Biology subjects

Hazra, D.

Publications and source records attributed to Hazra, D..

7 recordsLinked to original sources

bioRxiv2024

Subtractive proteomics unravel the potency of D-Alanine-D-Alanine Ligase as the drug target for Burkholderia pseudomallei

Melioidosis, also known as Whitmores disease, is caused by the deadly pathogen Burkholderia pseudomallei and remains a significant global health concern, particularly in South Asia. The disease is contracted through exposure to contaminated soil, water, air, and food. Infected individuals often present with abscesses in internal organs such as the lungs, spleen, and liver, and in soft tissues, with severe cases leading to septic shock and acute pneumonia. The rising incidence and mortality rates, coupled with B. pseudomalleis ability to form biofilms and develop resistance to antibiotics like cephalosporins, make treatment increasingly challenging. This highlights the urgent need for novel therapeutic approaches. D-Alanine-D-Alanine ligase (Ddl), a crucial enzyme involved in the final stage of bacterial cell wall synthesis, which protects the pathogen from the hostile cellular environment of the host. While many bacteria have two isoforms of this enzyme, B. pseudomallei possesses only the DdlB isoform, presenting a significant vulnerability. Our study represents the first successful attempt to target DdlB through a combination of molecular docking and molecular dynamics simulations. These investigations provide strong evidence that Conivaptan acts as an effective inhibitor of DdlB, offering a novel therapeutic approach for combating melioidosis.

bioinformatics↗

bioRxiv2024

Designing a novel Scaffold-Based Multi-Epitope Vaccine to Combat Melioidosis Caused by Burkholderia pseudomallei: An In-silico and Immunoinformatics approach

Burkholderia pseudomallei, the gram-negative bacteria causing melioidosis, is becoming a serious threat to healthcare settings. In recent years, B. pseudomallei has been identified as an emerging and significant etiological agent responsible for localized pyogenic infections primarily observed in India and South Asia. At present, no vaccine against melioidosis is available in the treatment system. This study has undertaken an in-silico reverse vaccinology approach to design a novel multi-epitope vaccine for treating B. pseudomallei-mediated infections. B-cell and T-cell epitopes have been predicted and stitched to develop a multi-epitope vaccine. The predicted vaccine is found to be non-toxic, non-allergic, and immunogenic in nature. Immune simulation results indicate that the designed vaccine can generate an immune response resembling a real-life scenario. The 610 amino-acid long vaccine construct has been codon-optimized and could be cloned in the E. coli K12 system. These findings from this immunoinformatics study offer a foundation for developing a tailored, safe, and potent vaccine targeting B. pseudomallei.

bioinformatics↗

bioRxiv2024

PfHT1 controls glucose uptake in malaria parasite: molecular dynamics study in plasma membrane like environment reveals ligand induced conformational changes trigger closed conformation and alters binding pocket geometry

Plasmodium falciparum hexose transporter 1 protein or PfHT1 is the major glucose transporter of the parasite and indispensable for its survival at the blood stage of infection. PfHT1 transports the hexose sugar to meet the energy demand of the parasite. Studying the mechanism of transport and designing structure specific inhibitors against PfHT1 is an intelligent strategy to kill malaria parasite by starving it out because at the blood stage the sole carbon source of Plasmodium falciparum is glucose. In this study the conformational dynamics of PfHT1 has been studied in detail in the apo and holo (inhibitor bound) form using Molecular Dynamics Simulation. Which reveals that PfHT1 undergoes ligand induced closed state if compared with the apo form. The geometry of ligand binding pocket also shifts from the apo form in the presence of inhibitors. A de novo drug designing approach based on the skeleton of leads obtained from screening nearly 4500 compounds, has produced inhibitors of PfHT1 with higher specificity and affinity. The drug screening data as well as the conformational dynamics study was validated using Molecular Dynamics Simulation platform where a near physiological atmosphere was created for PfHT1 by constructing a lipid phase (phospholipid bilayer) sandwiched between aqueous phases (mimics extracellular and cytosolic polar environment).

bioinformatics↗

bioRxiv2024

Designing a Novel 3D Scaffold for Multiepitope Vaccine Development: Engineering Ag85a Protein for Enhanced Stability and Antigenicity

