Amylases from Aspergillus oryzae

An even more serious disadvantage of this technique is that it often impairs the biological activity of the modified protein. The activities of hen s egg lysozyme (EC 3.2.1.17) and alpha amylase from Aspergillus oryzae (EC 3.2.1.1) were lessened by diazo coupling of glycosides or aniline.12 Whether the decrease in activity was due to the modification of critical residues, or to the introduction of aromatic structures, is not yet clear however, enzymes subjected to the diazocoupling conditions in the absence of the diazonium salts retained their activity, implying that the reaction conditions themselves were not responsible for the loss of activity. 

Amylose is a linear polymer of glucose mainly linked with an al,4-glycosidic bond. Maltooligosaccharides have been effectively prepared by polycondensation of a-D-maltosyl fluoride using an a-amylase from Aspergillus oryzae as the catalyst in a mixed solvent of methanol-phosphate buffer (119). 

Studies of the hydrolyses of cyclohexa-, cyclohepta-, and cyclo-octa-amyloses by Taka-amylase A (one of the a-amylases from Aspergillus oryzae) indicated that each cycloamylose binds to the same active site of the enzyme. Since there is little difference in the respective AG, Af/, and AS values for enzymic hydrolysis of these cycloamyloses, their binding modes appear to be similar. The extent of multiple attack on the cycloamyloses was not affected by temperature. A 4-phenylazobenzoyl derivative of Taka-amylase A has been used to investigate the active site of the enzyme. A. oryzae a-amylase has a synergistic effect on the action of the glucoamylase from A. awamori var. kawachi ... 

The action of Taka-amylase A, an a-amylase from Aspergillus oryzae, has been studied quantitatively by a product analysis method using unlabelled maltotriose and maltotriose labelled at the reducing end as substrates. ... 

Chang, C. T., M. S. Tang, and C. F. Lin. 1995. Purification and Properties of Alpha-Amylase from Aspergillus Oryzae Atcc 76080. Biochemistry Molecular Biology International 36 (1) 185-193. 

Maltose syrup As glucose syrup process parameters adjusted for higher proportion of maltose in hydrolysate (amylase from Aspergillus oryzae)... 

Possible synergistic effects in the combined actions of an a-amylase (from Aspergillus oryzae) and a glucoamylase (from A, awamori) have been investigated. ... 

An interesting recent approach provided an effective strategy to improve protein secretion demonstrating an advance that can induce ER and cytosolic chaperones simultaneously. In this work, it was investigated the effect of heat shock response activation on recombinant protein secretion. HSFl gene, a heat shock transcription factor, which can constitutively activate HSR (Heat shock response), was overexpiessed in a S. cerevisiae recombinant strain with potential production of a-amylase from Aspergillus oryzae. The results demonstrated that activation of HSR increased the yield of heterologous a-amylase (Hou et al., 2013). 

While alpha amylases from many sources are known, the present discussion will deal mainly with the alpha amylase of malted barley, pancreatic amylase and the amylase of Aspergillus oryzae. These... 

The amylase of Aspergillus oryzae causes a very rapid decrease in the viscosity of its substrates and a very rapid disappearance from its reaction mixtures of products which give color with iodine. When examined under favorable conditions71 at 40° with Lintner s soluble potato starch, the achroic point was reached with highly purified maltase-free amylase when approximately 12% of the glucose linkages of the substrate had been ruptured. 

The data show that the extent of the hydrolysis of starch by the amylase of Aspergillus oryzae depends within wide limits upon the concentration of amylase used. Like those for pancreatic amylase already discussed (Figure 2), these hydrolysis curves show a change from a rapid to a slow phase of the reaction and tend to flatten at higher values as the concentration of amylase is increased. Again, with different concentrations of the amylase of Aspergillus oryzae there is no evidence of a common limit such as is observed with different concentrations of beta amylase (Figure 1). 

Products Formed from Lintner s Soluble Potato Starch by Purified Maltase-free Pancreatic Amylase or Amylase of Aspergillus oryzae (Data of Alfin and Caldwell64 and of Volz and CaldweU78)... 

Studies of the rate of the hydrolysis of dextrins isolated from a reaction mixture after the extensive hydrolysis of starch by maltase-free malted barley alpha amylase, led Myrback11 to conclude that the flattening of the reaction curves with this amylase is not due to equilibrium between the amylase and the products of the hydrolysis. As indicated above, similar conclusions have been reached for pancreatic amylase and for the amylase of Aspergillus oryzae.41,7a... 

Adenosine deaminase (EC 3.5.4.4) an enzyme, M, 217,000 (2 subunits M, 103,000 each) which deami-nates adenosine to inosine. It is present in taka-diastase preparations from Aspergillus oryzae, and is sometimes confused with Taka amylase (see). 

Taka amylase a bacterial a-amylase (EC 3.2.1.1) isolated and crystallized from Aspergillus oryzae taka diastase preparations. T. a. (Af, 50,000) is a calcium-containing, single-chain protein with V-terminal alanine and C-terminal serine. Like the tetrameric Bacillus subtilis a-amylase (Af, 96,000), T.a. is resistant to sodium dodecylsulfate but is reversibly denatured by 6 M guanidine or 8 M urea. T.a. must not be confused with Adenosine deaminase (see), which is also present in taka diastase. 

Fischer, brilliant results were achieved, and in succession the a-amylases of pig pancreas, of Bacillus subtilis, of human saliva, of human pancreas, and of Aspergillus oryzae, and the /3-amylase of malt, were successfully crystallized. Important biological deductions were gained from this study whereas the amylases of human pancreas and saliva cannot be distinguished from one another, amylases from pig pancreas and from human pancreas are different. These differences are manifested in molecular weight, crystalline forms, electrophoretic mobility, and influence of the pH on the activity however, all the amylases have the same specific biochemical action. The identity of the enzymes seems to be dependent on the species and not on the organ. Interest in biologically active proteins led Meyer to a study of the protein hormones, a field in which he was very active at the time of his death. 

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