Development of DNA, RNA Relating Enzyme-Inhibitory Polysaccharides, Analysis of Their Inhibition Mechanism and the Application

研究了多糖对5种限制性内切酶、2种DNA连接酶和3种逆转录酶的抑制活性。所有对这些酶有抑制作用的糖类都是硫酸盐类。这种抑制作用源于这些多糖与酶蛋白的结合，而不是与底物DNA和RNA的结合。因此，抑制程度是酶依赖性的。哺乳动物病原体的逆转录酶比禽类病原体的逆转录酶对多糖更敏感，DNA连接酶对多糖的抗性远高于反转录酶。海藻热水提取物是与酶抑制多糖相关的DNA、RNA的良好来源。这些提取物中的有效成分是褐藻中的岩藻硫酸盐和红藻中的卡拉胶。这些海藻糖制剂的硫含量低于肝素和其他动物来源的粘多糖，但它们对…的抑制作用多糖的活性远高于动物多糖。这些事实表明，除了糖的硫酸化程度外，糖链的结构和硫酸盐在糖段中的位置对抑制活性也有重要的作用。草药和香料提取物中的有效成分是类黄酮和单宁，但这些物质的糖基化似乎是抑制活性所必需的。卡拉胶在热溶液中倒入CaCl2溶液或直接冷却时形成凝胶，此外，它们还能与许多不同亲和力的限制性酶结合。角叉菜胶珠和角叉菜胶丝被认为是纯化限制性内切酶的良好亲和性凝胶，赤子爱胜子岩藻糖硫酸酯粗品和丁香提取物粗品对M-MuLV和HIV的逆转录酶具有高度的抑制作用，在低至0.15µg/ml和10-100µg/ml的浓度下，这两种粗品完全抑制HIV对MT-4细胞的感染。较少

Inhibitory activity of polysaccharides on 5 restriction enzymes, 2 DNA ligases, and 3 reverse transcriptases was investigated. All the saccharides inhibitory to these enzymes were the ones sulfated. The inhibition was derived from the binding of these polysaccharides to enzyme proteins, but not from the binding to the substrate DNA and RNA. Therefore the level of inhibition was enzyme-dependent. Reverse transcriptases from mammal pathogens were more sensitive to polysaccharides than those from avian pathogens and DNA ligases were far more resistant to polysaccharides than reverse transcriptases.Hot water extracts of seaweeds were good sources of DNA, RNA relating enzyme-inhibitory polysaccharides. Effective constituents in these extracts were fucan sulfates in the cases of brown algae and carrageenans in the cases of red algae. Sulfur contents of these seaweed saccharide preparations were lower than those of heparin and other mucopolysaccharides of animal origin, but their inhibitory a … More ctivity was much higher than the polysaccharides from animals. These facts indicate that, in addition to the level of sulfation of saccharides, structure of the saccharide chains and the positions of sulfate in saccharide moieties have an important role for the inhibitory activity.Effective constituents in the extracts of herbs and spices were identified to be flavonoids and tannins, but glycosylation of these substances appears to be essential for the inhibitory activity.Carrageenans form gels when their hot solutions were poured into CaCl_2 solution or just cooled and, in addition, they can bind to a number of restriction enzymes with different affinities. Beads and filaments of carrageenans were regarded as good affinity gels for the purification of restriction enzymes.Crude preparations of fucan sulfate from Eisenia arborea and of clove extracts were highly inhibitory to the reverse transcriptases from M-MuLV and HIV, and the infection of HIV to MT-4 cells was completely inhibited by these preparations at the concentrations of as low as 0.15 mug/ml and 10-100 mug/ml, respectively. Less