Figure 13.

ACC oxidase becomes fragmented into polypeptides ranging in size from 8 to 26 kDa when assayed in the presence of oxygen, Fe(II) and Asc with or without ACC. Left lane, buffer only; middle lane, Fe(II) and Asc; right lane, Fe(II), Asc and ACC. The C-terminal 15-kDa fragment has the N-terminal sequence F187QDNKVS. The C-terminal 12-kDa fragment has the N-terminal sequence V215NLGD. All the other fragments have the same N-terminal sequence as intact ACCO. (Reprinted with permission from Zhang et al. (1997). Metal-catalysed oxidation and mutagenesis studies on the iron(II) binding site of 1-aminocyclopropane-1-carboxylate oxidase, Biochemistry 36:15999–16007, Copyright 1997 American Chemical Society.)