Publications by authors named "Parimal Kar"

The spleen tyrosine kinase (Syk) is a key regulator in immune cell signaling and is linked to various mechanisms in cancer and neurodegenerative diseases. Although most computational research on Syk focuses on novel drug design, the molecular-level regulatory dynamics remain unexplored. In this study, we utilized 5 × 1 μs all-atom molecular dynamics simulations of the Syk kinase domain, examining it in combinations of activation segment phosphorylated/unphosphorylated (at Tyr525, Tyr526) and the "DFG"-Asp protonated/deprotonated (at Asp512) states to investigate conformational variations and regulatory dynamics of various loops and motifs within the kinase domain.

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Musa balbisiana (Bhim Kol), an exotic fruit that offers numerous benefits can be fermented to obtain a unique indigenous wine. This study explores the fermentation of Musa balbisiana (Bhim Kol) fruit to produce a unique indigenous wine using strain of Saccharomyces cerevisiae and sugar over a 21-day period. Chemical profiling via GC-MS analysis revealed the presence of major volatile compounds such as butan-1-ol, propanoic acid, 2-phenylethanol, oxolane-2,5-dione etc.

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Context: Flaviviruses cause severe encephalitic or hemorrhagic diseases in humans. Its members, Kyasanur forest disease virus (KFDV) and Alkhumra hemorrhagic fever virus (ALKV), cause hemorrhagic fever and are prevalent in India and Saudi Arabia, respectively, while the tick-borne encephalitis virus (TBEV) causes a dangerous encephalitic infection in Europe and Asia. However, little information is available about the targets of immune responses for these deadly viruses.

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Fibroblast Growth Factor Receptor (FGFR) is connected to numerous downstream signalling cascades regulating cellular behavior. Any dysregulation leads to a plethora of illnesses, including cancer. Therapeutics are available, but drug resistance driven by gatekeeper mutation impedes the treatment.

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The Hepatitis C Virus (HCV), responsible for causing hepatitis and a significant contributor to liver disorders, presents a challenge for treatment due to its high genetic variability. Despite efforts, there is still no effective medication available for this virus. One of the promising targets for drug development involves targeting glycoprotein E2.

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The Janus kinases (JAK) are crucial targets in drug development for several diseases. However, accounting for the impact of possible structural rearrangements on the binding of different kinase inhibitors is complicated by the extensive conformational variability of their catalytic kinase domain (KD). The dynamic KD contains mainly four prominent mobile structural motifs: the phosphate-binding loop (P-loop), the αC-helix within the N-lobe, the Asp-Phe-Gly (DFG) motif, and the activation loop (A-loop) within the C-lobe.

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Epidermal growth factor receptor (EGFR)-targeted therapy has been proven vital in the last two decades for the treatment of multiple cancer types, including nonsmall cell lung cancer, glioblastoma, breast cancer and head and neck squamous cell carcinoma. Unfortunately, the majority of approved EGFR inhibitors fall into the drug resistance category because of continuous mutations and acquired resistance. Recently, autophagy has surfaced as one of the emerging underlying mechanisms behind resistance to EGFR-tyrosine kinase inhibitors (TKIs).

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S-palmitoylation is a dynamic lipid-based protein post-translational modification facilitated by a family of protein acyltransferases (PATs) commonly known as DHHC-PATs or DHHCs. It is the only lipid modification that is reversible, and this very fact uniquely qualifies it for therapeutic interventions through the development of DHHC inhibitors. Herein, we report that 4″-alkyl ether lipophilic derivatives of EGCG can effectively inhibit protein S-palmitoylation in vitro.

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Activation-induced cytidine deaminase (AID) is the key mediator of antibody diversification in activated B-cells by the process of somatic hypermutation (SHM) and class switch recombination (CSR). Targeting AID to the Ig genes requires transcription (initiation and elongation), enhancers, and its interaction with numerous factors. Furthermore, the HIRA chaperon complex, a regulator of chromatin architecture, is indispensable for SHM.

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Cancer is a condition in which a few of the body's cells grow beyond its control and spread to other outward regions. Globally, gastric cancer (GC) is third most common cause of cancer-related mortality and the fourth most common kind of cancer. Persistent infection of VacA-positive () modulates cellular physiology and leads to GC.

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The need for more advanced and effective monkeypox (Mpox) treatments has become evident with numerous Mpox virus (MPXV) outbreaks. Over the years, interest has increased in developing targeted medicines that are efficient, safe, and precise while avoiding adverse effects. Here, we screened 32409 compounds against thymidylate kinase (TMPK), an emerging target for Mpox treatment.

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In the present study, we investigated the conformational dynamics of histo-blood group antigens (HBGAs) and their interactions with the VP8* domain of four rotavirus genotypes (P[4], P[6], P[19], and P[11]) utilizing all-atom molecular dynamics simulations in explicit water. Our study revealed distinct changes in the dynamic behavior of the same glycan due to linkage variations. We observed that LNFPI HBGA having a terminal linkage shows two dominant conformations after complexation, whereas only one was obtained for LNFPI with a terminal linkage.

