Computational and Experimental Investigation of the Antimicrobial Peptide Cecropin XJ and its Ligands as the Impact Factors of Antibacterial Activity

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• 作者：Dongliang Liu ; Jun Liu ; Weilan Wang ; Lijie Xia ; Jianhua Yang ; Surong Sun…
• 关键词：Antimicrobial peptides ; Cecropins ; Amphiphilicity ; Comparative modeling ; Ligand
• 刊名：Food Biophysics
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：11
• 期：4
• 页码：319-331
• 全文大小：2,440 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Food Science
  Biophysics and Biomedical Physics
  Analytical Chemistry
  
• 出版者：Springer New York
• ISSN：1557-1866
• 卷排序：11

文摘

Cecropin XJ, as a heat stable antimicrobial peptide (AMP), displayed broad bacteriostatic activities, effectively inhibited proliferation of cancer cells and induced cell apoptosis in vitro. However, it exhibited little hemolytic activity and very low cytotoxicity to erythrocytes and normal cells. Although exerts multiple remarkable bioactivities, the refined molecular conformation of native Cecropin XJ remains unsolved. The aim of the present study is to comprehensively investigate the physicochemical characteristics and structure-function relationship of this antimicrobial peptide by using a series of bioinformatics and experimental approaches. In this study, we revealed that the mature Cecropin XJ consists of 41 amino acids, containing two α-helical structures from Lys7 to Lys25 and from Ala29 to Ile39. The phylogenetic tree indicated that Cecropin XJ belongs to the Class I AMPs of cecropin family. Hydrophobic analysis showed Cecropin XJ is a typical amphiphilic molecule. The surface of Cecropin XJ was found to have a much wide range of electrostatic potential from −83.243 to +83.243. The amphipathicity and surface potential of Cecropin XJ partially supported the AMP pore-forming hypothesis. Scanning electron microscopy experimentally confirmed the damages of Cecropin XJ to microbial membrane. Four predicted docking sites respectively for magnesium ion (Mg2+), adenosine diphosphate (ADP), bacteriopheophytin (BPH), and guanosine triphosphate (GTP) were found on the surface of Cecropin XJ. Thereinto, Mg2+ was experimentally proved to suppress the antibacterial activity of Cecropin XJ; both GTP and ADP enhanced the bactericidal activities to varying degrees. The present study provides a foundation for further investigation of molecular evolution, structural modification, and functional mechanisms of Cecropin XJ.