Abstract: A fungium-producing chitinase was isolated from the dead body of Anisopliae. A chitinase was isolated from the culture of Metarhizium anisopliae and purified to electrophoretic homogeneity by the steps of ammonium sulfate precipitation,DEAE-cellulose and hydrophobic interaction column chromatography. Its molecular mass was estimated to be about 61.5 kD by SDS-PAGE,and 57.14 kD by mass spectroscopy.The isoelectric temperature and pH of the enzyme activity were 55 ℃ and 6.0 respectively.The isoelectric point was 4.02.Its N-terminal sequence was VIGPAAPL. The carbohydrate content was 56.2% by the phenol-sulfuric acid method. Michaelis constant of the enzyme was 14.5 μmol•L^-1.The enzyme activity was stable under 45 ℃ and in the pH range of 3.0—9.5. The activity was enhanced by Zn²⁺、Ca²⁺、Ba²⁺ and Mn²⁺,and was strongly inhibited by Hg²⁺、Co²⁺ and Fe²⁺.EDTA also inhibited the activity.Ser was the possible essential residue for enzyme activity.

摘要： 从自然罹病死亡的金龟子体内分离到一株金龟子绿僵菌（Metarhizium anisopliae）,它在几丁质的诱导下能产生较高活性的几丁质酶.发酵液经硫酸铵盐析、DEAE纤维素柱层析、Phenyl Sepharose^TM 6 Fast Flow疏水柱层析等方法，得到电泳纯的几丁质酶.用SDS-PAGE测得该酶相对分子质量为61.5 kD，而经质谱分析为57.14 kD.最适反应温度为55 ℃，最适反应pH值为6.0，酶的等电点pI为4.02，其N末端序列为VIGPAAPL，用硫酸-酚法测得其含糖量为56.2%.水解几丁质的K_m为14.5 μmol•L^-1.该酶在45 ℃，pH值3.0～9.5较为稳定.Zn²⁺、Ca²⁺、Ba²⁺和Mn²⁺离子对几丁质酶活性有明显的促进作用，而Hg²⁺、Co²⁺和Fe²⁺离子完全抑制几丁质酶的活性.此酶还可被EDTA所抑制，表明金属离子为其活性所必需.PMSF试剂对几丁质酶的活力影响比较大，丝氨酸可能是酶活力的必需基团.