+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

A Lytic Polysaccharide Monooxygenase with Broad Xyloglucan Specificity from the Brown-Rot Fungus Gloeophyllum trabeum and Its Action on Cellulose-Xyloglucan Complexes

A Lytic Polysaccharide Monooxygenase with Broad Xyloglucan Specificity from the Brown-Rot Fungus Gloeophyllum trabeum and Its Action on Cellulose-Xyloglucan Complexes

Applied and Environmental Microbiology 82(22): 6557-6572

Fungi secrete a set of glycoside hydrolases and lytic polysaccharide monooxygenases (LPMOs) to degrade plant polysaccharides. Brown-rot fungi, such as Gloeophyllum trabeum, tend to have few LPMOs, and information on these enzymes is scarce. The genome of G. trabeum encodes four auxiliary activity 9 (AA9) LPMOs (GtLPMO9s), whose coding sequences were amplified from cDNA. Due to alternative splicing, two variants of GtLPMO9A seem to be produced, a single-domain variant, GtLPMO9A-1, and a longer variant, GtLPMO9A-2, which contains a C-terminal domain comprising approximately 55 residues without a predicted function. We have overexpressed the phylogenetically distinct GtLPMO9A-2 in Pichia pastoris and investigated its properties. Standard analyses using high-performance anion-exchange chromatography-pulsed amperometric detection (HPAEC-PAD) and mass spectrometry (MS) showed that GtLPMO9A-2 is active on cellulose, carboxymethyl cellulose, and xyloglucan. Importantly, compared to other known xyloglucan-active LPMOs, GtLPMO9A-2 has broad specificity, cleaving at any position along the β-glucan backbone of xyloglucan, regardless of substitutions. Using dynamic viscosity measurements to compare the hemicellulolytic action of GtLPMO9A-2 to that of a well-characterized hemicellulolytic LPMO, NcLPMO9C from Neurospora crassa revealed that GtLPMO9A-2 is more efficient in depolymerizing xyloglucan. These measurements also revealed minor activity on glucomannan that could not be detected by the analysis of soluble products by HPAEC-PAD and MS and that was lower than the activity of NcLPMO9C. Experiments with copolymeric substrates showed an inhibitory effect of hemicellulose coating on cellulolytic LPMO activity and did not reveal additional activities of GtLPMO9A-2. These results provide insight into the LPMO potential of G. trabeum and provide a novel sensitive method, a measurement of dynamic viscosity, for monitoring LPMO activity. Currently, there are only a few methods available to analyze end products of lytic polysaccharide monooxygenase (LPMO) activity, the most common ones being liquid chromatography and mass spectrometry. Here, we present an alternative and sensitive method based on measurement of dynamic viscosity for real-time continuous monitoring of LPMO activity in the presence of water-soluble hemicelluloses, such as xyloglucan. We have used both these novel and existing analytical methods to characterize a xyloglucan-active LPMO from a brown-rot fungus. This enzyme, GtLPMO9A-2, differs from previously characterized LPMOs in having broad substrate specificity, enabling almost random cleavage of the xyloglucan backbone. GtLPMO9A-2 acts preferentially on free xyloglucan, suggesting a preference for xyloglucan chains that tether cellulose fibers together. The xyloglucan-degrading potential of GtLPMO9A-2 suggests a role in decreasing wood strength at the initial stage of brown rot through degradation of the primary cell wall.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 057031186

Download citation: RISBibTeXText

PMID: 27590806

DOI: 10.1128/aem.01768-16

Related references

The effect of a lytic polysaccharide monooxygenase and a xylanase from Gloeophyllum trabeum on the enzymatic hydrolysis of lignocellulosic residues using a commercial cellulase. Enzyme and Microbial Technology 113: 75-82, 2018

PH-Dependent Relationship between Catalytic Activity and Hydrogen Peroxide Production Shown via Characterization of a Lytic Polysaccharide Monooxygenase from Gloeophyllum trabeum. Applied and Environmental Microbiology 85(5):, 2019

Non-enzymatic biodegradation of cellulose by the brown rot fungus Gloeophyllum trabeum. Phytopathology 86(11 Suppl. ): S87, 1996

A family of AA9 lytic polysaccharide monooxygenases in Aspergillus nidulans is differentially regulated by multiple substrates and at least one is active on cellulose and xyloglucan. Applied Microbiology and Biotechnology 100(10): 4535-4547, 2016

Xyloglucan Endotransglucosylase-Hydrolase17 Interacts with Xyloglucan Endotransglucosylase-Hydrolase31 to Confer Xyloglucan Endotransglucosylase Action and Affect Aluminum Sensitivity in Arabidopsis. Plant Physiology 165(4): 1566-1574, 2014

Enhanced lignocellulosic biomass hydrolysis by oxidative lytic polysaccharide monooxygenases (LPMOs) GH61 from Gloeophyllum trabeum. Enzyme and Microbial Technology 77: 38-45, 2015

Two-way translocation of ions in the brown rot fungus Gloeophyllum trabeum. Phytopathology 86(11 Suppl. ): S120, 1996

Two-way translocation of cations by the Brown rot fungus Gloeophyllum trabeum. International Biodeterioration and Biodegradation 39(2-3): 181-188, 1997

Xyloglucan and xyloglucan endo-transglycosylases (XET): Tools for ex vivo cellulose surface modification. Biocatalysis and Biotransformation 24(1-2): 107-120, 2006

Xyloglucan-cellulose interaction depends on the sidechains and molecular weight of xyloglucan. Plant Physiology and Biochemistry 42(5): 389-394, 2004

Localization of xyloglucan in the macromolecular complex composed of xyloglucan and cellulose in pea stems. Plant and Cell Physiology 35(3): 439-444, 1994

Non-enzymatic degradation of wood by the brown rot fungus Gloeophyllum trabeum. Phytopathology 87(6 Suppl. ): S48, 1997

Quinone reduction systems of the brown rot fungus Gloeophyllum trabeum. Phytopathology 92(6 Suppl.): S145, 2002

Purification of a quinone reductase from the brown rot fungus Gloeophyllum trabeum. Phytopathology 91(6 Suppl.): S73, 2001

Xyloglucan oligosaccharides with at least two alpha-D-xylose residues act as acceptor substrates for xyloglucan endotransglycosylase and promote the depolymerisation of xyloglucan. Physiologia Plantarum 88(1): 105-112, 1993