Protein Tyrosine Phosphatase 1B is the founding member of the protein tyrosine phosphatase (PTP) family, which was isolated and identified based on its enzymatic activity and amino acid sequence. PTPs catalyze the hydrolysis of the phosphate monoesters specifically on tyrosine residues. Members of the PTP family share a highly conserved catalytic motif, which is essential for the catalytic activity. PTPs are known to be signaling molecules that regulate a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. This PTP has been shown to act as a negative regulator of INS signaling by dephosphorylating the phosphotryosine residues of INS receptor kinase. This PTP was also reported to dephosphorylate epidermal growth factor receptor kinase, as well as JAK2 and TYK2 kinases, which implicated the role of this PTP in cell growth control, and cell response to IFN stimulation.
Store, frozen at -20°C for longer periods of time.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Avoid multiple freeze-thaw cycles.
Amino acid sequence
1) Prepare 180µl assay buffer into a suitable container: The final concentrations are 11mM Tris-HCl (pH7.5), 55mM NaCl, 2.2mM DTT, 1.1mM MnCl2, 1.1mM EDTA and 33mM pNPP.
2) Equilibrate to 37°C and monitor at A405nm until the value is constant using a spectrophotometer.
3) Add 20µl of recombinant PTP-1B protein 12.5ug/ml in 0.1% BSA in DW.
4) Record the increase in A405nm for 5 minutes.