Protein tyrosine phosphatase: enzymatic assays

Methods. 2005 Jan;35(1):2-8. doi: 10.1016/j.ymeth.2004.07.002.

Abstract

Activity assays for tyrosine phosphatases are based on the hydrolysis of a arylphosphate moiety from a synthetic substrate yielding a spectroscopically active product. Many different substrates can be used for these assays with p-nitrophenyl phosphate (pNPP), fluorescein diphosphate (FDP), and 6,8-difluoro-4-methylumbellyferyl phosphate (DiFMUP) being the most efficient and versatile. Equally, larger molecules such as phosphotyrosyl peptides can also be used to mimic more natural substrates. Activity assays include the determinations of the rate of dephosphorylation and calculations of kinetic constants such as k(cat) and K(M). These assays are useful to identify and characterize tyrosine phosphatases and are commonly used to evaluate the efficiency of inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Fluoresceins
  • Hydrogen-Ion Concentration
  • Hymecromone / analogs & derivatives*
  • Kinetics
  • Nitrophenols
  • Organophosphorus Compounds
  • Protein Tyrosine Phosphatase, Non-Receptor Type 1
  • Protein Tyrosine Phosphatases / analysis*
  • Protein Tyrosine Phosphatases / antagonists & inhibitors

Substances

  • 6,8-difluoro-4-methylumbelliferyl phosphate
  • Fluoresceins
  • Nitrophenols
  • Organophosphorus Compounds
  • nitrophenylphosphate
  • Hymecromone
  • Protein Tyrosine Phosphatase, Non-Receptor Type 1
  • Protein Tyrosine Phosphatases