Description
PTP1B (protein tyrosine phosphatase-1B) is a ubiquitous, nontransmembrane protein tyrosine phosphatase, originally identified in human placenta. It is implicated in the negative regulation of insulin receptor signaling, and is a potential therapeutic target for treatment of type 2 diabetes and obesity. The phosphopeptide substrate supplied with this kit contains sequence from the insulin receptor β subunit domain that must be autophosphorylated to achieve full receptor kinase activation. This "activation loop" is the target of several protein phosphatase regulators of insulin signaling, including, notably, PTP1B. The PTP1B inhibitor suramin is supplied as a control for inhibitor detection. Suramin is a reversible and competitive inhibitor of PTP1B, with a Ki of 5.5 µM