Vinyl sulfone functionalized silica: a ready to use'' pre-activated material for immobilization of biomolecules

The combination of silica as support and vinyl sulfone as reactive group led to a pre-activated material that readily reacts to form covalent bonds by Michael-type addition with both amine and thiol groups naturally occurring in biomolecules in mild conditions compatible with the biological nature of the enzymes. A simple two step synthetic strategy was designed to access this functionalized hybrid material. Two types of vinyl sulfone silicas (N-type and S-type) differing in the chemical nature of the linkers between the silica particle and the reactive vinyl sulfone group were prepared by implementation of this strategy. The capabilities of those vinyl sulfone silicas were evaluated with the model enzymes invertase, lactase and lysozyme. Both S-type and N-type vinyl sulfone silicas coupled efficiently with the model enzymes even at 4 degrees C by simple combination of the species and the immobilized enzymes retained the enzymatic activity. The linker showed to play a major role in the non covalent interactions between the enzymes and the silicas. In terms of capacity, the S-type material is the best option although its poor flow rate when packed in columns invalidates its applications for low pressure liquid chromatography. The capabilities of the N-type material were successfully put to the test as a pre-packed column for the immobilization of invertase and further demonstrated with two real cases of relevance in proteomics: (i) purification of glutathione-S-transferase (GST) and (ii) identification of proteins that interact with thioredoxin h2 from Pisum sativum.