Kinetic and thermodynamic study of ALP enzyme in the presence and absence MWCNTs and Pt-NPs nanocomposites

Abstract

In this study, nanocomposite materials including multi-wall carbon nanotubes (MWCNTs) coated with platinum nanoparticles (Pt-NPs) were synthesized. The formation of Pt-NPs using green chemistry method and MWCNTs from waste synthetic oil was characterized using TEM, FESEM, AFM, and FTIR techniques. The diameter of prepared Pt-NPs and MWCNTs was in the different ranges of nanometer26.80–44.66 nm and 56.49–89.38 nm respectively. Raman and EDX techniques were employed to confirm MWCNT-COOPt and MWCNT-Pt formation. ALP dephosphorylates various natural substrates, and high levels of alkaline phosphatase are linked to a variety of diseases, including dynamic bone disease, hepatitis, and prostate cancer. This study aims to determine the kinetic and thermodynamic parameters of ALP enzyme in the presence/ or absence of nano materials unlike Pt-NPs. The Vmax value of ALP without NPs was 0.931 × 10-3 mol mL−1 min−1, while in the presence of nanomaterials, the Vmax had values of 1.207 × 10-3, 1.145 × 10-3, 1.249 × 10-3, and 0.975 × 10-3 mol mL−1 min−1, the Km value was decreased with increasing of NPs concentration in the Pt NPs. Km values were 0.118, 0.106, 0.191, and 0.098, and the Vmax/Km ratio were 10.20, 10.74, 6.51, and 9.86 min−1 at 80 mg/mL of MWCNT-Pt, MWCNT-COOPt, MWCNT-COO, and Pt-NPs respectively. The results revealed that the kinetic parameters (Vmax, Km, and Vmax/Km) and thermodynamic parameters (ΔH*, ΔE, ΔS* and ΔG*) were slightly increased as the concentration of MWCNT-based nanomaterials increased. This effect might be due to changes in enzyme configuration following immobilization.