Department of Pharmaceutics, University of Washington, Seattle, Washington (H.Z., C.W., A.B., K.E.T., B.P.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (A.B., B.P.); In Vitro ADMET Laboratories Inc., Columbia, Maryland (A.P.L.); Department of Pharmacokinetics, Pharmacodynamics and Drug Metabolism, Merck & Co., Inc., Boston, Massachusetts (P.W.F.); Genentech Inc., South San Francisco, California (R.H.T., S.C.K.); and Drug Metabolism Department, Gilead Sciences Inc., Foster City, California (B.J.S., B.P.M.).
Department of Pharmaceutics, University of Washington, Seattle, Washington (H.Z., C.W., A.B., K.E.T., B.P.); Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington (A.B., B.P.); In Vitro ADMET Laboratories Inc., Columbia, Maryland (A.P.L.); Department of Pharmacokinetics, Pharmacodynamics and Drug Metabolism, Merck & Co., Inc., Boston, Massachusetts (P.W.F.); Genentech Inc., South San Francisco, California (R.H.T., S.C.K.); and Drug Metabolism Department, Gilead Sciences Inc., Foster City, California (B.J.S., B.P.M.)
Drug Metab Dispos. 2020 Jul;48(7):528-536. doi: 10.1124/dmd.120.090738. Epub 2020 Apr 29.
Current challenges in accurately predicting intestinal metabolism arise from the complex nature of the intestine, leading to limited applicability of available in vitro tools as well as knowledge deficits in intestinal physiology, including enzyme abundance. In particular, information on regional enzyme abundance along the small intestine is lacking, especially for non-cytochrome P450 enzymes such as carboxylesterases (CESs), UDP-glucuronosyltransferases (UGTs), and sulfotransferases (SULTs). We used cryopreserved human intestinal mucosa samples from nine donors as an in vitro surrogate model for the small intestine and performed liquid chromatography tandem mass spectrometry-based quantitative proteomics for 17 non-cytochrome P450 enzymes using stable isotope-labeled peptides. Relative protein quantification was done by normalization with enterocyte marker proteins, i.e., villin-1, sucrase isomaltase, and fatty acid binding protein 2, and absolute protein quantification is reported as picomoles per milligram of protein. Activity assays in glucuronidations and sequential metabolisms were conducted to validate the proteomics findings. Relative or absolute quantifications are reported for CES1, CES2, five UGTs, and four SULTs along the small intestine: duodenum, jejunum, and ileum for six donors and in 10 segments along the entire small intestine (A-J) for three donors. Relative quantification using marker proteins may be beneficial in further controlling for technical variabilities. Absolute quantification data will allow for scaling factor generation and in vivo extrapolation of intestinal clearance using physiologically based pharmacokinetic modeling. SIGNIFICANCE STATEMENT: Current knowledge gaps exist in intestinal protein abundance of non-cytochrome P450 enzymes. Here, we employ quantitative proteomics to measure non-cytochrome P450 enzymes along the human small intestine in nine donors using cryopreserved human intestinal mucosa samples. Absolute and relative abundances reported here will allow better scaling of intestinal clearance.
目前，准确预测肠道代谢所面临的挑战源于肠道的复杂性，这导致现有的体外工具的适用性有限，同时也缺乏对肠道生理学（包括酶的丰度）的了解。特别是，关于小肠沿程的区域酶丰度的信息缺乏，特别是对于非细胞色素 P450 酶（如羧酸酯酶 [CESs]、UDP-葡糖醛酸基转移酶 [UGTs] 和磺基转移酶 [SULTs]）。我们使用 9 位供体的冷冻保存人肠黏膜样本作为小肠的体外替代模型，并用基于液相色谱串联质谱的稳定同位素标记肽对 17 种非细胞色素 P450 酶进行定量蛋白质组学分析。相对蛋白定量通过与肠细胞标志物蛋白（即微绒毛蛋白-1、蔗糖酶异麦芽糖酶和脂肪酸结合蛋白 2）归一化来完成，并以皮摩尔/毫克蛋白报告绝对蛋白定量。进行了葡萄糖醛酸化和连续代谢的活性测定，以验证蛋白质组学发现。对沿小肠的十二指肠、空肠和回肠的 6 位供体和整个小肠的 10 个节段（A-J）的 6 位供体，报告了 CES1、CES2、5 种 UGT 和 4 种 SULT 的相对或绝对定量。使用标志物蛋白进行相对定量可能有助于进一步控制技术变异性。绝对定量数据将允许生成比例因子，并使用基于生理的药代动力学模型对体内肠清除率进行外推。意义：非细胞色素 P450 酶的肠道蛋白丰度存在当前的知识空白。在这里，我们使用定量蛋白质组学方法，使用冷冻保存的人肠黏膜样本，在 9 位供体中测量人小肠中的非细胞色素 P450 酶。这里报告的绝对和相对丰度将允许更好地缩放肠清除率。
