几种单糖对黄粉虫NAGase活力的影响  

Effects of Monosaccharide on Activity of N-Acetyl-β-D-Glucosaminidase from Tenebrio molitor Linneeus

作　　者：潘小芳[1] 辛碧芬[2] 谢晓兰[1] 齐娟[1] 赖志青[1] 

机构地区：[1]泉州师范学院化生学院,福建泉州362000 [2]泉州师范学院继续教育学院,福建泉州362000

出　　处：《泉州师范学院学报》2006年第6期99-103,共5页Journal of Quanzhou Normal University

基　　金：福建省教育厅科技计划项目(JA04260)

摘　　要：以素有“动物营养宝库”之称的高蛋白昆虫-黄粉虫为材料,以N-乙酰-β-D-氨基葡萄糖苷酶(NAGase,EC 3.2.1.52)为研究对象.采用0.05 mol/L pH7.5Tris-HCl缓冲液抽提、硫酸铵分级分离沉淀从黄粉虫体内获得NAGase粗酶制剂.研究葡萄糖(glu)、半乳糖(gal)、果糖(fru)对NAGase催化水解对硝基苯-N-乙酰氨基葡萄糖苷(pNP-NAG)活力的影响,结果表明,glu、gal、fru对该酶均有抑制作用,抑制强弱次序为:gal>glu>fru.gal对该酶的抑制作用表现为反竞争型,其抑制常数KIS为226 mmol/L;而glu对酶的作用表现为竞争型抑制,抑制常数KI为338mmol/L.N-acetyl-β-D-glucosaminidase （NAGase, EC 3. 2. 1. 52） from Tenebrio molitor Linneeus was obtained by extraction with 0. 05 mol/L pH7.5Tris-HCl and ammonium sulfate fractionation. In this paper, the effects of monosaccharide on the activity of NAGase from Tenebrio molitor Linneeus were studied. The results showed that glucose, galactose and fructose were chosen as inhibitors of NAGase for the hydrolysis of pNP-NAG. The effects of these effectors on the NAGase activity were reversible with remaining enzyme activity. The order of inhibition is galactose〉 glucose〉fructose. The inhibitory kinetics of monosaccharide on the enzyme was further studied. The inhibitory type of gal on the enzyme was found to be uncompetitive and the inhibitory constant （K1） was determined to be 226 mmol/L. Glucose was classified as competitive inhibitors and its inhibitory constant was determined to be 338 mmol/L.

关 键 词：黄粉虫 N-乙酰-Β-D-氨基葡萄糖苷酶 单糖 抑制机理 

分 类 号：Q356.1[生物学—遗传学]