黄鳝肠道蛋白酶的应用研究

将黄鳝内脏混合物提取液作同工酶电泳,得到3条蛋白酶同工酶条带,其中ProteaseⅠ条带与从黄鳝肠道中提取的蛋白酶纯品SDS-PAGE条带重合,表明从黄鳝内脏混合物中可以提取到黄鳝肠道蛋白酶纯品.金属离子Cu2 和Ba2 对酶有激活作用,EDTA、Mn2 、Pb2 对酶有抑制作用,而Ca2 、Mg2 、K 、Na 对酶活性无明显影响.通过酶与化学试剂的配伍试验测得:CO23-、SO32-、硼砂对酶活性无影响,甘露醇、橄榄油、聚乙烯醇对酶活性有轻微抑制作用,SO42-、H2PO4-、BO32-和海藻酸钠对酶有轻微激活作用,而洗涤剂中常用的表面活性剂SDS、LAS、CHAPS和TritonX-100在低浓度时对酶活性无明显影响,酶在0·02%的SDS、0·05%的LAS和0·1%的CHAPS中保持相对稳定,40min酶活保持在50%左右.酶专一底物测试结果表明:黄鳝肠道蛋白酶对弹性蛋白酶的专一底物刚果红弹性蛋白(elastin-CongoRed)有水解活性,而对胰蛋白酶和胰凝乳蛋白酶的专一底物N苯甲酰L精氨酸乙酯(BAEE)和N乙酰L酪氨酸乙酯(ATEE)无水解活性,表明黄鳝肠道蛋白酶为弹性蛋白酶.

Primary Study on Application Properties of the Protease of the Monopterus albus

Zymography analysis of the extract from the the bowels of Monopterus albus suggested that three distinct proteases were present. One strip of those is identical with the strip of the purified enzyme by SDS-PAGE. So it can be forecasted that the identical protease can be gained from the compound of the guts. When EDTA and metal ions are added, Cu~ 2 and Ba~ 2 can activate the activity of the enzyme, EDTA, Mn~ 2 and Pb~ 2 can strongly inhibit the enzyme activity, the else metal ions such as Ca~ 2 , Mg~ 2 , K~ , Na~ can't affect enzyme activity. The alkaline protease is an important ingredient of detergent. To study the cooperation of enzyme with surfactant, four surfactants including LAS, SDS, CHAPS, Triton X-100 were used in this study. The result suggested that the enzyme is stable in surfactant solution and four surfactants didn't inhibit the activity of it. The common thickening agents, such as Soil temperature80, Agar, Poly vinyl alcohol, Olive oil, etc as well as the chemistry reagents, also didn't inhibit the activity of the enzyme. The result indicated that the protease of Monopterus albus showed strong activity against casein and elastin-Congo Red(specific substrate for elastase), but no activity against N-Acetyl-L-tyrosine ethyl ester monohydrate(specific substrate for chymotrypsin) and Benzoyl-L-arginine ethyl ester Hcl(specific substrate for trypsin). Taken all of application properties together, the protease of the Monopterus albus is a type of alkaline protease with a broad prospect.