A5073122376- Research on Leishmaniasis Studies
- Cancer therapeutics and mechanisms
- Toxin Mechanisms and Immunotoxins
- Synthesis and Biological Evaluation
- Amino Acid Enzymes and Metabolism
- Nanoparticles: synthesis and applications
- Microbial Metabolic Engineering and Bioproduction
- Synthesis and bioactivity of alkaloids
- Cell death mechanisms and regulation
- Neutropenia and Cancer Infections
- PARP inhibition in cancer therapy
- Topic Modeling
- Anesthesia and Neurotoxicity Research
- Intelligent Tutoring Systems and Adaptive Learning
- Bioactive Compounds and Antitumor Agents
- Advanced Text Analysis Techniques
- Chemical synthesis and pharmacological studies
- Botanical Research and Applications
- Biochemical and Molecular Research
- Paraoxonase enzyme and polymorphisms
- Microbial metabolism and enzyme function
- Phytochemicals and Medicinal Plants
- Genetic factors in colorectal cancer
- Polyomavirus and related diseases
- Enzyme Catalysis and Immobilization
Ahmedabad University
2017-2024
Indian Association for the Cultivation of Science
2014-2016
Indian Institute of Chemical Biology
1996-2014
Université de Strasbourg
2014
National Institutes of Health
2014
National Cancer Institute
2014
Center for Cancer Research
2014
Centre National de la Recherche Scientifique
2014
MRC Laboratory of Molecular Biology
2014
The University of Texas MD Anderson Cancer Center
2012
Abstract Poly(ADP-ribose) polymerases (PARP) attach poly(ADP-ribose) (PAR) chains to various proteins including themselves and chromatin. Topoisomerase I (Top1) regulates DNA supercoiling is the target of camptothecin indenoisoquinoline anticancer drugs, as it forms Top1 cleavage complexes (Top1cc) that are trapped by drugs. Endogenous carcinogenic lesions can also trap Top1cc. Tyrosyl-DNA phosphodiesterase 1 (TDP1), a key repair enzyme for Top1cc, hydrolyzes phosphodiester bond between...
Research Article2 October 2012Open Access The lignan niranthin poisons Leishmania donovani topoisomerase IB and favours a Th1 immune response in mice Sayan Chowdhury Molecular Parasitology Laboratory, Indian Institute of Chemical Biology, Jadavpur, Kolkata, India Search for more papers by this author Tulika Mukherjee Department Chemistry, Rupkatha Mukhopadhyay Infectious Diseases Immunology Division, Budhaditya Souvik Sengupta Sharmila Chattopadhyay Drug Development Diagnostics Biotechnology...
Toward developing antileishmanial agents with mode of action targeted to DNA topoisomerases <i>Leishmania donovani</i>, we have synthesized a large number derivatives betulin. The compound, natural triterpene isolated from the cork layer <i>Betula</i> spp. plants exhibits several pharmacological properties. Three compounds (disuccinyl betulin, diglutaryl dihydrobetulin, and disuccinyl dihydrobetulin) inhibit growth parasite as well relaxation activity enzyme type IB topoisomerase...
Topoisomerase 1 (Top1) is essential for removing the DNA supercoiling generated during replication and transcription. Anticancer drugs like camptothecin (CPT) its clinical derivatives exert their cytotoxicity by reversibly trapping Top1 in covalent complexes on (Top1cc). Poly(ADP-ribose) polymerase (PARP) catalyses addition of ADP-ribose polymers (PAR) onto itself Top1. PARP inhibitors enhance CPT trials. However, molecular mechanism which PARylation regulates nuclear dynamics not fully...
ABSTRACT The unicellular organism Leishmania undergoes apoptosis-like cell death in response to external stress or exposure antileishmanial agents. Here, we showed that 3- O ,28- -disuccinyl betulin (DiSB), a potent topoisomerase type IB inhibitor, induced parasitic by generating oxidative stress. characteristic feature of the process resembled programmed (PCD) seen higher eukaryotes. In current study, generation reactive oxygen species (ROS), followed depolarization mitochondrial membrane...
The aim of this study was to resolve the putative pathway responsible for death induced by peganine hydrochloride dihydrate isolated from Peganum harmala seeds at cellular, structural and molecular level in Leishmania donovani, a causative agent fatal visceral leishmaniasis.The mode action assessed using various biochemical approaches including phosphatidylserine exposure, estimation mitochondrial transmembrane potential situ dUTP nick end labelling staining nicked DNA parasite. Molecular...
