Protein tyrosine phosphatase activity assay kit

Serum electrolytes were analyzed by the Lausanne University Hospital: Total calcium (NM-BAPTA method), phosphate (phosphomolybdate method), and creatinine (modified Jaffé method). Intact FGF23 was analyzed using an ELISA (Kainos Japan CY-4000) following the manufacturer’s instructions. Protein phosphotyrosyl phosphatase (PTP) activity was measured in kidney lysates using fluorometric Protein Tyrosine Phosphatase Activity Assay Kit (#K829, BioVision Inc., Milpitas CA, USA) according to the manufacturer’s instructions. For quantification of Rho-GTPase activity in kidney homogenates, colorimetric Rac1 and RhoA G-LISA Activation Assay Kits (BK128-S and BK124-S Cytoskeleton Inc., Denver CO, USA) were used according to the manufacturer’s instructions.

The PTP1B activity was measured by using the fluorometric Protein tyrosine phosphatase activity assay kit (BioVision). The recombinant PTP1B and immunoprecipitated PTP1B were applied to the working solution by following the instruction and acquiring the fluorescence from (Ex/Em = 368/460 nm) with the Synergy HT multi-detection microplate reader (Bio-TeK, Winooski, VT, USA). The data were collected with kinetic mode with a 20 s period for 10 min for calculate the change in fluorescence with time.