Stilbene vinyl sulfonamides as fluorogenic sensors of and traceless covalent kinetic stabilizers of transthyretin that prevent amyloidogenesis.Suh, E.H., Liu, Y., Connelly, S., Genereux, J.C., Wilson, I.A., Kelly, J.W.
(2013) J.Am.Chem.Soc. 135: 17869-17880
- PubMed: 24180271
- DOI: 10.1021/ja408230k
- Primary Citation of Related Structures:  4HJS, 4HJU
- PubMed Abstract:
Small molecules that react selectively with a specific non-enzyme drug-target protein in a complex biological environment without displacement of a leaving group (tracelessly) are rare and highly desirable. Herein we describe the development of a fam ...
Small molecules that react selectively with a specific non-enzyme drug-target protein in a complex biological environment without displacement of a leaving group (tracelessly) are rare and highly desirable. Herein we describe the development of a family of fluorogenic stilbene-based vinyl amides and vinyl sulfonamides that covalently modify transthyretin (TTR) tracelessly. These small molecules bind selectively to TTR in complex biological environments and then undergo a rapid and chemoselective 1,4-Michael addition with the pKa-perturbed Lys-15 ε-amino group of TTR. Replacing the vinyl amide in 2 with the more reactive vinyl sulfonamide in 4 hastens the conjugation kinetics. X-ray cocrystallography verified the formation of the secondary amine bond mediating the conjugation in the case of 2 and 4 and confirmed the expected orientation of the stilbene within the TTR binding sites. Vinyl amide 2 and vinyl sulfonamide 4 potently inhibit TTR dissociation and amyloid fibril formation in vitro. The TTR binding selectivity, modification yield, and reaction chemoselectivity of vinyl sulfonamide 4 are good enough in human plasma to serve as a starting point for medicinal chemistry efforts. Moreover, vinyl sulfonamide 4 is fluorogenic: it exhibits minimal background fluorescence in complex biological environments, remains dark upon binding to TTR, and becomes fluorescent only upon reaction with TTR. The fluorogenicity of 4 was utilized to accurately quantify the native TTR concentration in Escherichia coli lysate using a fluorescence plate reader.
Department of Chemistry, ‡The Skaggs Institute for Chemical Biology, §Department of Integrative Structural and Computational Biology, and ∥Department of Molecular and Experimental Medicine, The Scripps Research Institute , La Jolla, California 92037, United States.