Dephostatin is a protein-tyrosine phosphatase (PTP1B and SH-PTP1) inhibitor known to control the intracellular signal transduction in various biological processes frequently negatively regulating protein-tyrosine phosphorylation. Dephostatin is a competitive protein-tyrosine phosphatase inhibitor isolated from a Streptomyces strain and has been used as a study tool for various processes and diseases. Shown to inhibit the growth of Jerkat cells and protein tyrosine phosphatase activity in membrane preparations from human neoplastic T cell lines.
Due to its oxidizing effects, dephostatin was shown to release calcium from intracellular calcium pools and induce amylase secretion in rat pancreatic acinar cells. Additionally, it possesses the potential to be a nitric oxide (NO) donor for protein S-nitrosylation.