title: Enhanced protein affinity and selectivity of clustered-charge anion-exchange adsorbents.
abstract: In this work, we examined the possibility of improving ion-exchange adsorbent performance by nanoscale structuring of ligands into clusters of fixed size rather than a random distribution of individual charges. The calcium-depleted form of the protein alpha-lactalbumin, which displays a cluster of acidic amino acid residues, showed enhanced adsorption affinity and capacity on clustered-charge pentalysinamide and pentaargininamide adsorbents as compared to single-charge lysinamide and argininamide adsorbents of matched total charge. Two differently charge-clustered mutants of rat microsomal cytochrome b(5), E11Q and E44Q, with the same total charge also were well differentiated by clustered-charge adsorbents. Thus, an organized rather than random distribution of charges may produce adsorbents with higher capacity and selectivity, especially for biomolecules with inherent charge clustering.
authors.affiliation: Biomedical Engineering Program, Department of Biology and Biochemistry, University of Houston, 4800 Calhoun, Houston, Texas 77204-4004, USA.
authors.forename: Joseph Y
authors.initials: JY
authors.lastname: Fu
authors.forename: Sindhu
authors.initials: S
authors.lastname: Balan
authors.forename: Ajish
authors.initials: A
authors.lastname: Potty
authors.forename: Van
authors.initials: V
authors.lastname: Nguyen
authors.forename: Richard C
authors.initials: RC
authors.lastname: Willson
mesh_terms: D000327:Adsorption; D000837:Anion Exchange Resins / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000837:Anion Exchange Resins; D011506:Proteins