纳豆激酶酶学性质的初步研究

Study on the Characterization of Nattokinase

通过(NH4)2SO4对NK分级盐析浓缩,发现用饱和度为65%的(NH4)2SO4盐析,浓缩10倍,NK回收率最高,可达到87.1%.对其纤溶活性研究表明,NK在40℃以下时,纤溶活性相对稳定,65℃以上时,活性迅速下降;pH<4时,显著抑制NK活性;Mg2+对其纤溶活性有显著激活作用,Zn2+,Ca2+,Fe2+和Cu2+对NK有不同的抑制作用,而Al3+则使NK活性完全丧失.

The nattokinase （NK） was purified from natto through procedures of saline extraction, ammonium sulfate precipitation,we found that,when the saturation of ammonium sulfate was 65 %,the overall yield of NK was 87.1%. It＇s stable below 40 ℃, but the activity of fibrinolytic activity descend rapidly upwards 65 ℃. It＇s inactivated below pH 4. The fibrinolytic activity was strongly activated by Mg^2＋,was inhibited by Zn^2＋, Ca^2＋, Fe^2＋ and Cu^2＋ in different degree, and was depressed completely by the presence of Al^3＋.