Oxidative Power: Tools for Assessing LPMO Activity on Cellulose

Abstract

Lytic polysaccharide monooxygenases (LPMOs) have sparked a lot of research regarding their fascinating mode-of-action. Particularly, their boosting effect on top of the well-known cellulolytic enzymes in lignocellulosic hydrolysis makes them industrially relevant targets. As more characteristics of LPMO and its key role have been elucidated, the need for fast and reliable methods to assess its activity have become clear. Several aspects such as its co-substrates, electron donors, inhibiting factors, and the inhomogeneity of lignocellulose had to be considered during experimental design and data interpretation, as they can impact and often hamper outcomes. This review provides an overview of the currently available methods to measure LPMO activity, including their potential and limitations, and it is illustrated with practical examples.

Enzymatic debranching is a key determinant of the xylan-degrading activity of family AA9 lytic polysaccharide monooxygenases

“…5 a). These product forms are commonly observed in reactions with C1-oxidizing LPMOs [ 44 , 45 ]. The MS analysis confirmed that the reductant-free control reaction did not yield oxidized products.…”

Spatioselective surface chemistry for the production of functional and chemically anisotropic nanocellulose colloids

“…Chemical and enzymatic oxidations are established for cellulose with the aim of oxidizing selected hydroxyl groups, to aldehydes and carboxylic groups, or via hydrolysis and oxidization of the glycosidic bond. In the case of enzymatic oxidation with, e.g., lytic polysaccharide monooxygenases (LPMOs), 129,130 oxidation is coupled with simultaneous cleavage of the glycosidic bond, usually at the C 1 and C 4 positions. 129 The cleavage and oxidation lead to products of oxidized solubilized molecules or oxidized cellulose substrates.…”

“…In the case of enzymatic oxidation with, e.g., lytic polysaccharide monooxygenases (LPMOs), 129,130 oxidation is coupled with simultaneous cleavage of the glycosidic bond, usually at the C 1 and C 4 positions. 129 The cleavage and oxidation lead to products of oxidized solubilized molecules or oxidized cellulose substrates. 131 Enzymatic modi-cations are hence both hydrolyzing and functionalizing and can be applied to the various cellulose hierarchies.…”

“…, lytic polysaccharide monooxygenases (LPMOs), 129,130 oxidation is coupled with simultaneous cleavage of the glycosidic bond, usually at the C 1 and C 4 positions. 129 The cleavage and oxidation lead to products of oxidized solubilized molecules or oxidized cellulose substrates. 131 Enzymatic modifications are hence both hydrolyzing and functionalizing and can be applied to the various cellulose hierarchies.…”

Comparative Secretome Analyses of Trichoderma/Arabidopsis Co-cultures Identify Proteins for Salt Stress, Plant Growth Promotion, and Root Colonization

“…However, it is obvious that the percentage of proteins with known functions is almost twice as high in the exudate preparation from fungi grown in the coculture with 50 mM NaCl compared to all other exudate preparations. More importantly, 9% of all identified fungal proteins in the exudate of the co-culture with 150 mM NaCl are lytic polysaccharide monooxygenases (Andlar et al, 2018;Forsberg et al, 2019;Almeida et al, 2021;Calderaro et al, 2021;Jagadeeswaran et al, 2021). These enzymes are major contributors to the recycling of carbon in nature, mainly by degradation of plant lignocellulose (Sagarika et al, 2021;Vuong and Master, 2021;Zerva et al, 2021).…”