Alternatively, cation exchange resins can be activated by transforming their
carboxyl groups into acid chlorides, which then form stable amide bonds with the
amino groups of an enzyme.
N
O
O
NH
O
O
OH
OH
NH 2
pH 7-9
= carrier
= enzyme
Enz
imidocarbonate
Br-C≡N
pH 9-11
Enz
Enz
C
NH 3
HBr
C
C
C
Scheme 3.46 Covalent immobilization of enzymes onto natural polymers
N
O
CO 2 H
COCl
HN
OH
O
O
O
NH 2
NH 2
base
pH 7-8
carboxy-resin
Enz
Enz
= carrier
Enz
= enzyme
Enz
Enz
H
C
SOCl 2
C
C
C
C
C
OH
C
hydroxy-resin
O
Cl
Scheme 3.47 Covalent immobilization of enzymes onto synthetic polymers
S
N
N
O
O
O
Si
N=C=S
O
O
O
Si
NH 2
O
O
O
Si
NH 2
EtO
OEt
OEt
Si
OH
O
CH
CH
O
NH 2
NH 2
N
CH
CH
N
O
O
O
Si
+
Enz
= carrier
Enz = enzyme
Enz
Enz
Enz
Cl 2 C=S
EtOH
H
H
C
C
C
C
C
C
Scheme 3.45 Covalent immobilization of enzymes onto inorganic carriers
372
3 Special Techniques