Phenolsulphotransferase Activity Research Articles

PLATELET PHENOLSULPHOTRANSFERASE DEFICIENCY IN DIETARY MIGRAINE

Patients with dietary migraine were found to have significantly lower levels of platelet phenolsulphotransferase activity than either migrainous patients without a history of dietary provocation or normal controls. Of the two known human variants of this enzyme, the phenol-inactivating P form, for which no endogenous substrate has so far been identified, was more severely involved than the M enzyme, which inactivates monoamines (including tyramine). Such commonly implicated, dietary triggering agents as chocolate and cheese may contain as-yet-unidentified phenolic substrates of phenolsulphotransferase P; if the platelet enzyme deficiency were mirrored by low gut activity, abnormally large amounts of potentially toxic substances might gain access to the circulation in consequence.

A genetic study of platelet phenolsulphotransferase activity in normal and schizophrenic twins

In a series of 19 identical and 16 fraternal twin pairs, the activities of the two forms of the enzyme, phenolsulphotransferase, denominated M and P, were investigated in blood platelets. Both were shown to be under a high degree of genetic control. No differences were found between 11 schizophrenic patients from discordant twin pairs, compared with their well cotwins and 12 male and female volunteer twin pairs, for either form of the enzyme.

Human platelet phenol sulphotransferase: Assay procedure, substrate and tissue correlations

Procedures for the precise assay of human platelet phenol sulphotransferase activity were determined. The coefficient of variation of the assay was 5.8% when the enzyme activity was expressed per 10 8 platelets, and was 9.4% when it was expressed per mg soluble platelet protein. Mean platelet phenol sulphotransferase (PST) activity in samples from 102 randomly selected adults was 1.2 ± 0.4 units/10 8 platelets (mean ± S.D.), with a range from 0.2 to 2.9. The mean activity for umbilical cord blood platelet PST was 0.93 ± 0.3 units/10 8 platelets (mean ± S.D., n = 27). The substrate used routinely for the assay was 3-methoxy-4-hydroxyphenylglycol (MHPG). There was a significant correlation between the formation of MHPG sulfate by individual platelet preparations and the formation of sulfated product with each of the following substrates: tyramine ( r = 0.92, n = 21); dopamine ( r = 0.82, n = 16); 5-hydroxytryptamine ( r = 0.94, n = 20); acetaminophen ( r = 0.77, n = 17); and alphamethyldopa ( r = 0.77, n = 17) ( p < 0.001 for each). Platelet PST activity correlated significantly with human renal cortex PST activity ( r = 0.54, n = 20, p < 0.02). The correlation coefficient between platelet PST activity and jejunal mucosal enzyme activity in eight patients was 0.67. These results raise the possibility that human platelet PST activity measured with MHPG as substrate might reflect the enzyme activity in other tissues and the degree of sulfate conjugation of a variety of substrates.

Studies on the Arylsulphatase and phenol sulphotransferase activities of Aspergillus oryzae.

1. Crude extracts of Aspergillus oryzae grown under conditions of sulphur limitation possess high arylsulphatase activity. 2. This activity can be greatly enhanced by the inclusion of tyramine or a number of other phenols in the assay medium. 3. The arylsulphatase activity of these extracts can be resolved into three distinct fractions by chromatography on DEAE-cellulose. 4. The effect of tyramine is restricted to one of these fractions only. 5. Evidence is presented which indicates that this effect is the consequence of a phenol sulphotransferase activity, which shows no requirement for 3'-phosphoadenosine 5'-phosphate as a cofactor, and which will not transfer sulphate from 3'-phosphoadenosine 5'-sulphatophosphate to potential phenolic acceptors. 6. The three enzymes differ also in their molecular weights and substrate specificities.

Biogenic amines and their metabolites as substrates for phenol sulphotransferase (EC 2.8.2.1) of brain and liver.

AbstractPhenol sulphotransferase activity in homogenates of rat liver and brain was determined spectrophotometrically. Rat liver had about 100‐fold more phenol sulphotransferase activity than brain; however, both tissues showed about the same spectrum of activity towards the phenolic compounds tested. Dopamine and its acidic and neutral metabolites and the neutral metabolites of norepinephrine were the compounds most readily sulphury‐lated in vitro. They were also the compounds most readily sulphurylated in vivo when they were injected intraventricularly together with labelled Na2SO4. When labelled Na2SO4 was injected alone, we detected conjugation of endogenous phenols. One of the compounds formed was identified by its chromatographic characteristics as 3‐methoxy‐4‐hydroxy‐phenylethyleneglycol sulphate. We detected other conjugates which appeared to be the sulphate esters of 3,4‐dihydroxyphenylethyleneglycol; 3,4‐dihydroxyphenylacetic acid; and homovanillic acid. In brain, sulphate conjugation may be a major route of metabolism for many of the phenolic compounds related to the biogenic amines and possibly for phenolic drugs which enter the brain.