A new model for random screening inhibitors of vascular endothelial growth factor receptor 1 kinase.
Abstract
AIM: To establish a 96-well plate based kinase assay using a recombinant vascular
endothelial growth factor (VEGF) receptor 1 kinase domain protein.
METHODS: A human VEGF receptor 1 kinase domain protein was expressed in E coli,
and its activity was monitored by its ability of phosphorylating the polyE4Y
substrate coated on the walls of 96-well plates with antibody recognition and a
colorimetric readout. A random screening of a sample organic compound library was
carried out, and the hits were characterized with a transformed cell line stably
expressing VEGF receptor 1 protein.
RESULTS: An efficient E coli expression system for human VEGF receptor 1 kinase
domain protein was constructed, and the purified recombinant protein was used to
establish a practical screening assay for kinase inhibitors in vitro. Two
thousand eight hundred organic compounds were screened, and two disubstituted
furans (A1 and A5) with new structure showed inhibition of VEGF receptor 1
kinase. Compound A1 inhibited only phosphorylation of substrate, while compound
A5 inhibited both autophosphorylation and substrate phosphorylation. Both
inhibitors affected phosphorylation in the transformed cells.
CONCLUSION: The recombinant receptor kinase based assay is simple and effective
in identifying kinase inhibitors.
Keywords:
endothelial growth factor (VEGF) receptor 1 kinase domain protein.
METHODS: A human VEGF receptor 1 kinase domain protein was expressed in E coli,
and its activity was monitored by its ability of phosphorylating the polyE4Y
substrate coated on the walls of 96-well plates with antibody recognition and a
colorimetric readout. A random screening of a sample organic compound library was
carried out, and the hits were characterized with a transformed cell line stably
expressing VEGF receptor 1 protein.
RESULTS: An efficient E coli expression system for human VEGF receptor 1 kinase
domain protein was constructed, and the purified recombinant protein was used to
establish a practical screening assay for kinase inhibitors in vitro. Two
thousand eight hundred organic compounds were screened, and two disubstituted
furans (A1 and A5) with new structure showed inhibition of VEGF receptor 1
kinase. Compound A1 inhibited only phosphorylation of substrate, while compound
A5 inhibited both autophosphorylation and substrate phosphorylation. Both
inhibitors affected phosphorylation in the transformed cells.
CONCLUSION: The recombinant receptor kinase based assay is simple and effective
in identifying kinase inhibitors.