Preferential association of membrane phospholipids with the human erythrocyte hexose transporter

This study reports the results of an investigation to determine to what extent the influence of membrane lipids on the human erythrocyte sugar transporter protein activity (Caruthers, A. and Melchior, D.L. (1988) Annu. Rev. Physiol. 50, 257-271) is related to lipid/protein associations in the membrane bilayer. Differential scanning calorimetry was carried out on the human erythrocyte transport protein reconstituted into artificial bilayers formed from preselected lipids. it was found that the transport protein displays a preferential and in some cases strongly preferential affinity for specific lipid types. This association is a function of lipid head group, backbone and hydrocarbon chain length. It appears that the affinity of the transport protein for various lipids can correlate with the lipid's ability to influence transporter activity. This study further suggests that certain lipids (in this case sphingomyelin) can induce an oligomeric association of HEST monomers in the bilayer.