Structural study of antimicrobial peptide Maximin H5
| Autor: | Chun-Hwa Chen, 陳俊樺 |
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| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 Amphibian skin is a rich resource of antimicrobial peptides, serves as the first line of defense of creatures attacked by microbes. The antimicrobial peptide studied here is an antimicrobial peptide from skin secretion of toad, Bombina maxima. It is a novel maximin H peptide which is produced through posttranslational modification of a precursor protein, and was named Maximin H5. By analyzing the composition of amino acids, it contains three acidic aspartates, but has no basic amino acids. Based on the previous study, it seemed to be sensitive only to Gram positive bacteria. So far, few acidic antimicrobial peptides were found and little was known about their three-dimensional structures and mechanisms of killing microbes. In order to understand the structure-function relationship of maximin H5, we used NMR spectroscopy and structure calculation techniques to determine its three-dimensional structure and elucidate the bactericidal mechanism from the characteristics of three-dimensional structure. Estimated the secondary structures from the chemical shift index, we found maximin H5 seemed to have helical structure at C-terminal region, but there is no obvious helical structure existed based on the calculated structure. Moreover, the surface charge of maximin H5 distribution graph showed that there is no amphipathic structure existed. In addition, its overall negative charge made it hard to attach to bacterial membrane. In conclusion, we propose the bactericidal mechanism of maximin H5 may not directly interact with the membrane of bacteria. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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