The binding of G proteins to immobilized delipidated rhodopsin

We have shown that delipidated rhodopsin immobilized on Concanavalin A-Sepharose is capable of binding transducin from crude bovine rod outer segment proteins and GIP-binding proteins (G proteins) of Go/Gi-type from solubilized bovine brain membrane as well. The binding is reversible in the presence of a solution containing 1.2% octyl-beta, D-glucopyranoside and 1 mM GTP. Also, alpha-subunits account for a large fraction of the G proteins which are bound to and then eluted from the immobilized rhodopsin. Concanavalin A-bound delipidated rhodopsin seems to be a useful model in isolating and purifying different G-proteins from crude cell lysates and solubilized membranes as well as for studying G-protein-receptor interaction.