Biology subjects

Kumar, A.

Publications and source records attributed to Kumar, A..

At least 379 records · Page 21Linked to original sources

bioRxiv2023

Thiol reductive stress activates the hypoxia response pathway

Owing to their capability to disrupt the oxidative protein folding environment in the endoplasmic reticulum (ER), thiol antioxidants such as dithiothreitol (DTT) are used as ER-specific stressors. We recently showed that thiol antioxidants modulate the methionine-homocysteine cycle by upregulating an S-adenosylmethionine-dependent methyltransferase, rips-1, in Caenorhabditis elegans. However, the changes in cellular physiology induced by thiol stress that modulate the methionine-homocysteine cycle remain uncharacterized. Here, using forward genetic screens in C. elegans, we discover that thiol stress enhances rips-1 expression via the hypoxia response pathway. We demonstrate that thiol stress activates the hypoxia response pathway. The activation of the hypoxia response pathway by thiol stress is conserved in human cells. The hypoxia response pathway enhances thiol toxicity via rips-1 expression and confers protection against thiol toxicity via rips-1-independent mechanisms. Finally, we show that DTT might activate the hypoxia response pathway by producing hydrogen sulfide. Our studies reveal an intriguing interaction between thiol-mediated reductive stress and the hypoxia response pathway and challenge the current model that thiol antioxidant DTT disrupts only the ER milieu in the cell.

molecular biology↗

bioRxiv2023

Pretraining strategies for effective promoter-driven gene expression prediction

The ability to deliver genetic cargo to human cells is enabling rapid progress in molecular medicine, but designing this cargo for precise expression in specific cell types is a major challenge. Expression is driven by regulatory DNA sequences within short synthetic promoters, but relatively few of these promoters are cell-type-specific. The ability to design cell-type-specific promoters using model-based optimization would be impactful for research and therapeutic applications. However, models of expression from short synthetic promoters (promoter-driven expression) are lacking for most cell types due to insufficient training data in those cell types. Although there are many large datasets of both endogenous expression and promoter-driven expression in other cell types, which provide information that could be used for transfer learning, transfer strategies remain largely unexplored for predicting promoter-driven expression. Here, we propose a variety of pretraining tasks, transfer strategies, and model architectures for modelling promoter-driven expression. To thoroughly evaluate various methods, we propose two benchmarks that reflect data-constrained and large dataset settings. In the data-constrained setting, we find that pretraining followed by transfer learning is highly effective, improving performance by 24 - 27%. In the large dataset setting, transfer learning leads to more modest gains, improving performance by up to 2%. We also propose the best architecture to model promoter-driven expression when training from scratch. The methods we identify are broadly applicable for modelling promoter-driven expression in understudied cell types, and our findings will guide the choice of models that are best suited to designing promoters for gene delivery applications using model-based optimization. Our code and data are available at https://github.com/anikethjr/promoter_models.

genomics↗

bioRxiv2023

Interferon inhibits a model RNA virus via a limited set of inducible effector genes

Interferons control viral infection by inducing the expression of antiviral effector proteins encoded by interferon-stimulated genes (ISGs). The field has mostly focused on identifying individual antiviral ISG effectors and defining their mechanisms of action. However, fundamental gaps in knowledge about the interferon response remain. For example, it is not known how many ISGs are required to protect cells from a particular virus, though it is theorized that numerous ISGs act in concert to achieve viral inhibition. Here, we used CRISPR-based loss-of-function screens to identify a markedly limited set of ISGs that confer interferon-mediated suppression of a model alphavirus, Venezuelan equine encephalitis virus (VEEV). We show via combinatorial gene targeting that three antiviral effectors - ZAP, IFIT3, and IFIT1 - together constitute the majority of interferon-mediated restriction of VEEV, while accounting for less than 0.5% of the interferon-induced transcriptome. Together, our data suggests a refined model of the antiviral interferon response in which a small subset of "dominant" ISGs may confer the bulk of the inhibition of a given virus.

microbiology↗

bioRxiv2023

Seasonal plasticity and energy efficiency in migratory buntings is an assemblage of alterations in metabolic and gut microbe adaptations.

