activatable peptides; fluorescent imaging; proteases; MMP2; cancer cells
Issue Date
2022-02
Publisher
MDPI
Citation
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, v. 23, NO. 3, article no. 1605, Page. 1-12
Abstract
Activity-based monitoring of cell-secreted proteases has gained significant interest due to the implication of these substances in diverse cellular functions. Here, we demonstrated a cell-based method of monitoring protease activity using fluorescent cell-permeable peptides. The activatable peptide consists of anionic (EEEE), cleavable, and cationic sequences (RRRR) that enable intracellular delivery by matrix metalloproteinase-2 (MMP2), which is secreted by living cancer cells. Compared to HT-29 cells (MMP2-negative), HT-1080 cells (MMP2-positive) showed a strong fluorescence response to the short fluorescent peptide via cell-secreted protease activation. Our approach is expected to find applications for the rapid visualization of protease activity in living cells.