Selection of peptides binding to the alpha 5 beta 1 integrin from phage display library.
The alpha 5 beta 1 integrin binds fibronectin through the integrin recognition sequence Arg-Gly-Asp (RGD). We have used a 6-amino acid peptide library expressed on filamentous phage to identify peptide ligands for alpha 5 beta 1. We found that this integrin selectively binds RGD-containing peptides from the library. Of the 32 different sequences obtained, 28 had the RGD motif, 3 contained sequences related to RGD, and only 1 had a clearly different sequence. One of the RGD-containing phage encoded a potentially cyclic insert CRGDCL. The cyclic peptide GAC*RGDC*LGA (where * denotes cysteines forming a disulfide bond) was 10-fold more efficient than any of the linear RGD-containing hexapeptides in inhibiting the binding of RGD-expressing phage to alpha 5 beta 1 or the attachment of alpha 5 beta 1-expressing cells to fibronectin. This peptide also inhibited cell attachment mediated by the alpha v beta 1, alpha v beta 3, and alpha v beta 5 integrins with about 10-fold higher efficiency than linear GRGDSP. One peptide containing an RGD-related sequence, NGRAHA, was also found to inhibit phage attachment and cell adhesion, especially adhesion mediated by the alpha v beta 5 integrin. These results indicate that novel and high affinity ligands for integrins can be isolated from a random peptide library.
Koivunen
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E
Cancer Research Center, La Jolla Cancer Research Foundation, California 92037.
Gay
D A
DA
Ruoslahti
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E
D000595:Amino Acid Sequence; D000818:Animals; D001435:Bacteriophages; D001483:Base Sequence; D001667:Binding, Competitive; D016466:CHO Cells; D006224:Cricetinae; D016208:Databases, Factual; D005353:Fibronectins / Q000378:metabolism; D015723:Gene Library; D016023:Integrins / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D009842:Oligopeptides / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D017469:Receptors, Fibronectin; D014162:Transfection
D005353:Fibronectins; D016023:Integrins; D009838:Oligodeoxyribonucleotides; D009842:Oligopeptides; D017469:Receptors, Fibronectin; C047981:arginyl-glycyl-aspartic acid