摘要
肠激酶(EK,EC3.4.21.9)是一种在基因工程产品中广泛应用的工具酶.以小分子荧光物质甘氨酰-天冬氨酰-天冬氨酰-天冬氨酰-天冬氨酰-赖氨酰-β-萘胺(Gly-Asp-Asp-Asp-Asp-Lys-β-naphthylamide,GD4K-β-naphthylamide)为底物,采用荧光跟踪法研究了不同氨基酸、几种常用有机溶剂、EDTA、DTT等对牛肠激酶(BEK)活力的影响.结果表明:L-赖氨酸(L-Lys)、丙酮、EDTA、DTT对该酶的活性有较强的抑制作用,IC50分别约为25,50,50和120mmol/L.进一步研究了L-Lys与丙酮对BEK活力的抑制机理以及抑制类型,结果表明:L-Lys对该酶的抑制机理为可逆抑制,其抑制类型为竞争型抑制类型,其抑制常数KI为12.02mmol/L.丙酮对BEK的抑制类型表现为不可逆抑制.
Enterokinase（BEK, EC 3.4.21.9）is an important enzyme widely used in gene engineering. In this study, the inhibitory effects of several amino acids,organic solvents,EDTA and DTT on the activity of bovine enterokinase（BEK） for the hyclrolysis of Gly-Asp-Asp-Asp-Asp-Lys-β-naphthylamide were investigated by monitoring the change of fluorescent. The results indicated that L- Lys,acetone,EDTA and DTT had strong inhibitory effect on the activity of BEK,with the concentrations of 25,50,50 and 120 mmol/ L,respectively leading to 50% enzyme activity lost. The research result showed that the mechanism of L-Lys effect on BEK activity was reversible,belonging to competitive type inhibitory. The inhibition constant of L-Lys（KI）was 12.02 mmol/L. The results also showed that the mechanism of acetone inhibiting effect on BEK was irreversible.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第5期725-728,共4页
Journal of Xiamen University：Natural Science
基金
福建省重点科技项目(2007N0051)
细胞生物学与肿瘤细胞工程教育部重点实验室开发课题(2009103)资助
