定向优化的海南沼蛙temporin衍生肽抗耐甲氧西林金黄色葡萄球菌生物被膜机制及抗感染作用研究

耐甲氧西林金黄色葡萄球菌（MRSA）是社区和医院获得性感染的主要病原菌，能在受损宿主组织内形成生物被膜，增强细菌对药物的抵抗力，引起严重感染。因此新型抗菌药物研发迫在眉睫。本课题组发现海南沼蛙temporin抗菌肽结构简单，是分子改造的良好模板。本项目结合抗菌肽天然模板法和基于抗菌肽大数据分析的序列模板法，以抗MRSA活性为导向，进行temporin抗菌肽的优化设计。已获得抗MRSA活性突出、作用靶点不同的衍生肽GHaR与GHa11R，且具有抗生物被膜活性。为探索衍生肽作用机理及成药潜力，将深入开展temporin衍生肽的优化改造，辅以活性预测实现高通量筛选；确定不同衍生肽的细菌作用靶点，筛选与其有协同作用的抗生素；通过RNA-Seq测序等技术研究不同衍生肽抗生物被膜机制；并对体外抗感染效果进行评价。本研究着眼于两栖类皮肤活性多肽的研究，为新一代抗感染创新药物研发提供理论和分子基础。

Methicillin-resistant Staphylococcus aureus (MRSA) is the most commonly identified drug-resistant pathogen all over the world. MRSA has been considered a major cause of community-acquired and hospital-acquired infections that are becoming increasingly difficult to combat because of emerging resistance to all current antibiotic classes. MRSA can irreversibly attach to various surfaces to develop biofilms, such as on the damaged host tissue and implanted materials in clinic. Biofilm is defined as a community of bacterial cells enclosed in a protective and adhesive matrix of primarily polysaccharide material. The bacteria in biofilms are more resistant to antimicrobial agents than planktonic cells, which makes the infections difficult to eradicate caused by biofilm forming bacteria. Therefore, it is an urgent requirement to research and develop new antimicrobial agents. Antimicrobial peptides play an important role in innate immune system in organisms. It’s difficult for bacteria to develop resistance to antimicrobial peptides, leading them to a novel antibiotic candidate. In our previous study, temporin peptides of Hylarana guentheri containing 13 amino acid residues were identified, which are excellent templates for the optimization and development of novel antimicrobial peptides because of their short sequences and simple structures. In this study, natural-occurring peptide template method and sequence template method based on big data analysis of antimicrobial peptides will be used to optimize the design of temporin peptides. The high-throughput screening will be achieved through the prediction of antimicrobial activity by online tools. The derived peptide GHaR and GHa11R with outstanding anti-MRSA activity have been obtained. They showed different targets on bacterial cells. In order to design and screen antibacterial peptides with clear mechanism and excellent potential, we will carry out optimization of temporin derived peptides, investigate the mechanism of antibacterial and antibiofilm, and evaluate the anti-infection effect in vitro. This study focuses on the research and development of active polypeptide of amphibian skin, providing theoretical and molecular basis for the research and development of new generation of innovative anti-infection drugs.