Exoenzymic activity of alpha-amylase immobilized on a phenol-formaldehyde resin

Boundy, Joyce A.; Smiley, K. L.; Swanson, C. L.; Hofreiter, B. T.

doi:10.1016/s0008-6215(00)83219-x

Cited by 23 publications

(8 citation statements)

References 6 publications

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“…Immobilization of a-amylase alters its action pattern from an endo-enzymatic to an exo-enzymatic mode (2,17,19), and in the present report similar changes are described for the immobilized 13-glucanase.…”

Section: Introductionsupporting

confidence: 81%

“…First the free access of substrate to the active site of the endo-13-glucanase may be sterically impeded from the matrix-attachment. Such an effect has been noticed with insolubilized a-amylase which in comparison with dissolved a-amylase is more effective in at-tacking the ends of the carbohydrate chains of starch substrates (2,17,19). Second, the commercial glucanase contains in addition to endo-13-glucanase both 13-glucosidase and exo-13-glucanase activity which catalyze consecutive reactions in the degradation of barley 13-glucan to glucose.…”

Section: Action Patternmentioning

confidence: 98%

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Immobilization of β-glucanase and studies on its degradation of barley β-glucan

Svensson

Ottesen

1978

Carlsberg Res. Commun.

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A commercial fungal 13-glucanase preparation was immobilized by various methods including adsorption to DEAE-cellulose, cross-linking with glutaraldehyde, adsorption to a phenol-formaldehyde resin (Duolite) and to perlite followed by fixation with glutaraldehyde, covalent binding to glutaraldehyde-treated, partially hydrolyzed or partially aminolyzed nylon, and covalent binding in the Ugi-reaction to polyisonitrile-nylon. The recovery of enzymatic activity varied from 0.02 to 4.5% and the immobilized enzyme preparations showed specific activities from 1 to 25% of that of the starting material. DEAE-cellulose-, nylon-and Duolite-13-glucanase were used in packed bed reactors for continuous hydrolysis of barley 13-glucan. The Duolite-13-glucanase was most active in depolymerizing this polysaccharide. The action pattern of insoluble crude 13-glucanase (Duolite-13-glucanase) on barley 13-glucan was very different from that of the crude enzyme preparation in solution. Comparison with the mode of action of a homogeneous preparation of endo-l,4-13-glucanase in dissolved and immobilized form, respectively, indicated that this change in action pattern was partly due to coimmobilization of enzymes catalyzing consecutive steps in the hydrolysis of barley 13-glucan to glucose and partly to steric hindrance of the interaction between the immobilized enzyme and the interior regions of the substrate.

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Section: Introductionsupporting

confidence: 81%

Section: Action Patternmentioning

confidence: 98%

Immobilization of β-glucanase and studies on its degradation of barley β-glucan

Svensson

Ottesen

1978

Carlsberg Res. Commun.

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“…Urokinase covalently immobilized on glyoxal agarose exhibited changed selectivity towards glutathione S -transferase [198,229]. α-Amylase immobilized on silica [230] or covalently bound to CNBr-activated carboxymethyl cellulose [231] afforded products whose composition differed from that obtained with the native enzyme. This was largely attributed to the fact that the size of the pores where the enzyme molecules are located determines the accessibility of the substrates, depending on their size.…”

Section: Immobilization To Upgrade Industrial Enzymesmentioning

confidence: 99%

From Protein Engineering to Immobilization: Promising Strategies for the Upgrade of Industrial Enzymes

Singh

Tiwari

Singh

et al. 2013

IJMS

388

195

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Enzymes found in nature have been exploited in industry due to their inherent catalytic properties in complex chemical processes under mild experimental and environmental conditions. The desired industrial goal is often difficult to achieve using the native form of the enzyme. Recent developments in protein engineering have revolutionized the development of commercially available enzymes into better industrial catalysts. Protein engineering aims at modifying the sequence of a protein, and hence its structure, to create enzymes with improved functional properties such as stability, specific activity, inhibition by reaction products, and selectivity towards non-natural substrates. Soluble enzymes are often immobilized onto solid insoluble supports to be reused in continuous processes and to facilitate the economical recovery of the enzyme after the reaction without any significant loss to its biochemical properties. Immobilization confers considerable stability towards temperature variations and organic solvents. Multipoint and multisubunit covalent attachments of enzymes on appropriately functionalized supports via linkers provide rigidity to the immobilized enzyme structure, ultimately resulting in improved enzyme stability. Protein engineering and immobilization techniques are sequential and compatible approaches for the improvement of enzyme properties. The present review highlights and summarizes various studies that have aimed to improve the biochemical properties of industrially significant enzymes.

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“…Thus, the modified modulus defined by Weisz & Prater,22 that involves only measured overall reaction rates, has been used. It is defined by: 4,,, = R Z r V/D:"Cs V, (4) where R is the radius ofthe particle and D:" is the effective diffusivity of the substrate in the porous support. Cs is the concentration at the surface of the particle and depends on external diffusional limitations.…”

Section: Internal Diffusionmentioning

confidence: 99%

Effect of diffusional resistances on the action pattern of immobilized alpha‐amylase

Siso

Graber

Condoret

et al. 1990

J of Chemical Tech & Biotech

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Alpha-amylase from Aspergillus oryzae has been immobilized onto corn grits and porous silica (specific areas 180 and 440 m2 g-I). Kinetic parameters of immobilized enzyme have been determined.Immobilization of alpha-amylase results in the formation of less polymerized products resulting in an apparent decrease in the number of transglycosylation reactions, for both maltotetraose and starch as substrates, when compared with free enzyme.Diffusional limitations for substrate and products have been quantijed in the case of the three supports used. External diffusional resistances were important in all cases for the reaction products, whilst they became negligible for the substrate in the case of silica supports. Moreover, internal transfer limitations were identified with silica 180 m2 g -' support. It was demonstrated that diffitsional resistances were in direct relation to the apparent modijcation of the enzyme action pattern afer immobilization.

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Exoenzymic activity of alpha-amylase immobilized on a phenol-formaldehyde resin

Cited by 23 publications

References 6 publications

Immobilization of β-glucanase and studies on its degradation of barley β-glucan

Immobilization of β-glucanase and studies on its degradation of barley β-glucan

From Protein Engineering to Immobilization: Promising Strategies for the Upgrade of Industrial Enzymes

Effect of diffusional resistances on the action pattern of immobilized alpha‐amylase

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