Abstract 5675: Optimization of a Seneca Valley Virus (SVV) 3C protease substrate for virus-directed enzyme prodrug therapy.

Author(s):  
Linde A. Miles ◽  
John T. Poirier ◽  
Charles M. Rudin
2019 ◽  
Vol 400 (3) ◽  
pp. 405-415
Author(s):  
Sebastian W. Meister ◽  
Natalie M. Hendrikse ◽  
John Löfblom

Abstract Proteases are crucial for regulating biological processes in organisms through hydrolysis of peptide bonds. Recombinant proteases have moreover become important tools in biotechnological, and biomedical research and as therapeutics. We have developed a label-free high-throughput method for quantitative assessment of proteolytic activity in Escherichia coli. The screening method is based on co-expression of a protease of interest and a reporter complex. This reporter consists of an aggregation-prone peptide fused to a fluorescent protein via a linker that contains the corresponding substrate sequence. Cleavage of the substrate rescues the fluorescent protein from aggregation, resulting in increased fluorescence that correlates to proteolytic activity, which can be monitored using flow cytometry. In one round of flow-cytometric cell sorting, we isolated an efficiently cleaved tobacco etch virus (TEV) substrate from a 1:100 000 background of non-cleavable sequences, with around 6000-fold enrichment. We then engineered the 3C protease from coxsackievirus B3 (CVB3 3Cpro) towards improved proteolytic activity on the substrate LEVLFQ↓GP. We isolated highly proteolytic active variants from a randomly mutated CVB3 3Cpro library with up to 4-fold increase in activity. The method enables simultaneous measurement of proteolytic activity and protease expression levels and can therefore be applied for protease substrate profiling, as well as directed evolution of proteases.


2018 ◽  
Vol 160 ◽  
pp. 183-189 ◽  
Author(s):  
Qiao Xue ◽  
Huisheng Liu ◽  
Zixiang Zhu ◽  
Fan Yang ◽  
Qinghong Xue ◽  
...  

2020 ◽  
Vol 11 ◽  
Author(s):  
Wei Wen ◽  
Qiongqiong Zhao ◽  
Mengge Yin ◽  
Liuxing Qin ◽  
Junjie Hu ◽  
...  

2021 ◽  
pp. ji2001030
Author(s):  
Wei Wen ◽  
Xiangmin Li ◽  
Haoyuan Wang ◽  
Qiongqiong Zhao ◽  
Mengge Yin ◽  
...  

Author(s):  
Rakhi Dhankhar ◽  
Anubhuti Kawatra ◽  
Aparajita Mohanty ◽  
Pooja Gulati

Abstract:: Enzyme prodrug therapy has gained momentum in the recent years due to their ability to improve therapeutic index (benefits versus toxic side-effects) and efficacy of chemotherapy in cancer treatment. Inactive prodrugs used in this system are converted into active anti-cancerous drugs by enzymes, specifically within the tumor cells. This therapy involves three components namely prodrug, enzyme and gene delivery vector. Past reports have clearly indicated that the choice of enzyme used, is the major determinant for the success of this therapy. Generally, enzymes from non-human sources are employed to avoid off-target toxicity. Exogenous enzymes also give a better control to the clinician regarding the calibration of treatment by site-specific initiation. Amongst these exo-enzymes, microbial enzymes are preferred due to their high productivity, stability and ease of manipulation. The present review focuses on the commonly used microbial enzymes particularly cytosine deaminase, nitroreductase, carboxypeptidase, purine nucleoside phosphorylase in prodrug activation therapy. Various aspects viz. source of the enzymes, types of cancer targeted, mode of action and efficacy of the enzyme/prodrug system, efficient vectors used and recent research developments of each of these enzymes are comprehensively elaborated. Further, the results of the clinical trials and various strategies to improve their clinical applicability are also discussed.


Author(s):  
Ravinder Sharma ◽  
Pooja A. Chawla ◽  
Viney Chawla ◽  
Rajeev Verma ◽  
Nandita Nawal ◽  
...  

