GM3 affects carboxyl methylation in the human erythrocyte membrane.

Effects of gangliosides in human erythrocyte membrane using carboxyl methyltransferase have been investigated. As GM3 concentration increased, methylatability for membrane was increased. But bovine brain ganglioside mixture did not alter methylatability even at a higher concentration. When 30 microM of GM3 was used in erythrocyte membrane, methylatability was increased by 32%. When purified-glucose transporters were reconstituted into egg phosphatidylcholine-liposome with GM3, methylatability was increased by 37%. Thus conformational difference of membrane according to localization of GM3 in intact human erythrocyte membrane or liposome possibly increases the methylatability and activity of glucose transporter itself.