Translating antibody-binding peptides into peptoid ligands with improved affinity and stability.

Bordelon, Tee

Bobay, Benjamin

Murphy, Andrew

Reese, Hannah

Shanahan, Calvin

Odeh, Fuad

Broussard, Amanda

Kormos, Chad

Menegatti, Stefano

2023-09-01T14:22:05Z

2023-09-01T14:22:05Z

2019-09

2023-09-01T14:22:04Z

A great number of protein-binding peptides are known and utilized as drugs, diagnostic reagents, and affinity ligands. Recently, however, peptide mimetics have been proposed as valuable alternative to peptides by virtue of their excellent biorecognition activity and higher biochemical stability. This poses the need to develop a strategy for translating known protein-binding peptides into peptoid analogues with comparable or better affinity. This work proposes a route for translation utilizing the IgG-binding peptide HWRGWV as reference sequence. An ensemble of peptoid analogues of HWRGWV were produced by adjusting the number and sequence arrangement of residues containing functional groups that resemble both natural and non-natural amino acids. The variants were initially screened via IgG binding tests in non-competitive mode to select candidate ligands. A set of selected peptoids were studied in silico by docking onto putative binding sites identified on the crystal structures of human IgG₁, IgG₂, IgG₃, and IgG₄ subclasses, returning values of predicted binding energy that aligned well with the binding data. Selected peptoids PL-16 and PL-22 were further characterized by binding isotherm analysis to determine maximum capacity (Q_max ˜ 48-57 mg of IgG per mL of adsorbent) and binding strength on solid phase (K_D ˜ 5.4-7.8 10^-7 M). Adsorbents PL-16-Workbeads and PL-22-Workbeads were used for purifying human IgG from a cell culture supernatant added with bovine serum, affording high values of IgG recovery (up to 85%) and purity (up to 98%) under optimized binding and elution conditions. Both peptoid ligands also proved to be stable against proteolytic enzymes and strong alkaline agents. Collectively, these studies form a method guiding the design of peptoid variants of cognate peptide ligands, and help addressing the challenges that, despite the structural similarity, the peptide-to-peptoid translation presents.

S0021-9673(19)30571-0

0021-9673

1873-3778

https://hdl.handle.net/10161/28913

eng

Elsevier BV

Journal of chromatography. A

10.1016/j.chroma.2019.05.047

CHO Cells

Animals

Cattle

Humans

Cricetulus

Alkalies

Peptides

Peptoids

Immunoglobulin G

Antibodies

Ligands

Temperature

Antibody Affinity

Binding Sites

Amino Acid Sequence

Protein Binding

Adsorption

Cricetinae

Proteolysis

Molecular Docking Simulation

Translating antibody-binding peptides into peptoid ligands with improved affinity and stability.

Journal article

Bobay, Benjamin|0000-0003-4775-3686

284

299

Duke

School of Medicine

Clinical Science Departments

Radiology

Published

1602