Subtle modification of 2,2-dipicolylamine lowers the affinity and improves the turn-on of Zn(II)-selective fluorescent sensors.
The spectroscopic and proton- and Zn(II)-binding properties of two new members of the Zinpyr family of fluorescent sensors are reported. In ZP1B and ZP3B, a (2-picolyl)(4-picolyl)amine (2,4-DPA) moiety is installed in place of the di(2-picolyl)amine (2,2-DPA) ligand used in the parent sensors ZP1 and ZP3. This modification has the benefit of both lowering the proton-induced turn-on at physiological pH levels and altering the Zn(II) affinity so as to detect only the most concentrated stores of this ion in biological samples. Comparison of the proton affinities of all four probes, as determined by potentiometric titrations, contributes to our understanding of the solution properties of this family of sensors.
Wong
Brian A
BA
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Friedle
Simone
S
Lippard
Stephen J
SJ
D000588:Amines / Q000737:chemistry*; D002460:Cell Line; D002470:Cell Survival; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D015394:Molecular Structure; D010848:Picolinic Acids / Q000737:chemistry*; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry*
C501847:2,2'-dipicolylamine; D000588:Amines; D005456:Fluorescent Dyes; D010848:Picolinic Acids; D015032:Zinc