Affinity for α‐tocopherol transfer protein as a determinant of the biological activities of vitamin E analogs

FEBS Letters

Arita, Makoto³  Kiyose, Chikako²  Sato, Yuji³  Hosomi, Akihiro³  Arai, Hiroyuki³  Inoue, Keizo³  Igarashi, Osamu²  Ueda, Tadahiko¹ 

[1] Tokyo Metropolitan Research Laboratory of Public Health, Hyakunin-cho 3-24-1, Shinjuku-ku, Tokyo 169, Japan;Institute of Environmental Science for Human Life, Ochanomizu University, Ohtsuka 2-1-1, Bunkyo-ku, Tokyo 112, Japan;Department of Health Chemistry, Faculty of Pharmaceutical Sciences, University of Tokyo Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan

关键词: Vitamin E;    α-Tocopherol;    Transfer protein;    Ligand specificity;    Anti-oxidant;    αTTP;    α-tocopherol transfer protein;   

DOI  :  10.1016/S0014-5793(97)00499-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

α-Tocopherol transfer protein (αTTP), a product of the gene which causes familial isolated vitamin E deficiency, plays an important role in determining the plasma vitamin E level. We examined the structural characteristics of vitamin E analogs required for recognition by αTTP. Ligand specificity was assessed by evaluating the competition of non-labeled vitamin E analogs and α-[³H]tocopherol for transfer between membranes in vitro. Relative affinities (RRR-α-tocopherol=100%) calculated from the degree of competition were as follows: β-tocopherol, 38%; γ-tocopherol, 9%; δ-tocopherol, 2%; α-tocopherol acetate, 2%; α-tocopherol quinone, 2%; SRR-α-tocopherol, 11%; α-tocotrienol, 12%; trolox, 9%. Interestingly, there was a linear relationship between the relative affinity and the known biological activity obtained from the rat resorption-gestation assay. From these observations, we conclude that the affinity of vitamin E analogs for αTTP is one of the critical determinants of their biological activity.

【 授权许可】

Unknown