Overview
It is recommended to prepare fresh solutions in working buffers before use, or aliquot stock solutions reconstituted in distilled water and keep at -20°C. Upon use, dilute the stock solution in the desired working buffer. Prevent repeated thawing and freezing cycles. Centrifuge all product preparations before use (10,000 g for 1 min).
Tertiapin-RQ (TPN-RQ) is a derivative of Tertiapin (#STT-250), a native toxin originally isolated from the venom of the bee, Apis mellifera. Tertiapin blocks a range of inward-rectifier K+ channels (Kir), in particular ROMK1 (Kir1.1) and GIRK (Kir3 family)1. Tertiapin also inhibits acetylcholine induced K+ currents in mammalian cardiomyocytes2,3. Compared to Tertiapin, TPN-RQ contains an Arg substitution at Ile-8 and the oxidation-liable Met-13 is substituted with a Gln residue. Similar to Tertiapin, TPN-RQ blocks ROMK1 and GIRK channels4.
Kir channels have diverse physiological functions based on their type and their location. ROMK1 is expressed in the kidneys and brain, but its role in the central nervous system remains unknown. Recent studies suggested that the ROMK1 channel plays a role in mental illness. Consistent with this hypothesis, TPN-RQ suppressed neuronal activity and exhibited an antidepressive and anxiogenic effects in animal models4.
