title: Synthesis and screening of a rationally designed combinatorial library of affinity ligands mimicking protein L from Peptostreptococcus magnus.
abstract: Rational design and combinatorial chemistry were utilized to search for lead protein L (PpL) mimetics for application as affinity ligands for the purification of antibodies and small fragments, such as Fab and scFv, and as potential diagnostic or therapeutic agents. Inspection of the key structural features of the complex between PpL and human Fab prompted the de novo design and combinatorial synthesis of a 169-membered solid-phase ligand library, which was assessed for binding to human IgG and subsequent selectivity for the Fab fragment. Eight ligands were selected, chemically characterized and compared with a commercial PpL-adsorbent for binding pure immunoglobulin fractions. The most promising lead, ligand 8/7, when immobilized on an agarose support, behaved in a similar fashion to PpL in isolating Fab fragments from papain digests of human IgG to a final purity of 97%.
authors.affiliation: Centro de Engenharia Biológica e Química, Instituto Superior Técnico, Lisboa, Portugal.
authors.forename: A Cecília A
authors.initials: AC
authors.lastname: Roque
authors.forename: M Angela
authors.initials: MA
authors.lastname: Taipa
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Lowe
mesh_terms: D000345:Affinity Labels / Q000737:chemistry* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry*; D002846:Chromatography, Affinity; D020650:Combinatorial Chemistry Techniques; D004268:DNA-Binding Proteins / Q000737:chemistry*; D015195:Drug Design; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000302:isolation & purification* / Q000378:metabolism*; D007074:Immunoglobulin G / Q000302:isolation & purification / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D018716:Molecular Mimicry; D015394:Molecular Structure; D019151:Peptide Library; D010462:Peptostreptococcus / Q000737:chemistry; D011485:Protein Binding
chemical_list: D000345:Affinity Labels; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; C116593:L-protein, Peptococcus magnus; D008024:Ligands; D019151:Peptide Library