Synergistic Screening of Peptide-Based Biotechnological Drug Candidates for Neurodegenerative Diseases using Yeast Display and Phage Display

Abstract

Peptide therapeutics are robust and promising molecules for treating diverse disease conditions. These molecules can be developed from naturally occurring or mimicking native peptides, through rational design and peptide libraries. We developed a new platform for the rapid screening of the peptide therapeutics for disease targets. In the course of the study, we aimed to employ our platform to screen a new generation of peptide therapeutics candidates against aggregation prone protein targets. Two peptide drug candidates for the protein aggregation prone diseases namely Parkinson s and Alzheimer s diseases were screened. Currently, there are several therapeutic applications that are only effective in masking or slowing down symptom development. Nonetheless, different approaches are developed for inhibiting amyloid aggregation in the secondary nucleation phase, which is critical for amyloid fibril formation. Instead of targeting secondary nucleated protein structures, we tried to inhibit monomeric amyloid units as a novel approach for halting disease-condition. To achieve this, we combined yeast surface display and phage display library platforms. We expressed alpha-synuclein, amyloid beta 40 and amyloid beta 42 on yeast surface, and we selected peptides by using phage display library. After iterative biopanning cycles optimized for yeast cells, several peptides were selected for interaction studies. All of the peptides have been used in vitro characterization methods which are QCM-D measurement, AFM imaging, and ThT assay, and they have yielded promising results in order to block fibrillization or interact with amyloid units as a sensor molecule candidate. Therefore, peptides are good choice for diverse disease-prone molecule inhibition particularly those inhibiting fibrillization. Additionally, these selected peptides can be used as drugs and sensors to detect disease quickly and halt disease progression.

Highly Potent Peptide Therapeutics To Prevent Protein Aggregation In Huntington’s Disease

“…We knew from the previous study that these candidate inhibitory peptides interact with the monomeric units of Htt proteins 14 . Here we wanted to evaluate whether the interaction enabled or blocked the aggregation in the Htt proteins.…”

“…The candidate inhibitory peptides tested in this study were screened against the monomeric units of Htt proteins, both wild-type (Htt(Q25)) and mHtt fragments such as Htt(Q46) and Htt(Q103) 14 . The monomeric units of these proteins were expressed on the yeast surface, which allowed for proper eukaryotic folding/misfolding.…”

“…The peptides were introduced by the phage display library. The ligand peptides were selected by biopanning without immobilizing yeast cells 14 . The capacity of peptide to bind monomeric Htt fragments permits the inhibition of aggregation at a very early stage in the course of disease progression.…”