Designing multi epitope vaccine (MEV) by reverse vaccinology has become immensely important in the area of vaccine research due to the emergence of new pathogens as well as rise of multi drug resistant old evils like tuberculosis. Administering a vaccine may have the best possibility to save mankind from these unforeseeable events. The strategy of designing a MEV in-silico lies in a few basic steps, including procuring the amino acid sequence of the B cell and T cell epitopes from literature search, bioinformatics approach to construct a potent immunogen capable of eliciting both humoral and cell mediated response. But the challenge lies in the construction of a stable protein with a compact tertiary structure. Merely joining the epitopes one after another, may not be sufficient to achieve this. In this study, a methodology has been detailed to tackle this great challenge using a simple approach of protein engineering. A scaffold based MEV has been designed for the very first time against Mtb by converting a vaccine candidate protein, Ag85A into a scaffold by truncating its non-immunogenic regions so the gaps could be filled by the highly immunogenic epitopes. The stability of the MEV was estimated by molecular dynamics simulation.

biochemistry↗

bioRxiv2024

Single-Cell Peripheral Immunoprofiling of Lewy Body Disease in a Multi-site Cohort

Studies implicated peripheral organs involvement in the development of Lewy body disease (LBD), a spectrum of neurodegenerative diagnoses that include Parkinsons Disease (PD) without or with dementia (PDD) and dementia with Lewy bodies (DLB). This study characterized peripheral immune responses unique to LBD at single-cell resolution. Peripheral mononuclear cell (PBMC) samples were collected from sites across the U.S. The diagnosis groups comprise healthy controls (HC, n=164), LBD (n=132), Alzheimers disease dementia (ADD, n=98), other neurodegenerative disease controls (NDC, n=21), and immune disease controls (IDC, n=14). PBMCs were activated with three stimulants, stained by surface and intracellular signal markers, and analyzed by flow cytometry, generating 1,184 immune features. Our model classified LBD from HC with an AUROC of 0.90{+/-}0.06. The same model distinguished LBD from ADD, NDC, IDC, or other common conditions associated with LBD. Model predictions were driven by pPLC{gamma}2, p38, and pSTAT5 signals from specific cell populations and activations.

neuroscience↗

bioRxiv2023

De novo drug designing coupled with brute force screening and structure guided lead optimization gives highly specific inhibitor of METTL3: a potential cure for Acute Myeloid Leukaemia

Expression of METTL3, a SAM dependent methyltransferase, which deposits m6A on mRNA is linked to poor prognosis in Acute Myeloid Leukaemia and other type of cancers. Down regulation of this epitranscriptomic regulator has been found to inhibit cancer progression. Silencing the methyltransferase activity of METTL3 is a lucrative strategy to design anticancer drugs. In this study 3600 commercially available molecules were screened against METTL3 using brute force screening approach. However, none of these compounds take advantage of the unique Y-shaped binding cavity of the protein, raising the need for de novo drug designing strategies. As such, 125 branched, Y-shaped molecules were designed by "stitching" together the chemical fragments of the best inhibitors that interact strongly with the METTL3 binding pocket. This results in molecules that have the three-dimensional structure and functional groups which enable it to fit in the METTL3 cavity like fingers in a glove, having unprecedented selectivity and binding affinities. The designed compounds were further refined based on Lipinskis rule, docking score and synthetic accessibility. The molecules faring well in these criteria were simulated for 100ns to check the stability of the protein inhibitor complex followed by binding free energy calculation.

bioinformatics↗

bioRxiv2022

Identification of potential natural compound inhibitors and drug like molecules against human METTL3 by docking and molecular dynamics simulation

Nucleotide level chemical modification in transcriptome is critical in regulating different cellular processes, including cancer. The most investigated epitranscriptomic modification is methylation at the N6-position of adenosine (m6A). This dynamic modification process is carried out by: writer, reader and eraser proteins. Writers are methyltransferases, METTL3 is the major writer that works in association with METTL14, an accessory protein. Extensive study revealed that cancer progression for acute myeloid leukaemia, gastric cancer, colorectal cancer, hepatocellular carcinoma, and lung cancer is directly contributed by irregular expression of METTL3. Targeting METTL3, has opened a new window in the development of new inhibitors/drugs. In this study, 80 commercially available compounds were found from an unbiased screening by molecular docking, showing better score when compared with the existing substrate/substrate-analogue and the inhibitor bound crystal structures in terms of docking score and binding energy calculation. Among this pool of compounds, the best seven small molecules, AMF, RAD, JNJ, MEH, ECP, MHN, SGI, have been selected and further validated by different computational tools like binding energy calculation, molecular dynamics simulation etc. The novel hits found in this study can function as lead compounds which can be developed into inhibitors as well as drugs, specific against METTL3.

bioinformatics↗