Starch hydrolytic activity

It is now supposed that gibberellic acid stimulates the hormonal production of a-amylase (and, probably, of /9-amylase and others) in the aleurone layer surrounding the endosperm starch-reserve. Gibberellic acid released 400 mg. equivalents of D-glucose per g. in 90 hours in wheat grains, with a maximum hydrolytic activity after 60 hours. The effect on /9-amylase was thought to be a release (to the extent of 85%) from the protein-bound, insoluble form.876... 

Microwave heating has not evoked a great deal of attention in the area of starch modification. Effective starch modification is achieved when the microwave energy is coupled with hydrolytic activity originating from added mineral acid. The... 

Radziszewski, Ber., 1887, 20, 2934 1885, 18, 355 Dubsky, J. prakt. Chem., 1916, [2], 93,137. Tor the hydrolytic activity of hydrogen peroxide towards other types of organic compounds, such as albumin, gelatin, and starch, see Neuberg and Muira, Btochem. Zeitsck, 1911, 36, 37. 

The zymogram in Figure 5 shows a starch degradation zone with the same Rf value as the protein band corresponding to DDase, leading to the conclusion that DDase itself was the enzyme displaying the hydrolytic activity observed in the donor/acceptor assays. 

Inactive form of starch hydrolytic enzyme, Q -aiiiylase, was incorporated in starch matrix. Degradation of the starch matrix by ct-amylase when the incorporated enzyme was activated in the pre.sence of Intelligent biosensor for Kost, 1994... 

Two approaches are discussed for the preparation of enzymatically controlled drug delivery systems a calcium-responsive biodegradable drug delivery system based on a mixture of starch with HPMC (hydroxypropyl methyl cellulose ether) (biodegradable) and the starch hydrolytic enzyme, alpha-amylase, in its non-active form and a glucose responsive insulin delivery system based on the hydrogel poly(2-hydroxyethyl methacrylate-co-N,N-dimethylaminoethyl methacrylate), with entrapped glucose oxidase, catalase and insulin. In both systems, the sensitivity... 

II Hydrolytic activity of enzyi es especially amylase was higher in pretreated seeds indicating faster utilization of starch for enhanced seedling growth therein Catalase was also higher in pretreated seeds ... 

Gibberellic acid and (2,4-dichlorophenoxy) acetic acid increased the glycoside content of Omithogalum umbellatum, as measured by a biological assay of extracts. The active principle, strophanthidin, is one of the cardiac glycosides. 7 There is little reference in the literature to this type of work, but the hydrolytic effects of gibberellic acid on starch may shift the equilibrium toward phenyl glycoside formation in some plant species. 

Based on the mechanisms of enzyme hydrolysis of starch and the diffusion processes of enzyme and the starch digestion products in the plastic matrix, the following assumptions were made (a) the diffusion of both the enzyme and the products in the plastic matrix obeys the Pick s first law, (b) the diffusion coefficient is constant throughout the matrix during the reaction, (c) the hydrolytic reactions take place only inside the hydrophobic plastic matrix, and (d) the reaction between the enzyme and the substrate is a modified Michaelis-Menten type and the product (P), will competitively inhibit the enzyme activity ... 

Molecular separation along with simultaneous chemical transformation has been made possible with membrane reactors [17]. The selective removal of reaction products increases conversion of product-inhibited or thermodynamically unfavourable reactions for example, in the production of ethanol from com [31]. Enzyme-based membrane reactors were first conceived 25 years ago by UF pioneer Alan Michaels [49]. Membrane biocatalytic reactors are used for hydrolytic conversion of natural polymeric materials such as starch, cellulose, proteins and for the resolution of optically active components in the pharmaceutical, agrochemical, food and chemical industries. Membrane bioreactors for water treatment were introduced earher in this chapter and are discussed in detail in Chapters 2 and 3. 

For measuring the activity of hydrolytic enzymes the method of agarose gel plates was applied [4]. For measuring the proteases activity a gelatin was used as a substrate, for amylases - starch, for cellulases -carboxymethylcellulose (CMC), for pectinases the apple pectin was used. The concentration of substrate in gel was always 1%. To make the reaction of substrate hydrolysis reaction the plates with the samples were incubated... 

---