Amylase activity

Malted barley contains a- and P-amylases along with proteases and phytases. Most standardi2ed microbial en2yme preparations for industrial starch conversion contain approximately 100 times more amylase activity than malt. In beermaking, malt is not just valuable for its en2ymes but also for flavor compounds. 

Shipe, J. R. and Savory, J. Kinetic nephlometric procedure for measurement of amylase activity in serum. Clin. Chem. (1972), 18, 1323-1325. 

Ceska, M. Birath, R. and Brown, B. A new and rapid method for the clinical determination of amylase activities in human serum and urine. Optimum conditions. 

In this chapter we describe the use of pea seeds to express the bacterial enzyme a-amylase. Bacterial exoenzymes like the heat stable a-amylase from Bacillus licheni-formis are important for starch hydrolysis in the food industry. The enzymatic properties of a-amylase are well understood [13,14], it is one of the most thermostable enzymes in nature and it is the most commonly used enzyme in biotechnological processes. Although fermentation in bacteria allows highly efficient enzyme production, plant-based synthesis allows in situ enzymatic activity to degrade endogenous reserve starch, as shown in experiments with non-crop plants performed under greenhouse conditions [12,15]. Finally, the quantitative and sensitive detection of a-amylase activ-... 

The expression profile of the USP promoter was monitored under field conditions using a-amylase activity as a reporter. The earliest sign of a-amylase activity was observed 8 DAP. Although the absolute level remained low, a -10-fold increase in promoter activity was detected between 12 and 13 DAP. The activity steadily increased during seed development reaching maximum levels of about 6000 CU kg-1 in mature seeds (Fig. 12.2). 

Once any directly fermentable sugars have been used up the yeast can only be fed by sugars produced from the starch. The only starch that can be broken down is the damaged starch. This explains why a certain amount of starch damage and some amylase activity is desirable in a bread flour. 

The Hagberg Falling Number test only just qualifies for this section as it is an effective way of measuring the a-amylase activity of wheat or flour. It has the considerable advantage that it is unaffected by any added fungal a-amylase. In addition, it only requires a supply of distilled water and electricity - there is no need for chemical glassware or any reagents. 

The technical issues with these products are as follows The malt must not introduce sufficient starch splitting enzymes to make the product unhandleable. The base flour used has, therefore, to be a strong flour with a low level of amylase activity. This requirement makes the product expensive. 

Rye Starch. Rye starch gelatinises at or around the temperature at which a-amylase has its maximum activity (55-70°C). a-Amylase activity tends to be high in rye flour so steps have to be taken to minimise it. One step is to acidify the dough either by adding acid or... 

AII listed products contain pancrelipase. Pancrelipase contains not less than 24 USP units of lipase activity, not less than 100 USP units of amylase activity, and not less than 100 USP units of protease activity per mg. 

Pancreatic amylase is very labile and sensitive to its chemical environment. Its lability is accelerated by purification and by such factors as dilution of its aqueous solutions, dialysis of its aqueous solutions against water, unfavorable hydrogen ion activities and unfavorable temperatures.29-31, 36,33 The loss of amylase activity in solutions of pancreatic amylase increases with increasing temperature and is very rapid between 50° and 60°. The inactivation of pancreatic amylase in aqueous solution may be retarded by the addition of certain anions, of which the chloride ion is outstanding 37-39 by the addition of certain cations, of which... 

The alpha amylase of malted barley, the amylase of Aspergillus oryeae and pancreatic amylase all are thermolabile proteins that rapidly lose their amylase activities upon exposure to unfavorable temperatures, to unfavorable hydrogen ion activities, or to other unfavorable chemical environments. The loss of amylase activity in aqueous solutions increases with increasing temperatures and is exceedingly rapid for each of these amylases at 50°. The inactivation of each of these amylases at unfavorable temperatures or at unfavorable hydrogen ion activities may be retarded by the presence of suitable concentrations of calcium ions. 

Maltose, the endproduct of amylase activity, was measured by the method of Dahlquist (16). 3Peptide=supernatant protein which was not precipitated when trichloroacetic acid (TCA) solution was added to 5% TCA (W/V) (17). 

Another approach of energy transfer-based probe has been demonstrated for a-Amylase sensing/98 In this case amylose was doubly labeled, by fluorescein derivative (donor) and Procion Red MX8B (acceptor). As a-Amylase catalyzes the cleavage of the amylose into smaller units, the average distance between fluorescein and Procion Red increases, which reduces the degree of quenching. The rate of increase in fluorescence intensity is proportional to ee-amylase activity. 

F. Apple, P. Benson, L. Preese, S. Eastep, L. Bilodeau, G. Heiler, Lipase and Pancreatic Amylase Activities in Tissues and Patients with Hyperamylasemia , Am. J. Clin. Pathol. 1991, 96, 610-614. 

Several plant defensins have also been found to be inhibitors of various enzymes in plant pests. The plant defensins Slctl, SIo 2, and SIa3 were the first plant defensins where inhibition of a-amylase was shown at low concentration whereas purothionins inhibited a-amylase activity only at high concentrations. Blal and BIa2 isolated from barley are two more representatives of proteinaceous a-amylase inhibitors in the plant defensin family. ... 

Enzymes activities are particularly sensitive to the anticoagulant used in collecting the specimen. Heparin inhibits acid phosphatase (W16) and muramidase (Z5). Amylase activity is inhibited by oxalate or citrate (MIO), and lactic dehydrogenase and acid phosphatase lose activity in oxalate (C2). Alkaline phosphatase is stable in oxalate, oxalate-fluoride, or heparin, but 25 mAf citrate inhibits 50% of the activity, and as little as 50 mlf EDTA is completely inhibitory (B19). Leucine aminopeptidase is inhibited by EDTA, as is creatine phosphokinase (F3). Amylase activity has been reported to be only 83% of that in serum when oxalate or citrate-plasma is used (MIO). Heparin plasma appears to have no inhibitory effect. Despite the fact that clotting factor V is not stable in oxalate or EDTA, these are often used as anticoagulants to obtain plasma for prothrombin determinations (Z2, Z4). 

Melsner, et al. reported Inhibition of growth and protease and amylase activity In S. llttoralls larvae after feeding on... 

Oral Tablets, powder, or delayed-release capsules containing varying amounts of lipase, protease, and amylase activity. See manufacturers literature for details. 

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