碩士 / 國立臺灣大學 / 漁業科學研究所 / 83 / Growth hormone (GH) enhances the growth rate of aquacultured fish. However,it is hardly to extract native GH from pituitary glands. Recombinant GH (rGH) produced by Escherichia coli may solve this difficulty. But E. coli-produced rGH exists in inclu-sion bodies (I.B.) without folding structure. In order to obtain biologically active rGH, we found that rGH had to be renatured at the following parameters for refolding : (1) dialysis buffer was under the condictions of pH 10, 0-4℃,adding the mixture of 2mM oxidized glutathione , 2mM reduced glutathione and 0.1M L-
arginine (2G+0.1L); (2) the concentration of I.B. was 0.5 mg/ml and (3) dialysis starting at 6M guanidine hydrocholide (Gdn.Cl)but ending at 0.07M Gdn.Cl within 24h. About 20% of folding rGH were obtained from I.B.. In addition, at least 17.7% of folding rGH were got from the remainder I.B. after reprocessing.We cul-tured 100ml of E. coli BL21(DE3) containing GH-expression plasmid (Tsai et al.,1995), about 95.3mg I.B ( dry weight) were produced after 20h induction by 0.1mM β-lactose, and resulted in 19.06mg folding rGH.The processed rGH was administrated biweekly by in- traperitoneal injections to juvenile striped mullet (Mugil cepha-lus) for 12 weeks, and the succeed observed periods were 4 weeks.
The average body weight of low dosage group (0.1ug rGH/g) has significant differences (P<0.05) from that of control group (wi- thout treatment) since the fourth week after injection. The net weight gain and feed efficiency of low dosage group resulted in increases in 138% and 65%, respectively, relative to the control group at week 12 onwards. After cease of injection, the effect of low dosage rGH on growth enhancement continued at least till the 16th week. Results prove that folding rGH has a biological ac-
tivity even in the extremely low quantity. Therefore, rGH surely will achieve the better economic benefit in the aquaculture.
| Identifer | oai:union.ndltd.org:TW/083NTU02451008 |
| Date | January 1995 |
| Creators | Xie, Ming Hui, 謝銘煇 |
| Contributors | Cai, Huai Zhen, 蔡懷楨 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 85 |
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