scholarly journals Cyclodextrin-grafted polymers functionalized with phosphanes: a new tool for aqueous organometallic catalysis

2014 ◽  
Vol 10 ◽  
pp. 2642-2648 ◽  
Author(s):  
Jonathan Potier ◽  
Stéphane Menuel ◽  
David Mathiron ◽  
Véronique Bonnet ◽  
Frédéric Hapiot ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Nmr Spectroscopy ◽  
Size Exclusion Chromatography ◽  
Water Soluble ◽  
Size Exclusion ◽  
Grafted Polymers ◽  
Organometallic Catalysis ◽  
Exclusion Chromatography

New cyclodextrin (CD)-grafted polymers functionalized with water-soluble phosphanes were synthesized in three steps starting from polyNAS. Once characterized by NMR spectroscopy and size-exclusion chromatography, they were used as additives in Rh-catalyzed hydroformylation of 1-hexadecene. The combined supramolecular and coordinating properties of these polymers allowed increasing the catalytic activity of the reaction without affecting the selectivities.

scholarly journals Effect of Posttranslational Modifications on the Structure and Activity of FTO Demethylase

2021 ◽  
Vol 22 (9) ◽  
pp. 4512
Author(s):  
Michał Marcinkowski ◽  
Tomaš Pilžys ◽  
Damian Garbicz ◽  
Jan Piwowarski ◽  
Damian Mielecki ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Size Exclusion Chromatography ◽  
Posttranslational Modifications ◽  
Size Exclusion ◽  
Saxs Data ◽  
Wide Range ◽  
Exclusion Chromatography ◽  
Demethylase Activity ◽  
Structure And Activity

The FTO protein is involved in a wide range of physiological processes, including adipogenesis and osteogenesis. This two-domain protein belongs to the AlkB family of 2-oxoglutarate (2-OG)- and Fe(II)-dependent dioxygenases, displaying N6-methyladenosine (N6-meA) demethylase activity. The aim of the study was to characterize the relationships between the structure and activity of FTO. The effect of cofactors (Fe2+/Mn2+ and 2-OG), Ca2+ that do not bind at the catalytic site, and protein concentration on FTO properties expressed in either E. coli (ECFTO) or baculovirus (BESFTO) system were determined using biophysical methods (DSF, MST, SAXS) and biochemical techniques (size-exclusion chromatography, enzymatic assay). We found that BESFTO carries three phosphoserines (S184, S256, S260), while there were no such modifications in ECFTO. The S256D mutation mimicking the S256 phosphorylation moderately decreased FTO catalytic activity. In the presence of Ca2+, a slight stabilization of the FTO structure was observed, accompanied by a decrease in catalytic activity. Size exclusion chromatography and MST data confirmed the ability of FTO from both expression systems to form homodimers. The MST-determined dissociation constant of the FTO homodimer was consistent with their in vivo formation in human cells. Finally, a low-resolution structure of the FTO homodimer was built based on SAXS data.

Detection and quantification of branching in polyacrylates by size-exclusion chromatography (SEC) and melt-state 13C NMR spectroscopy

Polymer ◽  
2009 ◽  
Vol 50 (11) ◽  
pp. 2373-2383 ◽  
Author(s):  
Patrice Castignolles ◽  
Robert Graf ◽  
Matthew Parkinson ◽  
Manfred Wilhelm ◽  
Marianne Gaborieau
Keyword(s):  
Nmr Spectroscopy ◽  
Size Exclusion Chromatography ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Size Exclusion ◽  
Exclusion Chromatography ◽  
Detection And Quantification

Analysis of the substituent distribution along the chain of water-soluble methyl cellulose by combination of enzymatic and chemical methods

Holzforschung ◽  
2004 ◽  
Vol 58 (1) ◽  
pp. 97-104 ◽  
Author(s):  
B. Saake ◽  
S. Lebioda ◽  
J. Puls
Keyword(s):  
Anion Exchange ◽  
Size Exclusion Chromatography ◽  
Methyl Cellulose ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Degree Of Substitution ◽  
Water Soluble ◽  
Size Exclusion ◽  
Exclusion Chromatography ◽  
C Nmr

Abstract Four methyl cellulose samples in the degree of substitution range from 0.5 to 2.0 were characterised by combination of different analytical methods. Samples were analysed regarding their partial degree of substitution by hydrolysis and anion exchange chromatography with pulsed amperometric detection. For calibration of the chromatographic system, standard substances were isolated by preparative HPLC and their structure was confirmed by 13C-NMR spectroscopy. For two methyl cellulose samples per-acetylation and 13C-NMR with inverse gated decoupling was carried out for comparison with the chromatographic analysis. Endoglucanase fragmentation of methyl celluloses was performed and water-soluble and insoluble fractions were analysed separately. A preparative size exclusion chromatography system for enzymatic-degraded water-soluble methyl cellulose was developed and the molar masses of the individual fractions were examined by analytical size exclusion chromatography. By combination of endoglucanase fragmentation, preparative chromatography, hydrolysis and anion exchange chromatography an approach for the analysis of the substitutent distribution along the polymeric chain of water-soluble methyl cellulose could be established.

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