人Na^+、K^+-ATPase α1亚单位M1～M2膜外区片段结合活性的研究

Binding activity of polypeptide containing human Na^+,K^+-ATPase α1 subunit M1-M2 extracellular segment

目的研究包含人Na+、K+-ATPaseα1亚单位M1～M2膜外区的多肽片断(HES1衍生物),是否具有与哇巴因结合的能力。方法采用Fmoc固相合成法进行多肽合成,产物经HPLC纯化,并进行质谱分析。然后采用放射性配体受体结合法检测其与哇巴因的结合能力。结果人Na+、K+-ATPaseHES1衍生物与3H-哇巴因具有一定的结合能力。3H-ouabain与Na+,K+-ATPaseHES1衍生物结合的平衡解离常数为24.58nmol·L-1,受体密度为492.43fmol·mg-1蛋白。IC50=3.078×10-7mol·L-1。结论人Na+、K+-ATPaseHES1衍生物具有与哇巴因结合的活性,为其作为一种新型药物奠定实验基础。

Objective To assess the binding activity of polypeptide containing human Na^＋, K^＋-ATPase αl subunit M1-M2 extracellular segment （HES1 derivative）. Methods HES1 derivative was synthesized by Fmoc method and purified by high-performance liquid chromatography-mass spectrometry, and its binding activity was identified by radioligand binding assay. Results 3H-ouabain and synthetic HES1 derivative showed some binding activity with the equilibrium dissociation constant （KD） of 24.58 nmol/L, with the the receptor density of 492.43 fmol. mgt pro. and IC50 of 3.078 × 10^-7 mol/L. Conclusion HES 1 derivative can bind to ouabain and has the potential of becoming an effective therapeutic agent.