title: Identifying substrates for endothelium-specific Tie-2 receptor tyrosine kinase from phage-displayed peptide libraries for high throughput screening.
abstract: The peptide substrate specificity of Tie-2 was probed using the phage display method in order to identify efficient substrate for high throughput screening. Two random peptide libraries, pGWX3YX4 and pGWX4YX4, were constructed, in which all twenty amino acid residues were represented at the X positions flanking the fixed tyrosine residue Y. A fusion protein of GST and the catalytic domain of human Tie-2 was used to perform the phage phosphorylation. The phosphorylated phage particles were enriched by panning over immobilized anti-phosphotyrosine antibody pY20 for a total of 5 rounds. Four phage clones (3T61, 3T68, C1-90 and D1-15) that express a peptide sequence that can be phosphorylated by the recombinant catalytic domain of human Tie-2 were identified. Synthetic peptides made according to the sequences of the 4 selected clones from the two libraries, which had widely different sequences, were active substrates of Tie-2. Kinetic analysis revealed that D1-15 had the best catalytic efficiency with a k(cat)/K(m) of 5.9x10(4) M(-1) s(-1). Three high throughput screening assay formats, dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA), radioactive plate binding (RPB) and time-resolved fluorescent resonance energy transfer (TR-FRET) were developed to assess the suitability of these phage display selected peptides in screening Tie-2 inhibitors. Three out of four peptides were functional in the DELFIA assay and D1-15 was functional in the TR-FRET assay.
authors.affiliation: Department of Molecular Sciences, GlaxoSmithKline Research and Development, 5 Moore Drive, Research Triangle Park, NC 27709, USA. sjd20506@gsk.com
authors.forename: S J
authors.initials: SJ
authors.lastname: Deng
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: C A
authors.initials: CA
authors.lastname: Simmons
authors.forename: J T
authors.initials: JT
authors.lastname: Moore
authors.forename: G
authors.initials: G
authors.lastname: Tian
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D020650:Combinatorial Chemistry Techniques / Q000379:methods; D004730:Endothelium, Vascular / Q000201:enzymology*; D004735:Energy Transfer; D004926:Escherichia coli; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D019151:Peptide Library; D010766:Phosphorylation; D014176:Protein Biosynthesis; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D042787:Receptor, TIE-2; D011994:Recombinant Proteins / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity
chemical_list: D009838:Oligodeoxyribonucleotides; D009842:Oligopeptides; D019151:Peptide Library; D011994:Recombinant Proteins; D020794:Receptor Protein-Tyrosine Kinases; D042787:Receptor, TIE-2