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三种有机溶剂,二氧六环、二甲基甲酰胺和乙二醇,都不同程度地抑制中华猕猴桃蛋白酶催化水解赖氨酸对硝基本酯(CBZ-LYS-pNP)能力,其动力学行为符合Michaelis-Menten方程式,二氧六环的抑制作用类似于竞争性抑制类型,二甲基甲酰胺和乙二醇为非竞争性抑制,其抑制常数,分别为k_1=5.6×10~(-2)、0.58和1.60mol/L,光谱分析表明,酶在有机溶剂中,空间构象也发生了变化,随着二氧六环和二甲基甲酰胺浓度的增大,酶分子的α-螺旋度下降,无规卷曲度上升,荧光发射强度比天然酶略有增高或降低,变化的规律性不够,紫外差光谱显示,酶在6％二甲基甲酰胺中有一个243nm的负峰,此负峰随浓度的增大而增大,并略向红移,在24％二甲基甲酰胺中,负峰红移至248nm处。
Three kinds of organic solvents, such as dioxane, dimethylformamide and ethylene glycol, inhibited the ability of Chinese kiwifruit to catalyze the hydrolysis of lysine to nitroprusside (CBZ-LYS-pNP) to varying degrees, and its kinetic behavior According to the Michaelis-Menten equation, the inhibitory effect of dioxane is similar to that of competitive inhibition. Dimethylformamide and ethylene glycol are noncompetitive inhibitors with inhibition constants of k 1 = 5.6 × 10 -2 ), 0.58 and 1.60 mol / L, respectively. The spectral analysis showed that the spatial conformation of the enzyme also changed in the organic solvent. As the concentration of dioxane and dimethylformamide increased, the α-helicity Decreased, random curl increased, the fluorescence emission intensity slightly higher than the natural enzyme or decreased, the regularity of variation is not enough, UV spectrum showed that the enzyme in 6% dimethylformamide has a 243nm negative peak, the negative The peak increased with increasing concentration and slightly shifted to red. In 24% dimethylformamide, the peak shifted red to 248 nm.