2 research outputs found
Importance of Net Hydrophobicity in the Cellular Uptake of All-Hydrocarbon Stapled Peptides
All-hydrocarbon stapled peptides
make up a promising class of protein–protein
interaction regulators; their potential therapeutic benefit arises
because they have a high binding affinity and specificity for intracellular
molecules. The cell permeation efficacy of these peptides is a critical
determinant of their bioactivity. However, the factors that determine
their cellular uptake remain an active area of research. In this study,
we evaluated the effect of stapled (or cross-linked) formation on
the cellular uptake of six known all-hydrocarbon stapled peptides.
We found that the rate of cellular uptake of unstapled peptides (i.e.,
those bearing olefinic non-natural amino acids that are not subjected
to olefin metathesis) was higher than that for the corresponding stapled
peptides. Additionally, the insertion of these olefinic non-natural
amino acids into peptide sequences significantly increased their rate
of cellular uptake. According to the high-performance liquid chromatography
retention times, the overall hydrophobicity of unstapled peptides
was greater than that of stapled peptides, followed by that of the
original peptides without olefinic non-natural amino acids. There
was not a close correlation between helical content and the rate of
cellular uptake of these peptides. Therefore, the increase in overall
hydrophobicity resulting from the introduction of non-natural amino
acids, rather than the structural stabilization resulting from staple
formation, is the key driver promoting cellular uptake. Macropinocytosis,
a form of fluid-phase endocytosis, was involved in the cellular uptake
of all six peptides