Difference in transglycosylation between human pancreatic and salivary alpha-amylases.
Transglycosylation reactions of alpha-amylases from human pancreatic juice and saliva were examined by using O-6-deoxy-6-[(2-pyridyl)amino]-alpha-D-glucopyranosyl-(1 leads to 4)-O-alpha-D-glucopyranosyl-(1 leads to 4)-O-alpha-D-glucopyranosyl-(1 leads to 4)-O-alpha-D-glucopyranosyl-(1 leads to 4)-D-glucopyranose as a substrate and O-alpha-D-glucopyranosyl-(1 leads to 4)-O-alpha-D-glucopyranosyl-(1 leads to 4)-1-deoxy-1-[(2-pyridyl)amino]-D-glucitol as an acceptor. The transfer reaction was estimated by quantitation of O-alpha-D-glucopyranosyl-(1 leads to 4)-1-deoxy-1-[(2-pyridyl)amino]-D-glucitol produced by the enzymes from the transfer products, because the acceptor was not hydrolyzed. The amount of O-alpha-D-glucopyranosyl-(1 leads to 4)-1-deoxy-1-[(2-pyridyl)amino]-D-glucitol in the digest with pancreatic alpha-amylase was six times that in the digest with salivary alpha-amylase at the stage when the substrate was completely consumed, and the difference increased gradually on further incubation. The phenomenon can be applied to differentiate the two alpha-amylases in human serum.
D002236:Carbohydrate Conformation; D006027:Glycosides / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009844:Oligosaccharides / Q000378:metabolism; D010189:Pancreatic Juice / Q000201:enzymology*; D012463:Saliva / Q000201:enzymology*; D000516:alpha-Amylases / Q000378:metabolism*
D006027:Glycosides; D009844:Oligosaccharides; D000516:alpha-Amylases