Bioaffinity Based Immobilization of Enzymes - Advances in Biochemical Engineering Biotechnology - page 214

3.3
Immobilization of Whole Cells

The high affinity of Con A for cell surface oligosaccharides has also facilitated the
immobilization of various cells including those of yeast [131],red blood cells [126,
128] and Trichosporon cutaneum [132]. An early study has also described the
co-immobilization of enzymes and living cells using Con A [133]. More recently
Habibi-Rezaei and Nemat-Gorgani [134] immobilized submitochondrial particles
prepared from beef liver mitochondria on Con A support for continuous catalytic
transformations involving succinate-cytochrome c reductase.

3.4
Immobilization Using Other Lectins

Very few reports are also available on use of lectins other than Con A in the
immobilization of glycoenzymes. Lens culinaris lectin that has Con A like sugar
specificity but about 50 times lower affinity for the sugars than does Con A was
used in a thermistor for facilitating the ready elution of glucose oxidase [128].
The Cajanus cajan lectin,that also recognizes glucose and mannose but with
lower affinity than Con A [135] on immobilization yields an affinity adsorbant
that effectively immobilizes and stabilizes several glycoenzymes [136]. Kokufuta
et al. [61] employed Ricinus communsis lectin for a novel application alongwith
E. coli

-galactosidase; the lectin was entrapped in polyion complex-stabilized
alginate gel beads to improve the availability of the enzyme substrate O -nitro-
phenyl-

b

b - D -galactoside for which the lectin has affinity.

4
Enzyme Immobilization Using Other Bioaffinity Supports

4.1
Enzyme Immobilization on Immobilized Metal Ion Supports

Immobilized metal affinity adsorption (IMA) is a collective term that was pro-
posed to include all kinds of adsorptions whereby metal atoms or ions immobi-
lized on polymers cause or dominate the interactions at the sorption site [137,
138]. Introduced originally by Porath and coworkers [139] IMA has been wide-
ly used in the chromatography/fractionation of proteins and is among the most
popular methods available todate [140]. IMA chromatography has also several
other applications including in the separation of red blood cells [141] and
recombinant E. coli cells containing surface hexahistidine clusters [142]. The
potential of IMA in enzyme immobilization is also being increasingly realized.
IMA is based upon affinity of surface functional groups of protein for the
immobilized metal ions. The strength of association between the chelated and
bound metal ion and the residues on protein surface may be quite high and even
approach the strength of interaction between enzyme and cofactor/inhibitor or
even that between antigen and antibody [140]. Considering that affinity of pro-