The addition of gibberellic acid to isolated aleurone layers of barley (Hordeum vulgare L.) causes the production and secretion of four alpha-amylases. Two of these are stable at pH 3.7 and are not inactivated by ethylenediaminetetraacetate. The other two represent the classical barley alpha-amylases; i.e., they are inactivated at pH 3.7 and by reagents which from complexes with divalent metal ...

Midgut hydrolytic enzymes of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) were identified and partially characterized. Km, Vmax, optimum pH, and specific activity were determined for proteolytic enzymes and αamylases. All hydrolytic enzyme activity had an optimum pH value in the alkaline pH range. We observed major serine protease activity, together with minor cysteine-like activity, th...

α-Amylases are widely used enzymes in starch saccharification and baking industries, and in textile desizing. These are endoenzymes which cleave α-1,4-glycosidic linkages randomly in starch, thus, generate maltose and malto oligosaccharides. The commercially available α-amylases have certain limitations like a limited activity at low pH and Ca2+dependence, therefore, the search for novel acid s...

Industrial enzyme market has been projected to reach US$ 6.2 billion by 2020. Major reasons for continuous rise in the global sales of microbial enzymes are because of increase in the demand for consumer goods and biofuels. Among major industrial enzymes that find applications in baking, alcohol, detergent, and textile industries are α-amylases. These are produced by a variety of microbes, whic...

We have examined the affinity shown by the immunoglobulin fraction from each of five sera containing macroamylase for amylases from different sources: human saliva or human, porcine, or ovine pancreas. High affinity constants, 0.4 x 1010 to 7.2 x 1010 LJmol, were found in competitive binding experiments with human or porcine pancreatic amylase. All but one serum yielded linear Scatchard plots, ...

Numerous types of nanoparticles and nanocomposites have successfully been employed for the immobilization and stabilization of amylolytic enzymes; α-amylases, β-amylases, glucoamylases and pullulanases. Nano-support immobilized amylolytic enzymes retained very high activity and yield of immobilization. The immobilization of these enzymes, particularly α-amylases and pullulanases, to the nanosup...

Halophiles are perceived as an excellent source of novel enzymes possessing inherent ability to function under saline and hypersaline environment conditions. The article covers and puts in perspective the structural and biocatalytic features of α-amylases from halophilic sources. The choice of α-amylase as the target enzyme is based on the fact that this is among the largest selling enzymes. Ol...

Th e eff ects of various carbon and nitrogen sources on production of α-amylase by Bacillus subtilis and its mutant derivates were investigated. Th e maximum production of α-amylase by all strains was obtained in the presence of mesoinositol as the carbon source. Th ere was no more signifi cant increase in enzyme yield in the case of the supplementation of nitrogen sources, whereas malt extract...

α-Amylases are glycoside hydrolase enzymes that act on the α(1→4) glycosidic linkages in glycogen, starch, and related α-glucans, and are ubiquitously present in Nature. Most α-amylases have been classified in glycoside hydrolase family 13 with a typical (β/α)8-barrel containing two aspartic acid and one glutamic acid residue that play an essential role in catalysis. An atypical α-amylase (BmaN...

a-Amylase was purified to apparent homogeneity from normal pancreas and a transplantable pancreatic acinar carcinoma of the rat by affinity chromatography on a-glucohydrolase inhibitor (a-GHI) bound to aminohexyl-Sepharose 4B. Recovery was 95-100% for both pancreas and tumour a-amylases. They were monomeric proteins, with Mr approx. 54000 on SDS/polyacrylamide-gel electrophoresis. Isoelectric f...