Observations on the metabolism of tyrosine O[35S]-sulphate in the rat

Abstract

Arylsulphate esters are normally present in appreciable amounts in mammalian urine where

Studies on l-tyrosine O-sulphate. 2. Identification of p-hydroxyphenylpyruvic acid [35S]sulphate as a metabolite of l-tyrosine O[35S]-sulphate in the rat

“…was subjected to paper chromatography showed that the mobility of the unknown metabolite (R, 028, see Dodgson et al 1961) corresponded to that of the authentic sample of p-hydroxyphenylpyruvic acid [35S]-sulphate when the latter was chromatographed in the presence of normal rat urine. A similar agreement was obtained between electrophoretic mobility of metabolite and authentic sample.…”

“…The disappearance of the metabolite from solution B was then followed by measuring the keto-enol difference spectrum ( Subsequently, solutions A and B were subjected to paper chromatography together with a portion of the original urine that had been freeze-dried immediately after collection. The Dodgson et al 1961). …”

“…of Dowex 50 resin as described above. The fractions corresponding to the first peak of radioactivity were collected at 20 as described by Dodgson et al (1961), and, after they were pooled (total vol. approx.…”

“…Potassium L-tyrosine O[858]-sulphate was prepared as described by Dodgson et al (1961). Other sulphate esters were obtained as described by Rose & Powell (1963).…”

“…Analogous transformations have been shown to occur with free L-tyrosine (Booth et al 1960) although the route is a relatively minor one. Dodgson et al (1961) assumed that the conversion of the phydroxyphenylpyruvic acid [35S]sulphate into the p-hydroxyphenylacetic acid ester would involve an enzymically controlled aerobic decarboxylation. This view should be re-appraised in the light of the relative ease with which the conversion appears to occur spontaneously in urine under mild experimental conditions.…”