中文摘要：

为了研究绵羊抗菌肽NK-Lysin主要活性区的生物学功能,试验设计并合成了3对功能区多肽片段,并利用径向扩散试验和最小抑菌浓度对其抗菌活性进行检测,分析了合成多肽对鸡血红细胞的毒性作用,筛选出抗菌效果最好的多肽对沙门氏菌攻毒的雏鸡进行治疗,检测其治疗效果。结果表明,合成多肽对大肠杆菌、沙门氏菌具有抑制活性,多肽片段长度、多肽C-端有无酰胺化及多肽内的二硫键是否成环对多肽的抗菌活性均有影响;筛选出的2个多肽在治疗雏鸡沙门氏菌攻毒的过程中能够明显降低死亡率,对雏鸡心脏、肝脏、肾脏的病理损伤也明显小于对照组。本研究结果为绵羊抗菌肽NK-Lysin作为候选抗菌药物的开发奠定了基础。

英文摘要：

In order to study the biological function of the main active region of sheep antimicrobial peptide NK-Lysin,three pairs of functional domain peptide fragments were designed and synthesized the antibacterial activity was detected by radial diffusion test and minimal inhibitory concentration.We analyzed the toxic effects of chicken red blood cells and screen the best peptides for treatment chicken challenged by Salmonella pullorum in this study.The rusults showed that synthesized peptides were inhibitory to Escherichia coli and Salmonella pullorum.Fragment length of peptides,C-terminal amidation and peptide inner loop were essential to antibacterial activity.Two of synthesized peptides were used to treat chichen challenged by Salmonella pullorum which obviously decreased the mortality of chicken.The pathological damage of heart,liver,kidney were less than that of control group.This study laid a foundation for the development of the sheep NK-Lysin peptides as candidate antimicrobial agents.