毛霉亮氨酸氨肽酶的纯化及性质研究  

Purification and Characterization of Leucine Aminopeptidase from Mucor

作　　者：潘进权[1] 

机构地区：[1]湛江师范学院生命科学与技术学院,广东湛江524048

出　　处：《食品科学》2012年第7期163-167,共5页Food Science

基　　金：广东省自然科学基金项目(9452404801001943);湛江师范学院基金项目(ZL0912)

摘　　要：采用硫酸铵盐析、离子交换层析、疏水层析、凝胶层析及超滤方法对毛霉胞外蛋白酶组分进行分离纯化,从毛霉的发酵麸曲中分离纯化得到氨肽酶组分,并对其性质进行探讨。结果表明:纯化的毛霉氨肽酶是亮氨酸氨肽酶,其对小肽N端的亮氨酸有非常强的水解活性;该氨肽酶在40℃、pH6.5有最大催化活性,在40℃以内,pH5.0～8.0有很好的稳定性;在所实验的几种蛋白酶抑制剂(PMSF、EDTA、E-64、Pepstatin A)中,仅EDTA可以完全抑制该氨肽酶的活性,由此说明,纯化的毛霉氨肽酶是一种金属蛋白酶;常见的金属离子中,Ca2+对该氨肽酶有激活作用,而Zn2+、Cu2+及Mn2+对其有强的抑制作用;该氨肽酶对大豆多肽的苦味有明显的去除效果,大豆多肽脱苦处理4h后其苦味基本消除。An aminopeptidase was purified and characterized from crude extracellular protease extract from wheat bran koji of Mucor through ammonium sulfate precipitation, ion exchange chromatography, hydrophobic chromatography, gel filtration chromatography and ultra-filtration. The purified aminopeptidase was identified as leucine aminopeptidase, which was very active in hydrolyzing N-terminal leucine of peptides. Its maximum activity was observed at pH 6.5 and 40 ℃. In addition, the leucine aminopeptidase was stable in the pH range of 5.0-8.0 and at temperatures below 40 ℃. However, it could be completely inhibited by the metal protease inhibitor EDTA, indicating that it belongs to the metal protease family. Ca^2＋ had an activating effect on it, while Zn^2＋, Cu^2＋ and Mn^2＋ were very active in inhibiting it. The enzyme was effective in removing bitter taste from soybean ploypeptides and basic elimination of bitter taste was achieved after 4 h of treatment with it.

关 键 词：毛霉 亮氨酸氨肽酶 纯化 性质 脱苦 

分 类 号：Q814.1[生物学—生物工程]