Fluorescent imaging agents

摘要

Provided is a family of intramolecularly quenched imaging agents for use in both in vivo and in vitro imaging that contain at least one enzymatically cleavable oligopeptide and two fluorophores or a fluorophore and a quencher. When subjected to proteolytic cleavage, at least one fluorophore is unquenched and becomes capable of producing a fluorescent signal upon excitation with light of an appropriate wavelength. Also provided are in vivo and in vitro imaging methods using such imaging agents.

主权项

1. An intramolecularly-quenched imaging agent represented by Formula II:
Mm-[[X]r—X1*—[X]p—X2*—[X]q]  (II) wherein:
X, independently, for each occurrence, is an amino acid residue;X1* and X2* are each independently X-L-F;L, independently, for each occurrence, is a linker moiety or a bond;F is a fluorophore, wherein one fluorophore quenches the other fluorophore;M is a biological modifier having a molecular weight between about 5 kDa to about 35 kDa;m is 1 or 2;r is an integer from 0 to 4;p is an integer from 1 to 5;q is an integer from 0 to 4; wherein the sum of r, p and q is 2, 3, 4 or 5; the imaging agent having a molecular weight from about 5 kDa to about 50 kDa and comprising an enzymatic cleavage site located between the fluorophores so that upon enzymatic cleavage, the fluorophores become unquenched and emit a fluorescent signal when excited by electromagnetic radiation of appropriate wavelength.