A new ligand for immunoglobulin g subdomains by screening of a synthetic peptide library.
By screening a synthetic peptide library of general formula (NH(2)-Cys1-X2-X3-X4)(2)-Lys-Gly-OH, a disulfide-bridged cyclic peptide, where X2-X3-X4 is the tripeptide Phe-His-His, has been selected as a ligand for immunoglobulin G (IgG). The peptide, after a preliminary chromatographic characterization, has proved useful as a new affinity ligand for the purification of polyclonal as well as monoclonal antibodies from biological fluids, with recovery yields of up to 90% (90% purity). The ligand is able to bind antibody fragments containing both Fab and Fc from different antibody isotypes, a fact suggesting the presence of at least two different antibody-binding sites. While the recognition site on Fab is unknown, comparative binding studies with Fc, in association with the striking similarities of the peptide (named Fc-receptor mimetic, FcRM) with a region of the human FcgammaRIII receptor, strongly indicate that the peptide could recognize a short amino acid stretch of the lower hinge region, which has a key role in autoimmune disease triggering. The unique properties make the ligand attractive for both the purification of antibody fragments and as a lead for the generation of Fc-receptor antagonists.
Verdoliva
Antonio
A
TECNOGEN S.C.p.A. Località La Fagianeria, 81015 Piana Di Monte Verna, Caserta, Italy.
Marasco
Daniela
D
De Capua
Antonia
A
Saporito
Angela
A
Bellofiore
Piero
P
Manfredi
Vincenzo
V
Fattorusso
Roberto
R
Pedone
Carlo
C
Ruvo
Menotti
M
D000595:Amino Acid Sequence; D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry; D015153:Blotting, Western; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry*; D008024:Ligands; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D019151:Peptide Library; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000737:chemistry*; D011817:Rabbits; D051381:Rats; D011961:Receptors, Fc / Q000737:chemistry; D016415:Sequence Alignment
D007074:Immunoglobulin G; D008024:Ligands; D019151:Peptide Library; D010456:Peptides, Cyclic; D011961:Receptors, Fc