title: Profiling the substitution pattern of xyloglucan derivatives by integrated enzymatic hydrolysis, hydrophilic-interaction liquid chromatography and mass spectrometry.
abstract: Plant polysaccharides constitute arguably the most complex family of biomacromolecules in terms of the stereochemistry and regiochemistry of their intramolecular linkages. The chemical modification of such polysaccharides introduces an additional level of complexity for structural determinations. We have developed an integrated analytical procedure combining selective enzymatic hydrolysis, hydrophilic interaction liquid chromatography (HILIC), and mass spectrometry (MS) to describe the substitution pattern of xyloglucan (XyG) and its chemo-enzymatic derivatives (cationic, anionic, and benzyl aminated). Enzymatic hydrolysis of XyG derivatives by a xyloglucan-specific endoglucanase (XEG) generates oligosaccharides amenable for mass spectrometric identification with distinct structures, based on enzymatic substrate recognition and hydrolytic pattern. Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-ToF-MS) and electrospray ionisation mass spectrometry (ESI-MS) offer qualitative mass profiling of the chemical derivatives. Separation and identification of the complex oligosaccharide profiles released by enzymatic hydrolysis is achieved by hyphenation of hydrophilic interaction liquid chromatography with mass spectrometry (HILIC-ESI-MS). Further fragmentation by tandem mass spectrometry (ESI-MS/MS) in positive mode enables the structural sequencing of modified XyG oligosaccharides and the identification of the substituent position without further derivatisation. This integrated approach can be used to obtain semi-quantitative information of the substitution pattern of hemicellulose derivatives, with fundamental implications for their modification mechanisms and performance.
authors.affiliation: Johan Gadolin Process Chemistry Centre, c/o Laboratory of Wood and Paper Chemistry, Åbo Akademi University, Porthansgatan 3-5, FI-20500 Turku/Åbo, Finland.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Johan Gadolin Process Chemistry Centre, c/o Laboratory of Wood and Paper Chemistry, Åbo Akademi University, Porthansgatan 3-5, FI-20500 Turku/Åbo, Finland.
authors.forename: Victor
authors.initials: V
authors.lastname: Kisonen
authors.affiliation: Johan Gadolin Process Chemistry Centre, c/o Laboratory of Wood and Paper Chemistry, Åbo Akademi University, Porthansgatan 3-5, FI-20500 Turku/Åbo, Finland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Willför
authors.affiliation: Johan Gadolin Process Chemistry Centre, c/o Laboratory of Wood and Paper Chemistry, Åbo Akademi University, Porthansgatan 3-5, FI-20500 Turku/Åbo, Finland; Wallenberg Wood Science Centre (WWSC), KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden. Electronic address: cxu@abo.fi.
authors.forename: Chunlin
authors.initials: C
authors.lastname: Xu
authors.affiliation: Wallenberg Wood Science Centre (WWSC), KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden; Division of Glycoscience, KTH Royal Institute of Technology, AlbaNova University Centre, SE-106 91 Stockholm, Sweden. Electronic address: franvila@kth.se.
authors.forename: Francisco
authors.initials: F
authors.lastname: Vilaplana
mesh_terms: D002480:Cellulase / Q000378:metabolism*; D002853:Chromatography, Liquid / Q000379:methods*; D005936:Glucans / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D013058:Mass Spectrometry / Q000379:methods*; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D053719:Tandem Mass Spectrometry; D014990:Xylans / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D005936:Glucans; D009844:Oligosaccharides; D011134:Polysaccharides; D014990:Xylans; C029353:xyloglucan; C007916:hemicellulose; D002480:Cellulase
keywords: Enzymatic hydrolysis; Glycomics; HILIC-ESI–MS/MS; Hemicelluloses; Mass spectrometry; Oligosaccharide sequencing