NOBIPOL, Department of Biotechnology, Norwegian University of Science and Technology (NTNU), Sem Saelands veg 6/8, NO-7491 Trondheim, Norway.
J Chromatogr A. 2013 Aug 30;1305:109-13. doi: 10.1016/j.chroma.2013.07.002. Epub 2013 Jul 4.
Water-soluble (1→3)-β-d-glucans with 1,6-linked branches (SBG) isolated from the cell walls of Saccharomyces cerevisiae were studied by size exclusion chromatography (SEC) with multi-angle laser light scattering (MALLS) detector using dimethylacetamide (DMAc) containing 0.5% (0.12M) LiCl, or dimethyl sulphoxide (DMSO) in the absence and presence of 0.25M LiCl, respectively, as eluents. The aggregating glucan could be dispersed as single chains in both solvents, with chain length distributions in reasonable agreement with results obtained previously with carboxymethylated glucans in aqueous solvent. However, DMAc is preferred over DMSO because of higher sensitivity in MALLS, and also because the latter produces SEC anomalies. SBG dissolves slowly in DMAc/LICl at room temperature, but heating accelerates the process. The rate of depolymerisation of SBG in DMAc/LiCl at high temperatures (70-105°C) was determined as a basis for defining dissolution procedures at elevated temperatures with a minimum of degradation. The result of the investigation is a simple and reliable protocol for preparing unaggregated, fully dissolved and undegraded SBG in DMAc/LiCl, which is well suited as a standard analysis of the molecular weight distribution of SBG-like molecules without chemical derivatization.
从酿酒酵母细胞壁中分离得到的具有 1,6 键合支链的水溶性（1→3）-β-d-葡聚糖（SBG），使用二甲基乙酰胺（DMAc）含有 0.5%（0.12M）LiCl 或二甲基亚砜（DMSO）作为洗脱剂，通过尺寸排阻色谱（SEC）与多角度激光光散射（MALLS）检测器进行了研究。在这两种溶剂中，聚集的葡聚糖都可以分散成单链，并且其链长分布与先前在水溶液中羧甲基化葡聚糖得到的结果相当一致。然而，DMAc 优于 DMSO，因为 MALLS 的灵敏度更高，而且后者会产生 SEC 异常。SBG 在室温下缓慢溶解于 DMAc/LiCl，但加热会加速溶解过程。在高温（70-105°C）下，在 DMAc/LiCl 中 SBG 的解聚速率被确定为在高温下制定溶解程序的基础，以在最小降解的情况下进行。研究结果是一种简单可靠的方法，可在 DMAc/LiCl 中制备未聚集、完全溶解和未降解的 SBG，无需化学衍生化，非常适合作为 SBG 样分子的分子量分布的标准分析。
