Diffusion coefficients of oxygen, hydrogen peroxide and glucose in a hydrogel

Stroe-Biezen, van Sam Saskia; Everaerts, FM Frans; Janssen, Ljj Jos; Tacken, RA Roland

doi:10.1016/0003-2670(93)80202-v

Cited by 127 publications

(85 citation statements)

References 8 publications

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“…4). D eff is two to three orders of magnitude lower than the diffusion coef®cients of gases into liquids or organic solutes into hydrogels (Reid et al, 1987;Van Stroe-Biezen et al, 1993). Similarly, Buenfeld et al (1998) observed high resistance of two-component water-borne polyurethane coatings to diffusion of chloride ions.…”

Section: Effective Diffusivity Of Dfp In Ecc D Effmentioning

confidence: 90%

High‐activity enzyme‐polyurethane coatings

Drevon

Danielmeier

Federspiel

et al. 2002

Biotech & Bioengineering

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The synthesis of water-borne polyurethane coatings in the presence of diisopropylfluorophosphatase (DFPase, E.C. 3.8.2.1) enabled the irreversible attachment of the enzyme to the polymeric matrix. The distribution of immobilized DFPase as well as activity retention are homogeneous within the coating. The resulting enzyme-containing coating (ECC) film hydrolyzes diisopropylfluorophosphate (DFP) in buffered media at high rates, retaining approximately 39% intrinsic activity. Decreasing ECC hydrophilicity, via the use of a less hydrophilic polyisocyanate during polymerization, significantly enhanced the intrinsic activity of the ECC. DFPase-ECC has biphasic deactivation kinetics, where the initial rapid deactivation of DFPase-ECC leads to the formation of a hyperstable and active form of enzyme.

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Section: Effective Diffusivity Of Dfp In Ecc D Effmentioning

confidence: 90%

High‐activity enzyme‐polyurethane coatings

Drevon

Danielmeier

Federspiel

et al. 2002

Biotech & Bioengineering

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“…Indeed, experimental studies with polyvinyl alcohol hydrogels have shown that diffusivity of H 2 O 2 within such hydrogels is about 4–5 times lower compared to aqueous solution. [51] Based on this, the gel-like properties within cells would be expected to limit diffusion of H 2 O 2 thereby allowing for enhanced local concentrations near its production site. Analogous to the structural organization of water molecules due to interactions with e.g.…”

Section: Reaction Of H2o2 With Thiol Proteins: Reaction Kinetics Vmentioning

confidence: 99%

The role of sulfenic acids in cellular redox signaling: Reconciling chemical kinetics and molecular detection strategies

Heppner

Janssen–Heininger

Vliet

2017

Archives of Biochemistry and Biophysics

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The reversible oxidation of protein cysteine residues is well recognized as an important regulatory mechanism in redox-dependent cell signaling. Cysteine oxidation is diverse in nature and involves various post-translational modifications (sulfenic acids, disulfides, etc.) and the specific functional or structural impact of these specific oxidative events is still poorly understood. The proximal product of protein cysteine oxidation by biological reactive oxygen species (ROS) is sulfenic acid (Cys-SOH), and experimental evidence is accruing for the formation of Cys-SOH as intermediate in protein cysteine oxidation in various biological settings. However, the plausibility of protein Cys-SH oxidation by ROS has often been put in question because of slow reaction kinetics compared to more favorable reactions with abundant thiol-based reductants such as peroxiredoxins (Prx) or glutathione (GSH). This commentary aims to address this controversy by highlighting the unique physical properties in cells that may restrict ROS diffusion and allow otherwise less favorable cysteine oxidation of proteins. Some limitations of analytical tools to assess Cys-SOH are also discussed. We conclude that formation of Cys-SOH in biological systems cannot always be predicted based on kinetic analyses in homogenous solution, and may be facilitated by unique structural and physical properties of Cys-containing proteins within e.g. signaling complexes.

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“…Thus, we can estimate D and g at any temperature. Here, we adopted g = 0.891 · 10 À3 kg m À1 s À1 [31] and D = 1.93 · 10 À5 cm 2 /s [32] at 25°C. The values of [O 2 ] and D thus calculated for our experimental conditions are summarized in Table 1.…”

Section: Appendix Amentioning

confidence: 99%