title: A small-molecule FRET reporter for the real-time visualization of cell-surface proteolytic enzyme functions.
abstract: Real-time imaging of cell-surface-associated proteolytic enzymes is critical to better understand their performances in both physiological and pathological processes. However, most current approaches are limited by their complexity and poor membrane-anchoring properties. Herein, we have designed and synthesized a unique small-molecule fluorescent probe, which combines the principles of passive exogenous membrane insertion and Förster resonance energy transfer (FRET) to image cell-surface-localized furin-like convertase activities. The membrane-associated furin-like enzymatic cleavage of the peptide probe leads to an increased fluorescence intensity which was mainly localized on the plasma membrane of the furin-expressed cells. This small-molecule fluorescent probe may serve as a unique and reliable reporter for real-time visualization of endogenous cell-surfaceassociated proteolytic furin-like enzyme functions in live cells and tissues using one-photon and two-photon microscopy.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371 (Singapore).
authors.forename: Jing
authors.initials: J
authors.lastname: Mu
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Muhammad Shafiq
authors.initials: MS
authors.lastname: Rajab
authors.forename: Meng
authors.initials: M
authors.lastname: Shi
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
authors.forename: Chiching
authors.initials: C
authors.lastname: Goh
authors.forename: Lei
authors.initials: L
authors.lastname: Lu
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Lai Guan
authors.initials: LG
authors.lastname: Ng
authors.forename: Bengang
authors.initials: B
authors.lastname: Xing
mesh_terms: D002384:Catalysis; D045744:Cell Line, Tumor; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D045683:Furin / Q000037:antagonists & inhibitors / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D006867:Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D010455:Peptides / Q000737:chemistry / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D010455:Peptides; D006867:Hydrolases; D045683:Furin
keywords: FRET; fluorescence microscopy; imaging agents; proteolytic enzymes; two-photon imaging