Drug candidates for inhibition of HIV-I replication can target Src family kinases (SFK), such as Hck, that interact with Nef protein of the virus. Compounds characterized by such inhibitory activity were identified via an assay for kinase activity of an SFK in a Nef:SFK complex. Illustrative of inhibitors identified using the kinase assay are various 2,3-diaminoquinaxolines and furo[2,3-d]pyrimidines. The inventive inhibitors were found to arrest HIV-I viral replication in vitro.