Oligodeoxynucleotide from SARS virus was selected and synthesized. Its complexes with alkaloid compounds were investigated by electrospray mass spectrometry. We found that three alkaloid compounds could interact with the DNA target molecule in five alkaloids analyzed. With increasing molar ratio of the three alkaloid compounds, the complexes between alkaloids and DNA with different stoichiometric ratios were found in their MS spectra. The order of the alkalinity of their gas phase corresponds to that of liquid phase, that is: Palmatine>Jatrorrhizine>Berberin. The relative abundance of these complexes in mass spectra can assess the relative affinities of above three alkaloid compounds with the DNA target molecule. In this paper, the binding sites between jatrorrhizine and DNA was deduced from the interaction experiments of jatrorrhizine with three nucleosides.
对土鳖虫水浸醇沉提取物2号样品进行了离子交换柱层析,得组分Ⅰ、Ⅱ、Ⅲ。实验结果表明,组分Ⅲ的溶栓活性明显高于组分Ⅰ和组分Ⅱ,其蛋白质含量为88.9%,分子量约为38,018,效价为313 UK/mg,比活力为352 UK/mg蛋白。将组分Ⅲ再进行凝胶过滤柱层析,得组分Ⅳ、Ⅴ、Ⅵ。组分Ⅵ的生物活性高于组分Ⅳ和组分Ⅴ,蛋白质含量为89.3%,电泳呈现两条带,分子量约为34,623和39,811,效价为77 UK/mg,比活力为86 UK/mg蛋白。将组分Ⅵ进行反相高效液相色谱柱层析,收集保留时间为17 m in的洗脱峰,得到土鳖虫纯蛋白质,呈白色絮状,极易溶于水。再一次用反相高效液相色谱检查其纯度,保留时间为17.073 m in,无杂质峰。纤溶活性实验结果表明,组分Ⅵ既有直接降解纤维蛋白的作用,同时也有纤溶酶原激活剂样作用。
