Dermcidin的表达、纯化、功能结构和表皮葡萄球菌抗Dermcidin的机理

发布时间：2018-05-09 01:41

本文选题：抗菌肽 + Dermcidin　；参考：《华东师范大学》2006年博士论文

【摘要】：近年来，由于抗生素的长期和高剂量使用，许多菌株对其产生耐药性，甚至出现了能够耐受几乎所有抗生素的“超细菌”。因此，寻找一种能够替代抗生素的药物迫在眉睫。抗菌肽是宿主先天防御系统的重要组成成分，而来自人皮肤的抗菌肽在抗感染的第一道防线中起主要作用。由于抗菌肽的使用不易产生耐药和交叉抗性，且具有抗细菌、真菌、病毒、原生动物、后生动物寄生物及肿瘤等活性，因此其将有望成为替代普通抗生素的一类新型药物。人汗腺抗菌肽Dermcidin是Schittek等科学家2001年从人体汗液中分离得到的新型小分子抗菌肽，它不仅能杀死革兰氏阴性、阳性细菌和部分真菌，而且还可能对某些癌症如乳腺癌有治疗作刚。它作为一种药物，对人体不存在抗原性，是代替抗生素的首选药物。但是，由于Dermcidin被发现的时间短，到目前为止，对它的研究仅限于其在染色体上的基因定位，从人汗液分离或化学合成该肽来研究其抗菌活性和一些检测方法的摸索。而对Dermcidin的理化性质、二级结构及其在抗菌过程中的结构-功能关系和作用机制的研究仍是一片空白。这些都限制了Dermcidin成为新型抗生素，在感染性疾病和炎症上广泛应用的可能。因此，大量获得Dermcidin，系统研究其结构-功能关系和作用机理是解决上述问题的关键。为了能快速并低成本地获得Dermcidin，，首先我们将Dermcidin基因克隆到毕赤酵母载体pPIC9中，并在毕赤酵母GS115中进行表达。实验结果显示毕赤酵母GS115系统所表达的Dermcidin在pH5.5～7.4范围内具有抗大肠杆菌和金黄色葡萄球菌的活性。这个结果说明在毕赤酵母中表达的DCD-1L能够抗部分革
[Abstract]:In recent years, because of the long-term and high-dose use of antibiotics, many strains have become resistant to antibiotics, and even "superbacteria" which can tolerate almost all antibiotics have emerged. Therefore, it is urgent to find a drug that can replace antibiotics. Antimicrobial peptides are important components of host innate defense system, and antimicrobial peptides from human skin play a major role in the first line of defense against infection. Because the use of antimicrobial peptides is not easy to produce drug resistance and cross resistance, and has anti-bacterial, fungal, virus, protozoan, metazoan parasite and tumor activities, so it is expected to be a new type of drugs to replace ordinary antibiotics. Human sweat gland antimicrobial peptide (Dermcidin) is a new small molecular antimicrobial peptide isolated from human sweat by Schittek and other scientists in 2001. It can not only kill Gram-negative, positive bacteria and some fungi, but also may cure some cancers such as breast cancer. As a kind of medicine, it has no antigenicity to human body and is the first choice to replace antibiotics. However, due to the short time that Dermcidin was discovered, so far, the study of Dermcidin is limited to its gene location on chromosome, isolation or chemical synthesis of the peptide from human sweat to study its antibacterial activity and exploration of some detection methods. However, the study of physicochemical properties, secondary structure, structure-function relationship and action mechanism of Dermcidin is still a blank. All these limit the possibility of Dermcidin becoming a new antibiotic and widely used in infectious diseases and inflammation. Therefore, the key to solve the above problems is to obtain Dermcidin in large quantities and systematically study its structure-function relationship and mechanism. In order to obtain Dermcidin quickly and cheaply, we first cloned the Dermcidin gene into Pichia pastoris vector pPIC9 and expressed it in Pichia pastoris GS115. The results showed that the Dermcidin expressed by Pichia pastoris GS115 system had the activity of resisting Escherichia coli and Staphylococcus aureus in the range of pH5.5~7.4. The results indicate that DCD-1L expressed in Pichia pastoris can resist partial leather.
【学位授予单位】：华东师范大学
【学位级别】：博士
【学位授予年份】：2006
【分类号】：R341

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