Sulfotransferase 2A1 forms estradiol-17-sulfate and celecoxib switches the dominant product from estradiol-3-sulfate to estradiol-17-sulfate.

摘要: Abstract Using recombinant sulfotransferases (SULTs) expressed in E. coli , β-estradiol (E2) sulfonation was examined to determine which SULT enzyme is responsible for producing E2-17-sulfate (E2-17-S). SULTs 1A1*1, 1A1*2, 1A3, 1E1 and 2A1 all sulfated E2 varying extents. No activity observed with SULT1B1. Among the studied, SULT2A1 produced primarily E2-3-sulfate (E2-3-S), but also some E2-17-S trace amounts of disulfate. had a K m value 1.52 μM formation E2-3-S 2.95 μM E2-17-S. highest V max 493 pmol/min/mg protein E2-3-S, 8.8- 47-fold higher than maximal rates disulfate, respectively. formed more efficiently. However, when celecoxib (0–160 μM) included incubation either or human liver cytosol, switched from concentration-dependent manner. The ratio E2-17-S/E2-3-S went up 15 SULT2A1, saturated at 1 cytosol. In both cases, formed, unreacted remained unchanged, suggesting probably bound separate effector site cause conformational change favored production ability alter position may part explain its success experimental prevention treatment breast cancer.