Properties of Aspergillus niger Protease Isolated from Katsuobushi

Katsuobushi에서 분리한 Aspergillus niger protease의 효소학적성질

Protease was purified from Aspergillus niger propagated on katsuobushi. The optimal pH and temperature of the enzyme were 7.2 and $45^{\circ}C$, respectively. The enzyme was stable at $pH\;5{\sim}8$ and at below $40^{\circ}C$. Enzyme activity was promoted by $K^{-}\;and\;Fe^{2+}$, whereas it was inhibited by $Hg^{2},\;Zn^{2},\;Mn^{2}\;and\;Cd^{2}$. The acidic, basic and neutral amino acid compositions were found to be 22.63, 13.57 and 63.80%, respectively. The content of nonpolar, poler and sulfur-containing amino acids were 39.72, 20.03 and 9.53% respectively, and aspartic and glutamic acids were abundant. The molecular weight was 42,000 and isoelectric point was estimated pH 5.6.

Katsuobushi에서 분리한 Aspergillus niger 균주에서 생산한 조효소로부터 정제한 protease의 최적 pH와 온도는 pH 7.2와 $45^{\circ}C$였으며, $pH\;5{\sim}6$ 범위내에서 $40^{\circ}C$ 이하에서 안정하였으며, 금속이온의 영향은 $K^{-}$와 $Fe^{2+}$는 효소활성을 증진시켰고 $Zn^{2},\;Mn^{2}$ 및 $Cd^{3}$등은 효소활성을 저해하였으며, 구성아미노산은 산성아미노산이 22.6%, 염기성아미노산이 13.57%. 중성아미노산이 63.8%였으며, 비극성아미노산, 극성아미노산 및 함황아미노산의 구성비는 각각 39.72%, 23.03% 및 9.35%이었다. 분자량은 42000, 등전점은 pH 5.6이었다.