Multiple sites on SARS‐CoV‐2 spike protein are susceptible to proteolysis by cathepsins B,K, L,S, and V

SARS‐CoV‐2 is the coronavirus responsible for the COVID‐19 pandemic. Proteases are central to the infection process of SARS‐CoV‐2. Cleavage of the spike protein on the virus''s capsid causes the conformational change that leads to membrane fusion and viral entry into the target cell. Since inhibition of one protease, even the dominant protease like TMPRSS2, may not be sufficient to block SARS‐CoV‐2 entry into cells, other proteases that may play an activating role and hydrolyze the spike protein must be identified. We identified amino acid sequences in all regions of spike protein, including the S1/S2 region critical for activation and viral entry, that are susceptible to cleavage by furin and cathepsins B, K, L, S, and V using PACMANS, a computational platform that identifies and ranks preferred sites of proteolytic cleavage on substrates, and verified with molecular docking analysis and immunoblotting to determine if binding of these proteases can occur on the spike protein that were identified as possible cleavage sites. Together, this study highlights cathepsins B, K, L, S, and V for consideration in SARS‐CoV‐2 infection and presents methodologies by which other proteases can be screened to determine a role in viral entry. This highlights additional proteases to be considered in COVID‐19 studies, particularly regarding exacerbated damage in inflammatory preconditions where these proteases are generally upregulated.     

Building an efficient intrusion detection system using grasshopper optimization algorithm for anomaly detection

Cluster Computing - Intrusion detection is one of the most crucial activities for security infrastructures in network environments, and it is widely used to detect, identify and track malicious...     

Blockchain-based e-cheque clearing framework with trust based consensus mechanism

Cluster Computing - The cheque based banking transactions are widely used all over the world. The reason is that it is a hustle free and trusted way of money transaction. The existing cheque...     

Genomic safe harbors permit high β-globin transgene expression in thalassemia induced pluripotent stem cells

Realizing the therapeutic potential of human induced pluripotent stem (iPS) cells will require robust, precise and safe strategies for genetic modification, as cell therapies that rely on randomly integrated transgenes pose oncogenic risks. Here we describe a strategy to genetically modify human iPS cells at 'safe harbor' sites in the genome, which fulfill five criteria based on their position relative to contiguous coding genes, microRNAs and ultraconserved regions. We demonstrate that ～10% of integrations of a lentivirally encoded β-globin transgene in β-thalassemia-patient iPS cell clones meet our safe harbor criteria and permit high-level β-globin expression upon erythroid differentiation without perturbation of neighboring gene expression. This approach, combining bioinformatics and functional analyses, should be broadly applicable to introducing therapeutic or suicide genes into patient-specific iPS cells for use in cell therapy.     

Structural and biological study of synthesized anthraquinone series of compounds with sulfonamide feature

Abstract

1, 4 and 5, 8-Positions as well as type of functionalities on these positions at anthraquinone-9, 10-dione are proposed to be significant for anticancer activity. Therefore, keeping this into consideration, a series of 1-substituted anthraquinone-based compounds are designed, synthesized, characterized and biologically evaluated for anticancer activity. The structure of synthesized compounds is confirmed by spectroscopic analysis, i.e. 1D (¹H and ¹³C) nuclear magnetic resonance (NMR), electrospray ionization-mass spectrometry (ESI-MS) studies and Fourier transform infrared (FT-IR) tools. Synthesized 1-substituted anthraquinone compounds showed cytotoxic effect against human breast cancer cell line (MCF-7), human prostate cancer cell line (PC-3) and Hela derivative human cell line (Hep 2C) (Hela derivative) cell lines. All the compounds showed mild antibacterial property in comparison to standard antibiotic streptomycin against Gram?+?ve and –ve bacteria. They also exhibit mild antifungal activity. In vitro calf thymus (ct)-DNA binding studies of synthesized series using UV–visible absorption spectra measurement and fluorescence tools indicate partial intercalative mode of binding. Electronic properties of synthesized analogues and mitoxantrone are compared using highest occupied molecular orbital–lowest occupied molecular orbital (HOMO–LUMO) calculation. Low energy gap between HOMO and LUMO of 1-substituted anthraquinone compounds indicates the highly charged structure of the molecules in comparison to mitoxantrone, and the same is proposed to be responsible for comparable cytotoxic activities of the synthesized 1-substituted anthraquinone molecules. Docking interaction of synthesized 1-substituted anthraquinone compounds and i-motif sequence indicates intercalative mode of binding of compounds with telomeric junction.

Communicated by Ramaswamy H. Sarma     

Manipulating substrate and pH in zymography protocols selectively distinguishes cathepsins K, L, S, and V activity in cells and tissues

Cathepsins K, L, S, and V are cysteine proteases that have been implicated in tissue-destructive diseases such as atherosclerosis, tumor metastasis, and osteoporosis. Among these four cathepsins are the most powerful human collagenases and elastases, and they share 60% sequence homology. Proper quantification of mature, active cathepsins has been confounded by inhibitor and reporter substrate cross-reactivity, but is necessary to develop properly dosed therapeutic applications. Here, we detail a method of multiplex cathepsin zymography to detect and distinguish the activity of mature cathepsins K, L, S, and V by exploiting differences in individual cathepsin substrate preferences, pH effects, and electrophoretic mobility under non-reducing conditions. Specific identification of cathepsins K, L, S, and V in one cell/tissue extract was obtained with cathepsin K (37 kDa), V (35 kDa), S (25 kDa), and L (20 kDa) under non-reducing conditions. Cathepsin K activity disappeared and V remained when incubated at pH 4 instead of 6. Application of this antibody free, species independent, and medium-throughput method was demonstrated with primary human monocyte-derived macrophages and osteoclasts, endothelial cells stimulated with inflammatory cytokines, and normal and cancer lung tissues, which identified elevated cathepsin V in lung cancer.     

Integrative Pathway-Based Approach for Genome-Wide Association Studies: Identification of New Pathways for Rheumatoid Arthritis and Type 1 Diabetes

Genome-wide association studies (GWAS) led to the identification of numerous novel loci for a number of complex diseases. Pathway-based approaches using genotypic data provide tangible leads which cannot be identified by single marker approaches as implemented in GWAS. The available pathway analysis approaches mainly differ in the employed databases and in the applied statistics for determining the significance of the associated disease markers.So far, pathway-based approaches using GWAS data failed to consider the overlapping of genes among different pathways or the influence of protein–interactions. We performed a multistage integrative pathway (MIP) analysis on three common diseases - Crohn''s disease (CD), rheumatoid arthritis (RA) and type 1 diabetes (T1D) - incorporating genotypic, pathway, protein- and domain-interaction data to identify novel associations between these diseases and pathways. Additionally, we assessed the sensitivity of our method by studying the influence of the most significant SNPs on the pathway analysis by removing those and comparing the corresponding pathway analysis results. Apart from confirming many previously published associations between pathways and RA, CD and T1D, our MIP approach was able to identify three new associations between disease phenotypes and pathways. This includes a relation between the influenza-A pathway and RA, as well as a relation between T1D and the phagosome and toxoplasmosis pathways. These results provide new leads to understand the molecular underpinnings of these diseases.The developed software herein used is available at http://www.cogsys.cs.uni-tuebingen.de/software/GWASPathwayIdentifier/index.htm.