About Calzyme Contact Us Locations Our Policies

  Welcome to Calzyme!

beta-Amylase

(1,4-a-D-Glucan maltohydrolase; EC 3.2.1.2)

ß-Amylase is an exoenzyme that releases successive maltose units from the nonreducing end of a polysaccharide chain by hydrolysis of a-1,4-glucan linkages. The shortest normal saccharide attacked is maltotetraose (Myrback, K. and G. Neumuller, The Enzymes, Vol. I, Part 1, p 653, 1950). Since it is unable to bypass branch linkages in branched polysaccharides such as glycogen or amylopectin, their hydrolysis is incomplete and a macromolecular limit dextrin remains.

The enzyme is useful in structural studies of starch and glycogen and can remove contaminating &223;-glucosidase. It has a molecular weight of 206,000 and an optimum pH 4.0 to 5.0. The enzyme is sulfhydryl sensitive and inhibited by heavy metals ions, p-mercuribenzoate, iodoacetamide and urea. Ascorbate inhibition has been attributed to cupric ion reduction and subsequent formation of an inactive cuprous enzyme complex (Rowe, A.W. and C.E. Weill, Biochim. Biophys. Acta, 65, 245, 1962).





The amount of enzyme which liberates, from soluble starch, one micromole of maltose per minute at pH 4.8 at 37°C.


  1. 0.0016 M Sodium acetate, pH 4.8.
  2. 2 M Sodium hydroxide (NaOH).
  3. Dinitrosalicylic acid color reagent: Dissolve 1.0 g 3,5-dinitrosalicylic acid in 20 ml 2 M NaOH. Add slowly, 30.0 g sodium potassium tartrate tetrahydrate. Dilute to a final volume of 100 ml with distilled water.
  4. 1% Starch: Dissolve 1.0 g soluble starch in 100 ml 0.02 M sodium phosphate buffer, pH 6.9, containing 0.006 M NaCl. Bring to a gentle boil to dissolve. Cool and make volume to 100 ml with distilled water.
  5. Maltose stock solution: 5 mM/ml. Prepare by dissolving 180 mg maltose in 100 ml distilled water and incubate at 37°C for 10 minutes prior to assay.
  6. Enzyme (§-amylase) solution. Dilute to a concentration of 1-10 µg/ml. Prepare at least 3 different concentrations within this range. Must be prepared fresh immediately prior to assay.



  1. Set spectrophotometer to 540 nm and water bath to 37°C.
  2. Using the maltose stock solution prepare a maltose standard curve with dilutions ranging from 0.3 to 5 mM/ml. Use distilled water as blank.
  3. Pipette 0.5 ml of respective enzyme dilutions into a series of numbered test tubes. Include one blank with 0.5 ml distilled water.
  4. Incubate tubes at 37°C for 10 minutes to achieve temperature equilibration.
  5. At timed intervals, add 0.5 ml starch solution (at 37°C) and incubate exactly 5 minutes at 37°C.
  6. Exactly 5 minutes following the addition of starch, add 1 ml dinitrosalicylic acid reagent to each tube at timed intervals.
  7. Incubate all tubes in a boiling water bath for 5 minutes.
  8. Cool to room temperature and add 10 ml distilled water.
  9. Read absorbance at 540 nm after zeroing the spectrophotometer with the blank.
  10. Determine mM or maltose liberated from standard curve.

 

©1999-2017 Calzyme All Rights Reserved powered by corezon
All logos and trademarks are properties of their respective companies. Product price, specification, warranty and availability subject to change without notice.
2-Phosphoenol Pyruvate Acid 3-Indoxyl Phosphate
3-Phosphoglycerate Kinase Acetone Powders
Acetyl Cholinesterase Acid Phosphatase
Actin Acylase
Adenosine 5'-diphosphate Adenosine 5'-monophosphate (AMP)
Adenosine 5'-triphosphate (ATP) Adenosine Deaminase
Alcohol Dehydrogenase Aldehyde Dehydrogenase
Aldolase Alkaline Phosphatase
alpha-Amylase alpha-D-Glucose-1-Phosphate
alpha-Glucosidase alpha-Ketoglutarate
Amylopectin Amylose
Apo-d-Amino Acid Oxidase Ascorbate Oxidase
Avidin beta-Amylase
beta-Glucosidase beta-Glucronidase
beta-NAD beta-NADH
beta-NADPH Bromelain
Butyryl Cholinesterase C-Reactive Protein
Carbonic Anhydrase Carboxypeptidase A
Carboxypeptidase B Carboxypeptidase Y
Catalase Catechol-o-Methyl Transferase
Cathepsin D Cholesterol Esterase
Chymotrypsin d-Amino Acid Oxidase
d-Glucose-6-Phosphate Deoxyribonuclease (DNase)
Deoxyribonucleic Acid (DNA) Elastase
Enterokinase Ferritin
G-6-phosphate Dehydrogenase gamma-Glutamyl Transferase
Glucose Oxidase Glutamate Dehydrogenase
Glutathione Peroxidase Glycerol Kinase
Glycerol-3-phosphate Dehydrogenase Glycosylated Albumin
Glycosylated Hemoglobin GOT (AST)
GPT (ALT) Hemoglobin
 Hexokinase Histamine-n-Methyl Transferase
Hyaluronic Acid Hyaluronidase
Insulin L-Arginase
L-gamma-Glutamide Nitroanilide Lactate Dehydrogenase
Lactoperoxidase Leucine Aminopeptidase
Lipase Lipoamide Dehydrogenase
Lipoxidase Luciferase
Lysozyme Malate Dehydrogenase
Mutarotase Myelin
Myoglobin Myosin
Oxyhemoglobin p-Nitrophenyl Phosphate
Pepsin Peroxidase
Phosphorylase-b Phspho(enol) Pyruvate Carboxylase
PNMT Prophospholipase A2
Protein Methylase II Pyruvate Kinase
Renin Rennin
Ribonuclease Sedoheptulose
Stachyose Superoxide Dismutase
Thyroglobulin Triose Phosphate Isomerase
Trypsin Trypsin Inhibitor
Tyrosinase Urease
Uricase Xanthine Oxidase


abc