不同抑制剂和激活剂对菠萝茎蛋白酶酶学特性的影响  

Study on the structure-activity relationship of stem bromelain in different inhibitors and activators

作　　者：赵力超[1] 陈洁兰[1] 王燕[1] 刘欣[1] 

机构地区：[1]华南农业大学食品学院,广东广州510642

出　　处：《食品工业科技》2013年第15期70-74,79,共6页Science and Technology of Food Industry

基　　金：高等学校博士学科点专项科研基金(20114404120026)

摘　　要：菠萝蛋白酶作为一种典型的巯基类蛋白酶,具有稳定性差、易失活的特性。本文通过研究多种抑制剂和激活剂对菠萝茎蛋白酶活力、动力学参数及光谱特性等的影响,总结其构效变化规律,试图解释菠萝蛋白酶失活及激活机理。结果表明:抑制剂与激活剂作用下菠萝茎蛋白酶的CD图谱均表现为α-螺旋度降低,β-折叠、β-转角以及无规卷曲含量不同程度提高,但抑制剂作用下螺旋降低,折叠与卷曲的升高程度更明显。此外,抑制剂与激活剂作用下菠萝茎蛋白酶的紫外差吸收光谱也显示差异,激活剂作用下主要表现为230nm以下的二级结构变化,而抑制剂除上述变化外,还显示生色基团Trp、Tyr、Phe的暴露吸收,表明抑制剂作用下酶分子构象变化更剧烈。本文可为菠萝茎蛋白酶的改性研究提供理论基础。Stem bromelain was a typical sulfhydryl protease, featured as poor stability and easy of inactivation. Inactivation and activation mechanisms to stem bromelain were examined in this paper, by studying the effects of inhibitors and activators on stem bromelain activity, kinetic parameters and spectral characteristics, and summarizing rule stem bromelain structural activity variation.Results showed that the CD spectra of stem bromelain effected by inhibitors and activators appears as decreasing α-Helix,and increasing β-Sheet,β-Tum and Random in varied degree.The inhibitors impacted on molecular conformation more than activators do.Such impact caused also UV absorption spectra varying.Activator impacted a secondary-structure reaction mainly below 230nm,while alcotate and inhibitors additionally caused exposure of Trp, Tyr and Phe, which meant a significant enzyme molecule conformation react.This study provided a theoretical basis for the consequent research of enzymatic modification.

关 键 词：菠萝茎蛋白酶 抑制剂 激活剂 紫外可见光谱 CD光谱 

分 类 号：TS201.25[轻工技术与工程—食品科学]