In the presence of ADP and GDP the tyrosine-phosphorylating activities of the viral as well as the cellular pp60src show a similar concentration-dependent inhibition in vitro. Addition of diadenosine 5′,5′″-pIp4 tetraphosphate (Ap4A) to the kinase assay leads to an inhibition of the viral kinase activity, whereas the cellular kinase is not influenced.

This content is only available as a PDF.