【作者】 赵立苹；

【导师】 黄登宇；

【作者基本信息】 山西大学 ， 生物化学与分子生物学， 2005， 硕士

【摘要】 本文研究分为两部分。主要研究的内容为中华稻蝗抗菌肽分离的初步研究。昆虫的免疫系统没有像高等动物所具有的免疫球蛋白和补体系统,在长期的进化过程中,发展出了一套独特的免疫系统。自Boman H.G.领导的研究小组从惜古比天蚕（Hyalophora cecropia）的蛹中诱导分离得到第一个昆虫抗菌肽——天蚕素（cecropin）后,昆虫的免疫研究进入了一个新时期,对昆虫抗菌肽的研究具有重要的理论意义和潜在的应用前景。本部分研究以不完全变态的直翅目昆虫中华稻蝗（Oxya chinensis）为材料,采用室内词养针刺损伤并用大肠杆菌（Escherchia coli）菌悬液浸泡的诱导方法,从中华稻蝗的前肠提取液中检测到了抗菌物质的存在,并做了初步的分离研究。这些抗菌物质对革兰氏阳性菌（金黄色葡萄球菌（Staphylococcus auerus）、藤黄微球菌（Baci（?）ssubtilis）及枯草杆菌（Micrococcus luteus））有广泛的抗性,而对革兰氏阴性菌（大肠杆菌（Escherchia coli））没有抗性。提取液通过Sephadex G-50柱层析做了初步分离,表明中华稻蝗经诱导产生了不同的抗菌类物质。电泳、高压液相和质谱法对抗菌比活性最大的粗峰的分析表明,中华稻蝗经诱导可能产生出分子量为3.6KD左右的不同的抗菌肽。这为中华稻蝗的诱导、中华稻蝗抗菌物质的进一步研究及中华稻蝗的免疫研究奠定了一定的基础。 在pUC118 DNA与配体小檗碱相互作用荧光特征的研究部分中,采用荧光分析法研究了中药黄连素的有效成分——小檗碱（Berberine）与质粒pUC118环状双链超螺旋DNA相互作用的荧光光谱特征,对其相互作用方式进行了初步探讨。研究结果表明,在Gly-Hcl缓冲液（pH=3.20）中,二者相互作用的荧光强度达到最大;二者相互作用达到稳态时,一个小檗碱分子约结合七个碱基对。二者的结合除嵌插方式外,还存在非特异的静电作用。不同的荧光猝灭剂对二者相互作用荧光强度的猝灭程度是不同的,游离的水合状态小檗碱最容易被[Fe（CN）₆]^-4猝灭。更多还原

【Abstract】 This paper includes two sections. The main section is the preliminary studies on antibacterial peptides isolated from Oxya chinensis imagoes. Insects have developed a special immuno system through the long evolutionary progress. From the first antibacterical pipetede, cecropin, was induced and isolated from the nympha of Hyalophora cecropia by the team of Bomon H G, Great progress has been made on the study of insect antibacterical substance in recent years. The insects used in the investigations belongs to Holometabola. In this section, Oxya chinensis imagoes, a hemimetalolous insect, as the research material, were fed by manual work and injured with a needle and then infected by E.coli. The isolation of antibacterial substances from the foreguts of Oxyu chinensis imagoes was preliminary studied. The antibacterial substances fiom the foreguts of Oxya chinensis imagoes can kill Gram-positive bacteria (Staphylococcus auerus, Bacillussubtilis, Mlcrococcus luteus), but has no effect on Gram-negative bacteria (Escherchia coli). These antibacterial substances distribute in different peak when extraction was isolated by chromatography on a column of Sephadex G-50, which shows that Oxya chinensis imago induced can produce different kinds of antibacterial substances Small antibacterial peptides, about 3.6kD, can be generated from the foreguts of Oxya chinensis imagoes induced by analysis of HPLC and Mass spectra. The paper provides foundation for further research on antibacterial substances and immunity defence of Oxya chinensis.The second section is the fluorescence characteristics of the interaction between Plasmid pUC118 DNA and ligand berbenne. DNA is a kind of important biological macromolecule. The study of DNA is an important field of biology, chemistry and medical science. In the study field of the nucleic acid chemistry, small molecule can be used as treatment drugs for cancers, nucleic acid chromomeres and structure probe et al. The interaction of nucleic acid and small molecule ligand is a heated-report of nucleic acid更多还原