EXPO3000—a new expandable polymer for synthesis and enzymatic assays

A new polymer for synthesis and enzymatic assays is presented which combines moderate loading with the biocompatibility of poly(ethylene glycol)-based resins. The polymer displays low swelling in all solvents until selective cleavage of a silyl based crosslinker expands the polar resin to render it penetratable for enzymes (an example with a 27 kDa protease is given). An efficient alkylation procedure for derivatization of long PEG-chains is also presented.