EN
Chloroperoxidase from Caldariomyces
fumago was immobilized in Eupergit® C, a commercial
mesoporous acrylic-based material. Due to low stability
of the enzyme under neutral and basic pH, the usual
covalent immobilization procedures cannot be applied
to this enzyme. Several strategies were followed in order
to achieve a stable interaction between the protein and
the support. The support was efficiently functionalized
with different reactive groups such as aromatic and
aliphatic amines, glutaraldehyde, diazonium ions, and
maleimide moieties; solvent-exposed amino acid residues
in chloroperoxidase were identified or created through
chemical modification, so that they were reactive under
conditions where the enzyme is stable. Enzyme load and
retained activity were monitored, obtaining biocatalysts
with specific activity ranging from 200 to 25,000 U/g.
The highest load and activity was obtained from the
immobilization of a chemically-modified CPO preparation
bearing a solvent-exposed free thiol group. This biocatalyst
efficiently catalyzed the transformation of β-estradiol, an
endocrine disruptor.