博士 / 國立臺灣大學 / 海洋研究所 / 93 / Strains of Microcystis have been cultured for their toxicity analysis, and their toxins were isolated for their specific toxicity tests. Mouse and Artemia toxicity assays were applied for the various strains and their respective LD50 and LC50 that were compared with the IC50 of protein phosphatase inhibition assay after converted to the toxin content of MCYST-LR equivalent. Strains that do not possess any PP1 inhibitory activity show no toxicity to either mice or brine shrimp larvae. Ranking of the animal toxicities coincided well with enzyme inhibitory activities. A solid phase extraction procedure was developed for the removal of interfering agents in Artemia assay and proved to be very effective. This SPE pretreatment in conjugation with the following assays can be applied for the MCYST screening in field cyanobacterial samples or in algal food supplements. MALDI-TOF and HPLC metabolomic analysis showed the SPE good in preserving the toxins and removing contaminants.
In the further study a series of microcystins were tested on the mouse toxicity, protein phosphatase inhibition activities of PP-1 and PP-2A from native or recombinant sources, and the covalent-bonding kinetics with recombinant PP-1c. Structure-Activity-Relationship studies showed mouse toxicities of different microcystins were in better correlation with their inhibitory activities against PP2Ac than PP1c. Different microcystins have different inhibitory activities on different enzyme sources, indicating the different interaction in molecular level. The covalent-bonding kinetics obtained from MALDI-TOF assays showed that less than 5% of total PP-1c covalent-bonding with MCYST-LR per hour under 30oC, revealing the slow reacting nature of covalent-bonding formation between PP-1c and microcystin-LR.
| Identifer | oai:union.ndltd.org:TW/093NTU05274007 |
| Date | January 2005 |
| Creators | Yi-Min Chen, 陳逸民 |
| Contributors | Rang Huang, Hong-Nong Chou, 黃穰, 周宏農 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 146 |
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