Identification and biophysical characterization of potential phytochemical inhibitors of carboxyl/choline esterase from Helicoverpa armigera for advancing integrated pest management strategies.

In the realm of disease vectors and agricultural pest management, insecticides play a crucial role in preserving global health and ensuring food security. The pervasive use, particularly of organophosphates (OPs), has given rise to a substantial challenge in the form of insecticide resistance. Carboxylesterases emerge as key contributors to OP resistance, owing to their ability to sequester or hydrolyze these chemicals. Consequently, carboxylesterase enzymes become attractive targets for the development of novel insecticides. Inhibiting these enzymes holds the potential to restore the efficacy of OPs against which resistance has developed. This study aimed to screen the FooDB library to identify potent inhibitory compounds targeting carboxylesterase, Ha006a from the agricultural pest Helicoverpa armigera. The ultimate objective is to develop effective interventions for pest control. The compounds with the highest scores underwent evaluation through docking studies and pharmacophore analysis. Among them, four phytochemicals-donepezil, protopine, 3',4',5,7-tetramethoxyflavone, and piperine-demonstrated favorable binding affinity. The Ha006a-ligand complexes were subsequently validated through molecular dynamics simulations. Biochemical analysis, encompassing determination of IC50 values, complemented by analysis of thermostability through Differential Scanning Calorimetry and interaction kinetics through Isothermal Titration Calorimetry was conducted. This study comprehensively characterizes Ha006a-ligand complexes through bioinformatics, biochemical, and biophysical methods. This investigation highlights 3',4',5,7-tetramethoxyflavone as the most effective inhibitor, suggesting its potential for synergistic testing with OPs. Consequently, these inhibitors offer a promising solution to OP resistance and address environmental concerns associated with excessive insecticide usage, enabling a significant reduction in their overuse.

Deciphering the drug delivery potential of Type1 lipid transfer protein from Citrus sinensis for enhancing the therapeutic efficacy of drugs.

Type1 Non-specific Lipid Transfer Protein (CsLTP1) from Citrus sinensis is a small cationic protein possessing a long tunnel-like hydrophobic cavity. CsLTP1 performing membrane trafficking of lipids is a promising candidate for developing a potent drug delivery system. The present work includes in-silico studies and the evaluation of drugs binding to CsLTP1 using biophysical techniques along with the investigation of CsLTP1's ability to enhance the efficacy of drugs employing cell-based bioassays. The in-silico investigations identified Panobinostat, Vorinostat, Cetylpyridinium Chloride, and Fulvestrant with higher affinities and stability of binding to the hydrophobic pocket of CsLTP1. SPR studies revealed strong binding affinities of anticancer drugs, Panobinostat (KD = 1.40 µM) and Vorinostat (KD = 2.17 µM) to CsLTP1 along with the binding and release kinetics. CD and fluorescent spectroscopy revealed drug-induced conformational changes in CsLTP1. CsLTP1-associated drug forms showed remarkably enhanced efficacy in MCF-7 cells, representing increased cell cytotoxicity, intracellular ROS, reduced mitochondrial membrane potential, and up-regulation of proapoptotic markers than the free drugs employing qRT-PCR and western blot analysis. The findings demonstrate that CsLTP1 binds strongly to hydrophobic drugs to facilitate their transport, hence improving their therapeutic efficacy revealed by the in-vitro investigations. This study establishes an excellent foundation for developing CsLTP1-based efficient drug delivery system.

Heterologous expression, biochemical characterization and prospects for insecticide biosensing potential of carboxylesterase Ha006a from Helicoverpa armigera.

Enzymes have attracted considerable scientific attention for their crucial role in detoxifying a wide range of harmful compounds. In today's global context, the extensive use of insecticides has emerged as a significant threat to the environment, sparking substantial concern. Insects, including economically important pests like Helicoverpa armigera, have developed resistance to conventional pest control methods through enzymes like carboxyl/cholinesterases. This study specifically focuses on a notable carboxyl/cholinesterase enzyme from Helicoverpa armigera (Ha006a), with the goal of harnessing its potential to combat environmental toxins. A total of six insecticides belonging to two different classes displayed varying inhibitory responses towards Ha006a, thereby rendering it effective in detoxifying a broader spectrum of insecticides. The significance of this research lies in discovering the bioremediation property of Ha006a, as it hydrolyzes synthetic pyrethroids (fenvalerate, λ-cyhalothrin and deltamethrin) and sequesters organophosphate (paraoxon ethyl, profenofos, and chlorpyrifos) insecticides. Additionally, the interaction studies between organophosphate insecticides and Ha006a helped in the fabrication of a novel electroanalytical sensor using a modified carbon paste electrode (MCPE). This sensor boasts impressive sensitivity, with detection limits of 0.019 µM, 0.15 µM, and 0.025 µM for paraoxon ethyl, profenofos, and chlorpyrifos, respectively. This study provides a comprehensive biochemical and biophysical characterization of the purified esterase Ha006a, showcasing its potential to remediate different classes of insecticides.

Ecological effects, remediation, distribution, and sensing techniques of chromium.

Chromium is detected in most ecosystems due to the increased anthropogenic activities in addition to that developed from natural pollution. Chromium contamination in the food chain results due to its persistent and non-degradable nature. The release of chromium in the ecosystem accretes and thereafter impacts different life forms, including humans, aquatic and terrestrial organisms. Leaching of chromium into the ground and surface water triggers several health ailments, such as dermatitis, eczematous skin, allergic reactions, mucous and skin membrane ulcerations, allergic asthmatic reactions, bronchial carcinoma and gastroenteritis. Physiological and biological treatments for the removal of chromium have been discussed in depth in the present communication. Adsorption and biological treatment methods are proven to be alternatives to chemical removal techniques in terms of cost-effectiveness and low sludge formation. Chromium sensing is an alternative approach for regular monitoring of chromium in different water bodies. This review intended to explore different classes of sensors for chromium monitoring. However, the spectrochemical methods are more sensitive in chromium ions sensing than electrochemical methods. Future study should focus on miniaturization for portability and on-site measurements without requiring a large instrument provides a good aspect for future research.

Mutation studies and structure-based identification of potential inhibitor molecules against periplasmic amino acid binding protein of Candidatus Liberibacter asiaticus (CLasTcyA).

Earlier reported crystal structure of CLasTcyA revealed unique features like relatively a larger substrate binding pocket, an extended C-terminal loop restricted by a disulfide bond and involvement of residues from hinge region in substrate binding. In present study, CLasTcyA mutants were created to evaluate the importance of these unique features through biophysical characterization. The Val58 in CLasTcyA was replaced by Trp, conserved in most cystine binding proteins, to reduce the size of the binding pocket. All other mutations were created in CLasTcyAV58W mutant as the presence of Trp could be used for intrinsic fluorescence studies. The CLasTcyAV58W showed a noticeable increase in binding affinity and thermal stability as compared to the native form. The mutation of two cysteines in triple mutant CLasTcyAV58W/C212S/C239S, removal of C-terminal extended loop in truncated CLasTcyAV58W/C212S and mutation of His95 from hinge region in the double mutant CLasTcyAV58W/H95A showed a marked decrease in stability-indicating the importance of the unique features in structure of CLasTcyA. The bioinformatics-based virtual screening was employed to screen the potential inhibitor molecules for detailed future studies. The results clearly establish the importance of unique features in structure-function relationship of CLasTcyA.