Which GLUT transporter has the lowest affinity for glucose?
GLUT isoforms display divergent Michaelis constants reflecting tissue metabolic roles and sensing. GLUT2 product of SLC2A2 on 3q26 expressed strongly in hepatocyte sinusoidal membrane pancreatic beta cell plasma membrane intestinal basolateral side and kidney tubule exhibits unusually high Km fifteen to twenty millimolar for glucose also transporting fructose galactose low affinity corresponding to lowest affinity among transporters. This high Km enables effective glucose sensor rather than supply line where rate varies roughly linearly across physiological plasma glucose three to fifteen mill
Ref: Thorens, Molecular Aspects of Medicine 2015: GLUT2 – Low Affinity Sensor Transporter.
