Solubilization and Physicochemical Characterization of 5-HT3 Receptor-Binding Sites

Publisher Summary This chapter describes the physicochemical characteristics of the 5-HT3 receptor and the different methods used to purify the 5-HT3 receptor. The successful solubilization of 5-HT3 receptor-binding sites can be achieved from an abundant source using a large spectrum of detergents and salt conditions. However, physicochemical studies require more restrictive conditions. The successful solubilization of membrane-bound receptor proteins requires an abundant source of receptors. The chapter reviews the properties of the most common biological detergents and highlights their respective advantages and disadvantages. The solubilization of the 5-HT3 receptor-binding sites allows the determination of several of their physical properties and leads to the purification of the ligand-binding protein(s). Proteins are estimated using the bicinchoninic acid (BCA) protein assay reagent with BSA as a standard. The physicochemical properties of amino acid sequence of the 5-HT3 receptor-binding subunit are altogether consistent with 5-HT3 receptor being a member of the superfamily of ionophoric receptors.