Egeberg and his coauthors reported that HS and inflammatory bowel disease similarities suggest a shared pathogenesis, including the worsening effect of smoking on both conditions; the appearance of scarring and sinus tract formation; the apparent involvement of T-helper 17 cells, interleukin-23, and tumor necrosis factor; and the coinvolvement of genes such as SULT1B1
and SULT1 E1 "Finally, an increased prevalence of spondylarthropathy has been reported in patients with IBD as well as in those with HS, raising the hypothesis that genetic, epigenetic, and/or environmental factors cooperate to lead to dysregulated inflammatory pathways across these immune-mediated diseases," they wrote.
At concentrations > 0.15 [micro]M, 3-OH-BaP inhibited its own sulfonation in cytosol fractions that were genotyped for SULT1A1 variants, as well as with expressed SULT1A1*1, SULT1A1*2, and SULT1E1, but not with SULT1A3 or SULT1B1. The inhibition fit a two-substrate kinetic model.
SULT1A1, SULT1B1, and SULT1E1 are the major phenol sulfotransferases expressed in human liver, with SULT1A1 (also known as ST1A3) found at the highest concentration (Honma et al.
The expression of human SULT1A1*1, SULT1A3, SULT1B1, and SULT1E1 in Escherichia coli has been described previously (Dajani et al.
The 100,000g supernatant fractions of SULT1A1*1, SULT1A3, SULT1B1, and SULT1E1 were partially purified by chromatographic methods (Falany et al.
coli expressing SULT1A1*1, SULT1A3, SULT1B1, and SULT1E1, and the purchased Sf-9 cytosol fraction (PanVera, Madison, WI) containing SULT1A1*2.
SULT1A3 and SULT1B1 did not exhibit substrate inhibition over a concentration range up to 5 [micro]M and showed much higher apparent [K.sub.m] values for 3-OH-BaP.
Expressed SULT1B1 showed a quite different inhibitory interaction with OH-PCBs, compared with SULT1A1*1, SULT1A1*2, SULT1A3, and SULTIE1, in that 6'-OHCB35 (A1) was a quite potent inhibitor (I[C.sub.50], 4.72 [micro]M) of 3-OH-BaP sulfonation (Table 3).
We observed substrate inhibition in HL cytosol and with SULT1A1 and SULT1E1, but not with SULTIA3 or SULT1B1. We studied the kinetics of substrate inhibition in liver cytosol and SULT1A1*2 and found that they fit a two-substrate model proposed for the sulfonation of estradiol by SULT1E1.
2002) and that a compound structurally related to OH-PCBs, 2,4,4'-trichloro-2'hydroxydiphenyl ether (triclosan), inhibited sulfonation and glucuronidation of 3-OHBaP and other substrates in HL cytosol and with SULT1A1, SULT1B1, and SULT1E1 (Wang et al.
SULT1B1, the thyroid hormone sulfotransferase, catalyzed the sulfonation of 3-OH-BaP; however, OH-PCBs that were potent inhibitors of SULT1A1 were only weak inhibitors of the SULT1Bl-catalyzed reaction.