Diversity-Oriented Stapling Yields Intrinsically Cell-Penetrant Inducers of Autophagy

Journal of the American Chemical Society

5 years ago

Diversity-Oriented Stapling Yields Intrinsically Cell-Penetrant Inducers of Autophagy

Joshua A. Kritzer, Yu-Shan Lin, Leila Peraro, Zhongju Zou, Kamlesh M. Makwana, Ashleigh E. Cummings, Hongtao Yu, Beth Levine, Haydn L. Ball

Autophagy is an essential pathway by which cellular and foreign material are degraded and recycled in eukaryotic cells. Induction of autophagy is a promising approach for treating diverse human diseases, including neurodegenerative disorders and infectious diseases. Here, we report the use of a diversity-oriented stapling approach to produce autophagy-inducing peptides that are intrinsically cell-penetrant. These peptides induce autophagy at micromolar concentrations in vitro, have aggregate-clearing activity in a cellular model of Huntington’s disease, and induce autophagy in vivo. Unexpectedly, the solution structure of the most potent stapled peptide, DD5-o, revealed an α-helical conformation in methanol, stabilized by an unusual (i,i+3) staple which cross-links two d-amino acids. We also developed a novel assay for cell penetration that reports exclusively on cytosolic access and used it to quantitatively compare the cell penetration of DD5-o and other autophagy-inducing peptides. These new, cell-penetrant autophagy inducers and their molecular details are critical advances in the effort to understand and control autophagy. More broadly, diversity-oriented stapling may provide a promising alternative to polycationic sequences as a means for rendering peptides more cell-penetrant.

Publisher URL: http://dx.doi.org/10.1021/jacs.7b01698

DOI: 10.1021/jacs.7b01698