XV. Hydrolases immobilized on Biozan R

Simionescu, Cr.; Dumitriu, Severian; Popa, Marcel; Dumitriu, Maria; Hritcu, Doina

doi:10.1007/bf01451542

Cited by 9 publications

(7 citation statements)

References 21 publications

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“…The coupling reaction of the hydrolases (invertase and amyloglucosidase) on xanthane (Biozan R, Hercules) is afFected by several factors [187]. The reactions were carried out in 6-31 h range for invertase and 4-24 h for amyloglucosidase.…”

Section: Peptide Binding Methodsmentioning

confidence: 99%

Polymeric Biomaterials As Enzyme and Drug Carriers* Part I: Immobilization of Enzymes

Dumitriu¹,

Popa²,

Dumitriu³

1988

Journal of Bioactive and Compatible Polymers

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INTRODUCTIONhe immobilization of drugs and enzymes refers to their attachment to solid supports. In many cases, the immobilized materials remain biologically active and can be used in numerous research investigations. The basic idea in immobilizing drugs or enzymes on solid supports is to control the gross movement of the immobilized material relative to that of the support. In most cases, the immobilized compounds can still undergo conformational changes. If the compound is connected to the support through a spacer arm, then the compound can move several Angstroms or micrometers relative to the support. However, the actual freedom of movement of immobilized materials depends on several factors, including (1) the type of immobilization chemistry employed, (2) the presence of interactions with the support and (3) the use of single or multiple points of attachment, as well as crosslinking between points on the immobilized material or between the immobilized material and the support.Several chemical techniques, plus many more variations, have been described for the immobilization of biochemicals on solid supports. These include trapping in gels or polymeric matrices, adsorption on surfaces, covalent attachment to organic and inorganic surfaces, and encapsulation in liposomes or other small vesicles [1,2]. *This is the first of a four-part review. Downloaded from 244The current interest in the immobilization of enzymes grew out of the early studies by Manecke [3] in Germany and Katchalski [4] in Israel in the early 1960s, for coupling enzymes and antibodies to polymeric supports. A few years later, natural hormones (adreno-corticotropic hormone, insulin) were covalently coupled to agarose beds and tested for biological activity against isolated mammalian cells [5,6].Many other compounds have been immobilized on solid supports in the intervening years, so that by 1990 it is estimated that over 500 different enzymes may be obtained.In recent years, the use of synthetic polymers as polymeric drugs or drug delivery systems has received increasing attention. Several symposia were organized to discuss the current state-of-the-art research in polymeric drugs [7], controlled release of bioactive materials [8,9] and the general biomedical applications of polymers [10,11]. Studies have largely been confined either to the development of sustained-release systems based on insoluble polymers [12] or to the development of polymeric drugs [7], i.e. soluble polymers which themselves display pharmacological activity. Up to now, more than 100 different drugs have been immobilized on bio-or non-biodegradable polymers.Fewer results have been published on the immobilization of pesticides and fertilizers [13][14][15][16][17][18].

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Section: Peptide Binding Methodsmentioning

confidence: 99%

Polymeric Biomaterials As Enzyme and Drug Carriers* Part I: Immobilization of Enzymes

Dumitriu¹,

Popa²,

Dumitriu³

1988

Journal of Bioactive and Compatible Polymers

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“…Michaelis-Menten affinity constant (mol/L) K mf glucose to fructose Michaelis-Menten affinity constant (mol/L) K mr fructose to glucose Michaelis-Menten affinity constant (mol/L) m E enzyme mass (g) P product r radius (m) −r r 1 substrate consumption reaction rate (mol/(L · s)) r r 2 product generation reaction rate (mol/(L · s)) r r i free enzyme reaction rate (mol/(L · s)) r r i volumetric reaction rate (mol/(L · s)) r p biocatalytic bead radius (m) → → ( ) r p n vector of residuals as function of the adjustment parameters vector S substrate SSE sum of the squared errors SSWR sum of the squares of the weighed residuals t time (s) V t total reaction volume (L) V p total beads volume (L)…”

