival of parasitic organisms, including Trypanosoma and Leishmania species. Methodology & results: Analogs of the 7-chloro- N-[3-(morpholin-4-yl)propyl]quinolin-4-amine were synthesized and their inhibitory activity against the enzymes cruzain and rhodesain as well as against promastigotes forms of Leishmania species and epimastigotes forms of Trypanosoma cruzi were evaluated. Five compounds showed activity against both enzymes with IC50 values ranging from 23 to 123 μM. Among these, compounds 3 and 4 displayed leishmanicidal activity; compound 4 was the most promising with IC50 values <10 μM and no cytotoxicity for uninfected cells. Conclusion: The results obtained indicate that cysteine proteases are likely to be the molecular target of compounds 3 and 4.

Babesia bovis: Effects of cysteine protease inhibitors on in vitro growth

2007 ◽  
Vol 117 (2) ◽  
pp. 214-217 ◽  
Author(s):  
Kazuhiro Okubo ◽  
Naoaki Yokoyama ◽  
Yadav Govind ◽  
Andy Alhassan ◽  
Ikuo Igarashi
Keyword(s):  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Babesia Bovis ◽  
In Vitro Growth ◽  
Cysteine Protease Inhibitors

scholarly journals A Tick Cysteine Protease Inhibitor RHcyst-1 Exhibits Antitumor Potential

2018 ◽  
Vol 46 (6) ◽  
pp. 2385-2400 ◽  
Author(s):  
Nana Wei ◽  
Zhibing Lin ◽  
Zhengmao Xu ◽  
Jie Cao ◽  
Yongzhi Zhou ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cysteine Protease ◽  
Tumor Therapy ◽  
Cysteine Proteases ◽  
Cysteine Protease Inhibitor ◽  
Cell Counting ◽  
Migration And Invasion ◽  
Mouse Tumor ◽  
Antitumor Effects

Background/Aims: We previously identified a potent and tight-binding inhibitor of cysteine proteases from Rhipicephalus haemaphysaloides, RHcyst-1, which belongs to the cystatin type 1 family. Cathepsins, which are members of the cysteine protease family, participate in various pathological processes, including the initiation and development of cancers. The present study aimed to investigate the antitumor effects of RHcyst-1 and to explore the underlying mechanism of these effects. Methods: Different tumor cells were treated with RHcyst-1 in vitro. Proliferation activity was evaluated using Cell Counting Kit-8, and migration and invasion were determined by wound healing and Transwell® invasion assays. In addition, a mouse tumor therapy model was established by inoculating the left forelimb of mice with B16-F10 cells, and tumor progression was evaluated by assessing tumor volume and survival. Flow cytometry was conducted to evaluate myeloid-derived suppressor cells (MDSCs), CD4+, and CD8+ T cell levels in PBMCs and spleens. Immunohistochemistry was performed to analyze immune cell infiltration and angiogenesis in the tumors. Results: RHcyst-1 significantly inhibited the proliferation, migration, and invasion of all four different tumor cells in vitro. Additionally, it inhibited tumor growth and improved survival in vivo. A decrease and an increase in MDSCs levels were observed in PBMCs and in the spleen, respectively, after RHcyst-1 application. Conclusions: Tick RHcyst-1 has potential antitumor efficacy, and the observed antitumor activities may be partly attributable to changes in cathepsin expression and MDSCs levels in the PBMCs and spleens. The findings of the present study suggest that RHcyst-1 may have the potential to be utilized in cancer treatment.

scholarly journals Apoferritin encapsulation of cysteine protease inhibitors for cathepsin L inhibition in cancer cells

RSC Advances ◽  
2019 ◽  
Vol 9 (63) ◽  
pp. 36699-36706 ◽  
Author(s):  
José C. Quilles Junior ◽  
Fernanda dos Reis Rocho Carlos ◽  
A. Montanari ◽  
Andrei Leitão ◽  
Viviane W. Mignone ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Cathepsin L ◽  
Cysteine Protease Inhibitors ◽  
Selective Uptake

Novel apoferritin encapsulated cysteine protease inhibitors are developed with enhanced and selective uptake by cancer cells, and sustained pH-induced release of the agent. The persistent inhibition of cathepsin L is demonstrated in vitro.

scholarly journals Identification, Characterization and Synthesis of Natural Parasitic Cysteine Protease Inhibitors — More Potent Falcitidin Analogs

2021 ◽  
Author(s):  
Stephan Brinkmann ◽  
Sandra Semmler ◽  
Christian Kersten ◽  
Maria A. Patras ◽  
Micheal Kurz ◽  
...  
Keyword(s):  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Therapeutic Option ◽  
In Silico Analysis ◽  
Biosynthetic Gene Cluster ◽  
Acyl Residue ◽  
Cysteine Protease Inhibitors ◽  
Protease Inhibition ◽  
Parasite Plasmodium Falciparum

Protease inhibitors represent a promising therapeutic option for the treatment of parasitic diseases such as malaria and human African trypanosomiasis. Falcitidin was the first member of a new class of inhibitors of falcipain 2, a cysteine protease of the malaria parasite Plasmodium falciparum. Using a metabolomics dataset of 25 Chitinophaga strains for molecular networking enabled identification of over 30 natural analogs of falcitidin. Based on MS/MS spectra, they vary in their amino acid chain length, sequence, acyl residue, and C terminal functionalization; therefore, they were grouped into the four falcitidin peptide families A-D. The isolation, characterization and absolute structure elucidation of two falcitidin-related pentapeptide aldehyde analogs by extensive MS/MS spectrometry and NMR spectroscopy in combination with advanced Marfey's analysis was in agreement with the in silico analysis of the corresponding biosynthetic gene cluster. Total synthesis of chosen pentapeptide analogs followed by in vitro testing against a panel of proteases revealed selective parasitic cysteine protease inhibition and additionally low-micromolar inhibition of α-chymotrypsin. The pentapeptides investigated here showed superior inhibitory activity compared to falcitidin.

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