PULLG6 assay for the measurement of pullulanase employs a water soluble defined substrate, namely 4,6-O-benzylidene-4-nitrophenyl-63-α-D-maltotriosyl-maltotriose (BPNPG3G3), coupled with the ancillary enzymes α-glucosidase and β-glucosidase. Upon hydrolysis of the substrate at the 1,6-α-linkage by pullulanase or limit-dextrinase, the released 4-nitrophenyl-β-maltotrioside is immediately hydrolysed to glucose and 4-nitrophenol by the concerted action of the α-glucosidase and β-glucosidase enzymes in the reagent mixture. The reaction is terminated and phenolate ions are developed by addition of dilute alkali. The absorbance is read at 400 nm and the value obtained correlates directly with pullulanase activity.
Spectrophotometric at 400 nm
Features & Benefits:
High sensitivity Suitable for manual and auto-analyser formatsAll reagents stable for >1 year after preparation
10 min for pullanase preparations30 min for malt extracts containing limit-dextrinase
0.18 U/mL for pullulanase preparations (50-fold dilution)0.01 U/g for limit dextrinase in milled malt