α-Tocopherol binding to human serum albumin.
Given the ability of human serum albumin (HSA) to bind hydrophobic ligands, the binding mode of α-tocopherol, the most representative member of the vitamin E family, is reported. α-Tocopherol binds to HSA with Kd0 = (7.0 ± 3.0) × 10(-6) M (pH 7.2, 25.0°C). Competitive and allosteric modulation of α-tocopherol binding to full-length and truncated (Asp1-Glu382) HSA by endogenous and exogenous ligands suggests that it accommodates preferentially in the FA3-FA4 site. As HSA is taken up into cells, colocalizes with the α-tocopherol transfer protein, and contributes to ligand secretion via ABCA1, it might participate in the distribution of α-tocopherol between plasma, cells, and tissues.
Division of Biomedical Sciences, Department of Theoretical and Applied Sciences, Center of Neuroscience, University of Insubria, Busto Arsizio (VA), Italy. gabriella.fanali@uninsubria.it
Gabriella
G
Fanali
Mauro
M
Fasano
Paolo
P
Ascenzi
Jean-Marc
JM
Zingg
Angelo
A
Azzi
D002352:Carrier Proteins / Q000378:metabolism; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D011485:Protein Binding / Q000187:drug effects; D012709:Serum Albumin / Q000378:metabolism*; D013816:Thermodynamics; D014859:Warfarin / Q000494:pharmacology; D024502:alpha-Tocopherol / Q000378:metabolism*
D002352:Carrier Proteins; D012709:Serum Albumin; C017763:alpha-tocopherol transfer protein; D014859:Warfarin; D024502:alpha-Tocopherol