Effect of the Microenvironment on the Mode of Action of Immobilized Enzymes

Katchalski, Ephraim; Silman, Israel; Goldman, Rachel

doi:10.1002/9780470122792.ch7

Cited by 110 publications

(14 citation statements)

References 278 publications

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“…In an earlier study, Petrikovics et al (2007) indicated that encapsulation of certain OP hydrolyzing enzymes within DP can enhance enzyme activity. Katchalski et al (1971) also reported that immobilized enzymes exhibited higher activity than the corresponding free enzymes. With Rh, we did not experience activity enhancements, but the DP carrier system retained the original Rh activity (Figure 2).…”

Section: Discussionmentioning

confidence: 94%

Nano-intercalated rhodanese in cyanide antagonism

et al. 2010

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Present studies have focused on nano-intercalated rhodanese in combination with sulfur donors to prevent cyanide lethality in a prophylactic mice model for future development of an effective cyanide antidotal system. Our approach is based on the idea of converting cyanide to the less toxic thiocyanate before it reaches the target organs by utilizing sulfurtransferases (e.g., rhodanese) and sulfur donors in a close proximity by injecting them directly into the blood stream. The inorganic thiosulfate (TS) and the garlic component diallydisulfide (DADS) were compared as sulfur donors with the nano-intercalated rhodanese in vitro and in vivo. The in vivo and in vitro experiments showed that DADS is not a more efficient sulfur donor than TS. However, the utilization of external rhodanese significantly enhanced the in vivo efficacy of both sulfur donor-nitrite combinations, indicating the potential usefulness of enzyme nano-delivery systems in developing antidotal therapeutic agents.

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Section: Discussionmentioning

confidence: 94%

Nano-intercalated rhodanese in cyanide antagonism

et al. 2010

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“…Shifts in pH have been reported in past studies using CLAs, with changes in maxima towards a more alkaline or acidic pH (Lamb and Stuckey, ; Lye et al, ). Katchalski et al () explains the phenomenon of a pH shift for the immobilized enzyme as a change in charge between the microenvironment of the immobilized enzyme and the bulk continuous phase. Electrostatic interactions existing within the microenvironment influences the shift depending on the nature of the charge; a shift towards alkaline or acidic pHs based on the charge being negative or positive, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…One property that changes depending on the electrostatic interactions existing between the enzyme and its support is the reaction pH optima. Due to these interactions, the concentration of hydrogen ions can differ between both the microenvironment and the bulk phase allowing for a shift in acidity/alkalinity (Katchalski et al, ). Similar observations have been reported (Goldstein, ; Lamb and Stuckey, ; Lye et al, ).…”

Section: Introductionmentioning

confidence: 99%

Immobilization of enzymes using non‐ionic colloidal liquid aphrons (CLAs): Activity kinetics, conformation, and energetics

Ward

Stuckey

2015

Biotech & Bioengineering

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This study seeks to examine the ability of non-ionic/non-polar Colloidial Liquid Aphrons (CLAs) to preserve enzyme functionality upon immobilization and release. CLAs consisting of micron-sized oil droplets surrounded by a thin aqueous layer stabilized by a mixture of surfactants, were formulated by direct addition (pre-manufacture addition) using 1% Tween 80/mineral oil and 1% Tween 20 and the enzymes lipase, aprotinin and α-chymotrypsin. The results of activity assays for both lipase and α-chymotrypsin showed that kinetic activity increased upon immobilization by factors of 7 and 5.5, respectively, while aprotinin retained approximately 85% of its native activity. The conformation of the enzymes released through desorption showed no significant alterations compared to their native state. Changes in pH and temperature showed that optimum conditions did not change after immobilization, while analysis of activation energy for the immobilized enzyme showed an increase in activity at higher temperatures. Furthermore, the effect of bound water within the aphron structure allowed for some degree of enzyme hydration, and this hydration was needed for an active conformation with results showing a decrease in ΔH* for the immobilized system compared to its native counterpart.

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“…In case of AP, an increased stability of the enzyme toward acidic reaction conditions was observed. It is tempting to speculate that PE act as a buffering system and thereby stabilize the pH of the enzyme microenvironment . Both immobilized enzymes were, without any loss of activity, stored for 30 d at 4 °C and also their reuse with minor loss of activity was possible over at least five cycles of activity assays.…”

Section: Discussionmentioning

confidence: 99%

Immobilization of Enzymes on PLGA Sub‐Micrometer Particles by Crosslinked Layer‐by‐Layer Deposition

Sieber

Siegrist

Schwarz

et al. 2017

Macromolecular Bioscience

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Enzyme immobilization is of high interest for industrial applications. However, immobilization may compromise enzyme activity or stability due to the harsh conditions which have to be applied. The authors therefore present a new and improved crosslinked layer-by-layer (cLbL) approach. Two different model enzymes (acid phosphatase and β-galactosidase) are immobilized under mild conditions on biocompatible, monodisperse, sub-micrometer poly(lactide-co-glycolide) (PLGA) particles. The resulting PLGA enzyme systems are characterized regarding their size, surface charge, enzyme activity, storage stability, reusability, and stability under various conditions such as changing pH and temperature. The developed and characterized cLbL protocol can be easily adapted to different enzymes. Potential future uses of the technology for biomedical applications are discussed. PLGA-enzyme particles are therefore injected into the blood circulation of zebrafish embryos in order to demonstrate the in vivo stability and activity of the designed system.

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Effect of the Microenvironment on the Mode of Action of Immobilized Enzymes

Cited by 110 publications

References 278 publications

Nano-intercalated rhodanese in cyanide antagonism

Nano-intercalated rhodanese in cyanide antagonism

Immobilization of enzymes using non‐ionic colloidal liquid aphrons (CLAs): Activity kinetics, conformation, and energetics

Immobilization of Enzymes on PLGA Sub‐Micrometer Particles by Crosslinked Layer‐by‐Layer Deposition

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