Stilbene Vinyl Sulfonamides as Fluorogenic Sensors of and Traceless Covalent Kinetic Stabilizers of Transthyretin That Prevent Amyloidogenesis

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• 作者：Eul Hyun Suh ; Yu Liu ; Stephen Connelly ; Joseph C. Genereux ; Ian A. Wilson ; Jeffery W. Kelly
• 刊名：Journal of the American Chemical Society
• 出版年：2013
• 出版时间：November 27, 2013
• 年：2013
• 卷：135
• 期：47
• 页码：17869-17880
• 全文大小：695K
• 年卷期：v.135,no.47(November 27, 2013)
• ISSN：1520-5126

文摘

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 pK_a-perturbed Lys-15 蔚-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.