Determination of the number-average degree of polymerization of cellodextrins and cellulose with application to enzymatic hydrolysis
Determination of the number-average degree of polymerization of cellodextrins and cellulose with application to enzymatic hydrolysis
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DOI：
10.1021/bm049235j
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发表时间：
2005-05-01
影响因子：
6.2
通讯作者：
Lynd, LR
中科院分区：
文献类型：
--
作者：
Zhang, YHP;Lynd, LR
建立了一种快速、准确地测定不溶性纤维素和可溶性纤维糊精的数均聚合度(DPN)的方法，即用苯酚-硫酸法测得的葡萄糖单体浓度除以改良的2，2‘-联苯磺酸法(BCA)测得的还原型浓度。改进的BCA方法，以75℃孵育30分钟为特征，没有导致β-葡萄糖苷键断裂，而在更高的温度下观察到大量的断裂。在用BCA法测量还原端浓度之前，不溶性纤维素在冷磷酸中的增溶对微晶纤维素等几种模型纤维素是不必要的，但对于大纤维纤维素，如Whatman 1号滤纸，则需要这样的增溶。苯酚-硫酸法可用于测定可溶纤维糊精的葡萄糖单体浓度，也可用于不溶纤维素经液化前的葡萄糖单体浓度的测定。的标准差
A rapid and accurate method for determining the number-average degree of polymerization (DPn) was established for insoluble cellulose and soluble cellodextrins as the ratio of glucosyl monomer concentration determined by the phenol-sulfuric acid method divided by the reducing-end concentration determined by a modified 2,2'-bicinchoninate (BCA) method. The modified BCA method, featuring incubation at 75 degrees C for 30 min, did not result in beta-glucosidic bond cleavage, whereas substantial cleavage was observed at higher temperature. Solubilization of insoluble cellulose in cold phosphoric acid prior to measurement of the reducing-end concentration by the BCA method was found not to be necessary for several model celluloses such as microcrystalline cellulose, but such solubilization was required for large fibers of cellulose such as Whatman No. 1 filter paper. The phenol-sulfuric acid method can be used for measuring the glucosyl monomer concentration of soluble cellodextrins, and also for insoluble cellulose if preceded by a liquefaction step. Standard deviations of