Quenched Fluorophores Conjugated to Peptides Via Linkers Containing Dithio Groups
Disclosed are dithio compounds that include a quenched fluorophore and a non-fluorophore peptide linked via a dithio bond to the fluorophore. The dithio compounds may be used in methods for detecting thiol-containing compounds or dithio-containing compounds. The dithio compounds also may be used as cellular probes where the peptide portion of the compounds targets the compounds to a specific cellular location.
1 . A dithio compound having a formula F—S—S—P wherein F comprises a quenched fluorophore and P comprises a peptide.
2 . The dithio compound of claim 1 having a formula:
3 . The dithio compound of claim 1 having a formula:
4 . The dithio compound of claim 1 having a formula:
5 . The dithio compound of claim 1 , wherein the peptide comprises a signal peptide sequence.
6 . The dithio compound of claim 1 , wherein the peptide comprises the arginine-rich RNA-binding motif (ARM) of the human immunodeficiency virus Tat peptide.
7 . The dithio compound of claim 1 , wherein the peptide comprises an RGD sequence.
8 . The dithio compound of claim, wherein the peptide comprises a hormone ligand for a G-coupled cell surface receptor.
9 . The dithio compound of claim 1 , wherein the peptide comprises an amino acid targeting sequence for a cellular nucleus.
10 . The dithio compound of claim 1 , wherein the peptide comprises an amino acid targeting sequence for a cellular endoplasmic reticulum.
11 . The dithio compound of claim 1 , wherein the peptide comprises an amino acid targeting sequence for a cellular mitochondria.
12 . The dithio compound of claim 1 having a formula F—X 1 —S—S—X 2 —P, wherein at least one of X 1 and X 2 comprises an aryl group.
13 . The dithio compound of claim 1 having a formula:
wherein R 1 comprises a fluorophore and R 2 comprises a peptide.
14 . The dithio compound of claim 1 having a formula:
wherein R 1 comprises a fluorophore and R 2 comprises a peptide.
15 . A method for preparing a dithio compound having a formula F—S—S—P wherein F comprises a quenched fluorophore and P comprises a peptide, the method comprising reacting precursors that include: (A) a first precursor that comprises a fluorophore; (B) a second precursor that comprises a peptide; and (C) a dithio reagent having a formula X 1 —S—S—X 2 , wherein X 1 and X 2 may be the same or different and each comprise reactive groups capable of reacting with the first precursor and the second precursor.
16 . The method of claim 15 , further comprising adding one or more cysteine residues to the N-terminus or C-terminus of the peptide in order to prepare the second precursor.
17 . A method for detecting a thiol- or dithio-containing compound, the method comprising: (A) reacting a dithio compound having a formula F—S—S—P wherein F comprises a quenched fluorophore and P comprises a peptide with the thiol- or dithio-containing compound to form at least one reaction product; and (B) detecting the at least one reaction product.
18 . The method of claim 17 , wherein the thiol- or dithio-containing compound is a protein.
19 . A method of preparing a dithio compound having a formula F—S—S—P wherein F comprises a quenched fluorophore and P comprises a peptide, the method comprising reacting precursors that include: (A) a first precursor having a formula F—S—S—F, and (B) a second precursor having a formula P-S—S—P.
20 . A kit comprising: (a) a reagent having a formula F—S—S—F; and (b) a reagent having a formula P-S—S—P; wherein F is a fluorophore and P is an aliphatic peptide.