Figure 1.

Competitive binding of BaP and BeP to rainbow trout AHR2α.

Trout AhR2α was synthesized by in vitro transcription and translation and incubated (18 h at 4°C) with [³H]TCDD (2 nM) and increasing concentrations of competitor, followed by analysis by velocity sedimentation as described in Materials and Methods. (a) Representative binding curves showing [³H]TCDD binding to AhR2α in the absence or presence of increasing concentrations of BaP (left panel) or BeP (right panel) or to unprogrammed lysate (UPL; a measure of non-specific binding). (b) Specific binding of [³H]TCDD in the presence of increasing concentrations of competitor, expressed as percent control specific binding (binding in the absence of competitor). Error bars indicate the range of values, from two independent binding assays.