Clinical Chemistry, Vol 33, 524-528, Copyright © 1987 by American Association for Clinical Chemistry

Rapid determination of alpha-amylase activity by use of a new chromogenic substrate

G Dupuy, G Hilaire and C Aubry

A new chromogenic substrate that is blocked at the nonreducing end, 4,6- benzylidene-alpha-D-4-nitrophenylmaltoheptaoside, is used to determine alpha-amylase (EC 3.2.1.1) activity in serum in a coupled assay with alpha-glucosidase (EC 3.2.1.20) and glucoamylase (EC 3.2.1.3) as auxiliary enzymes. The duration of the lag phase between 25 and 37 degrees C is less than 90 s, and the molar absorptivity of 4- nitrophenol is constant. The main cleavage product of the substrate by human pancreatic and salivary alpha-amylase is 4-nitrophenylmaltoside; in the presence of the auxiliary enzymes, greater than 95% of hydrolyzed substrate is accounted for as 4-nitrophenol. The combined reagent is stable for at least 20 days at 2-8 degrees C; precision is good, with CVs ranging from 1.7 to 3.3%; and the correlation of results with those by the 4-nitrophenylmaltoheptaoside method is excellent. Heparin (40 kilo-int. units/L), ascorbic acid (2.8 mmol/L), bilirubin (430 mumol/L), hemoglobin (170 mumol/L), glucose (55 mmol/L), and triglycerides (11 mmol/L) do not interfere in the assay.

The following articles in journals at HighWire Press have cited this article:

				K. Lorentz Routine {alpha}-Amylase Assay Using Protected 4-Nitrophenyl-1,4-{alpha}-D-maltoheptaoside and a Novel {alpha}-Glucosidase Clin. Chem., May 1, 2000; 46(5): 644 - 649. [Abstract] [Full Text] [PDF]

				T. Yoshino and I. Yamaguchi Possible Involvement of 5-HT2 Receptor Activation in Aggravation of Diet-Induced Acute Pancreatitis in Mice J. Pharmacol. Exp. Ther., December 1, 1997; 283(3): 1495 - 1502. [Abstract] [Full Text]