Inhibition of autophosphorylation of epidermal growth factor receptor by small peptides in vitro

• Published in: British journal of pharmacology Vol. 147; no. 4; pp. 402 - 411
• Main Authors: Abe, Mineo, Kuroda, Yoshihiro, Hirose, Munetaka, Watanabe, Yoshihiko, Nakano, Minoru, Handa, Tetsurou
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.02.2006; Wiley; Nature Publishing; Nature Publishing Group
• Subjects: Adenosine Triphosphate - metabolism; AG1478; Amino Acid Sequence; Binding Sites - drug effects; Binding Sites - physiology; Biological and medical sciences; Blotting, Western; Drug Interactions; DYQQD; EGF; EGFR; Electrophoresis, Polyacrylamide Gel; ENAEYLR; epidermal growth factor; In Vitro Techniques; Life Sciences & Biomedicine; lignocaine; Medical sciences; Molecular Sequence Data; Oligopeptides - chemical synthesis; Oligopeptides - chemistry; Oligopeptides - isolation & purification; Oligopeptides - pharmacology; Pharmacology & Pharmacy; Pharmacology. Drug treatments; Phosphorylation; Protein Tyrosine Phosphatases - antagonists & inhibitors; Quinazolines; Receptor, Epidermal Growth Factor - metabolism; Receptor, Insulin - metabolism; Receptor, Insulin - physiology; Science & Technology; tyrosine kinase; Tyrphostins - pharmacology; VPEYINQ; AG1478; ACTIVATION; DOMAIN; EGF; CRYSTAL-STRUCTURE; SODIUM-CHANNELS; tyrosine kinase; DYQQD; INACTIVATION GATE; BLOCK; lignocaine; SUPPRESSION; EGFR; ENAEYLR; VPEYINQ; INSULIN-RECEPTOR; epidermal growth factor; phosphorylation; Autophosphorylation; Phosphorylation; Peptides; Enzyme; Transferases; Anticonvulsant; Antiarrhythmic agent; In vitro; Epidermal growth factor receptor; Local anesthetic; Epidermal growth factor; Organic amide; Lidocaine; Protein-tyrosine kinase
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1038/sj.bjp.0706634

Inhibition of uncontrolled epidermal growth factor receptor (EGFR) is one of the approaches for the treatment of breast and lung cancers. We designed oligopeptides consisting of amino‐acid sequences of the major (Y1068, Y1148, and Y1173) and minor (Y992) autophosphorylation sites of EGFR. These peptides may be exogenous substrates or pseudosubstrates that interfere with the autophosphorylation of EGFR. The effects of the peptides on autophosphorylation of EGFR were studied. Purified EGFR was phosphorylated in vitro with EGF in the presence of various synthetic peptides. The phosphorylation level of EGFR was then evaluated after SDS–PAGE separation, followed by Western blot analysis with antiphosphotyrosine antibody. Ac‐VPEYINQ‐NH2 (Y1068) and Ac‐DYQQD‐NH2 (Y1148) showed the most potent inhibitory effects, followed by Ac‐ENAEYLR‐NH2 (Y1173). These peptides at 4 mM suppressed phosphorylation to 30–50%. Combination of the three kinds of peptides much more strongly inhibited autophosphorylation. The 50% inhibitory concentration (IC50) value was 0.5 mM as a mixture and was comparable to that of AG1478 (IC50, 0.3 mM) at 0.2 mM ATP. Neither Ac‐DIYET‐NH2 or Ac‐KIYEK‐NH2, designed previously based on the amino‐acid sequence of an autophosphorylation site of insulin receptor, nor their related (Ac‐KIFMK‐NH2) or unrelated (Ac‐LPFFD‐NH2) peptides showed an inhibitory effect. These results suggest that the small peptides that originated from the autophosphorylation sites of EGFR interact solely with EGFR. The peptides containing the sequences surrounding Y1068, Y1148, and Y1173 may be a promising seed for the development of therapeutic agents for breast and lung cancers. British Journal of Pharmacology (2006) 147, 402–411. doi:10.1038/sj.bjp.0706634