. "\"Catalysis of the transfer of a purine nucleoside, a purine base covalently bonded to a ribose or deoxyribose sugar, from one side of a membrane to the other.\" [GOC:ai]" . . "purine nucleoside transmembrane transporter activity" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .