Action of an endo-?-1,3(4)-glucanase on cellobiosyl unit structure in barley ?-1,3:1,4-glucan.

ABSTRACT: ?-1,3:1,4-Glucan is a major cell wall component accumulating in endosperm and young tissues in grasses. The mixed linkage glucan is a linear polysaccharide mainly consisting of cellotriosyl and cellotetraosyl units linked through single ?-1,3-glucosidic linkages, but it also contains minor structures such as cellobiosyl units. In this study, we examined the action of an endo-?-1,3(4)-glucanase from Trichoderma sp. on a minor structure in barley ?-1,3:1,4-glucan. To find the minor structure on which the endo-?-1,3(4)-glucanase acts, we prepared oligosaccharides from barley ?-1,3:1,4-glucan by endo-?-1,4-glucanase digestion followed by purification by gel permeation and paper chromatography. The endo-?-1,3(4)-glucanase appeared to hydrolyze an oligosaccharide with degree of polymerization 5, designated C5-b. Based on matrix-assisted laser desorption/ionization (MALDI) time-of-flight (ToF)/ToF-mass spectrometry (MS)/MS analysis, C5-b was identified as ?-Glc-1,3-?-Glc-1,4-?-Glc-1,3-?-Glc-1,4-Glc including a cellobiosyl unit. The results indicate that a type of endo-?-1,3(4)-glucanase acts on the cellobiosyl units of barley ?-1,3:1,4-glucan in an endo-manner.

SUBMITTER: Kuge T 

PROVIDER: S-EPMC4673573 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature