Resumen:
Sucrose synthases (SuSys) have been attracting great interest in recent years in industrial biocatalysis. They can be used for the
cost-effective production of uridine 5′-diphosphate glucose (UDP-glucose) or its in situ recycling if coupled to glycosyltransferases
on the production of glycosides in the food, pharmaceutical, nutraceutical, and cosmetic industry. In this study, the
homotetrameric SuSy from Acidithiobacillus caldus (SuSyAc) was immobilized-stabilized on agarose beads activated with
either (i) glyoxyl groups, (ii) cyanogen bromide groups, or (iii) heterogeneously activated with both glyoxyl and positively
charged amino groups. The multipoint covalent immobilization of SuSyAc on glyoxyl agarose at pH 10.0 under optimized
conditions provided a significant stabilization factor at reaction conditions (pH 5.0 and 45 °C). However, this strategy did not
stabilize the enzyme quaternary structure. Thus, a post-immobilization technique using functionalized polymers, such as
polyethyleneimine (PEI) and dextran-aldehyde (dexCHO), was applied to cross-link all enzyme subunits. The coating of the
optimal SuSyAc immobilized glyoxyl agarose with a bilayer of 25 kDa PEI and 25 kDa dexCHO com...