Effects of low intensity ultrasound on cellulase pretreatment

A peculiar segmented flow microfluidics for isoquercitrin biosynthesis based on coupling of reaction and separation

“…The decreased proportion of a-helices and random segments and the increased proportion of b-sheets in hesperidinase were more conducive for isoquercitrin production. Wang et al reported similar results for changes in the composition of cellulase structure with an 8.85% decrease in a-helix content (Wang et al, 2012b). Combined with the results of the previous experiments, the small proportion of a-helices in the reaction system was more favorable for the reaction.…”

Mechanistic analysis of ultrasound assisted enzymatic desulfurization of liquid fuels using horseradish peroxidase

“…Concurrent with these observations, the activity of the HRP enzyme showed 26% and 11% rise after ultrasound treatment at atmospheric and elevated static pressure, respectively. Similar results of structural transformations in the cellulase enzyme induced by ultrasound have been reported by Subhedar and Gogate (2014) and Wang et al (2012). Wang et al (2012) have reported a reduction of 8.85% in a-helix content with 29.5% increase in random coil content in the cellulase structure after sonication.…”

“…The reduction in fluorescence intensity is an evidence of decrease of population of exposed tryptophan residues on HRP surface, probably due to aggregation of the protein after exposure. These conformational changes in enzyme essentially lead to exposure of hydrophobic amino acid groups and structures inside the enzyme molecules (Gulseren et al, 2007;Jambrak et al, 2008;Subhedar and Gogate, 2014;Wang et al, 2012), as further confirmed by the CD analysis described below. The conformational changes in protein structure of the enzyme have also been evaluated using CD spectra of native and ultrasound treated enzyme.…”

“…The intrinsic fluorescence of the enzyme is mainly attributed to three amino acid residues, viz. Trp, Tyr and Phe (Subhedar and Gogate, 2014;Wang et al, 2012). Fig.…”

“…b-sheet and b-turns). Exposure of enzyme protein to ultrasound wave can induce conformational changes in the secondary structure of the protein, which in turn has an effect on its enzymatic activity (Gulseren et al, 2007;Subhedar and Gogate, 2014;Wang et al, 2012). Mogharrab et al (2007) have given a description of the structure of aromatic substrate binding site in HRP enzyme.…”