Book ChapterDOI
α-Amylase Measurement of Reducing Groups
Wirnt Rick,Hans Peter Stegbauer +1 more
- pp 885-890
TLDR
The present findings suggest that the hydrolysis of the polysaccharide chain occurs via the principle of ″multiple attack―, that is, once the enzyme-substrate complex is formed, the enzyme can hydrolyze several bonds of the polymer successively before the enzyme is again liberated in the free form.Abstract:
Publisher Summary
This chapter explains α-amylase, which hydrolyses α-14-glucan bonds in polysaccharides, such as starch, amylopectin and glycogen, and their degradation products with a chain length of at least 3 d-glucose residues. Damage to the α-amylase synthesizing tissues, in particular the pancreas, results in leakage of the enzyme from the parenchymal cells and its appearance in the serum. The present findings suggest that the hydrolysis of the polysaccharide chain occurs via the principle of ″multiple attack―, that is, once the enzyme-substrate complex is formed, the enzyme can hydrolyze several bonds of the polymer successively before the enzyme is again liberated in the free form. The amylase activity can be measured by means of the decrease in viscosity of a starch solution, the decrease in turbidity of a starch suspension, the decrease in the intensity of the starch-iodine reaction and the increase in the number of reducing groups. On the basis of the starch-iodine reaction it was concluded that iso-amylases occurred in all five serum fractions as separated by electrophoresis. α-amylase is applied in biochemistry, clinical chemistry and pharmacy.read more
Citations
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Journal ArticleDOI
Effects of Bacillus subtilis on the growth performance, digestive enzymes, immune gene expression and disease resistance of white shrimp, Litopenaeus vannamei.
Hadi Zokaeifar,José Luis Balcázar,Che Roos Saad,Mohd Salleh Kamarudin,Kamaruzaman Sijam,Aziz Arshad,Naghmeh Nejat +6 more
TL;DR: It is demonstrated that administration of B. subtilis strains, L10 and G1, can improve growth performance and disease resistance through an enhanced immune response in shrimp.
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The gut microbiome and degradation enzyme activity of wild freshwater fishes influenced by their trophic levels.
TL;DR: PICRUSt predictions of metagenome function revealed that fishes in different trophic levels affected the metabolic capacity of their gut microbiota, metabolic capacity and gut content enzyme activity.
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Mutants of Arabidopsis with Altered Regulation of Starch Degradation
TL;DR: Mutants of Arabidopsis thaliana (L.) Heynh with altered regulation of starch degradation were identified by screening for plants that retained high levels of leaf starch after a period of extended darkness, raising the possibility that hitherto unidentified factors play a key role in regulating or catalyzing starch degradation.
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Utilization of Amylose−Lipid Complexes as Molecular Nanocapsules for Conjugated Linoleic Acid
TL;DR: All complexes showed high retention of CLA in simulated stomach conditions, and the digestion of complexes by amylases results in high hydrolysis and CLA release by pancreatin and alpha-amylase, suggesting that amylose-CLA complexes can serve as molecular nanocapsules for protection and delivery of CLA.
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Effect of age, weaning and diet on digestive enzyme levels in the piglet.
TL;DR: It appears that the pig has sufficient pancreatic and gastric enzyme activity so that performance should not be limited, with the possible exception of the period shortly after weaning.
References
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Journal ArticleDOI
Multiple attack hypothesis of α-amylase action: Action of porcine pancreatic, human salivary, and Aspergillus oryzae α-amylases
John F. Robyt,Dexter French +1 more
TL;DR: In this article, three conceptual action patterns of α-amylase hydrolysis of amylose have been considered: single chain, multichain, and multiple attack, and curves were obtained relating the drop in amyloses-iodine color to the increase in reducing value for amylolysis by human salivary (HS), porcine pancreatic (PP), Aspergillus oryzae (AO), and 1 m H 2 SO 4.
Journal ArticleDOI
Dinitrosalicylic acid: a reagent for the estimation of sugar in normal and diabetic urine
James B. Sumner,Viola A. Graham +1 more
TL;DR: In this article, it was shown that the most suitable reagent would be a compound similar to picric acid in that it, would be reduced by glucose to form a highly colored nitroamino compound, but dissimilar to Picric acid, it would neither form colored compounds with acetone or creatinine nor be reduced in the presence of urinary constituents other than the sugars.
Journal ArticleDOI
A method for the determination of amylase in intestinal content.
TL;DR: A unit for amylase activity is defined, in accordance with recommendations for clinical and biochemical enzyme units recently made by the Joint Sub-Commission on Clinical Enzymes Units of the International Union of Biochemistry and the InternationalUnion of Pure and Applied Chemistry.