FIG 5.

Characterization of the invertase activity of INV₇₉₄₂ (a) and the effect of ionic (b) and osmotic (c) compounds on enzyme activity. All assays were performed using sucrose (Suc, 2 mM) as a substrate. In panel a, the products glucose (Glu) and fructose (Fru) were examined by ion-exchange chromatography. The assay buffer and the empty plasmid pRSFDuet-1 were used as negative controls (n.c.). In panels b and c, different concentrations of NaCl, KCl, NaNO₃, NH₄Cl, sorbitol, or mannitol were included in reaction mixtures, as indicated. The measured activities were normalized by comparing them with the starting values (at 0 mM). The data are presented as means from at least three independent replicates (n = 3 in panel b; n = 4 in panel c) with the standard deviations.