Korean Journal of Agricultural Science (농업과학연구)
- Volume 16 Issue 2
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- Pages.225-238
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- 1989
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- 2466-2402(pISSN)
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- 2466-2410(eISSN)
Purification and Characterization of Oriental Pear(Niitaka, Pyrus pyrifolia Nak.) Protease
동양배(신고(新高)) Protease의 정제(精製) 및 성질(性質)에 관(關)하여
- Kim, Seung Yeol (Dept. of Food Sci. and Tech. Coll. of Agriculture, Chungnam Nat'l Univ.) ;
- Chung, Hai Jung (Graduate school, Chungnam Nat'l Univ.) ;
- Kim, Seung Kyeom (Dept. of Food Sci. and Tech. Coll. of Agriculture, Chungnam Nat'l Univ.) ;
- Shin, Cheol Seung (Graduate school, Chungnam Nat'l Univ.)
- Published : 1989.12.31
Abstract
These studies were conducted to investigate the extraction, purification and characterization of oriental pear (Niitaka. Pyrus pyrifolia Nak.) protease, and the results obtained were as follows: 1. Oriental pear protease was effectively extracted by the method of homogenizing pear pulp with 0.7 volume of 0.1M-sodium phosphate buffer, pH 6.5 containing 5mM-cysteine, 40mM-2-mercaptoethanol and 2mM-EDTA at 10,000 rpm for 5 min. 2. The protease was purified by ammonium sulfate fractionation, Sephadex G-100 filtration and DEAE-Sephadex A-50 column chromatography, and the purified enzyme gave a single protein band on polyacrylamide gel electrophoresis. 3. The specific activity of purified enzyme was 29.65 unit/mg protein and the yield was 7.22%. 4. The moecular weight of the protease was estimated to be about 51,000 by SDS-polyacrylamide gel electrophoresis, and the enzyme had Km value of 54.5 mg/ml for casein. 5. The purified enzyme had a maximum activity at pH 6.0 and
동양배(신고(新高))에서 protease를 추출(抽出), 정제(精製)하여 그의 특성(特性)을 검토(檢討)한 결과(結果)는 다음과 같다. 1. 배의 protease는 배의 과육(果肉)-정량(定量)과 5mM의 cysteine, 40mM 2-mercaptoethanol 및 2mM의 EDTA를 함유(含有)하는 0.1M-sodium phosphate buffer(pH6.5)0.7배량(倍量)(v/w)을 homogenizer에 넣고 10,000rpm으로 5분간(分間) 추출(抽出)하는 것이 효과적(效果的)이었다. 2. 상기(上記) 방법(方法)에 의(依)해서 파쇄(破碎)한 것을 cheese cloth로 여과(濾過)하여 10,000g로 20분간(分間) 원심분리(遠心分離)하여 얻어지는 상징액(上澄液) 조효소액(粗酵素液)으로 하여 유안(硫安) 분획(分劃), Sephadex G-100 filtration 및 DEAE-Sephadex A-50 column chromatography를 거쳐 전기영동상(電氣泳動上)으로 단일(單一)한 효소단백질(酵素蛋白質)을 얻었다. 3. 정제효소(精製酵素)의 비활성(比活性)은 10.78배(倍) 증가(增加)하였고, 활성수율(活性收率)은 722%에 달(達)하였다. 4. 정제효소(精製酵素)의 분자량(分子量)은 SDS전기영동법(電氣泳動法)에 의(依)하여 측정(測定)하였을 때 51,000이었으며, Km값은
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