Amylases cell free

In 1878 the term enzyme, Greek for "in yeast," was proposed (8). It was reasoned that chemical compounds capable of catalysis, ie, ptyalin (amylase from saliva), pepsin, and others, should not be called ferments, as this term was already in use for yeast cells and other organisms. However, proof was not given for the actual existence of enzymes. Finally, in 1897, it was demonstrated that cell-free yeast extract ("zymase") could convert glucose into ethanol and carbon dioxide in exacdy the same way as viable yeast cells. It took some time before these experiments and deductions were completely understood and accepted by the scientific community. 

Some of the enzymes discussed above have been detected in filtered water samples free of particulate matter. These include the phosphatases and the starch-degrading amylases. Generally, free enzymes appear to be more abundant in sediments than in the water column (Kim and Zobell, 1972), but at times some of them, such as alkaline phosphatase, can be as active as their particle-bound forms (Berman, 1970). Dissolved extracellular enzymes are presumably excreted by various microorganisms, or perhaps are released during cell degradation or lysis. 

Poly(A)-rich mRNA prepared from rabbit pancreas directed the synthesis of a protein (mol. wt. 5.65 X 10 ), which, using a cell-free protein synthesizing system derived from wheat embryo, appeared to represent the product of o-amylase mRNA cell-free translation.This protein, which was 1500 daltons larger than the purified rabbit pancreas a-amylase, was resolved by isoelectric focusing into discrete species similar to those observed for purified a-amylase. The protein, which on peptide analysis demonstrated considerable identity with the a-amylase, was selectively precipitated by glycogen, but with a much lower recovery than that observed for rabbit on porcine pancreatic a-amylases. 

Cetylpyridinium chloride (CPC)/ hexane a-Amylase from brewers yeast and invertase from bakers yeast Enzyme activities in cells entrapped in RMs were high compared to free cells [284]... 

M acetic acid at 95°C. The resulting extract was treated using a heat-stable, commercial a-amylase [4, 36]. The amount of free chitosan in the cell wall of... 

In a procedure described for the simultaneous large-scale isolation of pullulanase and (1 4)-oc-D-glucan phosphorylase from Klebsiella pneumoniae, the pullulanase is solubilized from the cell wall by cholate treatment cells and cell debris are removed by partition in a poly(ethyleneglycol)-dextran two-phase system and from the upper phase of this system the pullulanase is isolated by ultrafiltration and precipitation with A -cetyl-iV, A -trimethylammonium bromide to 80% purity with 70% yield and in an a-amylase-free state. 

Spatial separation of carbohydrases within the cell must also be considered if the contentions of Matile [95] are correct. Matile suggests that the pea protein bodies (aleurone vacuoles), which store protein and phytin in the dry seed, become lysosomal when their reserves are depleted, and contain hydrolases (including ribonucleases, phosphatases, proteinases). Furthermore, he contends that a-amylase (and presumably the amylopectin-l,6-glucosidase) act as free enzymes in the cytoplasm and that the products of a-amylolysis then pass into the vacuole/lysosome for completion of the digestion process. While such a suggestion is appealing, it is still far from proven. 

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