RRC ID 69815
Author Hirota Y, Tsugawa N, Nakagawa K, Suhara Y, Tanaka K, Uchino Y, Takeuchi A, Sawada N, Kamao M, Wada A, Okitsu T, Okano T.
Title Menadione (vitamin K3) is a catabolic product of oral phylloquinone (vitamin K1) in the intestine and a circulating precursor of tissue menaquinone-4 (vitamin K2) in rats.
Journal J Biol Chem
Abstract Mice have the ability to convert dietary phylloquinone (vitamin K1) into menaquinone-4 (vitamin K2) and store the latter in tissues. A prenyltransferase enzyme, UbiA prenyltransferase domain-containing 1 (UBIAD1), is involved in this conversion. There is evidence that UBIAD1 has a weak side chain cleavage activity for phylloquinone but a strong prenylation activity for menadione (vitamin K3), which has long been postulated as an intermediate in this conversion. Further evidence indicates that when intravenously administered in mice phylloquinone can enter into tissues but is not converted further to menaquinone-4. These findings raise the question whether phylloquinone is absorbed and delivered to tissues in its original form and converted to menaquinone-4 or whether it is converted to menadione in the intestine followed by delivery of menadione to tissues and subsequent conversion to menaquinone-4. To answer this question, we conducted cannulation experiments using stable isotope tracer technology in rats. We confirmed that the second pathway is correct on the basis of structural assignments and measurements of phylloquinone-derived menadione using high resolution MS analysis and a bioassay using recombinant UBIAD1 protein. Furthermore, high resolution MS and (1)H NMR analyses of the product generated from the incubation of menadione with recombinant UBIAD1 revealed that the hydroquinone, but not the quinone form of menadione, was an intermediate of the conversion. Taken together, these results provide unequivocal evidence that menadione is a catabolic product of oral phylloquinone and a major source of tissue menaquinone-4.
Volume 288(46)
Pages 33071-80
Published 2013-11-15
DOI 10.1074/jbc.M113.477356
PII S0021-9258(19)54433-7
PMID 24085302
PMC PMC3829156
MeSH Animals Dimethylallyltranstransferase / genetics Dimethylallyltranstransferase / metabolism Female Intestinal Mucosa / metabolism* Male Mice Rats Rats, Sprague-Dawley Recombinant Proteins / genetics Recombinant Proteins / metabolism Species Specificity Vitamin K 1 / pharmacokinetics* Vitamin K 1 / pharmacology Vitamin K 2 / analogs & derivatives* Vitamin K 2 / metabolism Vitamin K 3 / metabolism* Vitamins / pharmacokinetics* Vitamins / pharmacology
IF 4.238
Human and Animal Cells IEC 6(RCB0993)