title: Characteristics and Applicability of Phytase of the Yeast Pichia anomala in Synthesizing Haloperoxidase.
abstract: The phytase of the yeast Pichia anomala is a histidine acid phosphatase based on signature sequences and catalytic amino acids identified by site-directed mutagenesis. Among modulators, N-bromosuccinimide and butanedione inhibit phytase, while Ca(2+) and Ni(2+) stimulate slightly. Vanadate exhibits competitive inhibition of phytase, making it bifunctional to act as haloperoxidase. Molecular docking supports vanadate to share its binding site with phytate. The T 1/2, activation energy (E a ), temperature quotient (Q 10), activation energy of thermal inactivation (Ed), and enthalpy (ΔH d (0) ) of the enzyme are 4.0 min (80 °C), 27.72 kJ mol(-1), 2.1, 410.62 kJ mol(-1), and ∼407.8 kJ mol(-1) (65-80 °C), respectively. The free energy of the process (ΔG d (o) ) increases from 49.56 to 71.58 kJ mol(-1) with rise in temperature, while entropy of inactivation (ΔS d (0) ) remains constant at ∼1.36 kJ mol(-1) K(-1). The supplementation of whole wheat dough with rPPHY resulted in 72.5 % reduction in phytic acid content of bread. These characteristics confirm that the phytase has adequate thermostability for its applicability as a food and feed additive.
authors.affiliation: Department of Microbiology, University of Delhi South Campus, New Delhi, India, 110021, swati.joshi.aj@gmail.com.
authors.forename: Swati
authors.initials: S
authors.lastname: Joshi
authors.forename: Tulasi
authors.initials: T
authors.lastname: Satyanarayana
mesh_terms: D010832:6-Phytase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D055162:Biocatalysis / Q000187:drug effects; D001939:Bread; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009195:Peroxidase / Q000096:biosynthesis* / Q000378:metabolism; D010843:Pichia / Q000201:enzymology*; D011489:Protein Denaturation / Q000187:drug effects; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013644:Tartrates / Q000494:pharmacology; D044366:Transition Temperature; D014908:Triticum; D014638:Vanadates / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D013644:Tartrates; D014638:Vanadates; D009195:Peroxidase; D010832:6-Phytase; C029768:tartaric acid