epidermal-growth-factor and benzamidine

The benzamides 1 and the benzamidines 2 as well as the cyclic benzamidines 3 were designed and synthesized as the mimics of 4-anilinoquinazolines for an inhibitor of EGFR tyrosine kinase. The specific inhibitions of EGFR tyrosine kinase were observed in the benzamides 1c and 1d, and the benzamidine 2a, whereas the specific inhibitions of v-Src kinase were observed in the benzamide 1j and the benzamidine 2d at a 10microg/mL concentration of compounds. The cyclic benzamidines 3a and 3b showed potent kinase inhibition of EGFR at a 1.0microg/mL concentration. According to the docking simulation using the X-ray structure of EGFR kinase domain in complex with erlotinib, the LigScore2 scoring function value of erlotinib was calculated as 5.61, whereas that of the benzamide 1c was 5.05. In a similar manner, the LigScore2 value of the cyclic benzamidine 3a was calculated as 5.10.

Topics: Benzamides; Benzamidines; Cell Line, Tumor; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Humans; Hydrogen Bonding; Inhibitory Concentration 50; Ligands; Models, Molecular; Molecular Conformation; Molecular Structure; Phosphorylation; src-Family Kinases

We reassessed the enzyme immunoassay (EIA) system for hEGF previously developed by our laboratory (Clin Chim Acta 156:51-60, 1985), since it appeared that the reported EIA system detected not only hEGF but also pS2 protein owing to minor contamination by pS2 protein in the hEGF sample used for immunization. In this study, we purified the hEGF sample using Benzamidine-Sepharose 6B column chromatography as a critical step for purification and newly developed an EIA system with specificity for hEGF. We also measured the hEGF level in serum, plasma, and urine from normal subjects by our new EIA system and found that the values measured by the previous system were 1.2-5.8-fold higher than the new system values. These results suggest that the previous system detected "hEGF" in excess owing to the nonspecificity of the antibody used. We investigated the molecular nature of immunoreactive hEGF detected in serum using our new system and confirmed that considerable amounts of immunoreactive hEGF exist as a high molecular weight form through S-S linkage with some macromolecule(s) in human blood as reported previously (Biochem Int 12:677-683, 1986).

Topics: Adult; Animals; Antibodies; Benzamidines; Chromatography, High Pressure Liquid; Epidermal Growth Factor; Female; Humans; Immunoenzyme Techniques; Male; Middle Aged; Rabbits; Reproducibility of Results; Sensitivity and Specificity; Sepharose; Serine Proteinase Inhibitors