PUB - Publikationen an der Universität Bielefeld

The aldehyde tag is appropriate to selectively label proteins, prepare antibody-drug conjugates or to immobilize enzymes or antibodies for biotechnological and medical applications. The cysteine within the consensus sequence CxPxR of the aldehyde tag is specifically oxidized by the formylglycine-generating enzyme (FGE) to the non-canonical and electrophilic amino acid C-alpha-formylglycine (FGly). Subsequent reductive amination is a common method for site-directed immobilization, which usually results in poor immobilization efficiency due to the reaction conditions. Here, we introduce a new solid support like agarose modified with an aryl substituted pyrazolone (Knoevenagel reagent) that was obtained in a facile and efficient 2-step synthesis. The modified agarose allowed the site-selective and efficient immobilization of aldehyde-containing small molecules, peptides and proteins - in particular enzymes - at physiological pH (6.2-8.2) without any additive or catalyst needed. In comparison to reductive amination, higher loadings and activities were achieved in various buffers at different concentrations and temperatures.