A loop engineering strategy improves laccase lcc2 activity in ionic liquid and aqueous solution

Abstract

Laccases, especially high redox potential laccases, play an important role in lignin degradation.

Proteins in Ionic Liquids: Reactions, Applications, and Futures

“…The increase in hydrophobicity is proposed to enhance interactions between domains 2 and 3 under the augmented ionicity of the ionic liquid solution. Based on the identified importance of the changes in hydrophobicity of the domain-connecting loop, a follow-up study focused on synergistic substitutions of alanine residues to (mainly) charged residues in the loop region (Wallraf et al, 2018). The improved rigidity imparted by removing the flexible alanine residues, afforded a particular synergistic improvement in activity at a concentration of 5–15% (v/v) [C 2 C 1 Im][EtSO 4 ] (Wallraf et al, 2018).…”

“…Based on the identified importance of the changes in hydrophobicity of the domain-connecting loop, a follow-up study focused on synergistic substitutions of alanine residues to (mainly) charged residues in the loop region (Wallraf et al, 2018). The improved rigidity imparted by removing the flexible alanine residues, afforded a particular synergistic improvement in activity at a concentration of 5–15% (v/v) [C 2 C 1 Im][EtSO 4 ] (Wallraf et al, 2018). Structural stability to improve activity has also been exploited for Myceliophthora thermophile laccase in [C 2 C 1 Im][EtSO 4 ], where immobilization on agarose also prevented inactivation of this enzyme by 50% (Fernández-Fernández et al, 2014).…”

KnowVolution of a Fungal Laccase toward Alkaline pH

“…Directed protein evolution allows protein properties to be tailored for application demands and provides valuable insights into structure–function relationships . Fungal laccases have been extensively reengineered in the last few years and targeted properties include enhanced heterologous expression; improved specific activity and/or stability; resistance in unnatural environments, such as organic solvents, ionic liquids, and alkaline pH (up to pH 8.0); and activity in physiological fluids (pH 7.4, 150 m m NaCl) . Studies regarding engineering of fungal laccases for activity at neutral/alkaline pH have been reported .…”

Engineering of a fungal laccase to develop a robust, versatile and highly-expressed biocatalyst for sustainable chemistry

“…Protein engineering can help us to improve the catalytic activity or stability of the enzyme at target conditions. [18][19][20][21] The easy manipulation, high recombination frequency and feasible secretion of heterologous proteins, make S. cerevisiae the preferred host for the directed evolution of fungal oxidorreductases. 20,[22][23][24][25] However, the low protein yields provided by S. cerevisiae as expression system is a major bottleneck to evaluate the biotechnological potential of the enzymes engineered in the lab.…”