Nucleic acid affinity of clustered-charge anion exchange adsorbents: Effects of ionic strength and ligand density

• Published in: Journal of Chromatography A Vol. 1218; no. 2; pp. 258 - 262
• Main Authors: Chen, Wen-hsiang, Fu, Joseph Y., Kourentzi, Katerina, Willson, Richard C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 14.01.2011; Elsevier
• Subjects: Adsorption; Analytical chemistry; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, Ion Exchange - methods; Clustered charge; DNA - chemistry; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects, investigation methods; Ion-exchange chromatography; Ligand density; Nucleic acids; Osmolar Concentration; Other chromatographic methods; RNA - chemistry; Saccharomyces cerevisiae; Salmon; Sodium Chloride - chemistry; Clustered charge; Nucleic acids; Adsorption; Ion-exchange chromatography; Ligand density; Peptides; RNA; Chromatographic retention; Adsorption isotherm; Selectivity; Coverage rate; Mobile phase; Langmuir isotherm; Ion exchange chromatography; lon-exchange chromatography; Ionic strength; DNA; Anion exchanger; Pentapeptide
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2010.11.024

In previous work we demonstrated the improved protein-binding capacity and selectivity of ion-exchange adsorbents displaying a “clustered” rather than random, distribution of surface charges. For example, anion-exchange adsorbents displaying 5 mM of positive charge in the form of 1 mM penta-argininamide show much higher affinity and capacity for alpha-lactalbumin than do adsorbents displaying the same 5 mM total charge in the form of single dispersed argininamide charges. We also found that clustered adsorbents selectively favor proteins with inherent charge clustering. In the present work, “clustered” penta-argininamide adsorbents showed DNA binding capacity comparable to that of conventional dispersed adsorbents with 10–100-fold higher ligand density. We also observed that at moderate ionic strength the DNA affinity of all adsorbents tested increased with salt while RNA affinity decreased, so that selectivity for DNA over RNA was enhanced as salt concentration increased.