A streamlined protocol for expression and purification of wild-type -arrestins

The two isoforms of beta-arrestins namely beta-arrestin 1 and 2 interact with, and regulate a broad repertoire of G protein-coupled receptors (GPCRs). While several protocols have been described in the literature for purification of beta-arrestins for biochemical and biophysical studies, some of these protocols involve multiple complicated steps that prolong the process and yield relatively smaller amounts of purified proteins. Here, we describe a simplified and streamlined protocol for expression and purification of beta-arrestins using E. coli as an expression host. This protocol is based on N-terminal fusion of GST tag and involves a two-step protocol involving GST-based affinity chromatography and size exclusion chromatography. The protocol described here yields sufficient amounts of high-quality purified beta-arrestins suitable for biochemical and structural studies.