한우유(韓牛乳)의 단백질(蛋白質)에 관(關)한 연구(硏究) 제(第)1보(報) DEAE-Cellulose에 의(依)한 한우유단백질(韓牛乳蛋白質)의 분별(分別)

Studies on Milk Protein of Korean Cattle I. Fractionation of Milk Protein on DEAE-Cellulose

본(本) 실험(實驗)에서는 현재(現在)까지 학문적(學問的)으로 충분(充分)히 밝혀지고 있지 않은, 한우유(韓牛乳)의 이화학적(理化學的) 성질(性質)을 구명(究明)하기 위(爲)하여 한우유(韓牛乳)의 주성분(主成分)을 분석(分析)하고, 또한 DEAE-cellulose를 사용(使用)하여 산(酸) casein, 유청단백질(乳淸蛋白質)을 분별(分別)하여 다음과 같은 결과(結果)를 얻었다. 1. 한우유(韓牛乳)의 비중(比重)은 1.036, 산도(酸度) 0.21, pH는 6.4였고 알콜시험(試驗)에서는 정상(正常)이었다. 2. 한우유(韓牛乳)의 수분함량(水分含量)은 88.39%였고, 무지고형분(無脂固形分) 9.53%였고, 지방(脂肪)은 2.08%, 단백질(蛋白質)은 3.99%, 유당(乳糖)은 4.76%였고 Sialic acid는 0.25%였다. 3. 총단백질중(總蛋白質中) casein이 3.07% 유청단백질(乳淸蛋白質)이 1.13%, lactoglobulin 0.34%, lactalbumin은 0.66%였다. 4. 6M 요소(尿素)를 함유(含有)한 0.005M TCU-buffer를 사용(使用)하여 DEAE-cellulose column에 의(依)해서 한우유(韓牛乳)의 산(酸) casein을 분별(分別)한 결과(結果) 4개(個)의 fraction을 얻었다. 5. 0.04M phosphate-buffer를 사용(使用)하여 DEAE-cellulose column에서 유청단백질(乳淸蛋白質)을 분별(分別)한 결과(結果) 4개(個)의 fraction을 얻어 각(各) fraction의 면적(面積)을 냈다.

An experiment has been carried out in order to analyze the main components of Korean Cattles' milk, and fractionate the milk protein by DEAE-cellulose column. The results obtained were summarized as follow. 1) The average values of specific gravity, pH and acidity of Korean Cattles milk which were negative in alcohol test were 1,036, 6.4 and 0.21, respectively. 2) The average values of total solids, solids-not-fat, protein, lactose and ash contents of Korean Cattles milk were 11.61%, 9.53%, 2.08%, 3.99%, 4.76% and 0.86%, respectively. 3) Distribution of casein, whey protein, N.P.N., protein precipitated in 12% TCA, lactoglobulin and lactalbumin contents of the milk were 3.07%, 1.13%, 0.10%, 4.06%, 0.34% and 0.66%, respectively. 4) Acid casein obtained from Korean Cattles milk was fractionated into four fractions on DEAE-cellulose column with 0.005M tris-citrate buffer containing 6M urea, pH 8.6, and the ratio of the fraction I, II, III and IV was 3.24%, 52.67%, 26.22% and 17.87%, respectively. 5) Whey protein obtained from Korean Cattles milk was also fractionated into four fractions on DEAE-cellulose column with 0.04M phosphate buffer, pH 5.8, and the ratio of the fraction I, II, III and IV was 41.74%, 10.17%, 1.50% and 46.59%, respectively.