摘要
从桑叶中提取的1-脱氧野尻霉素(DNJ)作为糖苷酶抑制剂具有降血糖的功能。为了解明桑叶DNJ对α-蔗糖酶的作用机制,应用酶抑制动力学分析桑叶DNJ(纯度>95%)对α-蔗糖酶的抑制特性。通过建立的α-蔗糖酶酶促反应体系表明,在α-蔗糖酶质量浓度≤500μg/mL、反应时间8min以内时,反应体系呈现良好的线性趋势;抑制活性检测表明,桑叶DNJ对α-蔗糖酶具有明显的抑制作用,其半抑制浓度(IC50)为5.67mg/mL;依据酶抑制动力学曲线特征推断桑叶DNJ对α-蔗糖酶具有明显可逆的非竞争性抑制作用,其抑制常数Ki为6.73mg/mL。
As a potent inhibitor of α-glycosidases,1-deoxynojirimycin （DNJ） purified from mulberry leaves has strong antidiabetic activity.In order to elucidate the functional mechanism of mulberry leaf DNJ to α-sucrase,the inhibitory characteristics of mulberry leaf DNJ （purity95%） to α-sucrase was analyzed by means of enzymatic inhibitory kinetics.The establishment of enzymatic reaction system indicated that,when the concentration of α-sucrase was below 500 μg/mL and the reaction time was within 8 min,the reaction system showed good linearity.Inhibition activity assay indicated that the activity of α-sucrase was obviously inhibited by mulberry leaf DNJ and the half inhibitory concentration （IC50） was 5.67 mg/mL.Based on the results of kinetic curves and Lineweaver-Burk plots of mulberry leaf DNJ＇s inhibition to α-sucrase,the inhibition was of the reversible noncompetitive inhibition pattern and the constant of inhibition （Ki） is 6.73 mg/mL.
出处
《蚕业科学》
CAS
CSCD
北大核心
2010年第6期885-888,共4页
ACTA SERICOLOGICA SINICA
基金
现代农业产业技术体系建设专项(蚕桑)
浙江省农业科学院创新提升工程项目(No.2008R06Y01D01)
