DE52 fractionation of reticulocyte lysate. Rabbit reticulocyte lysate was fractionated on a column of DE52 and fractions were combined into three pools designated A–C as described under Methods. (A) Fractions A, B, and C were immunoblotted for Hsp90, Hsp70, Hop, Hsp40, and p23. (B) GR (top) and apo-nNOS (bottom) activating activity of unfractionated reticulocyte lysate (RL) and the indicated combinations of fractions A, B, and C were assayed as described under Methods. (C) Apo-nNOS (solid bars) or GR (open bars) were activated with unfractionated reticulocyte lysate (RL) in the presence or absence of 10 μM radicicol (Rad). Data are mean ± SEM for three experiments.