Formation of Ligand Clusters on Multimodal Chromatographic Surfaces

Area of Science:

• Biochemistry
• Materials Science
• Chemical Engineering

Background:

• Multimodal chromatography utilizes multiple interaction modes (e.g., charge, hydrophobicity) for protein therapeutic purification.
• Understanding ligand behavior on surfaces is crucial for optimizing separation processes.

Purpose of the Study:

• To investigate the surface aggregation behavior of multimodal cation-exchange ligands using molecular dynamics simulations.
• To correlate ligand structure and surface density with aggregation patterns and their impact on surface properties.

Main Methods:

• Molecular dynamics simulations of ligands on a hydrophilic self-assembled monolayer surface.
• Analysis of ligand aggregation, surface pattern formation, and hydrophobic group accessibility.
• Development of quantitative methods to analyze patch size and length distributions.

Main Results:

• Flexible ligands with terminal hydrophobic groups aggregated, forming large hydrophobic/charge patches at high surface density (1 ligand/nm²).
• Less flexible ligands or lower surface density (1 ligand/3 nm²) reduced or eliminated aggregation.
• Flexible linkers enhanced aggregation and reduced hydrophobic group accessibility by promoting surface collapse.

Conclusions:

• Ligand flexibility and surface density significantly influence aggregation behavior in multimodal chromatography.
• Surface clustering impacts protein-surface interactions, affecting purification efficiency.
• Findings inform the design of advanced multimodal separation materials and predictive models.