中文摘要：

采用超滤、制备电泳对木瓜蛋白酶进行分离纯化。结果显示：超滤后木瓜蛋白酶的蛋白酶和壳聚糖酶比活力分别从435．10U／mg和2．17U／mg提高到531．39U／mg和2．65U／mg，纯化倍数均提高了1．22倍。制备电泳图谱上显示有五条明显的酶条带，酶活性测定显示条带2具有较高的壳聚糖酶比活力。采用SDS-PAGE和HPLC对此纯化酶组分进行纯度鉴定，结果显示为单一条带和单一峰，说明木瓜蛋白酶中存在具有水解壳聚糖活力的酶组分。HPLCMS／MS测定该纯化酶组分的氨基酸序列为MRITISGSPG SGTTTLGRSI AEKYSYRYVS AGEVFRGLAK ERNMDLAAFG KIAETDPAID LEIADARQKEI GESSDDIILE GRLAGWMVEN ADLKILLCAS PECRSTRIAA REGLTEKQAF EMTIEREACE AGRYMEYYEI DILDFSPYDL ILNSETFSAN ELFAIVDAAV SSLLKRE.

英文摘要：

The fraction with chitosanase activity in a commercial papain preparation was prepared by ultra-filtration separation followed by purification by preparation electrophoresis and its amino acid sequence was analyzed. After ultra-filtration separation with a I00000 MWCO membrane, the protease and chitosanase activities of the papain preparation both increased by 1.22 times, from 435.10 to 531.39 U/rag and from 2.17 to 2.65 U/mg, respectively. Five obvious bands were showed on the preparation electrophoresis pattern of retentates and the brand 2 with a molecular weight between 25 and 35 kD had high chitosanase activity and its homogeneity was demonstrated by SDS-PAGE and HPLC, indicating that there was the enzyme fraction with chitosanase activity in the papain preparation. The amino acid sequence of the enzyme fraction was determined by HPLC-MS/MS as follows： MRITISGSPG SGTITLGRSI AEKYSYRYVS AGEVFRGLAK ERNMDLAAFG KIAETDPAID LEIADARQKEI GESSDDIILE GRLAGWMVEN ADLKILLCAS PECRSTRIAA REGLTEKQAF EMTIEREACE AGRYMEYYEI DILDFSPYDL ILNSETFSAN ELFAIVDAAV SSLLKRE.