Circulatory system is the source of useful metabolites to enable organismal energy demands of muscle during different life states of birds including migration. In this study, we profiled the serum metabolites and fecal microbiome of redheaded buntings (Emberiza bruniceps) exhibiting diurnal non-migratory (nonM) pre-migratory (preM), migratory (M) and post-migratory (posM) states, when exposed to long days (14L:10D). Using gas chromatography, out of the identified 124 serum analytes, 38 showed significant variations (Fold change, VIP) between states. Out of these, 11 metabolites (short chain fatty acids, SCFAs-butanoate and hexanoate, lactate, pyruvate, ethylene and acetate oxime, pyridoxal phosphate (PLP), niacin, L-valine and carboximidic acids viz. phosphatidyl ethanolamine (PE) and diethyl carbamate) involved in energy pathways and enhanced immunity showed higher abundance in M state. While, upsurge of L-valine suggested energy contribution of glucogenic branched chain amino acids (BCAAs) in M state, that of leucine metabolite, was related to higher temperature in posM birds. Gut microbiota was analysed using faeces of buntings (n=6 each) during nonM and M states and alteration in bacterial compositions was observed; faeces of nonM birds were enriched in proteobacteria, while those of M were rich in firmicutes. This study reports the migratory state specific changes in the serum metabolome and faecal microbiome of the buntings and highlights the role of short chain fatty acids, SCFAs and branched chain amino acids, BCAAs during hypermetabolic state of migration.

animal behavior and cognition↗

bioRxiv2023

Assessment of genetic diversity patterns of different serotypes of dengue virus, prevalent in patients from Kerala, India: a strain specific mutation study and its relevance to pathogenesis

The mutations are the key mechanisms responsible for virus survival and its fitness in the host. This process of mutation is implicated in the development of pathogenesis of the dengue viral disease. We report that, all the four serotypes were found to be circulating in Kerala sate of India. Serotypes 1 and 3 were the predominant type (33.3 %) compared to others. The prevalence of co-infection of serotype 1 and 4 was the highest percentage (11.1 %) compared to serotype 2 and serotype 3 (5.5 %). We further highlighted the immunopathological mechanisms of antibody neutralization, CD4+ T cell response and antibody dependent enhancements (ADE) for the possible cause of disease severity in coinfections. Serotype-1 does not show much variations from the previously reported strains from various regions of India. However, serotype-2 showed variations in the sequences from the other strains of serotype-2 previously reported from various regions of India and formed a distinct clade in the genotype-4. Serotype-3 and serotype-4 showed similarity with previously reported strains from India. Moreover, serotype-1 was grouping in genotype-5. Importantly, the serotype-2 grouped with genoptype-4 but exist separately. Serotype-3 was found to be grouped with the genotype-3. The serotype-4 show the very much similarities from the genotype-1 and shows little difference from the previously reported strains from India. Further, mutation in DENV-3 sequences, at position 235 (C to T) and 322 (G to T) shows an important phenomenon which might be adopted by the virus to survive. As severe dengue is linked with the serotype-2, the genetic variations in this serotype points towards the much specific strategy to be adopted in near future to manage the severe dengue disease. In conclusion, we can say that, genetic diversity in the CprM region is present in the different serotypes circulating in the patients from Kerala India and this information may help in the management of dengue viral disease.

immunology↗

bioRxiv2023

Conformational stability of a peroxidase from Artocarpus lakoocha: Effect of pH, chaotrophs and temperature.

A novel heme-peroxidase has been extracted from the latex of the medicinal plant Artocarpus lakoocha (A. lakoocha), known for its potential anti-inflammatory and wound healing properties. To study its stability, structure, and dynamics, this protein was analyzed using far-UV circular dichroism, fluorescence spectroscopy, and activity measurements. The results demonstrated the presence of three folding states: the native state (N) at neutral pH, intermediate states including molten globule (MG) at pH 2 and acid-unfolded (UA) at pH 1.5 or lower, and acid-refolded (A) at pH 0.5, along with alkaline denatured (UB) at pH 8-12 and the third denatured state (D) at GuHCl concentrations exceeding 5 M. Absorbance studies indicated the presence of free heme in the pH range of 1-2. The protein showed stability and structural integrity across a wide pH range (3-10), temperature (70 {degrees}C), and high concentrations of GuHCl (5 M) and urea (8 M). This study is the first to report multiple partially folded intermediate states of A. lakoocha peroxidase, with varying amounts of secondary structure, stability, and compactness. These results demonstrate the high stability of A. lakoocha peroxidase and its potential for biotechnological and industrial applications, making it a valuable model system for further studies on its structure-function relationship.

biophysics↗

bioRxiv2023

Structural and regulatory insights into the glideosome-associated connector from Toxoplasma gondii

