Structure-related activity of tick defensin and antibody monitoring system in wildlife

防御素是一类重要的抗菌肽，广泛存在于脊椎动物、无脊椎动物和植物中。无脊椎动物防御素已被确定在蜱。在这项研究中，化学合成的蜱防御素被用来研究对中肠分离的细菌的活性谱。合成的蜱防御素对金黄色葡萄球菌有抗菌活性，但对伽氏疏螺旋体和共生嗜麦芽寡养单胞菌无抗菌活性。结果表明，蜱类抗菌肽的活性对于选择和保留莱姆病螺旋体等中肠特异性细菌具有重要意义。S的三级结构使其具有更强的活性。金黄色葡萄球菌在短时间内的杀灭效果优于初治金黄色葡萄球菌。杀蜱活性与蜱的防御结构有关。在野生动物监测系统中检测蜱类防御抗体，有助于了解蜱传疾病的危险性。

Defensins are major group of antimicrobial peptides and are found widely in vertebrates, invertebrates and plants. Invertebrate defensins have been identified in ticks. In this study, chemically synthesized tick defensins were used to investigate the activity spectrum against bacteria isolated from the midgut. Synthetic tick defensin showedantimicrobial activity against Staphylococcus aureus but not Borrelia garinii and symbiotic Stenotrophomonas maltophila. The results demonstrate that the activity of antimicrobial peptides from tick is important for selection and reservation of specific bacteria such as Lyme disease spirochetes in the midgut. The teriary structure brought more potent activity to S. aureus than primary one in short-time killing. The killing activity is related to the structure of tick defensing. Antibody against tick defensing in wildlife monitoring system can useful to know the risk of tick-borne diseases.