Preparation and characterisation of a Ni2+/Co2+-cyclam modified mesoporous cellular foam for the specific immobilisation of His6-alanine racemase

MsAcT in siliceous monolithic microreactors enables quantitative ester synthesis in water

“…Functionalisation of silica monoliths (MH)metalfunctionalised carrier. In an alternative approach for immobilisation via adsorption by the His linkage Ni and Co were incorporated 19,20 (Scheme 2B). Silica monoliths (1 g, oven-dried at 150°C overnight) were gently stirred and refluxed with 3-iodopropyl trimethoxysilane (0.41 mL) in 30 mL of dry toluene for 10 h under Ar atmosphere in the dark.…”

“…18 Metal ions can be introduced onto a solid support by chelators such as iminodiacetic acid (IDA), nitriloacetic acid (NTA) or cyclam. 19,20,[29][30][31][32][33] As cyclam is known to be a stable ligand for several metals, MH-cyclam-Ni and MH-cyclam-Co were prepared as described previously 20 (after minor modification). ICP mass spectrometry measurements gave the metal loading values of 8.96 mg Co (g silica) −1 ± 16% and 7.81 mg Ni (g silica) −1 ± 10%.…”

“…While effective immobilisation of the enzyme in the silica monolith's mesopores remained a critical factor, our studies primarily centered on the synthetic potential of the immobilised enzyme/microchannel reaction system. Two immobilisation methods were applied: (i) conventional covalent bonding tends to give more stable catalysts, but could reduce enzyme activity, 11,18 and (ii) specific adsorption onto the Ni/Co-modified support via the His-tag, 19,20,[29][30][31][32][33] since the His-tag is remote from the active site ( Fig. 1).…”

Smart Nanoparticles for Selective Immobilization of Acid Phosphatases

“…Immobilized metal‐chelate affinity chromatography (IMAC) is a well‐developed tool for pilot‐scale purification of poly‐His tagged proteins . Due to the reversibility of the binding process resulting in undesired release of the enzyme and/or the metal to the reaction medium, application of metal‐chelate affinity methods to produce supported biocatalysts was only recently considered ,. By proper choice of the chelating metal ion, stable biocatalyst preparations could be obtained …”

Effect of electrolytes on proteins physisorption on ordered mesoporous silica materials

“…It should be remarked that here we are deliberately not considering the important fact that proteins/enzymes can also be covalently attached to OMS through suitable functionalization procedures [42][43][44][45]. We are neglecting chemical immobilization since not useful for therapeutic purposes.…”