The phylum of Apicomplexa groups intracellular parasites that employ substratedependent gliding motility to invade host cells, egress from the infected cells and cross biological barriers. The glideosome associated connector (GAC) is a conserved protein essential to this process. GAC facilitates the association of actin filaments with surface transmembrane adhesins and the efficient transmission of the force generated by myosin translocation of actin to the cell surface substrate. Here, we present the crystal structure of Toxoplasma gondii GAC and reveal a unique, supercoiled armadillo repeat region that adopts a closed ring conformation. Characterisation of the membrane binding interface within the C-terminal PH domain as well as an N-terminal fragment necessary for association with F-actin suggest that GAC adopts multiple conformations. A multi-conformational model for assembly of GAC within the glideosome is proposed.

biochemistry↗

bioRxiv2023

Cortex-wide topography of 1/f-exponent in Parkinson's disease

Parkinsons Disease causes progressive and debilitating changes to the brain as well as to the mind. While the diagnostic hallmark features are the characteristic movement-related symptoms, the disease also causes decline in sensory processing, cognitive, emotional performance and most patients develop dementia over time. The extent of symptoms and the brain-wide projections of neuromodulators such as dopamine suggest that many brain regions are simultaneously affected in Parkinsons disease. To characterise such disease-related and brain-wide changes in neuronal function, we performed a source level analysis of resting state magnetoencephalogram (MEG) from two groups: Parkinsons disease patients and healthy controls. Besides standard spectral analysis, we quantified the aperiodic component of the neural activity by fitting a power law ({kappa}/f {lambda}) to the MEG spectrum and then studied its relationship with age and UPDRS. Consistent with previous results, the most significant spectral changes were observed in the high theta/low alpha band (7-10 Hz) in all brain regions. Furthermore, analysis of the aperiodic part of the spectrum showed that, in all but frontal regions, {lambda} was significantly larger in Parkinsons disease patients than in control subjects. Our results indicate for the first time that Parkinsons disease is associated with significant changes in population activity across the whole neocortex. Surprisingly, even early sensory areas showed a significantly larger {lambda} in patients than in healthy controls. Moreover, {lambda} was not affected by the L-dopa medication. Finally, {lambda} was positively correlated with patient age but not with UPDRS-III (summary measure of motor symptoms clinical rating). Because {lambda} is closely associated excitationinhibition balance, our results propose new hypotheses about manifestation of Parkinsons disease in cortical networks.

neuroscience↗

bioRxiv2023

Excitation and inhibition delays within a feedforward inhibitory pathway modulate cerebellar Purkinje cell output in mice

The cerebellar cortex computes sensorimotor information from many brain areas through a feedforward inhibitory (FFI) microcircuit between the input stage, the granule cell layer, and the output stage, the Purkinje cells. While in other brain areas FFI underlies a precise excitation vs inhibition temporal correlation, recent findings in the cerebellum highlighted more complex behaviors at the granule cell (GC) - molecular layer interneuron (MLI) - Purkinje cell (PC) FFI pathway. To dissect the temporal organization of the cerebellar FFI pathway, we combined ex vivo patch clamp recordings of PCs with a viral-based strategy to express Channelrhodopsin2 in a subset of mossy fibers (MFs), a major excitatory input to GCs. We show that light-mediated MF activation elicits excitatory and inhibitory currents in PCs with a wide range of temporal delays. Furthermore, in many recordings, excitation and inhibition were initiated by different groups of GCs, expanding PCs synaptic temporal integration. Using a computational model of the FFI pathway we demonstrated that this temporal expansion could strongly influence how PCs integrate MF inputs. Our findings suggest that MF inputs are also encoded by specific delays between excitation and inhibition in PCs.

neuroscience↗

bioRxiv2023

Urinary Glycosaminoglycans are Associated with Recurrent UTI and Urobiome Ecology in Postmenopausal Women

