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Rationally Designed Ligands for Use
in Affinity Chromatography
An Artificial Protein L
Ana Cecília A. Roque and Christopher R. Lowe
Summary
Synthetic affinity ligands can circumvent the drawbacks of natural immunoglobulin
(Ig)-binding proteins by imparting resistance to chemical and biochemical degradation
and to in situ sterilization, as well as ease and low cost of production. Protein L (PpL),
isolated from Peptostreptococcus magnus strains, interacts with the Fab (antigen-binding
fragment) portion of Igs, specifically with kappa light chains, and represents an almost
universal ligand for the purification of antibodies. The concepts of rational design and
solid-phase combinatorial chemistry were used for the discovery of a synthetic PpL mimic
affinity ligand. The procedure presented in this chapter represents a general approach with
the potential to be applied to different systems and target proteins.
Key Words: Affinity; biomimetic; ligands; synthetic; proteins; purification; design;
combinatorial synthesis; screening; Protein L.
1. Introduction
The manufacturing process of a biotherapeutic must follow Good Manufacturing
Practice guidelines, such that the final product is a “well characterized
biologic” complying with the exigencies from regulatory bodies, such
as the Food and Drug Administration (FDA) (1). Antibodies represent an
important and growing class of biotherapeutics, with a multibillion dollar
From: Methods in Molecular Biology, vol. 421: Affinity Chromatography: Methods and Protocols, Second Edition
Edited by: M. Zachariou © Humana Press, Totowa, NJ
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