Design and synthesis of a new class of membrane-permeable triazaborolopyridinium fluorescent probes

Sudath Hapuarachchige, Gilbert Montaño, Chinnasamy Ramesh, Delany Rodriguez, Lauren H. Henson, Casey C. Williams, Samuel Kadavakkollu, Dennis L. Johnson, Charles B. Shuster, Jeffrey B. Arterburn

Research output: Contribution to journalArticlepeer-review

42 Scopus citations


A new class of fluorescent triazaborolopyridinium compounds was synthesized from hydrazones of 2-hydrazinylpyridine (HPY) and evaluated as potential dyes for live-cell imaging applications. The HPY dyes are small, their absorption/emission properties are tunable through variation of pyridyl or hydrazone substituents, and they offer favorable photophysical characteristics featuring large Stokes shifts and general insensitivity to solvent or pH. The stability, neutral charge, cell membrane permeability, and favorable relative influences on the water solubility of HPY conjugates are complementary to existing fluorescent dyes and offer advantages for the development of receptor-targeted small-molecule probes. This potential was assessed through the development of a new class of cysteine-derived HPY-conjugate imaging agents for the kinesin spindle protein (KSP) that is expressed in the cytoplasm during mitosis and is a promising chemotherapeutic target. Conjugates possessing the neutral HPY or charged Alexa Fluor dyes that function as potent, selective allosteric inhibitors of the KSP motor were compared using biochemical and cell-based phenotypic assays and live-cell imaging. These results demonstrate the effectiveness of the HPY dye moiety as a component of probes for an intracellular protein target and highlight the importance of dye structure in determining the pathway of cell entry and the overall performance of small-molecule conjugates as imaging agents.

Original languageEnglish (US)
Pages (from-to)6780-6790
Number of pages11
JournalJournal of the American Chemical Society
Issue number17
StatePublished - May 4 2011
Externally publishedYes

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry


Dive into the research topics of 'Design and synthesis of a new class of membrane-permeable triazaborolopyridinium fluorescent probes'. Together they form a unique fingerprint.

Cite this