荧光光谱和圆二色谱研究重组内皮抑素与芦荟大黄素的相互作用

Study on the Interaction between Recombinant Endostatin with Aloe by Fluorescence and Circular Dichroism Methods

利用荧光光谱法和圆二色谱法研究了重组内皮抑素与中药有效成分芦荟大黄素的相互作用机制,求得两者在25℃和37℃的结合常数Ka为6.623×104和3.796×104。研究发现,Zn2+等5种金属离子能够竞争性降低重组内皮抑制与芦荟大黄素的结合常数,下降幅度为35%～55%,并且其影响程度随温度升高而增强。鸡胚尿囊膜血管生成实验结果表明,芦荟大黄素能增强重组内皮抑素的抗血管生成活性,使其对新生血管的抑制作用提高50%。

The interaction mechanism of recombinant endostatin with aloe-emodin was studied by fluorescence quenching method and circular dichroism spectra. The binding constants K-a at 25 degrees C and 37 degrees C was 6.623 x 10(4) and 3.796 x 10(4). The results showed that five metal ions, such as Zn2+, Cu2+, Fe2+, Tb2+ and Mn2+, could competitive decrease the binding constant from 35% to 55%, and present an increasing tendency with the increase of temperature. Bioassay of chick chorioallantoic membrane angiogenesis indicates that the aloe-emdin can enhance the angiogenesis activity of recombinant endostatin in test, the inhibiting effect to the new blood vessels was improved 50%. Bioassay of chick chorioallantoic membrane angiogenesis indicates that the aloe-emodin can enhance the angiogenesis activity of recombinant endostatin in test.