The multiple enhancements of deep eutectic solvent on cellulase significantly improve the saccharification efficiency of lignocellulosic biomass
关键字:TRYPTOPHAN RESIDUES; BETA-GLUCOSIDASE; LACCASE; ACID
摘要:The introduction of specific choline chloride (ChCl)- and betaine (Bet) -based deep eutectic solvents (DESs) into the conventional acetic acid - sodium acetate solution led to a significant increase in cellulase activity and stability. In particular, a higher enhancement in beta -glucosidase activity was obtained, which plays a key role in improving cellulase function. The DESs prolonged the half-life of cellulase. The addition of 10 % (v/v) ChCl/1,3propanediol (1:2) and 5 % (v/v) Bet/glycerol (1:2) resulted in the most significant improvement, with the halflife of cellulase reaching three times the initial half-life value. The above both DESs allowed the cellulase to maintain an excellent level of activity over time, even after 72 h. The DESs tightened the structure of the enzyme by changing its secondary structure, which had a stabilizing effect on the overall conformation. The density functional theory calculations of DESs revealed that the DES with a more stable structure more effectively protected the active conformation. The molecular dynamics simulation on beta -glucosidase indicated that the hydrogen bond donor end of the DES primarily formed hydrogen bonds with the enzyme, which induced a spatially compact conformation by increasing the alpha-helix content while reducing the beta -sheet content. It also restricted the movement of amino acids, particularly stabilizing the active site, and increased the hydrophilic region, thereby enhancing enzyme activity and stability. In addition, the DES formed a protective layer that prevented the unproductive adsorption of lignin on the enzymes during the hydrolysis of lignocellulosic feedstocks. These multiple improvements provided by DESs significantly increased the enzymatic saccharification efficiency of corn stover and poplar.
卷号:489
期号:
是否译文:否