| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Lima, João Carlos
Altice Portugal (Portugal)
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (10/10 displayed)
- 2024Cryoprotective Polysaccharides with Ordered Gel Structures Induce Ice Growth Anticipation and Survival Enhancement during Cell Cryopreservationcitations
- 2020Application of polyoxometalate-ionic liquids (POM-ILs) in dye-sensitized solar cells (DSSCs)citations
- 2017A non-invasive optical method for mapping temperature polarization in direct contact membrane distillationcitations
- 2016Molecular Weight Determination by Luminescent Chemo–enzymaticscitations
- 2015Tuning the Surface Chemistry of Nanoporous Carbons for Enhanced Nanoconfined Photochemical Activitycitations
- 2013Photoinduced reactions occurring on activated carbons. A combined photooxidation and ESR studycitations
- 2008Study of the effect of the phosphane bridging chain nature on the structural and photophysical properties of a series of gold(I) ethynylpyridine complexescitations
- 2008Probing the microenvironment of sol-gel entrapped cutinase: the role of added zeolite NaYcitations
- 2006Metallodendrimers containing both ruthenium (internal layer) and rhenium (external layer)citations
- 2000Fluorescence-labeled pyrenesulfonamide response for characterizing polymeric interfaces in composite materialscitations
Places of action
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article
Probing the microenvironment of sol-gel entrapped cutinase: the role of added zeolite NaY
Abstract
<p>Cutinase, an esterase from Fusarium solani pisi, was immobilized in sol-gel matrices of composition 1:5 tetramethoxysilane (TMOS):n-alkyltrimethoxysilane (n-alkylTMS). Fluorescence spectroscopy using the single tryptophan (Trp-69) residue of cutinase as a probe revealed that the polarity of the matrices decreased as their hydrophobicity increased up to the TMOS/n-butylTMS pair, which correlates with an increase in cutinase activity. Fluorescence emission was suppressed (a higher than two orders of magnitude reduction) in the TMOS/n-octylTMS matrix, suggesting a greater proximity of the tryptophan to a nearby disulfide bridge. When sol-gel matrices were prepared with added zeolite NaY, the fluorescence emission intensity maximum (λ<sub>max</sub>) of the tryptophan did not change. And although the presence of the zeolite led to the recovery of fluorescence emission from the TMOS/n-octylTMS matrix, the corresponding λ<sub>max</sub> fell in line with the values obtained for the matrices with lower n-alkyl chain lengths, indicating that the tryptophan does not sense the zeolite. On the other hand, the presence of the zeolite led to increases in cutinase activity in all the matrices. This suggests that the zeolite is in a position to affect the active site of the enzyme, located at the opposite pole of the enzyme molecule. Scanning electron microscopy and energy dispersive X-ray spectroscopy revealed that the zeolite particles were segregated to the pores of the matrices. Optical microscopy following the staining of the protein with a fluorescent dye showed that the enzyme was distributed throughout the material, and tended to accumulate around zeolite particles. By promoting the accumulation of the enzyme at the pores of the material, the zeolite should improve the accessibility of the enzyme to the substrates and lead to a higher enzymatic activity. Data obtained for sol-gel matrices with epoxy or SH groups provided further evidence that cutinase responded to changes in the chemical nature of the precursors.</p>