Synthetic Assembly of Bifluorescence-Labeled Glycopolymers as Substrates for Assaying α-Amylase by Resonance Energy Transfer

To meet the need for a convenient substrate for sensitive and continuous assay for α-amylase, we developed a fluorescence resonance energy transfer (FRET)-based polymer substrate. Radical copolymerization of FRET-component monomers in different ratios of fluorogenic donor and acceptor was utilized to prepare such polymers. A glycomonomer as a fluorogenic donor was derived from naphthylmethylated maltotetraose, and a dansyl derivative monomer was used as an acceptor. Their mixture and acryl amide were copolymerized in a typical radical polymerization to yield a bifluorescence-labeled polymer in good yield. All of the polymers showed effective FRET and were used for the continuous assay of human salivary α-amylase. The time course of α-amylase reactions led to the apparent kinetic parameters of <i>K</i>_m = 4 μM and <i>V</i>_max = 0.29 nmol/min. The results strongly suggested that FRET-sensitive polymers are conveniently accessible and applicable for the sensitive determination of biochemical events