Isolation and biochemical characterization of novel acid phosphatase and zinc-dependent acid phosphatase from the chicken's brain.

The AcPase exhibits a specific activity of 31.32 U/mg of protein with a 728-fold purification, and the yield of the enzyme is raised to 3.15 %. The Zn2+-dependent AcPase showed a purification factor of 1.34 specific activity of 14 U/mg of proteins and a total recovery of 5.14. The SDS-PAGE showed a single band corresponding to a molecular weight of 18 kDa of AcPase and 29 kDa of Zn2+-dependent AcPase. The AcPase enzyme has shown a wide range of substrate specificity for p-NPP, phenyl phosphate and FMN, while in the case of ZnAcPase α and ß-Naphthyl phosphate and p-NPP were proved to be superior substrates. The divalent metal ions like Mg2+, Mn2+, and Ca2+ increased the activity, while other substrates decreased the enzyme activity. The Km (0.14 mM) and Vmax (21 µmol/min/mg) values of AcPase were higher than those of Zn2+-AcPase (Km = 0.5 mM; Vmax = 9.7 µmol/min/mg). The Zn2+ ions activate the Zn2+-AcPase while Fe3+, Al3+, Pb2+, and Hg2+ showed inhibition on enzyme activity. Molybdate, vanadate and phosphate were found to be competitive inhibitors of AcPase with Ki values 316 µM, 185 µM, and 1.6 mM, while in Zn2+-AcPase tartrate and phosphate also showed competitive inhibition with Ki values 3 mM and 0.5 mM respectively.

Divalent metal ion in the active site of purple acid phosphatase modulates substrate binding: Kinetic and thermodynamic properties.

The purple acid phosphatase was purified from 5.9-fold to apparent homogeneity from Anagelis arvensis seeds using SP-Sephadex C-50 and Sephadex G-100 chromatography. The results of residual activity tests conducted using different temperature ranges (50-70 °C) were calculated as the activation energy (Ed = 72 kJ/mol), enthalpy (69.31 ≤ (ΔH° ≤ 69.10 kJ/mol), entropy (-122.48 ≤ ΔS° ≤ -121.13 J/mol·K), and Gibbs free energy (108.87 ≤ ΔG° ≤ 111.25 kJ/mol) of the enzyme irreversible denaturation. These thermodynamic parameters indicate that this novel PAP is highly thermostable and may be significant for use in industrial applications. However, it may be confirmed by stopped-flow measurements that this substitution produces a chromophoric Fe3+ site and a Pi-substrate interaction that is about ten times faster. Additionally, these data show that phenyl phosphate hydrolysis proceeds more rapidly in metal form of A. arvensis PAP than the creation of a µ-1,3 phosphate complex. The Fe3+ site in the native Fe3+-Mn2+ derivative interacts with it at a faster rate than in the Fe3+-Fe2+ form. This is most likely caused by a network of hydrogen bonds between the first and second coordination spheres. This suggests that the choice of metal ions plays a significant role in regulating the activity of this enzyme.

Carboxymethyl cellulose mediated growth of V2O5 nanorod by green strategy for energy storage utilization using electrochemical studies.

Vanadium pentoxide has the most exciting oxidation states, but, Vanadium pentoxide (V2O5) has low capacitance due to poor electrical conductivity and ionic diffusivity. So, encapsulating pentoxide in carbonaceous materials or metals, shrinking it to the nanoscale, or changing its morphology can improve capacitance performance. Herein, we describe a green synthesis of V2O5NPs with carboxymethyl cellulose (CMC) that typically acts as a reducing and stabilizing agent using the -COOH and -OH group. The physicochemical characterization of prepared samples reveals the prominent peak in UV-vis spectra at 265 nm confirming the formation of V2O5NPs with particle sizes between 200 and 220 nm. The theoretical surface area for the nanocomposite was 76.5 m2/g. The calcination temperature is essential to determine a material's specific capacitance. Due to decreased oxide agglomeration, the V2O5-green modified electrode exhibits superior electrochemical performance around 223 F g-1 than Ac alone (160 F g-1). The finding demonstrated excellent cyclic stability with reduced fluctuation in capacitance. Because of its exceptional electrochemical performance and simplicity of access, this AC/V2O5 nanocomposite can be helpful as an electrode for energy storage applications.

Red Blood Cells and Lipoproteins: Important Reservoirs and Transporters of Polyphenols and Their Metabolites.

Dietary polyphenols are protective for chronic diseases. Their blood transport has not been well investigated. This work examines multiple classes of polyphenols and their interactions with albumin, lipoproteins, and red blood cell (RBC) compartments using four models and determines the % polyphenol in each compartment studied. The RBC alone model showed a dose-response polyphenol association with RBCs. A blood model with flavanones determined the % polyphenol that was inside RBCs and bound to the surface using a new albumin washing procedure. It was shown that RBCs can methylate flavanones. The whole blood model separated the polyphenol into four compartments with the aid of affinity chromatography. More polyphenols were found with albumin and lipoproteins (high-density lipoproteins and low-density lipoproteins) than with RBCs. In the plasma model, the polyphenols associated almost equally between lipoproteins and albumin. RBCs and lipoproteins are shown to be important reservoirs and transporters of polyphenols in blood.