So many options but one choice: the human body prefers alpha-tocopherol. A matter of stereochemistry.
alpha-Tocopherol belongs to the group of vitamin E vitamers. Recent years findings indicate that alpha-tocopherol is more than just a simple fat-soluble anti-oxidant as it was found that it can also regulate gene expression. From all vitamin E vitamers human body preferentially retains alpha-tocopherol, but the reasons for this preference are still elusive. Different studies indicated that human body, through the action of two hepatic proteins, alpha-tocopherol transfer protein (alpha-TTP) and cytochrome P450 4F2 (CYP4F2), is able to make subtle structural differences between different vitamin E forms. This is an example of stereochemistry used as a discrimination factor between molecules with different biological activities.
Manolescu
B
B
Department of Biochemistry, Faculty of Medicine, University of Medicine and Pharmacy "Carol Davila", Bucharest. manolescub@yahoo.fr
Atanasiu
V
V
Cercasov
C
C
Stoian
I
I
Oprea
E
E
Buşu
C
C
D000975:Antioxidants / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D000072470:Cytochrome P450 Family 4; D006801:Humans; D013237:Stereoisomerism; D024502:alpha-Tocopherol / Q000378:metabolism*
D000975:Antioxidants; D002352:Carrier Proteins; C017763:alpha-tocopherol transfer protein; D003577:Cytochrome P-450 Enzyme System; D000072470:Cytochrome P450 Family 4; C117480:CYP4F2 protein, human; D024502:alpha-Tocopherol