title: Developing a peptide-based near-infrared molecular probe for protease sensing.
abstract: Recently near-infrared (NIR) molecular probes have become important reporter molecules for a number of types of in vivo biomedical imaging. A peptide-based NIR fluorescence probe consisting of a NIR fluorescence emitter (Cy5.5), a NIR fluorescence absorber (NIRQ820), and a protease selective peptide sequence was designed to sense protease activity. Using a MMP-7 model, we showed that NIRQ820 efficiently absorbs the emission energy of Cy5.5 resulting in a low initial signal. Upon reacting with its target, MMP-7, the fluorescence signal of the designed probe was increased by 7-fold with a K(cat)/K(m) of 100 000 M(-)(1) s(-)(1). The described synthetic strategy should have wide application for other NIR probe preparations.
authors.affiliation: Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA.
authors.forename: Wellington
authors.initials: W
authors.lastname: Pham
authors.forename: Yongdoo
authors.initials: Y
authors.lastname: Choi
authors.forename: Ralph
authors.initials: R
authors.lastname: Weissleder
authors.forename: Ching-Hsuan
authors.initials: CH
authors.lastname: Tung
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006801:Humans; D020783:Matrix Metalloproteinase 7; D008666:Metalloendopeptidases / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D015335:Molecular Probes / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D015335:Molecular Probes; D010446:Peptide Fragments; D010447:Peptide Hydrolases; D008666:Metalloendopeptidases; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7