Capturing and Amplifying Impurities from Recombinant Therapeutic Proteins Via Combinatorial Peptide Libraries: A Proteomic Approach

Pier      Giorgio Righetti; Egisto      Boschetti; Elisa      Fasoli

doi:10.2174/138920111798357285

Abstract

The technique of combinatorial peptide ligand libraries (CPLL), for capturing and amplifying low-abundance proteins in r-DNA products as well as in a number of other biological systems, is here analyzed in depth and reviewed. This methodology is based on a creation of several millions of bio-specific ligands composed of hexapeptides produced in a combinatorial way. When acting on an overloading and saturation principle, high-abundance species are captured in limited amounts, whereas low-abundance ones keep being concentrated on their bio-specific ligand till substantial harvesting from solution (the capture process occurring in general from ca. 50% up to 90% efficiency). Examples are given on tracking host-cell impurities present in, e.g., recombinant albumin or monoclonal antibodies. Additionally, other examples of detecting traces of additives and fining agents in such beverages as white and red wines are presented. The unique mechanisms underlying the protein capture in the CPLL methodology, as opposed to capture by homogeneous beads, as represented by ion-exchangers and by hydrophobic resins, are discussed in depth.

Keywords: Combinatorial peptide ligand libraries, host protein contaminants, low-abundance proteome, trace impurities, rDNA proteins, recombinant albumin, monoclonal antibodies, ion-exchangers, hydrophobic resins, recombinant DNA technology, host cell proteins, Current analytical methods, Current HPLC techniques, low sensitivity, Electrophoretic analytical methods