The Preliminary Studies On Antibacterial Peptides Isolated From Oxya Chinensis Imagoes And Fluorescence Characteristics Of The Interaction Between Plasmid PUC118 DNA And Ligand Berberine

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...