Table 1.

Activity of Starch-Related Enzymes in the Wild-Type and ssIII ssIV Double Mutant

EnzymeWild TypessIII ssIV
AGPase (biosynthetic assay)a44.95 ± 7.347.88 ± 5.4
Starch branching enzymeb168 ± 14.6173 ± 10.7
α-Amylasec0.218 ± 0.050.247 ± 0.03
β-Amylased0.90 ± 0.0012.65 ± 0.02
  • a Activity defined as nmol of ADP-glucose formed·min−1·mg protein−1.

  • b Activity is measured as the stimulation of the incorporation of carbon-14 from 14C-glucose 1-phosphate into glucan by phosphorylase and is given in nmol·min−1·mg protein−1.

  • c Ceralpha units.

  • d Betamyl units. Values are the mean ± se of three independent determinations.