Imine-Bonding in Membrane Transport of Monosaccharides: Invalidity of Kinetic Evidence

The proposition that carrier mediation of sugar transport may involve formation of imine complexes with specific cell membrane proteins has recently been advanced. However, the primary data presented accord more quantitatively with the presumption of a nonspecific reaction and furnish no evidence for the existence of the high-affinity glucose-binding sites which are essential to the proposed interpretation.