RESUMO
An exceptionally stable 1:2 complex [FeL(2)](3-) is formed from the ligand H(3)L and Fe(III). In contrast, the affinity of this ligand for other biometals is relatively small. These properties make H(3)L a highly promising candidate for medical applications (e.g. for the treatment of iron overload).
RESUMO
The production of D-ribulose-5-phosphate in an enzyme membrane reactor was examined. Phosphoryl transfer from ATP to D-ribulose was catalysed by D-ribulokinase isolated from Klebsiella pneumoniae. For production of D-ribulose-5-phosphate the phosphoryl donor ATP was used either in stoichiometric or in catalytic amounts. Using catalytic amounts of ATP requires a second enzyme, e.g. pyruvate kinase, to regenerate ATP. The kinetic parameters for D-ribulokinase and pyruvate kinase were determined to calculate the performance of an enzyme membrane reactor for continuous production of D-ribulose-5-phosphate. Both processes operated for more than 200 h. Regardless of whether ATP was used in catalytic or stoichiometric amounts, about the same production parameters were determined. In continuous production space/time yields of 117 g (with ATP regeneration) and 103 g (without ATP regeneration) of D-ribulose-5-phosphate l -1 per day were reached.
