Molecular binding of self-assembling peptide EAK16-II with anticancer agent EPT and its implication in cancer cell inhibition

Arginine-rich ionic complementary peptides as potential drug carriers: Impact of peptide sequence on size, shape and cell specificity

“…For instance, an 8-fold diluted complex showed stronger emission than the complex at original concentration, which could be due to inner filter effect demonstrated in previous study. 24 According to a previous study, the electrostatic interaction between protonated EPT and negatively charged glutamic acid was the major driving force that stabilized EPT in EAK16-II-based system, whereby each glutamic acid could bind one protonated EPT molecule. 24 When preparing the complex, the molar ratio of EPT to glutamic acid is 1:2.6, 1:2.5, 1:2.5 and 1:2.3 for EAR16-II, EAR8-II, EAR-IIa and ELR8-IIa systems, respectively.…”

“…22,24 The UV-adsorption of EPT at 295 nm was fitted linearly as a function of EPT concentration (1 × 10 -3 -1 × 10 -2 mg/mL) to obtain a calibration curve. The EPT standard sample was prepared by dissolving EPT in a mixture of 95% DMSO with 5% water.…”

“…24,32 The molecular state of EPT in the complexes was determined by EPT fluorescence emission spectra. As shown in Figure 2, all the four peptides stabilized protonated EPT in water as evidenced by the strong peak at~530 nm.…”

“…21 Protonated EPT was found to bind to EAK16-II peptide mainly via electrostatic interaction, and to be a more active form than neutral EPT. 24,25 The EAK16-II-EPT complex nanoparticles have been shown to enter cells through a caveolae-dependent endocytosis mechanism, and enhance the anticancer efficacy of EPT in vivo, 26 with enhanced blood circulation time relative to naked EPT. 27 These results presented promising potential of ionic complementary peptides as a delivery platform for hydrophobic anticancer agents.…”

Peptide Self-Assembled Nanostructures for Drug Delivery Applications

“…The in vitro experiments also demonstrated that the encapsulated anticancer drug ellipticine in the self-assembled nanofibers in protonated stage is more efficient than in the crystalline stage for cancer therapy. These EAK peptide self-assembled nanostructures and the two encapsulation methods could also be used for some other anticancer agents in drug delivery for cancer therapy [119].…”