Результаты поиска

Targeting the SARS-CoV2 nucleocapsid protein for potential therapeutics using immuno-informatics and structure-based drug discovery techniques.

The occurrence of the SARS-CoV2 infection has become a worldwide threat and the urgent need to discover therapeutic interventions remains paramount. The primary roles of the coronavirus nucleocapsid (N) protein are to interact with the viral genome and pack them into ribonucleoprotein complex. It also plays critical roles at many stages of the viral life cycle. Herein, we explore the N protein of SARS-CoV2 to identify promising epitope-based vaccine candidates and target the N-terminal domain of SARS-CoV2 N-protein for potential inhibitors using an integrative bioinformatics approach. We ident…

A novel preventive strategy against HIV-1 infection: combinatorial use of inhibitors targeting the nucleocapsid and fusion proteins.

The strategy of simultaneously attacking multiple targets is worthy of exploration in the field of microbicide development to combat HIV-1 sequence diversity and minimize the transmission of resistant variants. A combination of S-acyl-2-mercaptobenzamide thioester-10 (SAMT10), an inhibitor of the HIV-1 nucleocapsid protein (NCp7), and the fusion inhibitor sifuvirtide (SFT) may exert synergistic effects, since SFT can block viral fusion at an early stage of the viral cycle and SAMT10 can disrupt viral particles at a later stage. In this study, we investigated the effect of the combination of SA…

Динамические характеристики связующих остатков модернизируют связующие свойства нуклеиновой кислоты HIV-1 нуклеокапсидские белковые пальцы.

:: HIV-1 нуклеокапсидский белок (NC) — маленький основной протеин, содержащий two цинковые пальцы (ZF), отделенные короткой связкой. Она участвует в нескольких этапах цикла воспроизведения и выступает в качестве белка, сопровождающего нуклеиновую кислоту, в содействии переносу нуклеиновой кислотной нити во время обратной транскрипции. Недавний анализ three- размерные структуры комплексов NC-нуклеиновых кислот создали новое свойство: непараментированные гуанины, на которые распространяется НС, чаще добавляются в стерминальный цинковый палец (ZF2), чем в N-терминальный цинковый палец (ZF1). Несм

Совпадение в аннотации оригинала
The HIV-1 nucleocapsid protein (NC) is a small basic protein containing two zinc fingers (ZF) separated by a short linker. It is involved in several steps of the replication cycle and acts as a nucleic acid chaperone protein in facilitating nucleic acid strand transfers occurring during reverse transcription. Recent analysis of three-dimensional structures o…

Development of an indirect enzyme-linked immunosorbent assay based on the nucleocapsid protein of bovine parainfluenza virus type 3.

PURPOSE: Bovine parainfluenza virus type 3 (BPIV3) is an important pathogen in the bovine respiratory disease complex. The purpose of this study was to develop an efficient and rapid serological detection method, an indirect enzyme-linked immunosorbent assay (iELISA), for BPIV3. METHODS: The full-length N gene of BPIV3 was amplified from reverse-transcribed BPIV3 cDNA and ligated into the pET-28a prokaryotic expression vector. The recombinant target N protein was correctly expressed. After purification, the target N protein was used to immunize BALB/c mice to prepare polyclonal antibodies. Af

Rational design and high-yield expression of SARS-CoV-2 nucleocapsid antigen for a sensitive and specific in-house ELISA.

BACKGROUND: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a global pathogen with a high prevalence rate. Among diagnostic methods, serological assays have been effective for rapid screening and identifying a history of infection or vaccination. The nucleocapsid protein is the most conserved and immunogenic antigen of SARS-CoV-2, making it a key target for such tests. Although commercial kits are available for this purpose, a custom design with superior specificity, sensitivity, and accuracy can be both clinically and economically advantageous. In the present study, we designe…

Impact of the SARS-CoV-2 nucleocapsid 203K/204R mutations on the inflammatory immune response in COVID-19 severity.

BACKGROUND: The excessive inflammatory responses provoked by SARS-CoV-2 infection are critical factors affecting the severity and mortality of COVID-19. Previous work found that two adjacent co-occurring mutations R203K and G204R (KR) on the nucleocapsid (N) protein correlate with increased disease severity in COVID-19 patients. However, links with the host immune response remain unclear. METHODS: Here, we grouped nasopharyngeal swab samples of COVID-19 patients into two cohorts based on the presence and absence of SARS-CoV-2 nucleocapsid KR mutations. We performed nasopharyngeal transcriptom…

Determination of IgG1 and IgG3 SARS-CoV-2 Spike Protein and Nucleocapsid Binding-Who Is Binding Who and Why?

