TY - JOUR
T1 - Sulfation of iodothyronines by human sulfotransferase 1C1 (SULT1C1)
AU - Li, Xinying
AU - Clemens, Dahn L.
AU - Anderson, Robert J.
N1 - Funding Information:
We thank Dr. R. M. Weinshilboum for the SULT1C1 cDNA, and Dr. S-Y. Wu for the 3,3′-T 2 . This work was supported by the VA Medical Research Service
PY - 2000/12/1
Y1 - 2000/12/1
N2 - Sulfation is an important component of human thyroid hormone metabolism. The role of the human sulfotransferase 1C1 (SULT1C1) is not known. Because SULT1C1 is present in the adult thyroid, intra-thyroidal sulfation of thyroid hormones and their metabolites might occur. We tested this hypothesis by determining the ability of recombinant human SULT1C1 to catalyze iodothyronine sulfation. Apparent K(m) values for 3,3',5-triiodothyronine (T3), 3,3'-diiodothyronine (3,3'-T2), 3',5',3-triiodothyronine (rT3), and 3,3',5,5'-tetraiodothyronine (T4) with SULT1C1 were 28.7, 10.3, 10.2, and 59.3 μM, respectively. Thermal stability and responses to inhibitors also were tested with T3 as the substrate. Enzyme aliquots were measured simultaneously to determine SULT1C1 substrate preferences at optimal iodothyronine concentrations. SULT1C1 activity obtained with T3 was used as 100%, and the activities with 3,3'-T2, rT3, T4, and 3,5-diiodothyronine (3,5-T2) were 614, 314, 25, and 4%, respectively. We report for the first time the characterization of human SULT1C1 with T3 and the preferences of the enzyme for various iodothyronines. The presence of SULT1C1 in the adult thyroid gland raises the possibilities that the enzyme can contribute to intraglandular thyroid hormone processing and iodide reutilization. (C) 2000 Elsevier Science Inc.
AB - Sulfation is an important component of human thyroid hormone metabolism. The role of the human sulfotransferase 1C1 (SULT1C1) is not known. Because SULT1C1 is present in the adult thyroid, intra-thyroidal sulfation of thyroid hormones and their metabolites might occur. We tested this hypothesis by determining the ability of recombinant human SULT1C1 to catalyze iodothyronine sulfation. Apparent K(m) values for 3,3',5-triiodothyronine (T3), 3,3'-diiodothyronine (3,3'-T2), 3',5',3-triiodothyronine (rT3), and 3,3',5,5'-tetraiodothyronine (T4) with SULT1C1 were 28.7, 10.3, 10.2, and 59.3 μM, respectively. Thermal stability and responses to inhibitors also were tested with T3 as the substrate. Enzyme aliquots were measured simultaneously to determine SULT1C1 substrate preferences at optimal iodothyronine concentrations. SULT1C1 activity obtained with T3 was used as 100%, and the activities with 3,3'-T2, rT3, T4, and 3,5-diiodothyronine (3,5-T2) were 614, 314, 25, and 4%, respectively. We report for the first time the characterization of human SULT1C1 with T3 and the preferences of the enzyme for various iodothyronines. The presence of SULT1C1 in the adult thyroid gland raises the possibilities that the enzyme can contribute to intraglandular thyroid hormone processing and iodide reutilization. (C) 2000 Elsevier Science Inc.
KW - SULT1C1
KW - Sulfation
KW - Thyroid hormone metabolism
KW - Triiodothyronine
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U2 - 10.1016/S0006-2952(00)00475-5
DO - 10.1016/S0006-2952(00)00475-5
M3 - Article
C2 - 11077054
AN - SCOPUS:0034575601
SN - 0006-2952
VL - 60
SP - 1713
EP - 1716
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
IS - 11
ER -