光谱法和分子对接模拟技术研究托拉塞米与胃蛋白酶和胰蛋白酶的相互作用（英文）

发布时间：2018-10-20 17:43

【摘要】：托拉塞米(TOR)属于吡啶磺酰脲类袢利尿剂,被广泛有效地用于高血压,心脏衰竭,慢性肾功能衰竭和肝脏疾病的治疗。TOR在治疗过程中易引起的不良反应之一为轻微肠胃不适。然而,TOR与消化蛋白酶(胰蛋白酶和胃蛋白酶)分子间的相互作用鲜有报道。在模拟生理条件下,采用荧光光谱、紫外-可见吸收光谱、圆二色谱和分子对接技术研究了不同温度下托拉塞米(Torasemide,TOR)与胃蛋白酶(Pepsin)和胰蛋白酶(Trypsin)间的相互作用。所有荧光数据均进行了内滤光校正以获得更准确的结合参数。结果表明,TOR-Pepsin和TOR-Trypsin体系的猝灭常数(KSV)均与温度呈负相关,说明TOR与Pepsin及Trypsin之间的作用机制均为静态荧光猝灭。利用紫外-可见吸收光谱、同步荧光光谱、3D荧光光谱和圆二色光谱法考查了TOR对Trypsin和Pepsin构象的影响。结果发现胃蛋白酶或胰蛋白酶中酪氨酸残基的极性改变较色氨基更明显,TOR可改变色氨酸残基的微环境并降低Trypsin和Pepsin中β-折叠结构,进而可能影响其生理功能。分子对接结果表明,TOR与Pepsin的结合位点位于由Asp-32和Asp-215组成的活性中心周围,从而抑制Pepsin活性。而TOR通过疏水作用力结合在Trypsin的口袋型底物结合位点(S1口袋),促进底物进入酶活性中心,最终表现为Trypsin活性升高。该研究探讨了TOR与胃蛋白酶和胰蛋白酶的结合作用和毒性机制,为TOR的安全使用提供重要依据。
[Abstract]:Tora Semie (TOR), a pyridine sulfonylurea loop diuretic, is widely and effectively used in the treatment of hypertension, heart failure, chronic renal failure and liver disease. However, the interaction between TOR and pepsin (trypsin and pepsin) molecules is rarely reported. Under simulated physiological conditions, the interaction of Tora Semi (Torasemide,TOR) with pepsin (Pepsin) and trypsin (Trypsin) at different temperatures was studied by fluorescence spectra, UV-Vis absorption spectra, circular dichroism and molecular docking techniques. All fluorescence data were corrected by internal filter to obtain more accurate binding parameters. The results show that the quenching constant (KSV) of TOR-Pepsin and TOR-Trypsin system is negatively correlated with temperature, indicating that the mechanism of interaction between TOR and Pepsin and Trypsin is both static fluorescence quenching. The effects of TOR on the conformation of Trypsin and Pepsin were investigated by UV-Vis absorption spectra, synchronous fluorescence spectra, 3D fluorescence spectra and circular dichroism spectroscopy. The results showed that the polarity of tyrosine residues in pepsin or trypsin was more obvious than that in chromoamino group. TOR could change the microenvironment of tryptophan residues and decrease the 尾 -fold structure in Trypsin and Pepsin, which might affect its physiological function. The molecular docking results showed that the binding sites of TOR and Pepsin were located around the active sites composed of Asp-32 and Asp-215, which inhibited the activity of Pepsin. However, TOR binds to the pocket substrate binding site (S1 pocket) of Trypsin by hydrophobic force, which promotes the substrate to enter the enzyme active center, and finally shows the increase of Trypsin activity. In this study, the binding and toxic mechanism of TOR with pepsin and trypsin were discussed, which provided important basis for safe use of TOR.
【作者单位】：中央民族大学生命与环境科学学院;中央民族大学北京市食品环境与健康工程技术研究中心;
【基金】：The National Natural Science Foundation of China(21177163) 111 Project B08044 First-Class University First Class Academic Program of Minzu University of China(YLDX01013) Special Guidance Fund of Building World First-Class Universities(Disciplines)and Characteristic Development of Minzu Unviersity of China(2016) Coordinate Development of FirstClass and First-Class University Discipline Construction Funds(10301-0150200604) The Academic Team Construction Project of Minzu University of China(2015MDTD25C&13C) The Fundamental Research Funds for the Central Universities”(10301-01404031,2015) First-Class Universities and First-Class Discipline Construction Transitional Funds under Special Funding(2016.ph.D),2015MDTD08C
【分类号】：R446.1

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