The involvement of immunoglobulin (Ig) G3 in the humoral immune response to SARS-CoV-2 infection has been implicated in the pathogenesis of acute respiratory distress syndrome (ARDS) in COVID-19. The exact molecular mechanism is unknown, but it is thought to involve this IgG subtype's differential ability to fix, complement and stimulate cytokine release. We examined the binding of convalescent patient antibodies to immobilized nucleocapsids and spike proteins by matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) mass spectrometry. IgG3 was a major immunoglobulin found in a…

Discovery and structural characterization of chicoric acid as a SARS-CoV-2 nucleocapsid protein ligand and RNA binding disruptor.

The nucleocapsid (N) protein plays critical roles in coronavirus genome transcription and packaging, representing a key target for the development of novel antivirals, and for which structural information on ligand binding is scarce. We used a novel fluorescence polarization assay to identify small molecules that disrupt the binding of the N protein to a target RNA derived from the SARS-CoV-2 genome packaging signal. Several phenolic compounds, including L-chicoric acid (CA), were identified as high-affinity N-protein ligands. The binding of CA to the N protein was confirmed by isothermal titr…

Synthesis and evaluation of 1,2,3-dithiazole inhibitors of the nucleocapsid protein of feline immunodeficiency virus (FIV) as a model for HIV infection.

We disclose a series of potent anti-viral 1,2,3-dithiazoles, accessed through a succinct synthetic approach from 4,5-dichloro-1,2,3-dithiazolium chloride (Appel's salt). A series of small libraries of compounds were screened against feline immunodeficiency virus (FIV) infected cells as a model for HIV. This approach highlighted new structure activity relationship understanding and led to the development of sub-micro molar anti-viral compounds with reduced toxicity. In addition, insight into the mechanistic progress of this system is provided via advanced QM-MM modelling. The 1,2,3-dithiazole r

Kinetics of Nucleocapsid, Spike and Neutralizing Antibodies, and Viral Load in Patients with Severe COVID-19 Treated with Convalescent Plasma.

COVID-19 is an ongoing pandemic with high morbidity and mortality. Despite meticulous research, only dexamethasone has shown consistent mort … trimeric Spike protein and the receptor-binding domain (Spike-RBD), as well as against the complete Nucleocapsid protein and the RNA binding domain (N-RBD) were determined at baseline and weekly following CP infusion. Neutralizing antibody (pseudotype NAb) titers were determined at the same time points. Viral loads were determined semi-quantitatively by SARS-C …

A nanoenzyme linked immunochromatographic sensor for rapid and quantitative detection of SARS-CoV-2 nucleocapsid protein in human blood.

The establishment of a simple, low-cost, high-sensitive and rapid immunoassay for detecting SARS-CoV-2 antigen in human blood is an effective mean of discovering early SARS-CoV-2 infection and controlling the pandemic of COVID-19. Herein, a smartphone based nanozyme linked immunochromatographic sensor (NLICS) for the detection of SARS-CoV-2 nucleocapsid protein (NP) has been developed on demand. The system is integrated by disposable immunochromatography assay (ICA) and optical sensor devices. Immunoreaction and enzyme-catalyzed substrate color reaction were carried out on the chromatographic …

Distribution and Redistribution of HIV-1 Nucleocapsid Protein in Immature, Mature, and Integrase-Inhibited Virions: a Role for Integrase in Maturation.

UNLABELLED: During virion maturation, HIV-1 capsid protein assembles into a conical core containing the viral ribonucleoprotein (vRNP) complex, thought to be composed mainly of the viral RNA and nucleocapsid protein (NC). After infection, the viral RNA is reverse transcribed into double-stranded DNA, which is then incorporated into host chromosomes by integrase (IN) catalysis. Certain IN mutations (class II) and antiviral drugs (allosteric IN inhibitors [ALLINIs]) adversely affect maturation, resulting in virions that contain "eccentric condensates," electron-dense aggregates located outside s…

An engineered non-toxic superantigen increases cross presentation of hepatitis B virus nucleocapsids by human dendritic cells.

Virus like particles (VLPs) are potent immunogens capable of priming strong protective antibody responses due to their repetitive structural arrangement and affinity for specific B cell receptors. By contrast, T cell responses to VLPs can be weak due to inefficient uptake and processing by antigen presenting cells. We report here a novel strategy for increasing the T cell reactivity of a VLP, the nucleocapsid of hepatitis B virus, through covalent coupling of M1, an engineered form of the Streptococcal superantigen SMEZ2, that binds MHC II with high affinity but lacks its T cell mitogenic capa…

Immunogenicity of a truncated enterovirus 71 VP1 protein fused to a Newcastle disease virus nucleocapsid protein fragment in mice.

