title: Analysis of a bioactive beta-(1 --> 3) polysaccharide (Curdlan) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
abstract: This paper focuses on the development of MALDI sample preparation protocols for the analysis of a bioactive beta-(1 --> 3) polysaccharide, i.e. Curdlan. The crude Curdlan sample was first separated into a low molecular weight water-soluble portion and a high molecular weight water-insoluble portion. The water-soluble portion was analyzed using a standard MALDI sample preparation method developed for dextran analysis. Two low-mass (<4000 Da) polysaccharide distributions differing by 16 Da were observed. For the analysis of the water-insoluble portion, several sample preparation protocols were evaluated using GPC-fractionated samples. A sample preparation method based on the deposition of the analyte solution with a mixture of 2,5-dihydroxybenzoic acid (DHB) and 3-aminoquinoline (3AQ) matrices in dimethyl sulfoxide (DMSO) at elevated temperature of 70 degrees C was found to reliably produce good MALDI spectra. MALDI analysis of the water-insoluble Curdlan portion gave number-average (Mn) and weight-average (Mw) molecular weights and polydispersity of 8000 Da, 8700 Da, and 1.10, respectively.
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong. twdchan@cuhk.edu.hk
authors.forename: T-W D
authors.initials: TW
authors.lastname: Chan
authors.forename: K Y
authors.initials: KY
authors.lastname: Tang
mesh_terms: D000421:Alcaligenes / Q000737:chemistry*; D000634:Aminoquinolines / Q000032:analysis; D004121:Dimethyl Sulfoxide; D005841:Gentisates; D005936:Glucans / Q000032:analysis*; D062385:Hydroxybenzoates / Q000032:analysis; D007202:Indicators and Reagents; D012997:Solvents; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D047071:beta-Glucans
chemical_list: D000634:Aminoquinolines; D005841:Gentisates; D005936:Glucans; D062385:Hydroxybenzoates; D007202:Indicators and Reagents; D012997:Solvents; D047071:beta-Glucans; C003045:paramylon; C038459:curdlan; C010925:2,5-dihydroxybenzoic acid; D004121:Dimethyl Sulfoxide