Kinetic characterization of the inhibition of protein tyrosine phosphatase-1B by Vanadyl (VO) chelates.

Protein tyrosine phosphatases (PTPases) are a prominent focus of drug design studies because of their roles in homeostasis and disorders of metabolism. These studies have met with little success because (1) virtually all inhibitors hitherto exhibit only competitive behavior and (2) a consensus sequence H/V-C-X-R-S/T characterizes the active sites of PTPases, leading to low specificity of active site directed inhibitors. With protein tyrosine phosphatase-1B (PTP1B) identifed as the target enzyme of the vanadyl (VO) chelate bis(acetylacetonato)oxidovanadium(IV) [VO(acac)] in 3T3-L1 adipocytes [Ou et al.