Abstract: A sizeable proportion of currently marketed drugs come from heterocycles. The heterocyclic moiety 5-pyrazolone is well known five membered ring containing nitrogen. Derivatives of this wonder nucleus have exhibited activities as diverse as antimicrobial, anti-inflammatory, analgesic, antidepressant, anticonvulsant, antidiabetic, antihyperlipidemic, antiviral, antitubercular, antioxidant, anticancer and antiviral including action against severe acute respiratory syndrome (SARS) or 3C protease inhibitor. A number of drugs based on this motif have already made it to the market. Standard texts and literature on medicinal chemistry cite different approaches for the synthesis of 5-pyrazolones. The present review provides an insight view to 5-pyrazolone synthesis, their biological profile and structure activity relationship studies.


1994 ◽  
Vol 68 (9) ◽  
pp. 5384-5394 ◽  
Author(s):  
L Matusick-Kumar ◽  
W Hurlburt ◽  
S P Weinheimer ◽  
W W Newcomb ◽  
J C Brown ◽  
...  

2021 ◽  
Vol 22 (15) ◽  
pp. 7906
Author(s):  
Alexey A. Komissarov ◽  
Maria A. Karaseva ◽  
Marina P. Roschina ◽  
Andrey V. Shubin ◽  
Nataliya A. Lunina ◽  
...  

Regulated cell death (RCD) is a fundamental process common to nearly all living beings and essential for the development and tissue homeostasis in animals and humans. A wide range of molecules can induce RCD, including a number of viral proteolytic enzymes. To date, numerous data indicate that picornaviral 3C proteases can induce RCD. In most reported cases, these proteases induce classical caspase-dependent apoptosis. In contrast, the human hepatitis A virus 3C protease (3Cpro) has recently been shown to cause caspase-independent cell death accompanied by previously undescribed features. Here, we expressed 3Cpro in HEK293, HeLa, and A549 human cell lines to characterize 3Cpro-induced cell death morphologically and biochemically using flow cytometry and fluorescence microscopy. We found that dead cells demonstrated necrosis-like morphological changes including permeabilization of the plasma membrane, loss of mitochondrial potential, as well as mitochondria and nuclei swelling. Additionally, we showed that 3Cpro-induced cell death was efficiently blocked by ferroptosis inhibitors and was accompanied by intense lipid peroxidation. Taken together, these results indicate that 3Cpro induces ferroptosis upon its individual expression in human cells. This is the first demonstration that a proteolytic enzyme can induce ferroptosis, the recently discovered and actively studied type of RCD.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Rodrigo Ochoa ◽  
Mikhail Magnitov ◽  
Roman A. Laskowski ◽  
Pilar Cossio ◽  
Janet M. Thornton

Abstract Background Proteases are key drivers in many biological processes, in part due to their specificity towards their substrates. However, depending on the family and molecular function, they can also display substrate promiscuity which can also be essential. Databases compiling specificity matrices derived from experimental assays have provided valuable insights into protease substrate recognition. Despite this, there are still gaps in our knowledge of the structural determinants. Here, we compile a set of protease crystal structures with bound peptide-like ligands to create a protocol for modelling substrates bound to protease structures, and for studying observables associated to the binding recognition. Results As an application, we modelled a subset of protease–peptide complexes for which experimental cleavage data are available to compare with informational entropies obtained from protease–specificity matrices. The modelled complexes were subjected to conformational sampling using the Backrub method in Rosetta, and multiple observables from the simulations were calculated and compared per peptide position. We found that some of the calculated structural observables, such as the relative accessible surface area and the interaction energy, can help characterize a protease’s substrate recognition, giving insights for the potential prediction of novel substrates by combining additional approaches. Conclusion Overall, our approach provides a repository of protease structures with annotated data, and an open source computational protocol to reproduce the modelling and dynamic analysis of the protease–peptide complexes.


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