Tocopherols are essential micronutrients for mammals widely known as potent lipid-soluble antioxidants that are present in cell membranes. Recent studies have demonstrated that most of the carboxychromanol (CEHC), a tocopherol metabolite, in the plasma exists primarily in sulfate- and glucuronide-conjugated forms. To gain insight into the enzymatic sulfation of tocopherols and their metabolites, a systematic investigation was performed using all 14 known human cytosolic sulfotransferases (SULTs). The results showed that the members of the SULT1 family displayed stronger sulfating activities toward tocopherols and their metabolites. These enzymes showed a substrate preference for γ-tocopherol over α-tocopherol and for γ-CEHC over other CEHCs. Using A549 human lung epithelial cells in a metabolic labeling study, a similar trend in the sulfation of tocopherols and CEHCs was observed. Collectively, the results obtained indicate that SULT-mediated enzymatic sulfation of tocopherols and their metabolites is a significant pathway for regulation of the homeostasis and physiological functions of these important compounds.
生育酚是哺乳动物必需的微量营养素,被广泛认为是存在于细胞膜中的有效脂溶性
抗氧化剂。最近的研究表明,血浆中的大部分羧基苯并二氢
吡喃醇 (CEHC)(一种
生育酚代谢物)主要以
硫酸盐和
葡萄糖醛酸结合形式存在。为了深入了解
生育酚及其代谢物的酶促
硫酸化,使用所有 14 种已知的人类胞质磺基转移酶 (SULT) 进行了系统研究。结果表明,SULT1家族成员对
生育酚及其代谢物表现出更强的
硫酸化活性。这些酶显示出对 γ-
生育酚的底物偏好高于 α-
生育酚,对 γ-CEHC 的底物偏好高于其他 CEHC。在代谢标记研究中使用 A549 人肺上皮细胞,观察到
生育酚和 CEHC
硫酸化的类似趋势。总的来说,获得的结果表明,SULT 介导的
生育酚及其代谢物的酶促
硫酸化是调节这些重要化合物的稳态和生理功能的重要途径。