Highly selective cyclic peptide ligands for NeutrAvidin and avidin identified by phage display.
Screening combinatorial libraries of conformationally constrained peptides against macromolecular targets is utilized in identifying novel drug leads and in developing new reagents for chemical biology. In methods such as phage-display selections, biotinylated macromolecular targets are often immobilized on avidin- and streptavidin-functionalized supports. Thus, the characterization of peptides that bind avidin and streptavidin is necessary for accurate interpretation of screening and selection results. Toward this goal, we panned a phage-displayed cyclic peptide library against NeutrAvidin, a chemically deglycosylated version of avidin. The selection produced a highly homologous consensus motif (Asp-Arg/Leu-Ala-Ser/Thr-Pro-Tyr/Trp). Two of these cyclic peptides, CDRATPYC and CDRASPYC, bound both NeutrAvidin and avidin with low-micromolar dissociation constants, whereas their acyclic counterparts had negligible affinity (< 80-fold). Moreover, these cyclic peptides were very specific for their targets and did not bind the structurally and functionally similar protein, streptavidin. Thus, we have identified a new class of cyclic peptides, distinct from the much-studied streptavidin-binding His-Pro-Gln peptide motif. These results will not only allow for discriminating between desired and background cyclic peptide motifs in selections and screens but also provide a new protein/peptide model system and a useful reagent in chemical biology that can have utility in protein immobilization, purification, and chemical tagging.
Meyer
Scott C
SC
Department of Chemistry, University of Arizona, Tucson, AZ 85721, USA.
Gaj
Thomas
T
Ghosh
Indraneel
I
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001360:Avidin / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D001391:Azo Compounds / Q000378:metabolism; D017104:Bacteriophage M13 / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D015195:Drug Design; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019151:Peptide Library; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D019809:Streptavidin / Q000737:chemistry / Q000378:metabolism
D001391:Azo Compounds; C514999:CDRASPYC cyclic peptide; C514998:CDRATPYC cyclic peptide; D008024:Ligands; D019151:Peptide Library; D010456:Peptides, Cyclic; C093483:neutravidin; D001360:Avidin; C001413:HABA; D019809:Streptavidin