Screening a hydroxystilbene library for selective inhibition of the B cell antigen receptor kinase cascade

Protein tyrosine phosphorylation is a key post-translational modification used by eukaryotic cells in receptor mediated signal transduction. Selective inhibition of cellular phosphorylation would aid efforts to elucidate the individual events in a signaling pathway. A combinatorial library of putative kinase inhibitors has been screened using an antiphosphotyrosine blotting assay that can detect inhibition of individual phosphorylation events in whole cells. One member of the library, 3-hydroxy-4-methoxy-4'-nitro-trans-stilbene (2B), has been found to selectively disrupt the phosphorylation of several proteins in the B cell receptor mediated cascade while not affecting other cellular phosphorylation events. The kinase specificity of stilbene 2B is compared to known natural and synthetic kinase inhibitors.