Enterovirus 71 (EV71) is one of the viruses that cause hand, foot and mouth disease. Its viral capsid protein 1 (VP1), which contains many neutralization epitopes, is an ideal target for vaccine development. Recently, we reported the induction of a strong immune response in rabbits to a truncated VP1 fragment (Nt-VP1t) displayed on a recombinant Newcastle disease virus (NDV) capsid protein. Protective efficacy of this vaccine, however, can only be tested in mice, since all EV71 animal models thus far were developed in mouse systems. In this study, we evaluated the type of immune responses agai

Laboratory safe detection of nucleocapsid protein of Rift Valley fever virus in human and animal specimens by a sandwich ELISA.

A safe laboratory procedure, based on a sandwich ELISA (sAg-ELISA), was developed and evaluated for the detection of nucleocapsid protein (NP) of Rift Valley fever virus (RVFV) in specimens inactivated at 56 degrees C for 1h in the presence of 0.5% Tween-20 (v/v) before testing. Polyclonal capture and detection immune sera were generated respectively in sheep and rabbits immunized with recombinant NP antigen. The assay was highly repeatable and specific; it detected strains of RVFV from the entire distributional range of the disease, isolated over a period of 53 years; no cross-reactivity with…

Solution structure of the c-terminal dimerization domain of SARS coronavirus nucleocapsid protein solved by the SAIL-NMR method.

The C-terminal domain (CTD) of the severe acute respiratory syndrome coronavirus (SARS-CoV) nucleocapsid protein (NP) contains a potential RNA-binding region in its N-terminal portion and also serves as a dimerization domain by forming a homodimer with a molecular mass of 28 kDa. So far, the structure determination of the SARS-CoV NP CTD in solution has been impeded by the poor quality of NMR spectra, especially for aromatic resonances. We have recently developed the stereo-array isotope labeling (SAIL) method to overcome the size problem of NMR structure determination by utilizing a protein e…

Acidic domain of the phosphoprotein (P) of vesicular stomatitis virus differentially interacts with homologous and heterologous nucleocapsid protein (N).

The homologous and heterologous interactions between the nucleocapsid protein N and the phosphoprotein P of New Jersey and Indiana serotypes of vesicular stomatitis virus were studied. SP6 derived N and P mRNAs were cotranslated in rabbit reticulocyte lysate and the complexes formed thereof were analyzed by 7.5% nondenaturing polyacrylamide gel electrophoresis. P protein of VSV(NJ) has two binding sites for homologous N protein: One located within the C-terminal 11 amino acids (within domain III) is responsible for the formation of five specific complexes while the other site, which spans the …

Characterization of nucleolar localization signals in the avian infectious bronchitis virus nucleocapsid protein and their critical role in viral replication.

UNLABELLED: The nucleocapsid (N) protein of infectious bronchitis virus (IBV) is the most abundant viral protein in infected cells and is essential for virion assembly and for modulating host cellular processes. Although previous studies have reported nucleolar accumulation of IBV N, a comprehensive mapping of its nucleolar localization signals (NoLSs) is lacking. Here, we systematically mapped functional NoLSs within the IBV N protein and evaluated their contributions to viral replication. Under both infection and transient-transfection conditions, the N protein exhibited a dual cytoplasmic-n…

Nucleocapsid Antibodies as an Optimal Serological Marker of SARS-CoV-2 Infection: A Longitudinal Study at the Thomayer University Hospital.

BACKGROUND: The longitudinal study was conducted over the initial 2 years of the COVID-19 pandemic, spanning from June 2020 to December 2022, in healthcare workers (HCWs) of the Thomayer University Hospital. A total of 3892 blood samples were collected and analyzed for total nucleocapsid (N) antibodies. The aim of the study was to evaluate the dynamics of N antibodies, their relationship to the PCR test, spike (S) antibodies, interferon-gamma, and prediction of reinfection with SARS-CoV-2. METHODS: Blood collections were performed in three rounds, along with questionnaires addressing clinical…

A clot to uncover: SARS-CoV-2 nucleocapsid can outcompete the FOXP3 forkhead domain for DNA binding in vitro.

During COVID-19, systemic coagulopathy can lead to strokes and embolisms and may also contribute to long COVID. This coagulopathy is the result of overactivated platelets in circulation that lead to inappropriate clot formation. FOXP3 is a transcription factor involved in platelet development. Loss of FOXP3 function leads to abnormal platelets resembling those seen during COVID-19. Thus, FOXP3 may be dysregulated in COVID-19. The SARS-CoV-2 nucleocapsid (NC) is a multifunctional protein typically associated with viral genome packaging and virion assembly. However, it is also capable of binding…