TY - JOUR
T1 - Enzymatic characterization of human cytosolic sulfotransferases; identification of ST1B2 as a thyroid hormone sulfotransferase
AU - Fujita, Ken Ichi
AU - Nagata, Kiyoshi
AU - Yamazaki, Toru
AU - Watanabe, Eriko
AU - Shimada, Miki
AU - Yamazoe, Yasushi
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1999/5
Y1 - 1999/5
N2 - Sulfotransferases (ST) are contained as multiple forms in human tissues with overlapping substrate specificities. To identify a form which contributes to the metabolism of 3, 3',5-triiodothyronine (T3), the functional properties of human STs were compared using recombinant STs, ST1A3, ST1AS, ST1B2, ST1E4 and ST2A3. ST1B2 showed a high affinity (K(m) 46.2 μM) for T3 sulfation, whereas ST1A3, ST1A5, ST1E4 and ST2A3 showed high affinities to p-nitrophenol (K(m) 0.4 μM), dopamine (K(m) 7.1 μM), β- estradiol (K(m) 0.3 μM) and dehydroepiandrosterone (K(m) 3.3 μM), respectively. In Western blotting using antibodies raised against an individual ST, hepatic absolute amounts of these STs were determined. The content of ST1B2 in human liver correlated well with T3 sulfation activities in human liver (r=0.96). These results indicate that ST1B2 is biochemically distinct from other forms of ST, and is involved in the metabolism of T3 in human. In addition, studies of thermal stability and 2,6-dichloro-4- nitrophenol (DCNP) inhibition showed that ST1B2 was thermostable and more DCNP resistant than other forms of ST. Affinities for a co-factor, phosphoadenosine 5'-phosphosulfate, also differed 9-fold among 5 different forms of ST.
AB - Sulfotransferases (ST) are contained as multiple forms in human tissues with overlapping substrate specificities. To identify a form which contributes to the metabolism of 3, 3',5-triiodothyronine (T3), the functional properties of human STs were compared using recombinant STs, ST1A3, ST1AS, ST1B2, ST1E4 and ST2A3. ST1B2 showed a high affinity (K(m) 46.2 μM) for T3 sulfation, whereas ST1A3, ST1A5, ST1E4 and ST2A3 showed high affinities to p-nitrophenol (K(m) 0.4 μM), dopamine (K(m) 7.1 μM), β- estradiol (K(m) 0.3 μM) and dehydroepiandrosterone (K(m) 3.3 μM), respectively. In Western blotting using antibodies raised against an individual ST, hepatic absolute amounts of these STs were determined. The content of ST1B2 in human liver correlated well with T3 sulfation activities in human liver (r=0.96). These results indicate that ST1B2 is biochemically distinct from other forms of ST, and is involved in the metabolism of T3 in human. In addition, studies of thermal stability and 2,6-dichloro-4- nitrophenol (DCNP) inhibition showed that ST1B2 was thermostable and more DCNP resistant than other forms of ST. Affinities for a co-factor, phosphoadenosine 5'-phosphosulfate, also differed 9-fold among 5 different forms of ST.
KW - Escherichia coli
KW - Expression system
KW - Substrate specificity
KW - Sulfation
KW - Sulfotransferase
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U2 - 10.1248/bpb.22.446
DO - 10.1248/bpb.22.446
M3 - Article
C2 - 10375162
AN - SCOPUS:0033053169
VL - 22
SP - 446
EP - 452
JO - Biological and Pharmaceutical Bulletin
JF - Biological and Pharmaceutical Bulletin
SN - 0918-6158
IS - 5
ER -