beta-S-ARCA (3-O-Me-m7G(5)ppp(5)G) triammonium is a mRNA 7-methylguanosine (m7G) cap analog carrying a phosphorothioate (PS) moiety. beta-S-ARCA triammonium binds eIF4E via electrostatic interactions between its beta-sulfur atom and positively charged Arg and Lys residues in the protein binding site. beta-S-ARCA triammonium prevents the decapping by Dcp2, increases the mRNA half-life, enhances cap-dependent translation, and increases protein expression in cells. beta-S-ARCA triammonium has been applied in researching experimental mRNA-based anticancer vaccines[1][2].
