碩士 / 國立海洋大學 / 食品科學系 / 89 / Cystatin, a natural inhibitor of endogenous cysteine proteinases, was purified from mackerel and characterized. The cystatin was purified to electrophoretical homogeneity by 60oC heat treatment, ammonium sulfate fractionation, DEAE-Sepharose and Sephadex G-75 column chromatographs. The molecular weight was 21,000 estimated by SDS-PAGE and gel filtration of Sephadex G-75. Activity staining revealed 2 cysteine proteinase inhibitory activities. The purified cystatin was the lower molecular weight one. There were about 70 % and 50 % inhibitory activity left after 1 h incubation at 25 oC, pH 7.0 ~ 8.5, and pH 5.0 ~ 6.5, respectively. The optimum pH for the inhibitory activity against papain was 7.5. It was thermal stable, and still had 90 % activity left even after 30 min incubation at 30 ~ 60 oC or about 85 % activity left after 30 min boiling at 100 oC. The purified cystatin was also with high freezing or refrigerant tolerance, about 90 % activity remained after 60 days storage at -20 oC or 4 oC.
| Identifer | oai:union.ndltd.org:TW/089NTOU0253025 |
| Date | January 2001 |
| Creators | Chao An Chi, 趙安琪 |
| Contributors | Jiang Shann Tzong, 江善宗 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 67 |
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