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用硫酸铵盐析，磷酸盐除果胶和两次ＤＥＡＥ纤维素柱层析等方法，从毛花猕猴桃（ＡｃｔｉｎｉｄｉａｅｒｉａｎｔｈａＢｅｎｔｈ．）无细胞提取液中提纯蛋白酶，在聚丙烯酰胺凝胶电泳上呈现一条带，纯酶的活力为３２５Ｕ／ｍｇ，比活力提高８９倍，总收率约为３７％。用ＳＤＳ聚丙烯酰胺凝胶电泳测定分子量为２３ｋＤ，用等电聚焦电泳测定等电点为４８。酶的最适ｐＨ为３８，最适温度为４３℃左右。纯酶制剂对其底物牛血红蛋白的Ｋｍ值为５５６×１０－３ｍｍｏｌ。酶的紫外吸收光谱最大值为２７８ｎｍ。二巯基苏糖醇、巯基乙醇、Ｌ半胱氨酸盐酸盐等还原剂对该酶有明显的激活作用，而碘乙酸、对氯汞苯甲酸对其有抑制作用，这表明该酶属于巯基酶类。
Protease was purified from the cell-free extract of Actinidia delici al Benth. By ammonium sulfate salting-out, phosphate-removing pectin and twice-DEAE cellulose column chromatography. A band appeared on polyacrylamide gel electrophoresis , Pure enzyme activity of 325U / mg, 89 times the specific activity, the total yield of about 37%. The molecular weight was determined to be 23 kD by SDS polyacrylamide gel electrophoresis and the isoelectric point was 4.8 using isoelectric focusing. The optimum pH of the enzyme is 3 8, the optimum temperature is about 43 ℃. Pure enzyme preparation on its substrate bovine hemoglobin Km value of 5 56 × 10-3mmol. The maximum UV absorption spectrum of the enzyme was 278 nm. Thioglycolothiols, mercaptoethanol, L-cysteine hydrochloride and other reducing agents have a significant activation of the enzyme, and iodoacetic acid, p-mercuric chloride on its inhibition, indicating that the enzyme belongs to Mercaptozymes.