文蛤抗癌多肽对N-乙酰-β-D-氨基葡萄糖苷酶活力的影响  

Effects of anticancer peptide from Asiatic hard clam (Meretrix meretrix) on the activity of β-N-acetyl-D-glucosaminidase

作　　者：康劲翮[1] 冷波[1] 贺量[1] 范成成[1] 王勤[1] 石艳[1] 陈清西[1] 

机构地区：[1]厦门大学细胞生物学与肿瘤细胞工程教育部重点实验室、厦门大学生命科学学院,福建厦门361005

出　　处：《台湾海峡》2008年第1期33-36,共4页Journal of Oceanography In Taiwan Strait

基　　金：厦门市科技计划项目(3502Z20063021);厦门大学科技创新工程基金(XDKJCX20043001)资助

摘　　要：从文蛤体中分离纯化得到了抗癌多肽,研究该多肽对N-乙酰-β-D-氨基葡萄糖苷酶(NAGase)活力的影响,结果显示文蛤抗癌多肽对该酶有明显的抑制作用.在本文中,我们将深入地研究其抑制作用机理和抑制效应类型,结果表明:随着文蛤多肽加入量的增大,该酶活力呈指数下降,测得导致酶活力下降50%的抑制剂浓度(IC50)为112.9μg/cm3,该多肽对酶的抑制作用是一种可逆过程,抑制机理表现为混合型抑制类型,对游离酶(E)的抑制常数(KI)和酶-底物络合物的抑制常数(KIS)分别为77.03和697.44μg/cm3,说明文蛤抗癌多肽与游离酶的结合导致酶活力的丧失,明显的强于对酶-底物络合物的抑制效应,底物的存在对该酶被文蛤抗癌多肽抑制作用起了保护作用.An anticancer peptide from Asiatic hard clam （ Meretrix meretrix ） has been purified. In this paper, the effect of this peptide on N-acetyl-β-D-glucosaminidase （NAGase） from mud crab （Scylla serrata） was investigated. The results showed that the peptide inhibited the enzyme activity obviously. The inhibitory kinetics of the peptide on the enzyme was further studied. The results showed that the residual enzyme activity rapidly decreased with increasing concentrations of the peptide. The value of IC50, the inhibitor＇s concentration leading to loss of 50% activity, was estimated to be 112.9μg/cm^3. The inhibition reaction of the peptide with the enzyme was determined to be reversible and the inhibition type was determined to be mixed-type by Lineweaver-Burk plots. The inhibition constants K1 and K1s were determined to be 77. 03μg/cm^3 and 697. 44μg/cm^3, respectively. The results show that the loss of the activity of enzyme caused by the combination of peptide with free enzyme is obviously stronger than with the enzyme-substrate complex. The presence of substrate offers a protection for the enzyme against the peptide inhibition.

关 键 词：文蛤抗癌多肽 N-乙酰-Β-D-氨基葡萄糖苷酶 抑制作用 动力学 

分 类 号：Q356.1[生物学—遗传学]