摘要
为提高纤维素酶的热稳定性,研究了几种多羟基化合物对纤维素酶热稳定性的影响,利用酶热失活动力学和热力学及荧光光谱考察了其作用机理。研究表明,纤维素酶经60~90℃热处理,热失活速率常数逐渐增大,半衰期从119.51 min减少到35.55 min。纤维素酶热失活显著。添加多羟基化合物可以提高纤维素酶的热稳定性,保护效果依次为山梨醇〉甘露醇〉甘油〉海藻糖。纤维素酶的活化能ΔU＊、活化焓ΔH＊和活化自由能ΔG＊均有增加,活化熵ΔS＊变化不明显。表明添加山梨醇和甘露醇的酶的氢键数目增多,有利于酶构象的稳定。荧光光谱结果显示,多羟基化合物对酶的结构具有稳定作用。
In order to improve the thermostability of cellulase, this paper reported the effect of kinds of polyols on the thermostability of cellulase. Using enzyme kinetics of thermal inactivation and fluorescence spectrum, the action mechanism was investigated. Studies showed that thermal inactivation rate constants of cellulase increased gradually by heating in the range of 60-90 ~C, the half- life period reduced from 119.51 rain to 35.55 min. Cellulase thermal inactivation is remarkable. The addition of polyhydroxy compounds can improve the thermal stability of cellulase, protection effect in the order：sorbitol 〉mannitol〉glycerol〉trehalose. The thermodynamics constants of AU＊, AG＊and AH＊ of Cellulase were increased,the change of AS＊ was not obvious. It showed that the addition of sorbitol and mannitol led to the number of hydrogen bonding an increase of cellulase, thus benefited for stabilization of enzyme conformation. The result of fluorescence spectra showed polyhydroxy compounds have stable function on the structure of cellulase.
出处
《可再生能源》
CAS
北大核心
2014年第10期1534-1538,共5页
Renewable Energy Resources
基金
辽宁省高等学校创新团队项目(LT2012011)
关键词
多羟基
纤维素酶
热稳定性
热失活动力学
荧光光谱
polyhydroxy
cellulase
thermostability
the kinetics of thermal inactivation
fluores-eence spectra
