TY - JOUR
T1 - Sulfation of iodothyronines by recombinant human liver steroid sulfotransferases
AU - Li, Xinying
AU - Anderson, Robert J.
N1 - Funding Information:
We thank Diane Otterness, Dr. Ibrahim Aksoy, and Dr. Richard Weinshilboum for the SULT2A1 and SULT1E1 cDNAs, Dr. Inder Chopra for his gift of a sample of T3 sulfate, and Dr. Sing-yung Wu for his gift of 3,3′-T2. This work was supported by the VA Medical Research Service.
PY - 1999/10/5
Y1 - 1999/10/5
N2 - Sulfation is an important pathway in the metabolism of thyroid hormones. Sulfated iodothyronines are elevated in nonthyroidal illnesses and in the normal human fetal circulation. We assayed and characterized COS-1 cell expressed recombinant human liver dehydroepiandrosterone sulfotransferase (DHEA ST or SULT2A1) and estrogen sulfotransferase (EST or SULT1E1) activities for the first time with triiodothyronine (T3) as the substrate. Several biochemical properties that included apparent K(m) values, thermal stabilities, and responses to the inhibitors 2,6-dichloro-4-nitrophenol and NaCl were tested. SULT2A1, a member of the hydroxysteroid sulfotransferase family, used 3,3'-T2 more readily than T3 and 3,5-T2 as substrates, but had the lowest apparent K(m) value for T3 of any reported human SULT. SULT1E1, a member of the phenol sulfotransferase family, used 3,3'-T2 and rT3 more readily than T3, and also displayed the greatest specificity for T4 among human SULTs. SULT2A1 may contribute more to iodothyronine sulfation than previously suspected. Potential roles of both steroid sulfotransferases in the enhanced sulfation of nonthyroidal illnesses and fetal development invite further investigation.
AB - Sulfation is an important pathway in the metabolism of thyroid hormones. Sulfated iodothyronines are elevated in nonthyroidal illnesses and in the normal human fetal circulation. We assayed and characterized COS-1 cell expressed recombinant human liver dehydroepiandrosterone sulfotransferase (DHEA ST or SULT2A1) and estrogen sulfotransferase (EST or SULT1E1) activities for the first time with triiodothyronine (T3) as the substrate. Several biochemical properties that included apparent K(m) values, thermal stabilities, and responses to the inhibitors 2,6-dichloro-4-nitrophenol and NaCl were tested. SULT2A1, a member of the hydroxysteroid sulfotransferase family, used 3,3'-T2 more readily than T3 and 3,5-T2 as substrates, but had the lowest apparent K(m) value for T3 of any reported human SULT. SULT1E1, a member of the phenol sulfotransferase family, used 3,3'-T2 and rT3 more readily than T3, and also displayed the greatest specificity for T4 among human SULTs. SULT2A1 may contribute more to iodothyronine sulfation than previously suspected. Potential roles of both steroid sulfotransferases in the enhanced sulfation of nonthyroidal illnesses and fetal development invite further investigation.
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U2 - 10.1006/bbrc.1999.1419
DO - 10.1006/bbrc.1999.1419
M3 - Article
C2 - 10512730
AN - SCOPUS:0033527343
VL - 263
SP - 632
EP - 639
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 3
ER -