Binding of indole-acetic acid to cytosol proteins of embryonic chicken liver

3H-Indole acetic acid bound to cytosol proteins of embryonic chicken liver in vitro to an average capacity of at least 20 pmoles/mg binding protein. The auxin-binding protein complexes could be resolved into 4 major zones by anion exchange chromatography; they sedimented at 3-7 S in sucrose density gradients, and were also heterogenous in agarose gel electrophoresis.