TY - JOUR
T1 - Characterisation of branched gluco-oligosaccharides to study the mode-of-action of a glucoamylase from Hypocrea jecorina
AU - Jonathan, M.C.
AU - van Brussel, M.
AU - Scheffers, M.S.
AU - Kabel, M.A.
PY - 2015
Y1 - 2015
N2 - In the conversion of starch to fermentable glucose for bioethanol production, hydrolysis of amylopectin by a-amylases and glucoamylases is the slowest step. In this process, a-1,6-branched gluco-oligosaccharides accumulate and are slowly degraded. Glucoamylases that are able to degrade such branched oligosaccharides faster are economically beneficial. This research aimed at the isolation and characterisation of branched gluco-oligosaccharides produced from amylopectin digestion by a-amylase, to be used as substrates for comparing their degradation by glucoamylases. Branched gluco-oligosaccharides with a DP between five and twelve were purified using size exclusion chromatography. These structures were characterised after labelling with 2-aminobenzamide using UHPLC-MSn analysis. Further, the purified oligosaccharides were used to evaluate the mode-of-action of a glucoamylase from Hypocrea jecorina. The enzyme cleaves the a-1,4-linkage adjacent to the a-1,6-linkage at a lower rate than that of a-1,4-linkages in linear oligosaccharides. Hence, the branched gluco-oligosaccharides are a suitable substrate to evaluate glucoamylase activity on branched structures.
AB - In the conversion of starch to fermentable glucose for bioethanol production, hydrolysis of amylopectin by a-amylases and glucoamylases is the slowest step. In this process, a-1,6-branched gluco-oligosaccharides accumulate and are slowly degraded. Glucoamylases that are able to degrade such branched oligosaccharides faster are economically beneficial. This research aimed at the isolation and characterisation of branched gluco-oligosaccharides produced from amylopectin digestion by a-amylase, to be used as substrates for comparing their degradation by glucoamylases. Branched gluco-oligosaccharides with a DP between five and twelve were purified using size exclusion chromatography. These structures were characterised after labelling with 2-aminobenzamide using UHPLC-MSn analysis. Further, the purified oligosaccharides were used to evaluate the mode-of-action of a glucoamylase from Hypocrea jecorina. The enzyme cleaves the a-1,4-linkage adjacent to the a-1,6-linkage at a lower rate than that of a-1,4-linkages in linear oligosaccharides. Hence, the branched gluco-oligosaccharides are a suitable substrate to evaluate glucoamylase activity on branched structures.
KW - Amylopectin
KW - Gluco-oligosaccharide
KW - Glucoamylase
KW - Maltodextrins
U2 - 10.1016/j.carbpol.2015.06.023
DO - 10.1016/j.carbpol.2015.06.023
M3 - Article
SN - 0144-8617
VL - 132
SP - 59
EP - 66
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
IS - 5
ER -