2,3-Butanedione monoxime (C15-1249-802)

Application

2,3-Butanedione monoxime has been used:

• in single-molecule myosin V motility assays
• as an anesthetic in the approach of imaging transgenic animals
• to reduce rigor tension in muscle fibres
• as a media component for mice cardiomyocytes culture

Biochem/physiol Actions

2,3-Butanedione monoxime is inhibitor of ATP-sensitive K⁺ and Ca²⁺ channels.

DRK1 is a delayed rectifier (Kv2.1) cloned K⁺ channel from rat brain with consensus sites for protein kinase-dependent phosphorylation that might be expected to be functionally regulated by phosphorylation. 2,3-Butanedione monoxime (BDM) chemically removes phosphate groups from many proteins, and its action on DRK1 channels was examined after expression of DRK1 cRNA in Xenopus oocytes. In two-microelectrode voltage-clamp experiments, the application of 2,3-Butanedione monoxime to the bath inhibited DRK1 current (ki = 16.6 mM, H = 0.96) rapidly and reversibly, with a time course similar to the time course of solution change within the bath. DRK1 current was inhibited at all potentials; the time course of current activation, deactivation and inactivation were unaffected by 2,3-Butanedione monoxime. In inside-out patch-clamp experiments, the application of 2,3-Butanedione monoxime to the cytoplasmic surface similarly inhibited channel activity rapidly and reversibly (ki = 10.7 mM, H = 1.01) in the absence of rephosphorylating substrates. These results are inconsistent with a phosphatase effect, because such an effect should be irreversible in cell-free, ATP-free patches. Instead, the results suggest that 2,3-Butanedione monoxime can inhibit DRK1 channels directly from inside or outside of the membrane.