Department of Pharmaceutical Chemistry, Semmelweis University, Hogyes E. 9, 1092 Budapest, Hungary.
Center for Pharmacology and Drug Research & Development, Semmelweis University, 1085 Budapest, Hungary.
Int J Mol Sci. 2024 Oct 1;25(19):10575. doi: 10.3390/ijms251910575.
The enantioselective binding of three proton pump inhibitors (PPIs)-omeprazole, rabeprazole, and lansoprazole-to two key plasma proteins, α1-acid glycoprotein (AGP) and human serum albumin (HSA), was characterized. The interactions between PPI enantiomers and proteins were investigated using a multifaceted analytical approach, including high-performance liquid chromatography (HPLC), fluorescence and UV spectroscopy, as well as in silico molecular docking. HPLC analysis demonstrated that all three PPIs exhibited enantioseparation on an AGP-based chiral stationary phase, suggesting stereoselective binding to AGP, while only lansoprazole showed enantioselective binding on the HSA-based column. Quantitatively, the -enantiomers of omeprazole and rabeprazole showed higher binding affinity to AGP, while the -enantiomer of lansoprazole displayed greater affinity for AGP, with a reversal in the elution order observed between the two protein-based columns. Protein binding percentages, calculated via HPLC, were greater than 88% for each enantiomer across both transport proteins, with all enantiomers displaying higher affinity for AGP compared to HSA. Thermodynamic analysis indicated that on the HSA, the more common, enthalpy-controlled enantioseparation was found, while in contrast, on the AGP, entropy-controlled enantioseparation was observed. The study also identified limitations in using fluorescence titration due to the high native fluorescence of the compounds, whereas UV titration was effective for both proteins. The determined log values were in the range of 4.47-4.83 for AGP and 4.02-4.66 for HSA. Molecular docking supported the experimental findings by revealing the atomic interactions driving the binding process, with the predicted enantiomer elution orders aligning with experimental data. The comprehensive use of these analytical methods provides detailed insights into the enantioselective binding properties of PPIs, contributing to the understanding of their pharmacokinetic differences and aiding in the development of more effective therapeutic strategies.
三种质子泵抑制剂（PPIs）-奥美拉唑、雷贝拉唑和兰索拉唑对两种关键血浆蛋白，即α1-酸性糖蛋白（AGP）和人血清白蛋白（HSA）的对映选择性结合进行了特征描述。使用包括高效液相色谱（HPLC）、荧光和紫外光谱以及计算机分子对接在内的多方面分析方法研究了 PPI 对映异构体与蛋白质之间的相互作用。HPLC 分析表明，所有三种 PPI 在基于 AGP 的手性固定相上均表现出对映体分离，表明其对 AGP 具有立体选择性结合，而只有兰索拉唑在基于 HSA 的柱上表现出对映体选择性结合。定量地，奥美拉唑和雷贝拉唑的 -对映异构体对 AGP 表现出更高的结合亲和力，而兰索拉唑的 -对映异构体对 AGP 表现出更大的亲和力，在两种基于蛋白质的柱之间观察到洗脱顺序的反转。通过 HPLC 计算的蛋白结合百分比在每个对映异构体中均大于 88%，跨越两种转运蛋白，所有对映异构体对 AGP 的亲和力均高于 HSA。热力学分析表明，在 HSA 上，发现更常见的、受焓控制的对映体分离，而与之相反，在 AGP 上，观察到受熵控制的对映体分离。该研究还发现，由于化合物的天然荧光较高，荧光滴定存在局限性，而紫外滴定对两种蛋白质均有效。确定的 log 值范围为 AGP 的 4.47-4.83 和 HSA 的 4.02-4.66。分子对接通过揭示驱动结合过程的原子相互作用，支持实验结果，预测的对映体洗脱顺序与实验数据一致。这些分析方法的综合应用提供了对 PPIs 对映选择性结合特性的详细了解，有助于理解它们在药代动力学方面的差异，并有助于开发更有效的治疗策略。
