additional information |
meta-vanadate and ortho-vanadate, exhibits competitive inhibition of phytase, making it bifunctional to act as haloperoxidase. Molecular docking supports vanadate to share its binding site with substrate phytate, molecular docking study and inhibition mechanism, overview. The active site of haloperoxidase shows close similarity with histidine acid phytases. Inhibition of phytase by vanadate can make the enzyme behave as a vanadate-dependent haloperoxidase provided phosphoesterase activity of the enzyme is shut down by the vanadate. The vanadate exists as an anion at pH 3.0 and possibly binds to the active site cleft of phytase, which has a cluster of positively charged amino acids arginine, lysine, and histidine below the isoelectric point (pI) of the enzyme. Upon molecular docking of metavanadate with the rPPHY, it was observed to interact with the same amino acid residues of the catalytic site, with which substrate interacts. Both inhibitor and substrate might sit into the catalytic cleft of the enzyme which is placed between conserved alpha/beta-domain and a variable alpha-domain of rPPHY. When bonding of the substrate/inhibitor was analyzed, it is found to form bonds with arginine (R70), arginine (R74), and aspartate (D344). Inhibition kinetics of phytase by metavanadate. Inhibition of phytase by metavanadate suggests the applicability of rPPHY as haloperoxidase. The reaction is carried out with KBr, metavanadate, H2O2, and phenol red, while observed intermittently for change in color from red-orange to blue-violet |
Wickerhamomyces anomalus |
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