Glycosaminoglycans (GAGs) are linear, negatively charged polysaccharides composed of repeating disaccharide units of uronic acid and amino sugars. The luminal surface of the bladder epithelium is coated with a GAG layer. These urothelial GAGs are thought to provide a protective barrier and serve as a potential interaction site with the urinary microbiome (urobiome). Previous studies have profiled urinary GAG composition in mixed cohorts, but the urinary GAG composition in postmenopausal women remains undefined. To investigate the relationship between GAGs and recurrent UTI (rUTI), we profiled urinary GAGs in a controlled cohort of postmenopausal women. We found that chondroitin sulfate (CS) is the major urinary GAG in postmenopausal women and that urinary CS was elevated in women with active rUTI. We also associated urinary GAGs with urobiome composition and identified bacterial species that significantly associated with urinary GAG concentration. Corynebacterium amycolatum, Porphyromonas somerae, and Staphylococcus pasteuri were positively associated with heparin sulfate or hyaluronic acid and bacterial species associated with vaginal dysbiosis were negatively correlated to urinary CS. Altogether, this work defines changes in urinary GAG composition associated with rUTI and identifies new associations between urinary GAGs and the urobiome that may play a role in rUTI pathobiology.

biochemistry↗

bioRxiv2022

Analysing the role of SERPINE1 network in the pathogenesis of human glioblastoma

BackgroundGlioblastoma multiforme (GBM) is one of the most aggressive and difficult to treat brain tumour in humans with a 5 year survival rate of less than 6%. SERPINE1 is a novel tumour receptor found on GBM that modulates the progression of this cancer through growth signals and remodelling of the extracellular matrix. Hence, we investigated the role of SERPINE1 and its network proteins in pathogenesis of GBM and assessed its targetability. Material and methodsNetwork proteins of SERPINE1 in homo sapiens was identified using the String database, and the affinity of the protein-protein interaction of this network was analysed using Chimera software. The expression profile of SERPINE1 in the different brain regions was evaluated to correlate its relevance to GBM pathology. Selected small molecules from Calotropis gigantea were screened using AutoDock vina to assess targetability of human SERPINE1. ResultsVTN, PLG, TGFB1, VWF, FGF2 and CXCR1 were identified as the major network proteins of SERPINE1. The strongest interaction was observed between SERPINE1 and FGF2 (42884 H-bonds) followed by CXCR1 (20279 H-bonds). Our results suggest that SERPINE1 and its network proteins identified here play a vital role in GBM development and progression through brain parenchyma by creating the prime microenvironment for carcinogenesis, tumour invasion and migration. The highest expression of SERPINE1 was observed in the pons, medulla, midbrain, corpus callosum and spinal cord. Expression of SERPINE1 was consistent with high grade lesions of GBM, suggesting association of SERPINE1 with advanced stages of GBM. The selected small molecules from Calotropis gigantea were observed to have therapeutically feasible binding affinity (140 - 550 M) and predicted efficacy (290 - 1115 M) against human SERPINE1. ConclusionSERPINE1 plays a vital role in the progression of GBM through its critical network proteins identified in this study. The expression of SERPINE1 aligns with the advanced stages of GBM. Small molecules from Calotropis gigantea tested in this study can serve as lead compounds for developing novel anti-SERPINE1 therapeutics for advanced stages of GBM.

pharmacology and toxicology↗

bioRxiv2022

Transformer-based tool recommendation system in Galaxy

Galaxy is a web-based open-source platform for scientific analyses. Researchers use thousands of high-quality tools and workflows for their respective analyses. Tool recommender system predicts a collection of tools that can be used to extend an analysis. In this work, a tool recommender system is developed by training a Transformer-based neural network on workflows available on Galaxy Europe. Compared to the existing tool recommender system on Galaxy Europe that trains a recurrent neural network, the transformer-based neural network achieves two times faster convergence, has a four times lower model usage (model loading + prediction) time and shows a better generalisation that goes beyond training workflows. The scripts to create the recommendation model are available under MIT licence at https://github.com/anuprulez/galaxy_tool_recommendation_transformers.

bioinformatics↗

bioRxiv2022

Calcium flux through ER-TGN contact sites facilitates cargo export

Ca2+ influx into the trans-Golgi Network (TGN) promotes secretory cargo sorting by the Ca2+-ATPase SPCA1 and the luminal Ca2+ binding protein Cab45. Cab45 oligomerizes upon a local Ca2+ influx, and Cab45 oligomers sequester and separate soluble secretory cargo from the bulk flow of proteins in the TGN. However, how this Ca2+ flux into the lumen of the TGN is achieved remains elusive, as the cytosol has a very low steady-state Ca2+ concentration. The TGN forms membrane contact sites (MCS) with the Endoplasmic Reticulum (ER), whereby the close apposition of the two organelles allows the protein-mediated exchange of molecular species such as lipids. Here we show that the TGN export of Cab45 clients requires the integrity of ER-TGN MCS and IP3R-dependent Ca2+ fluxes in the MCS, suggesting Ca2+ transfer between these organelles. Using an MCS-targeted Ca2+ FRET sensor module, we measure the Ca2+ flow in these sites in real-time. These data show for the first time that ER-TGN MCS facilitates Ca2+ transfer required for SPCA1-dependent cargo sorting and export from the TGN, thus solving a fundamental question in cell biology. SummaryThe current study demonstrates that the trafficking of COMP and LyzC relies on Ca2+ flux between the endoplasmic reticulum (ER) and trans-Golgi Network (TGN). This process requires the activity of IP3 receptors, present in ER membranes, and depends on the integrity of the membrane contact site between these two organelles.

