title: Characterization of polystyrene-binding peptides (PS-tags) for site-specific immobilization of proteins.
abstract: In this study, we characterized polystyrene-binding peptides (PS-tags) that possess a specific binding affinity for hydrophilic polystyrene (phi-PS) plates. Both the FITC-labeled PS19-1 (RAFIASRRIKRP) and PS19-6 (RIIIRRIRR) peptides showed strong binding affinity for commercially available hydrophilic, but not hydrophobic, PS plates in the presence of the non-ionic surfactant Tween 20. The dissociation constants (K(d)) of the PS19-1 and PS19-6 peptides for the hydrophilic PS-A plate were 169 and 86 nM, respectively, and the K(d) of both peptides increased with the concentration of NaCl or urea. Based on adsorption yield and residual activity of glutathione S-transferase (GST) after fusion with the PS19-6 peptide or its variants, it was found that the basic amino acid in the PS-tags, i.e., Arg was essential for the strong binding affinity of PS-tags in both the peptide and peptide-fused protein forms The aliphatic amino acids in PS19-6 and PS19-6L, such as Ile or Leu, were also effective. Thus, a series of PS-tags that possess this unusual feature, especially the peptides PS19-6 (RIIIRRIRR) and PS19-6L (RLLLRRLRR), are potential candidate affinity peptide tags for site-specific immobilization of proteins onto hydrophilic PS plates, which show potential as solid supports for protein-based biochips.
authors.affiliation: Department of Chemistry and Materials Technology, Kyoto Institute of Technology, 1, Hashigami-cho, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan. kumada@chem.kit.ac.jp
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kumada
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kuroki
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Yasui
authors.forename: Takuhito
authors.initials: T
authors.lastname: Ohse
authors.forename: Michimasa
authors.initials: M
authors.lastname: Kishimoto
mesh_terms: D000327:Adsorption; D000596:Amino Acids / Q000737:chemistry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D005982:Glutathione Transferase / Q000737:chemistry / Q000235:genetics; D057927:Hydrophobic and Hydrophilic Interactions; D055767:Immobilized Proteins / Q000737:chemistry*; D007930:Leucine / Q000737:chemistry; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011137:Polystyrenes / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000737:chemistry
chemical_list: D000596:Amino Acids; D055767:Immobilized Proteins; D010455:Peptides; D011137:Polystyrenes; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D007930:Leucine; D016650:Fluorescein-5-isothiocyanate