维生素类物质对黄粉虫NAGase活力的影响

用Tris-HCl缓冲液抽提、硫酸铵分级沉淀从黄粉虫体内获得N-乙酰氨基葡萄糖苷酶(NAGase,EC3.2.1.52)研究VC、VB1、VB2、VB5、VB6、VB12等对黄粉虫NAGase活力的影响。结果表明:VC、VB1、VB6对NAGase起抑制作用;而VB5、VB2、VB12对NAGase的作用不明显。进一步研究VC和VB6的抑制作用动力学,结果表明:VC和VB6对酶的抑制作用可逆,VC为混合型抑制,VB6为非竞争型抑制。测得VC对酶的抑制常数KI与KIS分别为37.63mmol/L、95.64mmol/L;VB6对酶的抑制常数KI与KIS均为13.75mmol/L。

Effects of Some Vitamins on the Activity of NAGase from Yellow Mealworm

N-acetylglucosaminidase (NAGase,EC 3.2.1.30) from Yellow Mealworm was obtained by ammonium sulfate fractionation after extraction with Tris-HCl buffer. The effects of Vitamin B6、Vitamin C 、Vitamin B1、Vitamin B12、Vitamin B2 and Vitamin B5 on NAGase activity were investigated. The results indicated that Vitamin C 、Vitamin B6、Vitamin B1 could inhibit enzyme activity,and almost no effect of Vitamin B2、Vitamin B5、Vitamin B12 on enzyme activity. The inhibitory kinetics of Vitamin C 、Vitamin B6、Vitamin B1 on the enzyme was further studied. The result showed that Vitamin C was reversible mix inhibitor of the enzyme and Vitamin B6 was reversible noncompetitive inhibitor of the enzyme .The values of KI and KIS of Vitamin C for enzyme were determined to be 37.63 mmol/L and 95.64 mmol/L,respectively. The values of KI and KIS of Vitamin B6 for NAGase were determined to be 13.75 mmol/L.