Taka-diastase

Myrback66 74-77 studied products obtained from a number of different starches after the prolonged action of unpurified taka diastase. He... 

Ribonuclease T2 (5) was found in 1957 by Sato and Egami in Taka-diastase (12). Since the partially purified RNase T2 was found to preferentially attack phosphodiester bonds of adenosine-3 -phosphate in RNA (80), this enzyme had long been expected to be specific for adenylic acid phosphodiester bond if it could be completely purified. However, sufficiently purified RNase T2 showed no absolute base specificity (81, 82) and was found rather to split all phosphodiester bonds in RNA with a preference for adenylic acid bonds. Thus, RNase T2 is effective in the analysis of the base composition of RNA. 

Digest starchy samples with taka-diastase before saponification. Saponify (hot), extract un-saponifiables with petroleum ether. Silica solid-phase extraction in the sample cleanup mode (high-fat samples only). 

Taka-diastase). After two months about 75% of the o-glucosidic linkages were ruptured. Fermentable sugar was removed and the dextrins were fractionated after concentration of the filtrate (Table XXI). Fractions III and IV contained amorphous disaccharides (non-fermentable or... 

Taka diastase produced commercially with Aspergillus oryzae by surface culture Takamine... 

Taka-Diastase Origin Aspergillus oryzae Fluka... 

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. 

After three years of work, Holley and his associates managed to collect 1 g of alanine transfer RNA, which they used to study the sequence of the polynucleotide. To perform this task, investigators used three different enzymes pancreatic ribonuclease, taka-diastase (Tl), and snake venom phosphodiesterase. 

Like all ribonucleases, pancreatic ribonuclease attacks phosphodiester linkages between the 3 and 5 positions of the RNA nucleotide moieties to yield 2, 3 -cyclic phosphate derivatives. The cyclic phosphates are then further hydrolyzed to yield the 3 -phosphate derivatives. The specificity of pancreatic ribonuclease is such that it restricts its activity to the phosphodiester bonds that involve 3, 5 -linkages between a pyrimidine and any other base. Therefore, the product of the ribonucleic acid digestion with ribonuclease contains 3 -pyrimidine mononucleotides and oligonucleotides with a 3 -cytidylic or uridylic mononucleotide. Taka-diastase (Tl) is a ribonuclease that attacks the polynucleotides to yield 3 guanosine mononucleotides and oligonucleotides with a terminal 3 -guanylic acid. 

To study sequence, a sample of the RNA was divided into two batches, one treated with RNase and the other with taka-diastase. At the end of the incubation, in both cases the RNA is split into mononucleotides and oligonucleotides. Various mono- and oligonucleotides can be separated by chromatography on DEAE-cellulose columns. In the case of dinucleotides, the two nucleotides are split by alkaline treatment, and the mononucleotides are separated by paper chromatography or electrophoresis. The position of the 3 -... 

On the left, those obtained after digestion with taka-diastase. All nucleotides end with pyrimidine structures. 

In part B are given the ribonuclease and taka-diastase sites of action with the first 11 residues of the alanine tRNA (after R.W. Holley). 

In most food sample matrices, acid and/or enzymatic treatment is needed to release thiamine from phosphate and proteins. Different acids and enzymes have been proposed, including hydrochloric, trichloroacetic and sulfuric acids single enzymes such as papain and pepsin, or enzyme mixtures such as taka-diastase or claradiastase. Hydrolysis using claradiastase coupled with hydrochloric acid has proven to be the most efficient treatment. 

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