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Concerning the emergence of resistance to current anti-influenza drugs, our previous phenotypic-based screening study identified the compound A9 as a promising lead compound. This chalcone analog, containing a 2,6-dimethoxyphenyl moiety, exhibited significant inhibitory activity against oseltamivir-resistant strains (H1N1 pdm09), with an EC value of 1.34 μM.

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At the beginning of the last century, multiple pandemics caused by influenza (flu) viruses severely impacted public health. Despite the development of vaccinations and antiviral medications to prevent and control impending flu outbreaks, unforeseen novel strains and continuously evolving old strains continue to represent a serious threat to human life. Therefore, the recently identified H10N7, for which not much data is available for rational structure-based drug design, needs to be further explored.

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Recent findings have highlighted the essential role of dual leucine zipper kinase (DLK) in neuronal degeneration. Saraswatharishta (SWRT), an ayurvedic formulation utilized in traditional Indian medicine, has demonstrated effectiveness in addressing neurodegenerative diseases. Herein, we aim to delve into the atomistic details of the mode of action of phytochemicals present in SWRT against DLK.

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The dengue virus (DENV), composed of four distinct but serologically related Flaviviruses, causes the most important emerging viral disease, with nearly 400 million infections yearly. Currently, there are no approved therapies. Although DENV infection induces lifelong immunity against the same serotype, the antibodies raised contribute to severe disease in heterotypic infections.

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and Epstein Barr virus (EBV) are group1 carcinogens and their role in Gastric cancer (GC) is well established. Previously we have shown that and EBV appears to support aggressive gastric oncogenesis through the upregulation of oncoprotein Gankyrin. Natural plant active molecules have the potential to interrupt oncogenesis.

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Article Synopsis
  • Rab5B is a monomeric G protein involved in early endocytosis and important signaling pathways, and its dysregulation is linked to various cancers, including leukemia and breast cancer.
  • The research identified eight potential inhibitors of Rab5B using molecular docking techniques, with strychnine showing the highest binding affinity.
  • Key interactions between the inhibitors and Rab5B were driven by Van der Waals forces, and specific amino acids were crucial for binding, indicating a direction for future drug development against Rab5B.
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Posttranslational protein arginylation has been shown as a key regulator of cellular processes in eukaryotes by affecting protein stability, function, and interaction with macromolecules. Thus, the enzyme Arginyltransferase and its targets, are of immense interest to modulate cellular processes in the normal and diseased state. While the study on the effect of this posttranslational modification in mammalian systems gained momentum in the recent times, the detail structures of human ATE1 (ATE1) enzymes has not been investigated so far.

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The Fibroblast Growth Factor Receptor1 (FGFR1) kinase wields exquisite control on cell fate, proliferation, differentiation, and homeostasis. An imbalance of FGFR1 signaling leads to several pathogeneses of diseases ranging from multiple cancers to allergic and neurodegenerative disorders. In this study, we investigated the phosphorylation-induced conformational dynamics of FGFR1 in apo and ATP-bound states all-atom molecular dynamics simulations.

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ABSTRACT Fibroblast Growth Factor (FGF) ligands and their receptors are crucial factors driving chemoresistance in several malignancies, challenging the efficacy of currently available anti-cancer drugs. The Fibroblast growth factor/receptor (FGF/FGFR) signalling malfunctions in tumor cells, resulting in a range of molecular pathways that may impact its drug effectiveness. Deregulation of cell signalling is critical since it can enhance tumor growth and metastasis.

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All-atom MD simulations provide the atomic details of glycan structure in solution, but extensive sampling is required for simulating the transition between rotameric states. For carbohydrate modeling, the motions of the glycosidic linkages in a glycan are often sampled well on the sub-μs time scale. Consequently, simulations of large glycans or glycoconjugates in aqueous environments are very challenging at the atomistic level because of a huge number of water molecules, which eventually slows down the conformational sampling.

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Nanoparticles (NPs) made of metals, polymers, micelles, and liposomes are increasingly being used in various biomedical applications. However, most of these NPs are hazardous for long- and short-term use and hence have restricted biomedical applications. Therefore, naturally derived, biocompatible, and biodegradable nanoconstructs are being explored for such applications.

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To fight against the devastating coronavirus disease 2019 (COVID-19), identifying robust anti-SARS-CoV-2 therapeutics from all possible directions is necessary. To contribute to this effort, we selected a human metabolites database containing waters and lipid-soluble metabolites to screen against the 3-chymotrypsin-like proteases (3CL) protein of SARS-CoV-2. The top 8 hits from virtual screening displayed a docking score varying between ~ - 11 and ~ - 14 kcal/mol.

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Dengue virus, a flavivirus that causes dengue shock syndrome and dengue hemorrhagic fever, is currently prevalent worldwide. A two-component protease (NS2B-NS3) is essential for maturation, representing an important target for designing anti-flavivirus drugs. Previously, consideration has been centered on developing active-site inhibitors of NS2B-NS3pro.

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