Kinetic analysis and structural studies of a high‐efficiency laccase from Cerrena sp. RSD1

Abstract

A high‐efficiency laccase, DLac, was isolated from Cerrena sp. RSD1. The kinetic studies indicate that DLac is a diffusion‐limited enzyme. The crystal structure of DLac was determined to atomic resolution, and its overall structure shares high homology to monomeric laccases, but displays unique substrate‐binding loops from those in other laccases. The substrate‐binding residues with small side chain and the short substrate‐binding loop IV broaden the substrate‐binding cavity and may facilitate large substrate diffusion. Unlike highly glycosylated fungal laccases, the less‐glycosylated DLac contains one highly conserved glycosylation site at N432 and an unique glycosylation site at N468. The N ‐glycans stabilize the substrate‐binding loops and the protein structure, and the first N ‐acetylglucosamine is crucial for the catalytic efficiency. Additionally, a fivefold increase in protein yield is achieved via the submerged culture method for industrial applications. Database The atomic coordinates of the structure of DLac from Cerrena sp. RSD1 and structural factors have been deposited in the RCSB Protein Data Bank (PDB ID: 5Z1X ).

Tree bark scrape fungus: A potential source of laccase for application in bioremediation of non-textile dyes

“…Enzymes immobilization has been observed to make the enzymes reusable, provide more stability and resistance under diverse conditions, and improve the catalytic activity of laccases [24]. Fungal laccases typically have 3 to 10 glycosylation sites, and 10% to 50% of their molecular weight has been attributed to glycosylation and deglycosylation of laccase has been observed to affect its enzyme kinetics [56]. In this study, after SDS-PAGE electrophoresis, a band excised from the gel was used for identification using MALDI_TOF analysis.…”

A highly thermotolerant laccase produced by Cerrena unicolor strain CGMCC 5.1011 for complete and stable malachite green decolorization

“…Most remarkably, at 70 ºC, t 1/2 of Lac2 was 1.67 h, which was longer than many reported laccases (Chen et al 2012;Ji et al 2018;Michniewicz et al 2006;Songulashvili et al 2012;Wu et al 2018;Zoya Alexandrovna et al 2010) and comparable to a thermostable laccase Lac37 II from T. trogii (Yang et al 2020). A comparison of thermal inactivation of Cerrena laccases is provided in Table 2.…”

“…WR1 Lcc3 50 60 70 2.0 0.67 0.13 NR (Chen et al 2012 ) Cerrena unicolor BBP6 LacA 60 70 < 2.0 < 1.0 NR (Ji et al 2018 ) Cerrena sp. RSD1 DLac 70 < 0.17 NR (Wu et al 2018 ) ABTS was used as the substrate …”

A Highly Thermotolerant Laccase Produced by Cerrena Unicolor Strain CGMCC 5.1011 for Complete and Stable Malachite Green Decolorization

“…Most remarkably, at 70 ºC, t 1/2 of Lac2 was 1.67 h, which was longer than many reported laccases (Chen et al 2012;Ji et al 2018;Michniewicz et al 2006;Songulashvili et al 2012;Wu et al 2018;Zoya Alexandrovna et al 2010) and comparable to a thermostable laccase Lac37 II from T. trogii (Yang et al 2020). A comparison of thermal inactivation of Cerrena laccases is provided in Table 2.…”