Mechanistic investigations of 1-aminocyclopropane 1-carboxylic acid oxidase with alternate cyclic and acyclic substrates.
The behavior of three cyclic and three acyclic analogues of 1-aminocyclopropane-1-carboxylic acid (ACC) with ACC oxidase has been analyzed with regard to turnover rates, product distribution, and O(2) uncoupling. The cyclic analogues all form ethylene, and the acyclic analogues all undergo decarboxylation. The degree of uncoupling varies from almost none (ACC) to 21-fold (glycine), while turnover rates (k(cat)) are all within a factor of 4-fold of that of ACC. The aggregate data point toward a rate-determining formation of an activated iron-oxo intermediate, which partitions between amine oxidation and reductive uncoupling in a manner that is dependent on substrate structure.
Thrower
Julia
J
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Mirica
Liviu M
LM
McCusker
Kevin P
KP
Klinman
Judith P
JP
D000144:Acids, Acyclic / Q000737:chemistry / Q000378:metabolism*; D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D000598:Amino Acids, Cyclic / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D008956:Models, Chemical; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013379:Substrate Specificity
D000144:Acids, Acyclic; D000598:Amino Acids, Cyclic; C023863:1-aminocyclopropane-1-carboxylic acid; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase