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

1987 ◽  
Vol 33 (4) ◽  
pp. 524-528 ◽  
Author(s):  
G Dupuy ◽  
G Hilaire ◽  
C Aubry
Keyword(s):  
Amylase Activity ◽  
Rapid Determination ◽  
Molar Absorptivity ◽  
Cleavage Product ◽  
Alpha Amylase ◽  
Lag Phase ◽  
Chromogenic Substrate ◽  
Salivary Alpha Amylase ◽  
Alpha Glucosidase

Abstract 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.

Enzyme-coupled ultraviolet determination of alpha-amylase activity with the GEMSAEC centrifugal analyzer.

1978 ◽  
Vol 24 (9) ◽  
pp. 1620-1624 ◽  
Author(s):  
W H Porter ◽  
R E Roberts
Keyword(s):  
Linear Response ◽  
Amylase Activity ◽  
Kinetic Studies ◽  
Alpha Amylase ◽  
Coefficients Of Variation ◽  
Endogenous Glucose ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Alpha Glucosidase ◽  
As Effects

Abstract We evaluated the Harleco alpha-glucosidase/hexokinase/glucose-6-phosphate dehydrogenase-coupled alpha-amylase method, bu use of the GEMSAEC centrifugal analyzer. Performance evaluation included kinetic studies of substrate and maltose hydrolysis as well as effects of endogenous glucose and fructose. The reagent was found to give a linear response with alpha-amylase activity to greater than 1200 U/liter. Within-run precision resulted in coefficients of variation (CV) of 0.9 to 3.2% over the range studied. Day-to-day precision corresponded to CV's of 2.4 to 4.4% over the same range of alpha-amylase procedure was found to be good (r = 0.997) for patients' sera examined.

Hydrolysis by human alpha-amylase of p-nitrophenyloligosaccharides containing four to seven glucose units.

1982 ◽  
Vol 28 (7) ◽  
pp. 1485-1489 ◽  
Author(s):  
H David
Keyword(s):  
Amylase Activity ◽  
Relative Rate ◽  
Kinetic Studies ◽  
Alpha Amylase ◽  
High Pressure Liquid Chromatographic ◽  
Salivary Alpha Amylase ◽  
Rate Of Hydrolysis ◽  
Liquid Chromatographic ◽  
Alpha Glucosidase ◽  
Coupled Assay

Abstract Kinetic and "high-pressure" liquid-chromatographic studies were performed on the reaction of human pancreatic and salivary alpha-amylase (EC 3.2.1.1) with p-nitrophenyloligosaccharides containing four to seven glucose units. The kinetic studies indicate that, as the temperature increases from 25 to 37 degrees C, the apparent Km of the enzyme for a given substrate increases slightly. However, as the number of glucose units in the substrate increases, the apparent Km decreases. The apparent Vmax increases as the temperature increases, and decreases as the number of glucose units in the substrate increases. In contrast, chromatographic data indicate that the relative rate of hydrolysis by alpha-amylase is pG7 greater than pG6 greater than pG5 greater than pG4. The differences between the kinetic and the chromatographic results are discussed. p-Nitrophenyl-alpha-maltopentaoside and p-nitrophenyl-alpha-maltohexaoside are superior to the other p-nitrophenyloligosaccharides as substrates for determining alpha-amylase activity in an alpha-glucosidase-coupled assay system.

New saccharogenic determination of alpha-amylase in serum and urine.

1979 ◽  
Vol 25 (2) ◽  
pp. 215-217 ◽  
Author(s):  
L van Leeuwen
Keyword(s):  
Human Serum ◽  
Amylase Activity ◽  
Glucose Dehydrogenase ◽  
Alpha Amylase ◽  
Endogenous Glucose ◽  
Alpha Glucosidase ◽  
Serum And Urine

Abstract I describe a new kinetic enzymatic saccharogenic method for assaying alpha-amylase in human serum and urine. alpha-Amylase liberates maltose from starch. This is successively acted on by alpha-glucosidase, mutarotase, and glucose dehydrogenase. The resulting conversion of NAD+ to NADH, measured at 340 nm, during a 20-min incubation reflects amylase activity. Endogenous glucose is destroyed before measurement of amylase activity is begun.

Inhaled Salmeterol Induces Salivary Alpha Amylase Activity in Healthy Subjects

2015 ◽  
Vol 135 (2) ◽  
pp. AB4
Author(s):  
Andrea A. Pappalardo ◽  
Sherlyana Surja ◽  
Caitlin M. Campion ◽  
Sarah J. Aldrich ◽  
James N. Moy
Keyword(s):  
Healthy Subjects ◽  
Amylase Activity ◽  
Alpha Amylase ◽  
Salivary Alpha Amylase

scholarly journals Salivary alpha-amylase activity and cortisol in horses with acute abdominal disease: a pilot study

2018 ◽  
Vol 14 (1) ◽  
Author(s):  
María Dolores Contreras-Aguilar ◽  
Damián Escribano ◽  
María Martín-Cuervo ◽  
Fernando Tecles ◽  
Jose Joaquín Cerón
Keyword(s):  
Pilot Study ◽  
Amylase Activity ◽  
Alpha Amylase ◽  
Salivary Alpha Amylase ◽  
Abdominal Disease

Determination of alpha-amylase activity: methods comparison and commutability study of several control materials

1995 ◽  
Vol 41 (3) ◽  
pp. 435-438 ◽  
Author(s):  
G Gubern ◽  
F Canalias ◽  
F J Gella
Keyword(s):  
Human Serum ◽  
Amylase Activity ◽  
Alpha Amylase ◽  
Human Origin ◽  
Serum Samples ◽  
Chromophore Group ◽  
Laboratory Control ◽  
Wide Range ◽  
Human Sera

Abstract Six different methods for alpha-amylase determination were compared by assaying human serum samples covering a wide range of alpha-amylase values. All the methods studied use as substrate a maltooligosaccharide with a chromophore group at the reducing end; some are chemically blocked at the nonreducing end. Intermethod comparison by regression and correspondence analyses showed significant differences for two methods. The commutability of 12 commercial control materials containing alpha-amylase was also assessed by the different methods in comparison with human serum specimens containing the pancreatic and salivary isoenzymes. We also studied the behavior of pancreatic and salivary materials prepared in our laboratory. Control materials with alpha-amylase of non-human origin were not commutable with the enzyme in human sera and should not be used for intermethod calibration.

Isopropylidine maltoheptosyl fructofuranoside, doubly blocked substrate for determination of endoamylase activity

1991 ◽  
Vol 37 (8) ◽  
pp. 1323-1328
Author(s):  
Z Ogawa ◽  
Y Matsubayashi ◽  
S Satoh ◽  
N Orita ◽  
H Itoh
Keyword(s):  
Human Serum ◽  
Coefficient Of Variation ◽  
Oxidation Rate ◽  
Amylase Activity ◽  
Mannitol Dehydrogenase ◽  
Coupled Reactions ◽  
Alpha Glucosidase ◽  
Serum And Urine

Abstract We synthesized o-(4,6-o-isopropylidene-alpha-D-glucopyranosyl)-(1----4)- [o-alpha-D-glucopyranosyl-(1----4])5-o-alpha-D-glucopyranosyl-(1----2)- alpha-D-fructofuranoside (IPG7F) and developed an assay for determining the activity of amylase in human serum and urine by using this substrate. Glucoamylase, alpha-glucosidase, and mannitol dehydrogenase are used as coupling enzymes. The coupled reactions are monitored by continuously measuring the oxidation rate of NADH. In this procedure, various substances in the test specimens do not interfere with the detection of amylase activity. Exactly one molecule of NADH is oxidized by one attack of amylase on the substrate, although four products can be produced in the reaction. The within-assay coefficient of variation (CV) ranged from 1.0% to 4.1% and the between-assay CV ranged from 2.6% to 5.3%. The results of our new assay correlate well with those of the amylase assay involving p-nitrophenol maltoheptaoside as substrate (r = 0.978) and with those of the amylase assay involving maltopentaose (r = 0.987).

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