Document Type
Article
Publication Title
Journal of Biological Chemistry
Abstract
The 1.6-Å crystal structure of the covalent ketimine complex of apple 1-aminocyclopropane-1-carboxylate (ACC) synthase with the potent inhibitor L-aminoethoxyvinylglycine (AVG) is described. ACC synthase catalyzes the committed step in the biosynthesis of ethylene, a plant hormone that is responsible for the initiation of fruit ripening and for regulating many other developmental processes. AVG is widely used in plant physiology studies to inhibit the activity of ACC synthase. The structural assignment is supported by the fact that the complex absorbs maximally at 341 nm. These results are not in accord with the recently reported crystal structure of the tomato ACC synthase AVG complex, which claims that the inhibitor only associates noncovalently. The rate constant for the association of AVG with apple ACC synthase was determined by stopped-flow spectrophotometry (2.1 × 105 M-1 s-1) and by the rate of loss of enzyme activity (1.1 × 105 M-1 s-1). The dissociation rate constant determined by activity recovery is 2.4 × 10-6 s-1. Thus, the calculated Kd value is 10-20 pM.
First Page
49735
Last Page
49742
DOI
10.1074/jbc.M208427200
Publication Date
12-20-2002
Recommended Citation
Capitani, Guido; McCarthy, Darla L.; Gut, Heinz; and Grütter, Markus G., "Apple 1-aminocyclopropane-1-carboxylate synthase in complex with the inhibitor L-aminoethoxyvinylglycine: Evidence for a ketimine intermediate" (2002). University Faculty Publications and Creative Works. 463.
https://digitalcommons.calvin.edu/calvin_facultypubs/463