抄録
Modification at the nonreducing end residue of p-nitrophenyl a-maltopentaoside (G5P) was carried out by using the transglycosylation of lysozyme or β-D-galactosidase. p-Nitrophenyl 35-O-β-IV acetylglucosaminyl-a-maltopentaoside was regioselectively formed through hen egg-white lysozyme-mediated reaction from di-1V acetylchitobiose as a donor and G5P as an acceptor, p-Nitrophenyl 45-O-β-D-galactosyl-β-maltopentaoside (LG5PI) with 65-O-β-D-galactosyl-β-maltopentaoside were similarly synthesized by β-D-galactosidase from Bacillus circulans from lactose and G5P. LG5PI was very useful as a novel synthetic substrate for the colorimetric assay of human amylase in serum. A series of modified maltooligosaccharides were shown to be effective for examining the interaction between the substrates and the active site of human salivary β-amylase.
