Development of Anti-Amyloidogenic Short-Synthetic Peptides, Rationally Designed Using a Sequence-Based Strategy

Abstract

An effective therapeutic strategy for the treatment of amyloidosis is the use of rationally-designed sequence-based short peptide for the inhibition of highly-organized cross-β-sheet predominating aggregates of misfolded amyloidogenic proteins. In this context, we investigated the anti-amyloidogenic potency of a hexapeptide (Tyr-Pro-Gln-Ile-Pro-Asn) on hen egg-white lysozyme (HEWL) amyloid formation at pH 2.2 and pH 7.5 using molecular docking techniques alongside an array of biophysical methodologies including fluorescence spectroscopy, UV-vis spectroscopy, FTIR spectroscopy, CD spectral analysis, confocal laser microscopy and transmission electron microscopy. The peptides, referred to as SqPs (Sequence-based Peptides) was meticulously designed based on the aggregation-prone region (APR) of HEWL. Notably, SqP1, amongst the others, exhibited a remarkable lysozyme amyloid inhibition rate of over 70% and ~50% at pH 2.2 and pH 7.5. Our proposed mechanism suggests that SqP1 engages with the APR of HEWL, establishing robust interactions with Trp62/Trp63 residue in the APR region of HEWL. This strong interaction imparted a stabilizing effect on the monomeric structure of HEWL at both the pH conditions, hindering conformation changes in the protein, and consequently restricts the formation of amyloidogenic fibrils. A sequence-based peptide inhibitor targeting lysozyme amyloid formation has not been documented previously. Thus, our findings hold significant implications, underscoring the pivotal role of rationally-designed synthetic peptides as potent amyloid inhibitors.