Cysteine protease inhibitors block schistosome hemoglobin degradation in vitro and decrease worm burden and egg production in vivo

1996 ◽  
Vol 81 (2) ◽  
pp. 179-189 ◽  
Author(s):  
Margaret M. Wasilewski ◽  
K.C. Lim ◽  
Jennifer Phillips ◽  
James H. McKerrow
Keyword(s):  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Worm Burden ◽  
Egg Production ◽  
Cysteine Protease Inhibitors ◽  
Hemoglobin Degradation

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.

Inhibition of Hemoglobin Degrading Protease Falcipain-2 as a Mechanism for Anti-Malarial Activity of Triazole-Amino Acid Hybrids

2020 ◽  
Vol 20 (5) ◽  
pp. 377-389 ◽  
Author(s):  
Vigyasa Singh ◽  
Rahul Singh Hada ◽  
Amad Uddin ◽  
Babita Aneja ◽  
Mohammad Abid ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cysteine Protease ◽  
Mammalian Cells ◽  
Antimalarial Activity ◽  
Docking Studies ◽  
Dependent Manner ◽  
Trophozoite Stage ◽  
Hemoglobin Degradation

Background: Novel drug development against malaria parasite over old conventional antimalarial drugs is essential due to rapid and indiscriminate use of drugs, which led to the emergence of resistant strains. Methods: In this study, previously reported triazole-amino acid hybrids (13-18) are explored against Plasmodium falciparum as antimalarial agents. Among six compounds, 15 and 18 exhibited antimalarial activity against P. falciparum with insignificant hemolytic activity and cytotoxicity towards HepG2 mammalian cells. In molecular docking studies, both compounds bind into the active site of PfFP-2 and block its accessibility to the substrate that leads to the inhibition of target protein further supported by in vitro analysis. Results: Antimalarial half-maximal inhibitory concentration (IC50) of 15 and 18 compounds were found to be 9.26 μM and 20.62 μM, respectively. Blood stage specific studies showed that compounds, 15 and 18 are effective at late trophozoite stage and block egress pathway of parasites. Decreased level of free monomeric heme was found in a dose dependent manner after the treatment with compounds 15 and 18, which was further evidenced by the reduction in percent of hemoglobin hydrolysis. Compounds 15 and 18 hindered hemoglobin degradation via intra- and extracellular cysteine protease falcipain-2 (PfFP-2) inhibitory activity both in in vitro and in vivo in P. falciparum. Conclusion: We report antimalarial potential of triazole-amino acid hybrids and their role in the inhibition of cysteine protease PfFP-2 as its mechanistic aspect.

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 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 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 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 Promethazine Exhibits Antiparasitic Properties In Vitro and Reduces Worm Burden, Egg Production, Hepatomegaly, and Splenomegaly in a Schistosomiasis Animal Model

2019 ◽  
Vol 63 (12) ◽  
Author(s):  
Daniel B. Roquini ◽  
Ramon M. Cogo ◽  
Ana C. Mengarda ◽  
Susana F. Mazloum ◽  
Cristiane S. Morais ◽  
...  
Keyword(s):  
Animal Model ◽  
Worm Burden ◽  
Egg Production ◽  
Ex Vivo ◽  
Anticholinergic Drug ◽  
Drug Repurposing ◽  
Content Type ◽  
Parasite Motility

ABSTRACT The treatment and control of schistosomiasis, a neglected disease that affects more than 200 million people worldwide, rely on the use of a single drug, praziquantel. A vaccine has yet to be developed, and since new drug design and development is a lengthy and costly process, drug repurposing is a promising strategy. In this study, the efficacy of promethazine, a first-generation antihistamine, was evaluated against Schistosoma mansoni ex vivo and in a murine model of schistosomiasis. In vitro assays demonstrated that promethazine affected parasite motility and viability, and it induced severe tegumental damage in schistosomes. The 50% lethal concentration (LC50) of the drug was 5.84 μM. Similar to promethazine, schistosomes incubated with atropine, a classical anticholinergic drug, displayed reduced motor activity. In an animal model, promethazine treatment was introduced at an oral dose of 100 mg/kg of body weight for five successive days at different intervals from the time of infection for the evaluation of the stage-specific susceptibility (prepatent and patent infections). Various parasitological criteria indicated the following in vivo antischistosomal effects of promethazine: there were significant reductions in worm burden, egg production, hepatomegaly, and splenomegaly. The highest worm burden reduction was achieved with promethazine in patent infections (>90%). Taken together, considering the importance of the repositioning of drugs in infectious diseases, especially those related to poverty, our data revealed the possibility of promethazine repositioning as an antischistosomal agent.

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