상백피에서 추출한 단백질 분해효소의 효소적 성질을 분석하였다. 상백피 추출액으로부터 분리한 단백질 함량은 1.12mg/ml, protease는 비활성도로서 5.14U/mg 수준이었다. 효소의 기질에 대한 특이성은 casein을 100으로 하였을 때 albumin 63, collagen 58, hemoglobin 45, gelatin 36의 비율로 가수분해하여 육류 단백질에 주로 함유된 collagen, hemoglobin을 분해하는 능력이 비교적 큰 것으로 나타났다. 효소의 최적온도는 60℃, 열안정성은 50∼80℃로서 비교적 열에 안정하였다. 효소의 최적 pH는 6.0이었으며 pH 6.0∼7.0에서 안정하였고 pH 9.0 이상에서는 활성이 급격히 저하되었다. 따라서 옛날부터 가정에서 고기를 삶을 때 연회를 위하여 사용하였던 상백피 중에 단백질 분해효소력이 존재함을 확인하였다.

Water extract of mulberry tree barks(Morus alba Linne) was studied for its proteolytic activity. Protein content of the extract was 1.12 ㎎/ml and its specific activity was 5.14 U/ml. The enzyme was active on various proteins : the relative acitities were 100 for casein, 63 for albumin, 58 for collagen, 45 for hemoglobin and 36 for gelatin, respectively. These suggested that the ability of the enzyme to hydrolyze meat was relatively high since those are major meat proteins. Optimum pH and temperature for proteolytic activity were : pH 6.0 and 60℃. And the enzyme was stable at the pH range of 6.0 to 7.0 and temperature between 50 and 80℃. Apparent proteolytic activities could support some scientific grounds of traditional application of mulberry tree barks to home cooking for meat tenderization.

• 신두호 | Doo Ho Shin
• 김동원 | Dong Won Kim
• 정용남 | Young Nam Jeoung