Heme transfer from Shr to apoShp. ApoShp(75 μM) was incubated with 10 μM Shr in 0.1 ml of 20 mM Tris-HCl, pH 8.0, at room temperature for 15 min. The sample was then loaded onto a 0.1-ml SP Sepharose column and eluted as described in the text. (A) SDS-PAGE analysis showing separation of Shr and Shp from their mixture. Lanes: 1, Shr/apoShp mixture before separation; 2, Shr isolated from the mixture; 3, Shp isolated from the mixture. (B) Spectra of apoShp (solid curve) and treated Shp (dashed curve). (C) Spectra of Shr (solid curve) and treated Shr (dashed curve). The arrows in panels B and C indicate the Y-axis of the corresponding spectrum.