Fig. 1.

In vitro cleavage of E(EDANS)-LPYPQPK(Dabcyl) and (HiLyte Fluor™647)-LPYPQPK(QXL™670). (A) Schematic representation of the dequenching assay. Arrows within the peptide sequence indicate preferential cleavage sites for FM and MX PEP. (C) In vitro cleavage of (HiLyte Fluor™647)-LPYPQPK(QXL™670) by FM PEP in phosphate buffer (pH 6.8) measured with the in vivo imaging system. (B, D) The peptides (5 and 3 μM, respectively) were incubated in the presence of FM and MX PEPs (1 μg/mL), pepsin (0.20 mg/mL), trypsin (0.22 mg/mL), or chymotrypsin (0.22 mg/mL). Mean ± SD, n = 3, fluorescence intensities in B and D were measured using plate reader and in vivo imaging system, respectively.