An in vitro selected binding protein (affibody) shows conformation-dependent recognition of the respiratory syncytial virus (RSV) G protein

Immunotechnology. 1999 Mar;4(3-4):237-52. doi: 10.1016/s1380-2933(98)00026-8.


Using phage-display technology, a novel binding protein (Z-affibody) showing selective binding to the RSV (Long strain) G protein was selected from a combinatorial library of a small alpha-helical protein domain (Z), derived from staphylococcal protein A (SPA). Biopanning of the Z-library against a recombinant fusion protein comprising amino acids 130-230 of the G protein from RSV-subgroup A, resulted in the selection of a Z-affibody (Z(RSV1)) which showed G protein specific binding. Using biosensor technology, the affinity (K(D)) between Z(RSV1) and the recombinant protein was determined to be in the micromolar range (10(-6) M). Interestingly, the Z(RSV1) affibody was demonstrated to also recognize the partially (54%) homologous G protein of RSV subgroup B with similar affinity. Using different recombinant RSV G protein derived fragments, the binding was found to be dependent on the presence of the cysteinyl residues proposed to be involved in the formation of an intramolecular disulfide-constrained loop structure, indicating a conformation-dependent binding. Results from epitope mapping studies, employing a panel of monoclonal antibodies directed to different RSV G protein subfragments, suggest that the Z(RSV1) affibody binding site is located within the region of amino acids 164-186 of the G protein. This region contains a 13 amino acid residue sequence which is totally conserved between subgroups A and B of RSV and extends into the cystein loop region (amino acids 173-186). The potential use of the RSV G protein-specific Z(RSV1) affibody in diagnostic and therapeutic applications is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies, Monoclonal / immunology
  • Antibodies, Viral / chemistry*
  • Antibodies, Viral / immunology*
  • Bacteriophages / genetics
  • Biosensing Techniques
  • Epitope Mapping
  • HN Protein*
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Peptide Library
  • Peptides / chemistry*
  • Peptides / immunology*
  • Protein Conformation
  • Protein Structure, Secondary
  • Recombinant Fusion Proteins / immunology
  • Respiratory Syncytial Virus, Human / chemistry
  • Respiratory Syncytial Virus, Human / immunology*
  • Staphylococcal Protein A / chemistry
  • Staphylococcal Protein A / immunology
  • Viral Envelope Proteins
  • Viral Proteins / immunology*


  • Antibodies, Monoclonal
  • Antibodies, Viral
  • HN Protein
  • Peptide Library
  • Peptides
  • Recombinant Fusion Proteins
  • Staphylococcal Protein A
  • Viral Envelope Proteins
  • Viral Proteins
  • attachment protein G