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研究了[Emim]DEP、[Emim]Ac和[Bmim]Cl对3,5-二硝基水杨酸(DNS)法测还原糖的影响,结果表明当离子液体浓度为0~20%(w/v,质量体积比,下同),3种离子液体对测量结果几乎无影响。在此基础上,比较了这3种离子液体对纤维素酶活力的影响。在3种离子液体中,[Emim]DEP对纤维素酶的抑制作用最小,但其浓度不宜超过10%以获得较高的相对酶活力。随后考察了纤维素酶在[Emim]DEP中的稳定性,相对酶活力总体上随着温度的升高和保存时间的延长而下降,但当[Emim]DEP浓度为5%时,在4℃保存24h后纤维素酶的相对活力却有所提高。纤维素酶在[Emim]DEP溶液中的紫外吸收光谱表明,[Emim]DEP使纤维素酶肽链的结构发生改变,并改变了酶分子构象,导致酶分子对底物的亲和力下降,影响了纤维素酶活力。
The effects of [Emim] DEP, [Emim] Ac and [Bmim] Cl on reducing sugar measured by DNS were studied. The results showed that when the concentration of ionic liquid was 0-20% (w / v, mass volume ratio, the same below), three kinds of ionic liquids have little effect on the measurement results. On this basis, the effects of these three ionic liquids on cellulase activity were compared. Of the three ionic liquids, [Emim] DEP has the least inhibitory effect on cellulase but its concentration should not exceed 10% to obtain higher relative enzyme activity. Subsequently, the stability of cellulase in [Emim] DEP was investigated. Relative enzyme activity generally decreased with increasing temperature and storage time, but at 5% [Emim] DEP, The relative activity of cellulase was increased after 24h storage. The UV absorption spectra of cellulase in [Emim] DEP solution showed that [Emim] DEP changed the structure of the cellulase peptide chain and changed the conformation of the enzyme molecule, resulting in the decrease of the affinity of the enzyme molecule to the substrate, affecting Cellulase activity.