Elucidating a mechanism for maltooligosacchride sensing at the small intestine enterocyte (1039.9)

As the primary products of starch digestion by pancreatic α-amylase, maltose and maltooligosaccharides, are the dominant substrates for α-glucosidases at the intestinal brush border. Here, immunobloting and biosynthetic labeling using [35S]-methionine revealed maltose induces the formation of a higher molecular weight (HMW) sucrose-isomaltase (SI) species with a higher rate for early trafficking and maturation which is more associated with Triton X-100 lipid rafts, resulting in higher apical sorting of these species. As this finding is potentially indicative of a maltose sensing ability by enterocytes, our goal is to investigate the sensing mechanism on the small intestine enterocytes for maltose sensing leading to the processing of HMW SI. Mass spectrometry study and endoglycosidase treatment of HMW SI showed the increased molecular weight of SI is a consequence of altered N- and O-glycosylation in the Golgi apparatus causing higher apical sorting of SI. In addition, metabolomics study on metabolites inv...