cell biology↗

bioRxiv2022

A novel multi-epitope peptide vaccine candidate targeting Hepatitis E virus: an in-silico approach

HEV is a foodborne virus transmitted through the fecal-oral route that causes viral hepatitis in humans worldwide. Ever since its discovery as a zoonotic agent, HEV was isolated from several species with an expanding range of hosts. HEV possesses several features of other RNA viruses but also has certain HEV-specific traits that make its viral-host interactions inimitable. HEV leads to severe morbidity and mortality in immunocompromised people and pregnant women across the world. The situation in underdeveloped countries is even more alarming. Even after creating a menace across the world, we still lack an effective vaccine against HEV. Till date, there is only one licensed vaccine for HEV available only in China. The development of an anti-HEV vaccine that can reduce HEV-induced morbidity and mortality is required. Live attenuated and killed vaccines against HEV are not accessible due to the lack of a tolerant cell culture system, slow viral replication kinetics and varying growth conditions. Thus, the main focus for anti-HEV vaccine development is now on the molecular approaches. In the current study, we have designed a multi-epitope vaccine against HEV through a reverse vaccinology approach (Figure 1). For the first time, we have used viral ORF3, capsid protein and polyprotein altogether for epitope prediction. These are crucial for viral replication and persistence and are major vaccine targets against HEV. The proposed in-silico vaccine construct comprises of highly immunogenic and antigenic T-cell and B-cell epitopes of HEV proteins and ORF3. The construct is capable of inducing an effective and long-lasting host immune response as evident from the simulations results. In addition, the construct is stable, non-allergic and antigenic for the host. Altogether, our findings suggest that the in-silico vaccine construct may be useful as a vaccine candidate for preventing HEV infections. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=164 SRC="FIGDIR/small/520355v1_fig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@354f48org.highwire.dtl.DTLVardef@1e80119org.highwire.dtl.DTLVardef@a04ed5org.highwire.dtl.DTLVardef@97bab0_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1:C_FLOATNO An overview of multi-epitope vaccine construct designing using different in-silico tools. C_FIG

immunology↗

bioRxiv2022

Discovery And Characterization of Small Molecule Inhibitors of Zika Virus Replication

Zika virus (ZIKV) is a flavivirus, and ZIKV infections in the past 15 years have been linked to Guillain-Barre syndrome and severe complications during pregnancy associated with congenital Zika syndrome. There are no approved therapies or vaccines for ZIKV. In recent years, advances in structure-based drug design methodologies have accelerated drug development pipelines for identifying promising inhibitory compounds against viral diseases. Among ZIKV proteins, NS2B-NS3 protease is an attractive target for antiviral drug development due to its vital role in the proteolytic processing of the single polyprotein. To find potential inhibitors against ZIKV, we used molecular docking at the NS2B-NS3 protease active site as a virtual screening approach with small molecules diverse scaffold-based library with rigorous druglikeness filters. The top-hit compounds with stable molecular dynamics trajectories were then subjected to in-vitro efficacy testing against ZIKV. In docking and molecular dynamics simulation studies, compound F1289-0194 showed stable binding to the NS2B-NS3 protease active site. Furthermore, viral load assays, immunofluorescence, and plaque reduction assays demonstrated that compound F1289-0194 significantly reduced ZIKV load and replication in Vero cells while maintaining cellular integrity. Thus, the compound F1289-0194 merits further investigation as a novel inhibitor against ZIKV replication.

cell biology↗

bioRxiv2022

Range restricted old and young lineages show the southern Western Ghats to be both museum and cradle of diversity for woody plants

