ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Carbon dioxide activation of 1-aminocyclopropane-1-carboxylate (ACC) oxidase in ethylene biosynthesis.

Poneleit, L. S.; Dilley, D. R.;

Postharvest Biology and Technology Year: 1993 Vol: 3 Issue: 3 Pages: 191-199 Ref: 12 ref.

1993

บทคัดย่อ

Carbon dioxide was required for, and markedly stimulated, the activity of ACC oxidase extracted from apple fruits (cv. Golden Delicious). Without supplemental CO2, enzyme activity was low and variable. The half-maximal CO2 concentration was 0.68% (v/v). Undissociated CO2 rather than HCO3- served as the activator of ACC oxidase. CO2 and dithiothreitol acted synergistically to activate the enzyme but CO2 activation was independent of dithiothreitol. CO2 increased the Km value for substrates ACC and ascorbic acid several fold and increased the Vmax about 10-fold. CO2 activation of ACC oxidase resembled that of Rubisco, the only other plant enzyme known to be activated by CO2. Although CO2 is known to be an inhibitor of ethylene action, it is required for making ACC oxidase catalytically competent to produce ethylene.