Camptothecin (CPT) selectively traps topoisomerase 1-DNA cleavable complexes (Top1cc) to promote anticancer activity. Here, we report the design and synthesis of a new class neutral porphyrin derivative 5,10-bis(4-carboxyphenyl)-15, 20-bis(4-dimethylaminophenyl)porphyrin (compound 8) as potent catalytic inhibitor human Top1. In contrast CPT, compound 8 reversibly binds with free enzyme inhibits formation Top1cc promotes reversal preformed CPT. Compound induced inhibition in live cells was...
Zinc oxide nanoparticles (ZnO NPs) with their wide range of consumer applications in day-to-day life received great attention to evaluate effects humans. This study has been attempted elucidate the DNA damage response mechanism a dermal model exposed ZnO NPs through Ataxia Telangiectasia Mutated (ATM)-mediated ChK1-dependent G2/M arrest. Further, viability parameters and involved cell death special reference consequences arising due were explored. Our showed that at concentrations 5 10 µg/ml...
Leishmania donovani are the causative agents of visceral leishmaniasis worldwide. Lack vaccines and emergence drug resistance warrants need for improved therapy newer therapeutic intervention strategies against leishmaniasis. In present study, we have investigated effect natural indoloquinoline alkaloid cryptolepine on L. AG83 promastigotes. Our results show that induces cellular dysfunction in promastigotes, which leads to death this unicellular parasite. Interestingly, our study suggest...
Background The development of 3, 3′-diindolyl methane (DIM) resistant parasite Leishmania donovani (LdDR50) by adaptation with increasing concentrations the drug generates random mutations in large and small subunits heterodimeric DNA topoisomerase I (LdTOP1LS). Mutation subunit LdTOP1LS at F270L is responsible for resistance to DIM up 50 µM concentration. Methodology/Principal Findings In search compounds that inhibit growth catalytic activity mutated (F270L), we have prepared three...
In parasites, ATP-binding cassette (ABC) transporters represent an important family of proteins related to drug resistance and other biological activities. Resistance leishmanial parasites therapeutic drugs continues escalate in developing countries, many instances, it is due overexpressed ABC efflux pumps. Progressively adapted baicalein (BLN)-resistant (pB(25)R) show overexpression a novel transporter, which was classified as ABCC2 or Leishmania donovani multidrug protein 2 (LdMRP2). The...
Formate hydrogenlyase (FHL) activity was induced in a strain of Escherichia coli S13 during anaerobic growth yeast extract-tryptone medium containing 100 mM formate. The cells obtained at the optimum phase were immobilized 2.5% (w/v) agar gel when 50-60% whole cell FHL retained. system had good storage stability and recycling efficiency. In lysis formate, an increase formate concentration to 1.18 M increased QH(2) (initial) value cell, subsequently cells, hydrogen evolution, general, ceased...
Most type IB topoisomerases do not require ATP and Mg 2+ for activity. However, as shown previously vaccinia topoisomerase I, we demonstrate that stimulates the relaxation activity of unusual heterodimeric from Leishmania donovani (LdTOP1L/S) in absence . The stimulation is independent hydrolysis but requires salt a co-activator. binds to LdTOP1L/S increases its rate strand rotation. Docking studies indicate amino acid residues His93, Tyr95, Arg188 Arg190 large subunit may be involved...
The unusual, heterodimeric topoisomerase IB of Leishmania shows functional activity upon reconstitution the DNA-binding large subunit (LdTOPIL; or L) and catalytic small (LdTOPIS; S). In present study, we generated N- C-terminal-truncated deletion constructs either identified proteins LdTOPIL39–456 (lacking amino acids 1–39 457–635) LdTOPIS210–262 1–210) as minimal interacting fragments. region LdTOPIL lies between residues 40–99 435–456, while for LdTOPIS it 210–215 245–262....
Abstract Escherichia coli cells with formate hydrogenlyase activity that were immobilized in agar beads produced hydrogen from glucose at the approximate yield of 0.6 mole per mole. Succinate or thiosulphate added to increased production two‐fold. Thiosulphate did not increase rate but reduced consumption for same amount compared control. Oxaloacetate and traces pyruvate instead succinate accumulated end when was present. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 492–494, 2001.
Leishmaniasis, attributed to the protozoan parasite