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The effects of morin and nordihydroguaiaretic acid (NDGA), two plant secondary metabolites, on porcine pancreatic phospholipase A2(PLA2) were investigated by isothermal titration calorimetry (ITC) andin silicodocking analyses. The binding energies obtained for NDGA and morin from the ITC studies are − 6.36 and − 5.91 kcal mol− 1, respectively. Similarly, the glide scores obtained for NDGA and morin towards PLA2were − 7.32 and − 7.23 kcal mol− 1, respectively. Further the docked complexes were subjected to MD simulation in the presence of explicit water molecules to check the binding stability of the ligands in the active site of PLA2. The bound ligands make hydrogen bonds with the active site residues of the enzyme and coordinate bonds with catalytically important Ca2+ion. The binding of ligands at the active site of PLA2may also contribute to the reported anti-inflammatory properties of NDGA and morin. [ABSTRACT FROM AUTHOR]

Inhibition of leukotriene biosynthesis is considered to be one of the potential treatment strategies for controlling inflammation, respiratory diseases and many neurodegenerative disorders. Designing of specific functional inhibitors against Lipoxygenases (LOX) has got considerable attention due to its ability to block leukotriene biosynthesis. Molecular docking analysis of two indole derivatives such as indoleacetic acid (IAA) and indolebutyric acid (IBA) are reported here. Both compounds give glide scores better than that of protocatechuic acid and nitro catechol, the two known LOX inhibitors. From the enzyme kinetic analysis, it was revealed that IAA and IBA inhibit competitively. The IC50values determined for both IAA and IBA were 42.98 μM and 17.82 μM, respectively. The binding free energy of these compounds was determined using isothermal titration calorimetric assay and was found to be − 6.12 kcal/mol for IAA and − 7.84 kcal/mol for IBA. From the analysis, it can be concluded that both IAA and IBA might be useful as anti-inflammatory agents. [ABSTRACT FROM PUBLISHER]

Flavoenzymes have been extensively studied for their structural and mechanistic properties because they find potential application as industrial biocatalysts. They are attractive for biocatalysis because of the selectivity, controllability and efficiency of their reactions. Some of these enzymes catalyse the oxidative modification of protein substrates. Among them oxygenases (monoxoygenases and dioxygenases) are of special interest because they are highly entantio as well as regio-selective and can be used for oxyfunctionalisation. Dioxygenase enzymes catalyse oxygenation reactions in which both di-oxygen atoms are incorporated into the product. A dioxygenase enzyme purified from Aspergillus fumigatus MC8 was subjected to protein digestion followed by peptide sequencing. The sequence analysis of the peptide fragments resulted in identifying its match with that of an extracellular dioxygenase sequence from the same species of fungus existing in the protein database. The sequence was submitted to protein homology/analogy recognition engine online server for homology modelling and the 3D structure was predicted. Subsequently, the in silico studies of the enzyme–substrate (protein–ligand) interaction were carried out by using the method of molecular docking simulations wherein the modelled dioxygenase enzyme (protein) was docked with the substrates (ligands), catechin and epicatechin. [ABSTRACT FROM PUBLISHER]