Fluorescence probe with a pH-sensitive trigger.
Acid-catalyzed hydrolysis was used as the mechanism to design a new type of environmentally sensitive fluorescence probe. A mild and selective periodate oxidation of the 2-amino alcohol of serine in the presence of a disulfide bond was developed to prepare dialdehyde peptides. Two identical fluorochrome hydrazide derivatives were then linked to the dialdehyde peptide forming an acid-labile hydrazone linkage. This self-quenched probe is weakly fluorescent at a physiological pH of 7.4 but shows more than 3-fold fluorescence enhancement at pH 4.5.
Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA.
Amit K
AK
Galande
Ralph
R
Weissleder
Ching-Hsuan
CH
Tung
D000595:Amino Acid Sequence; D002232:Carbocyanines / Q000138:chemical synthesis* / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry; D010455:Peptides / Q000737:chemistry
C511559:CY5G2 compound; D002232:Carbocyanines; D005456:Fluorescent Dyes; D009842:Oligopeptides; D010455:Peptides; C085321:cyanine dye 5