3β-羟基类固醇脱氢酶/类固醇Δ5,4-异构酶1(3β-HSD1)在人胎盘中从孕烯醇酮生物合成孕酮以维持正常妊娠中起关键作用。它们是否抑制胎盘3β-HSD1和抑制模式尚不清楚。在这项研究中,我们筛选了五种抑制人3β-HSD1的21种农药和杀菌剂,并将其与大鼠同源物3β-HSD4进行了比较。3β-HSD活性通过在NAD+存在下将孕烯醇酮催化成孕酮来测量。在21种化学物质中,唑(苯醚甲环唑),硫代氨基甲酸酯(硫双和费班)和有机氯(六氯酚)显着抑制人3β-HSD1,其半数最大抑制浓度(IC50)值为2.77、0.24、0.68和17.96μM,分别。我们还发现苯醚甲环唑,ferbam和六氯酚是3β-HSD1的混合/竞争性抑制剂,而thiram是混合/非竞争性抑制剂。对接分析表明苯醚甲环唑和六氯酚结合类固醇结合位点。苯醚甲环唑和六氯酚,除了硫双和费班之外,还显着抑制大鼠3β-HSD4活性,IC50为1.12和2.28µM,分别。Thiram和Ferbam可能通过干扰半胱氨酸残基显著抑制人3β-HSD1,而它们对大鼠3β-HSD4没有影响。总之,一些农药能有效抑制胎盘3β-HSD,导致孕酮形成的减少。
3β-Hydroxysteroid dehydrogenase/steroid Δ5,4-isomerase 1 (3β-HSD1) plays a critical role in the biosynthesis of progesterone from pregnenolone in the human placenta to maintain normal pregnancy. Whether they inhibit placental 3β-HSD1 and mode of inhibition remains unclear. In this study, we screened 21 pesticides and fungicides in five classes to inhibit human 3β-HSD1 and compared them to rat homolog 3β-HSD4. 3β-HSD activity was measured by catalyzing pregnenolone to progesterone in the presence of NAD+. Of the 21 chemicals, azoles (difenoconazole), thiocarbamates (thiram and ferbam) and organochlorine (
hexachlorophene) significantly inhibited human 3β-HSD1 with half maximal inhibitory concentration (IC50) values of 2.77, 0.24, 0.68, and 17.96 μM, respectively. We also found that difenoconazole, ferbam and
hexachlorophene are mixed/competitive inhibitors of 3β-HSD1 while thiram is a mixed/noncompetitive inhibitor. Docking analysis showed that difenoconazole and
hexachlorophene bound steroid-binding site. Difenoconazole and
hexachlorophene except thiram and ferbam also significantly inhibited rat 3β-HSD4 activity with IC50 of 1.12 and 2.28 µM, respectively. Thiram and ferbam significantly inhibited human 3β-HSD1 possibly by interfering with cysteine residues, while they had no effects on rat 3β-HSD4. In conclusion, some pesticides potently inhibit placental 3β-HSD, leading to the reduction of progesterone formation.