新型抗菌肽MDAP-2的结构优化与高效表达

日趋严重的病原菌耐药性问题使得新型抗生素替代品的研发迫在眉睫。抗菌肽因具有抗菌机制独特，不易产生耐药性，且不损伤动物体细胞和无免疫原性等特点已成为新药研发的热点。课题组在采用抑制性消减杂交技术筛选获得十余个家蝇抗菌肽基因，采用原核表达系统制备与其他抗菌肽基因的核苷酸及氨基酸序列同源性极低、抗菌活性高、抗菌谱广的新型抗菌肽MDAP-2基础上，针对其正、负电荷含量、肽链结构和两亲性对其序列进行分子修饰，提高其抗菌活性；通过抗菌肽MDAP-2-人血清白蛋白重组融合蛋白的构建，增加抗菌蛋白在动物体内的半衰期；通过抗菌肽MDAP-2-人血清白蛋白重组融合蛋白昆虫杆状病毒表达系统的构建，增加重组融合蛋白表达量，进而对抗菌肽MDAP-2重组融合蛋白体内外药效学及体内药代动力学进行研究，为动物用长效抗菌肽的开发奠定坚实的基础，以推进抗菌肽在一定程度上替代抗生素，减少抗生素使用，延缓病原菌耐药性产生的进程。

Increasingly serious pathogen resistance problems made new antibiotics substitutes research being imminent. For the unique antibacterial mechanism, no drug resistance, no immunogenicity, and does not damage animal cells, etc., antibacterial peptides have become hot issues of new drug research and development. Based on more than ten housefly antibacterial peptide genes screened by SSH techniques. Using prokaryotic expression system, we obtained a new type of antibacterial peptide MDAP-2, which have high antibacterial activity, wide antibacterial spectrum, and extremely low sequence homology with other antibacterial peptide genes. We will modify the sequence of MDAP-2 in the light of its positive and negative content, peptide chain structure, and amphiphilic features to improve its antibacterial activity. We will construct a recombinant fusion protein MDAP-2- HSARb (human serum albumin) to increase the half-life of MDAP-2 in animals. Through expressing MDAP-2- HSARb in insect baculovirus expression system to increase the expression amount of MDAP-2- HSARb recombinant fusion protein. And thus the pharmacodynamics in vivo, pharmacodynamics in vitro, and pharmacokinetic in vivo were studied. The project will lay a solid foundation for development of long-acting antibacterial peptide for animals. And it will promote the antibacterial peptides substitute for antibiotics to some extent, reduce antibiotic use, and delay the process of pathogenic bacteria drug resistance.