超声波对菠萝蛋白酶热稳定性及二级结构的影响

Effects of ultrasonic wave on the thermostability and secondary structure of bromelain

研究了菠萝蛋白酶经超声波处理后的活性、热稳定性和远紫外圆二色谱的变化。在超声波处理条件为240W,5min时,菠萝蛋白酶活性增大至119.05%,随着处理时间的延长,酶活性逐渐下降,在280W,35min时,酶活下降至58.60%。热稳定性分析发现,160W和200W的处理功率均可以改善菠萝蛋白酶的热稳定性,其中160W,5min时最为显著,菠萝蛋白酶在60℃中保存120min后的酶活残留率为63.49%,比未处理时提高了约20%。圆二色谱结果表明,在处理条件为200W,5min及160W,5min时,菠萝蛋白酶的α-螺旋分别减少为24.30%和26.80%,而β-折叠由34.50%分别增加到40.10%和44.50%,无规则转曲由18.60%分别增加到19.00%和13.50%。

The effects of ultrasonic wave on the activity,thermostability and Far-UV circular dichroism(CD)of bromelain were studied.The activity of bromelain increased to 119.05% under 240W ultrasound for 5min.With the extension of treatment period,the enzyme activity decreased gradually.It dropped to 58.60%.at 280W and 35min.It was found that the thermostability of bromelain was improved at 160W and 200W through thermostability analysis.Under 160W,5min treatment,the residue activity of bromelain was up to 63.49% aft...