- 새우젓 중의 단백질 분해효소에 대한 연구
- ㆍ 저자명
- 박길홍
- ㆍ 간행물명
- 韓國營養學會誌
- ㆍ 권/호정보
- 1986년|19권 6호|pp.363-373 (11 pages)
- ㆍ 발행정보
- 한국영양학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
This study was devised to elucidate whether soused shrimp exhibits a digestive action on boiled pork meats. and the mechanism by which sousing with a high concentration of sodium chloride preserves nutrients in foods for a prolonged peulcornerriod. Protease was isolated from soused shrimp using a combination of ammonium sulfate fractionation. DEAE - cellulose ion exchange chromatography and gel filtraulcornertion. The isolated protease had specific activity of 1.560 units. 210 purification foulcornerld with an yield of 38%. Its optimum pH and temperature were 8.0 and $43^{circ}C$ respectively. The molecular weight of the enzyme was 35.000. The Km value of the enzyme for casein was 1.6 x $10^{-6}$ M The e=yme required the presence of cuulcornerpric ion to exhibit its full activity. Eighty eight percent of the enzyme activity was inulcornerhibited by 3.5M NaCI showing a reversibly linear decrease of the enzyme activity as NaCI concentration increased. The nature of the inhibition by NaCl was reverulcornersible and noncompetitive. The protease activity in soused shrimp was well preserulcornerved with the elapse of time at least in part due to NaCI induced suppression of autodigestion. The enzyme was denatured by acid easily. i.e. 1% of the original activity remained after staying at pH 2 for 10 minutes. which is within the normulcorneral range of pH of the human stomach. Soused shrimp was observed to be one of those containing the highest protease activity compared with the other soused fooulcornerds such as soused oyster. squid. clam. and Pollack intestine with respect to speculcornerific activities of dialized 1:4 whole homogenates(w/v) in 5 mM sodium phosphaulcornerte - 2.4 mM j3 - mercaptoethanol buffer. pH 8.0. Casein and boiled meats including pork, beef, and chicken appeared to be the good substrates for the protease. Casein was the best. Therefore. the ingestion of boiled meats including pork together with soused shulcornerrimp would help digestion of boiled pork in human not only by increasing appeulcornertite also by the direct proteolytic digestion of boiled meats by soused shrimp toulcorner some extent. And a high concentration of sodium chloride inhibited the protease activity reversibly in a remarkable degree, which ensued in a significant retardatulcornerion of autodigestion of protein in foods by proteases, and hereby contributed to the preservation of foods for an extended period.