Affordable Access

Publisher Website

Effects of ionic strength and mobile phase pH on the binding orientation of lysozyme on different ion-exchange adsorbents

Authors
Journal
Journal of Chromatography A
0021-9673
Publisher
Elsevier
Publication Date
Volume
1194
Issue
1
Identifiers
DOI: 10.1016/j.chroma.2007.12.085
Keywords
  • Ion Exchange Chromatography
  • Binding Mechanism
  • Lysozyme
  • Ionic Strength
  • Mobile Phase Ph
  • Characteristic Charge
Disciplines
  • Biology
  • Design
  • Pharmacology

Abstract

Abstract Chromatography is the most widely used technique for the purification of biopharmaceuticals in the biotech industry. Surprisingly, process development is often still based on empirical studies or experience; recently high-throughput screening stations are employed to minimize development time and to improve screening quality. Still, experimental effort remains high and a more detailed understanding of adsorption mechanisms on a molecular level underlying chromatographic separation could help in the future to select and design chromatography steps in silico. In this study, we focused on the elucidation of protein orientation upon adsorption onto a chromatographic resin. We identified two characteristic binding sites of lysozyme on SP Sepharose Fast Flow and one multipoint interaction of lysozyme with SP Sepharose XL. Increasing ionic strength did not significantly influence the binding, whereas changes in the mobile phase pH led to a re-orientation on SP Sepharose FF. This phenomenon agrees well with theoretical considerations, including a detailed description of the surface charge distribution with changing pH and linear elution experiments, giving an idea why proteins are often retained on ion-exchange materials beyond their isoelectric point.

There are no comments yet on this publication. Be the first to share your thoughts.