The Western Ghats (WG) mountain chain is a global biodiversity hotspot with high diversity and endemicity of woody plants. The latitudinal breadth of the WG offers an opportunity to determine the evolutionary drivers of latitudinal diversity patterns. We examined the spatial patterns of evolutionary diversity using complementary phylogenetic diversity and endemism measures. To examine if different regions of the WG serve as a museum or cradle of evolutionary diversity, we examined the distribution of 470 species based on distribution modelling and occurrence locations across the entire region. In accordance with the expectation, we found that the southern WG is both a museum and cradle of woody plant evolutionary diversity, as a higher proportion of both old and young evolutionary lineages are restricted to the southern WG. The diversity gradient is likely driven by high geo-climatic stability in the south and phylogenetic niche conservatism for moist and aseasonal sites. This is corroborated by persistent lineage nestedness at almost all evolutionary depths (10-135 million years), and a strong correlation of evolutionary diversity with drought seasonality, precipitation and topographic heterogeneity. Our results highlight the global value of the WG, demonstrating, in particular, the importance of protecting the southern WG - an engine of plant diversification and persistence.

evolutionary biology↗

bioRxiv2022

PTPRC, KDM5C, GABBR1 and HDAC1 are the major targets of valproic acid in regulation of its anticonvulsant pharmacological effects.

BackgroundValproic acid (VPA) is a small molecule which is the 3rd most prescribed drug among anticonvulsant therapeutics. Understanding of the pharmacology of VPA targets will help optimally rationalise the therapeutic effects and also minimise the undesired outcomes. Hence this study analysed the human specific targets of VPA and assessed the affinity of VPA to these targets to interpret potential safe therapeutic range for VPA. Materials and MethodsThe targets of VPA were identified from the SwissTargetPrediction server and STITCH database and analysed for their affinity with VPA using Autodock vina 1.2.0. The volume of distribution (Vd, L) and the dose of VPA reported in the DrugBank database was used for estimation of the plasma and CSF concentration. The plasma and CSF Concentration Affinity (CA) ratio of VPA against each of the high affinity targets was assessed at variable Vd (0.1 to 0.4 L/kg) to identify the therapeutic safety window of VPA. ResultsThe plasma/CSF concentration of VPA range from 170 to 7000 {micro}M and 17 to 700 {micro}M respectively. The plasma concentration achieved was within the safety limits (170 to 700 {micro}M) at higher Vd (>10 L), while at lower Vd (<10L), the plasma or CSF concentration achieved was of concern at VPA dose of >1000 mg/day. The plasma concentration at very low Vd (< 2L) was of concern even at dose of 500 mg/day. The affinity of VPA against all its human specific targets ranged from 2.9 to 52.1 mM. The CA ratio of VPA against its high affinity target was observed to be greater than 0.8, indicating potentially significant modulation of these targets. The following four targets showed CA ratio of over 1: PTPRC, KDM5C, GABBR1 and HDAC1, indicating their preferential targeting by VPA. CES1 and SLC22A12 are high affinity targets of VPA which can contribute to its undesired pharmacological effects (CNS oedema and hepatotoxicity). ConclusionThis study offers a novel insight into the anticonvulsant and undesired pharmacology of VPA by specifically identifying the targets involved and recommends an evidence based approach to personalise dose titration of VPA to achieve optimal therapeutic benefits.

pharmacology and toxicology↗

bioRxiv2022

Investigating the folding dynamics of NS2B protein of Zika virus

NS2B protein of the Zika virus acts as a co-factor for NS3 protease where only the cytosolic domain of NS2B is sufficient for the protease activity. At the same time, NS2B also involves in remodeling the NS3 protease structure. In isolation, we previously proved the NS2B cytosolic domain (residues 49-95) as a disordered type peptide conformation. Further, this study investigated the overall dynamics of NS2B full-length protein. Our Alphafold2 structure modeling system revealed surprising similarities between selected flavivirus NS2B proteins. This similarity reflects that the NS2B protein across flavivirus is conserved fold-wise. The MD simulation of Zika virus NS2B full-length protein shows that the cytosolic domain as a part of full-length protein is a disorder region supporting our previous experimental finding, which suggests the disordered nature of the cytosolic domain in isolation. Since the cytosolic domain of NS2B is essential for protease activity, we have also investigated the folding and dynamics of the NS2B cytosolic domain (residues 49-95) that shows the disorder to alpha helix transition in TFE. On the other hand, in the presence of SDS, macromolecular crowder like ficoll and PEG do not induce secondary structural change. This dynamics study could have implications for some unknown folds of the NS2B protein.

biophysics↗