Key words: NK2 • GPCR • receptor binding assay • LEADseeker • SPA Imaging Beads
Neurokinins, also known as tackykinins, are a family of small neuropeptides. Members of this family include peptides, substance P (SP), neurokinin A (NKA), neurokinin B (NKB), and the recently discovered hemokinin-1 (1). Neurokinins are widely distributed throughout the central and peripheral nervous system where they act via G protein-coupled receptors (NK1, NK2, and NK3 receptors) as neurotransmitters and neuromodulators. They are also considered key mediators in the communication between neurons (particularly sensory neurons) and effector cells (e.g., smooth muscle, glands, and immune cells), a role that is significant to the pathophysiology of a wide variety of diseases including gastrointestinal disorders, emesis, chronic pain, depression, and asthma (2). Members of the neurokinin family favor specific receptors. SP, for instance, shows greatest affinity for NK1 receptors, NKA for NK2, and NKB for NK3 (3). Of these receptors, NK2 receptors are thought to be expressed mainly on smooth muscle cells (4). Additionally, NKA and its truncated form, NKA (4-10), are potent contractors of human colon circular muscle, an action mediated exclusively via NK2 receptors (5).
This application note describes a 384-well NK2 neuropeptide receptor binding assay developed using LEADseeker™ Multimodality Imaging System. The miniaturized assay is robust, achieving a Z’ value of 0.62 and a stability window of 18 h. These factors make the assay suitable for adaptation to automated screening formats.
LEADseeker Multimodality Imaging System 18-1140-71
Wheat Germ Agglutinin (WGA)-PEI Type A RPNQ0287