Purification and characterization of human liver dehydroepiandrosterone sulphotransferase

Abstract

A form of sulphotransferase capable of sulphating dehydroepiandrosterone and other steroids was purified from cytosol prepared from human liver. Dehydroepiandrosterone sulphotransferase was purified 621-fold when compared with the activity in cytosol using DEAE-Sepharose CL-6B and adenosine 3',5'-bisphosphate-agarose affinity chromatography. During affinity chromatography, dehydroepiandrosterone sulphation activity could be resolved from p-nitrophenol sulphation activity catalysed by phenol sulphotransferase by using a gradient of adenosine 3'-phosphate 5'-phosphosulphate. The purified enzyme was most active towards dehydroepiandrosterone but was capable of conjugating a number of other steroids, including pregnenolone, androsterone and beta-oestradiol. No activity towards p-nitrophenol or dopamine, substrates for the phenol sulphotransferase, was observed with the pure enzyme. A single band with a subunit molecular mass of 35 kDa was observed by Coomassie Blue staining following SDS/polyacrylamide-gel electrophoresis of the purified enzyme. A molecular mass of 68-70 kDa was calculated for the active form of the enzyme by chromatography on Sephacryl S-200, suggesting that the active form of the enzyme is a dimer.

Interactions of the human cytosolic sulfotransferases and steroid sulfatase in the metabolism of tibolone and raloxifene

“…Since the Δ4-isomer is progestagenic rather than estrogenic, the hormonal effect of Tib in a given tissue will be greatly dependent on the SULT isoforms expressed as well as the level of STS activity. The Δ4-Tib isomer is only inactivated by SULT2A1 that is not expressd in tissues such as the breast and endometrium, but is highly expressed in liver (15,38). This suggests that sulfation of 3α-OH Tib is a permanent inactivation reaction and since 3β-Tib sulfate can be desulfated it represents a more important therapeutic metabolite.…”

Sulfation of ractopamine and salbutamol by the human cytosolic sulfotransferases

“…Seven of the 11 human SULTs that belong to the SULT1 gene family are SULT1A1 and SULT1A2 (both believed to be the general detoxifying enzymes) (19,20), SULT1A3 (dopamine/ catecholamine sulfotransferase) (21), SULT1B1 (thyroid hormone sulfotransferase) (22), SULT1C2 and SULT1C4 (hydroxyarylamine sulfotransferases) (23,24) and SULT1E1 (estrogen sulfotransferase) (25). Three that belong to the SULT2 gene family are SULT2A1 (dehydroepiandrosterone sulfotransferase) (26,27), SULT2B1a (pregnenolone sulfotransferase) (28,29) and SULT2B1b (cholesterol sulfotransferase) (28,29). Finally, neuronal/brain sulfotransferase belongs to the SULT4 gene family (30,31).…”

Molecular cloning and expression of novel sulphotransferase-like cDNAs from human and rat brain

“…The phenol SULTs, P-PST-1 (ST1A1) and M-PST (ST1A3), which have been localized in brain [4,6], are also expressed in the liver and\or intestine at high levels. Hydroxysteroid SULTs identified in rat brain [19,20] are also expressed in liver [21,22]. The functions of the SULTs in brain are poorly understood, although sulphation and inactivation of monoamine neurotransmitters and enkephalins have been proposed as potential roles for the phenol SULTs.…”

“…Transfer of the RNA was monitored by UV shadowing to ensure that the majority of the RNA was transferred to the nylon membrane. The sequences used in the comparison were hST1B2 [10], hP-PST-1 [25], hMPST [26], hDHEA-ST [21] and hEST [16]. The amino acid sequences of the SULTs were aligned using the MacVector Sequence analysis software.…”