The Sulphation of p-hydroxyphenylpyruvic acid and related compounds by the rat liver cytosol.
Cytosol preparations of rat liver and kidney were examined for their ability to transfer sulphate from adenosine 3'-phosphate 5'-sulphatophosphate to p-hydroxyphenylpyruvic acid. Little activity towards this substrate was observed, and the main product detected in the reaction mixtures was identified as p-hydroxybenzyl alcohol O-sulphate. This was not formed from p-hydroxybenzaldehyde, a spontaneous oxidation product of p-hydroxyphenylpyruvic acid, by sulphation followed by a rapid enzyme-catalysed reduction of the intermediate phydroxybenzaldehyde O-sulphate. This product was formed mainly by this sequence of reactions, but the reverse, reduction followed by sulphation, also appeared possible. p-Hydroxybenzyl alcohol itself was very readily sulphated by both preparations, and the liver also produced a sulpho-conjugate of homogentisic acid. These observations are important in calculating the turnover of L-tyrosine O-sulphate in the mammalian system, and establish that p-hydroxyphenylpyruvic acid O-sulphate is an end product of its metabolism, rather than an intermediate in its synthesis by reversed transamination.
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D009928:Organ Specificity; D010667:Phenylpyruvic Acids / Q000378:metabolism*; D051381:Rats; D013464:Sulfuric Acids / Q000378:metabolism*
D010667:Phenylpyruvic Acids; D013464:Sulfuric Acids