α-淀粉酶及α-糜蛋白酶的脲变动力学研究

Studies on the unfolding kinetics of urea denaturedα-Amylase and α-Chymotrypsin by hydrophobic interaction chromatography

用疏水色谱(HIC)对8.0mol/L脲变性的α-淀粉酶(α-Amy)和α-糜蛋白酶(α-Chy)的变性动力学进行了研究。结果表明:α-Amy的变性为平缓的渐变过程,其变体数目较多,且绝大多数变体的疏水性都小于天然蛋白;α-Chy是骤变(可能是瞬间变性)过程,相对而言α-Chy的变体数目较少,且疏水性均大于天然蛋白。认为两种蛋白不同的脲变动力学行为,可能是因蛋白中α-螺旋含量以及蛋白质自身稳定性不同所致。

Hydrophobic interaction chromatography (HIC) was applied to study the kinetic behavior of αAmylase (αAmy) and αChymotrypsin (αChy) denatured by 8.0 mol/L urea.It was found that αAmy and αChy had different unfolding kinetics.The unfolding of αAmy is a gradually changed process,but as for αChy,the process is fast.The mutants of αAmy are more than that of αChy.Different unfolding kinetics may be due to different contents of αhelix and the stability of the proteins.