General strategy for the preparation of membrane permeable fluorogenic peptide ester conjugates for in vivo studies of ester prodrug stability
To study ester prodrug stability properties in living cells we have conjugated fluorogenic esters to the cell membrane permeable peptide Arg 9. The desired conjugates are prepared by coupling N-maleoyl amino acid esters of monoalkylated fluoresceins or fluorescein to TyrArg 9Cys. The photophysical properties of the monoalkylated fluorescein derivatives are described.