Sedimentation velocity on sucrose gradients.³⁵S-methionine–labeled H4 cells were extracted and sedimented on a linear sucrose gradient. Sixteen fractions were collected for immunoprecipitation-recapture experiments using the combination of antibodies shown to the left of each panel. CNO, pallidin and muted all peak in fractions 6 and 7, and pallidin (middle panel) and muted (bottom panel) coprecipitate with CNO. These data indicate that native CNO is part of a complex that includes pallidin and muted. The position of standards, ovalbumin (OVA, 3.6 Svedberg units) and bovine serum albumin (BSA, 4.6 Svedberg units) are indicated at the top. The migration of molecular weight markers (kDa) are shown to the left of each panel.