Section: Nomenclaturementioning

confidence: 99%

“…The immobilization of enzymes consists of fixing their protein chains to different supports by using various carrier and coupling techniques, which allow the enzyme to be physically separated from the substrate and product for reuse. [2] The advantages of immobilized-enzyme systems can be summarized as follows: (1) repetitive use of an enzyme batch in different reactors; (2) improved process control, as enzymes can be removed from reactants; (3) better stability since they promote the stabilization of the tertiary structure and antiturbulence factors; (4) enzyme-free products; (5) long half-lives and predictable decay rates; and (6) adequate for use when studying in vivo kinetics of enzymes. [3,4] In general, the main reason for the use of immobilized enzyme systems is related to the reduction of operating costs, caused by using high-price enzymes or obtaining products with low economic value in largescale continuous systems.…”

Section: Introductionmentioning

confidence: 99%

“…[3,4] In general, the main reason for the use of immobilized enzyme systems is related to the reduction of operating costs, caused by using high-price enzymes or obtaining products with low economic value in largescale continuous systems. However, the immobilized enzyme process has some disadvantages that require improvement: (1) low load of enzymes; (2) restricted diffusion of substrate to the enzyme; (3) low entrapment efficiency, occurrence of burst release, instability of encapsulated enzyme; and (4) little increase in the substrate affinity constant. [5] Glucose isomerase (GI) is widely used in the industry to catalyze the reversible conversion of α-D-glucose to β-D-fructose, which is part of the production process of high fructose corn syrup (HFCS) from corn starch.…”

Section: Introductionmentioning

confidence: 99%

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A new approach for describing and solving the reversible Briggs‐Haldane mechanism using immobilized enzyme

et al. 2019

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Recently immobilized enzymes have been widely used in industrial processes due to their outstanding advantages, such as high stability and recyclability; however, their kinetic behaviour is generally controlled by mass diffusion effects. Thus, in order to improve these enzymatic processes, a clear discernment between the kinetic and diffusion mechanisms that control the production of the metabolite require investigation. In practice, it is typical to establish apparent kinetics for immobilized enzyme operations, and the validity of the apparent kinetics is restricted to the studied cases. In this work, a new approach for mathematically describing the kinetic and diffusion mechanics in an immobilized biocatalyst bead is established, in which the fraction of residual enzymatic activity is included, and is defined as a measure of the active and available enzymes in the bead porous network. In addition, the diffusion and kinetic mechanisms are described by the effective diffusion coefficient and the free enzyme kinetics, since the porous network of the bead is assumed as the bioreaction volume. Therefore, free enzyme kinetics were determined from glucose to fructose bioconversion using a stirred tank reactor with free glucose‐isomerase, in which substrate and enzyme concentrations and temperature were varied. The fraction of residual enzymatic activity (η=0.553) and the effective diffusion coefficient (Deff=normal8.356×10−12m2/normals) were obtained from the isomerization of glucose to fructose using a stirred tank reactor with immobilized glucose‐isomerase in calcium alginate beads at different substrate and enzyme concentrations. Finally, simulations were carried out to establish the bioreaction solid‐phase characteristics that most significantly influence productivity.

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“…Several attempts concerning glucoamylase immobilization using either inorganic [1][2][3][4][5] and natural [6][7][8][9][10][11][12][13][14] supports, or synthetic organic matrices [15][16][17][18][19] have been made. Our earlier studies [20][21][22][23] evidenced the possibility of glucoamylase immobilization on spherical particles of the acrylic support.…”

Section: Introductionmentioning

confidence: 99%

Glucoamylase absorption and desorption process

Popa¹

1996

Journal of Biomaterials Science, Polymer Edition

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This paper reports the study of glucoamylase absorption and desorption processes on spherical particles constituting acrylic supports. The kinetic (reaction order, half-life of the reaction, reaction rate constant), and thermodynamic parameters (activation energy, pre-exponential factor) of the glucoamylase immobilization reaction dynamics inside the acrylic supports have been studied. Hindrance of the penetrants (protein molecules), which defeats the polymer's cohesive forces and passes through the diffusional barriers towards the sites available to receive it, denotes the influence of the diffusion phenomena, and might be expressed by the values of the effective diffusion coefficient and of the energetic parameters, as well. The desorption dynamics of glucoamylase in specific buffer concentration gradients and temperature are dependent on the eluent volume and on the protein eluate.

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XV. Hydrolases immobilized on Biozan R

Cited by 9 publications

References 21 publications

Polymeric Biomaterials As Enzyme and Drug Carriers* Part I: Immobilization of Enzymes

Polymeric Biomaterials As Enzyme and Drug Carriers* Part I: Immobilization of Enzymes

A new approach for describing and solving the reversible Briggs‐Haldane mechanism using immobilized enzyme

Glucoamylase absorption and desorption process

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