Kinetics and Fluorometric Analysis of Acid Phosphatase in the Presence of Fe3O4 Nanoparticle

Acid Phosphatase EC (3.1.3.2) or Orthophosphoric Monoester is a family of enzymes that hydrolyze the hydro-lysis of monoesters and phosphoric anhydrides to produce inorganic phosphate within the range of pH=4-7 and optimum pH of 5-5.3 at temperature of 37°C. Acid phosphatase used in this study is originated from the sweet potato of Ipomoea Batatas species which is a homodimer with molecular weight of approximately 110 kDa and each monomer of it has 473 amino acid subunits. In this study the effect of Fe3O4 nanoparticle on Acid Phosphatase and their effects on the kinetic activity as well as the fluorescence emission intensity of Acid Phosphatase were examined. In kinetic studies, Pharmacia UV-Vis spectrophotometer Ultrospect-1100Pro was used. Moreover, Shimadzu spectrofluorimeter Rf-5301PC was used for Fluorometric experiments. Kinetic stud-ies show that in the presence of different concentrations of Fe3O4 nanoparticle, Km has reduced and Vmax has increased; therefore, the nanoparticle in these concentrations has increased the enzyme activity. Studies on fluorescence emission intensity of the enzyme indicate that the nanoparticle in the desired concentrations has reduced the fluorescence emission intensity of the enzyme. Thus it has acted as the quencher for the enzyme. According to Stern-Volmer plot and with regard to the rate constant for quenching (Kq), the occurred quenching has been static. The thermodynamic parameters for Fe3O4 show that the dominant interaction for the binding of.Fe3O4 nanoparticle and enzyme has been hydrophobic interaction

Keywords:

Acid phosphatase , Kinetic activity , Fluorescence emission intensity , Quencher , Fe3O4