Probing Light-driven Ion Transportation of Microbial Rhodopsin under Different Osmotic Environments Using E. coli
| Autor: | Ho Wang, 王赫 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Studies of ion channels and pumps have been focused on animal-centric approach in the past, and indeed gained convincing achievements; while the progress of resolving structures and activities of eukaryotic ion channels are still mainly contributed by bacterial experimental models. Other than Xenopus oocytes, Escherichia coli is one of the often-adopted bacterium to express ion pumping microbial rhodopsin. Several factors, including osmotic pressure changes, could influence the physiology and structure of the membrane and further affect performance of expressed ion channels and pumps. This study investigates the ion transportation of ion-type microbial rhodopsins expressed in E. coli, Measuremtents of the light-driven photocurrents of microbial rhodopsins expressed on E. coli membrane under different osmotic environments were conducted. The results show that the external osmolarity affected the ion transportation behaviors of microbial rhodopsins expressed in E. coli. Such osmolarity changes affected differently at different expressed microbial rhodopsins. Observations of the E. coli morphological changes under different osmolarity environments supported the results of photocurrent measurements. We believe such approach provides new insights of using E. coli system to study ion transportation signals of microbial rhodopsins. Also, we propose directly measuring of the ion conductivity on the target protein expressed E. coli cells to investigate ion transportation activity. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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