engleski

Hydrazino peptidomimetic as modulators of protein-protein interaction

Design and synthesis of peptidomimetics represent an important field in chemistry, pharmacology and material science, as they circumvent the numerous limitations of natural peptides. We aimed to develop solid-phase methodology for smooth incorporation of hydrazido derivatives of natural alpha-amino acids into peptide chain and study interaction of designed peptidomimetics with biomolecules. Modulation of protein–protein interactions (PPIs) have emerged as one of the main challenges in chemical biology and drug discovery. Therefore, as a biological target, we chose a well-described p53-mDM2 model. Disruption of the p53-mDM2 interaction is an important goal for cancer therapy. To explore the utility of hydrazino-based peptidomimetics to interfere with these interaction, we designed a small library of compounds based on the biologically active octapeptide fragment of p53 protein. Three amino acids, Phe, Trp and Leu, directly participate in interaction, so we decided to replace two of them (Phe and Leu) and Tyr adjacent to Trp, with their hydrazino analogues. Prepared peptides were characterized by NMR spectroscopy. Detailed NMR analysis revealed presence of multiple conformations in D2O/DMSO solution, depending on number and position of hydrazino acids in a peptide sequence. Interaction between mDM2 protein and prepared peptides was assayed by fluorimetric titrations based on intrinsic fluorescence of both, mDM2 and peptides. For some peptides titration with mDM2 yielded non-additive change of fluorescence, allowing estimation of binding constants by multivariate least square analysis of complete titration spectra in HyperQuad programme. For all peptide/mDM2 complexes similar, micromolar affinity was determined, pointing out that various introductions of hydrazine-moiety do not interfere significantly with binding.

peptidomimetics ; hydrazino acids, protein-protein interaction

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