Comparison of Chitin and Amberlite IRA‐938 for α‐Galactosidase Immobilization

Figures & data

Figure 1. a) CDI activation of the support, b) Enzyme coupling without spacer arm (Method A), c) Enzyme coupling via spacer arm (Method B).

Table 1. Activation yields of chitin and Amberlite IRA‐938 with various amounts of CDI

CDI amount (mmol CDI/g support)	Activation yield (%)		Active group yield (meq/ g support)
	Chitin	Amberlite	Chitin	Amberlite
0.15	93	88.0	0.140	0.132
0.30	44	54.3	0.133	0.163
0.60	20	40.5	0.122	0.243
1.00	14	18.9	0.139	0.189

Table 2. Coupling parameters for the immobilization of α‐galactosidase on CDI activated chitin (A) and Amberlite IRA‐938 (B)

CDI amount (mmol CDI/g chitin)	Free enzyme	Coupling % (protein)	Immobilized enzyme	Activity yield (%)
	Specific activity (U/mg)		Specific activity (U/mg)
A)
0.15	1.29	74	0.68	53
0.30	1.29	72	0.73	57
0.60	1.29	65	0.74	57
1.00	1.29	73	0.87	67
B)
0.15	0.22	66	0.100	46
0.30	0.22	69	0.150	68
0.60	0.22	70	0.108	49
1.00	0.22	77	0.106	48

Table 3. Effect of protein amounts on the coupling efficiency of CDI activated chitin (A) and Amberlite IRA‐938 (B)

Free enzyme		Coupling (%) (protein)	Immobilized enzyme	Activity yield (%)
Protein (mg)	Specific activity (U/mg)		Specific activity (U/mg)
A)
0.5	0.96	100	0.60	63
1.0	0.96	96	0.64	67
2.0	0.96	74	0.55	57
5.0	0.96	69	0.30	31
10.0	0.96	61	0.24	25
B)
2.52	0.218	80	0.084	39
5.0	0.218	70	0.148	68
7.5	0.218	74	0.104	48
10.0	0.218	70	0.103	47
20.0	0.218	84	0.069	32

Table 4. Effect of protein amounts on the coupling efficiency of CDI activated chitin (1 mmol CDI/ g chitin) [A] and Amberlite IRA‐938 (0.3 mmol CDI/g resin) [B] with spacer arm(GABA)

Free enzyme		Coupling (%) (protein)	Immobilized enzyme	Activity yield (%)
Protein (mg)	Specific activity (U/mg)		Specific activity (U/mg)
A)
1	0.816	73	0.41	50
2	0.816	81	0.31	38
5	0.816	80.8	0.26	32
10	0.816	68	0.21	26
B)
2.5	0.275	84	0.114	42
5.03	0.275	82	0.039	14
7.52	0.275	75	0.045	16.4
10.02	0.275	70	0.034	12.4
20.04	0.275	13.9	0.035	12.7

Figure 2. Storage stability of free and immobilized α‐galactosidases at 4°C. (•): free enzyme, (□) immobilized enzyme : on chitin (A), on Amberlite IRA‐938 (B).