Comparison of beta-galactosidase immobilization by entrapment in and adsorption on poly(2-hydroxyethylmethacrylate) membranes

Baran, T
Arica, MY
Denizli, A
Hasırcı, Vasıf Nejat
beta-Galactosidase was immobilized in/on poly(2-hydroxyethyl methacrylate) (pHEMA) membranes by two different methods: adsorption on Cibacron F3GA derivatized pHEMA membranes (pHEMA-CB), and entrapment in the bulk of the pHEMA membranes. The maximum beta-galactosidase adsorption on pHEMA-CB membranes was obtained as 95.6 mu g cm(-2) in 2.0 mg cm(-3) enzyme solution. The adsorption phenomena appeared to follow a typical Langmuir isotherm. In the entrapment, an increase in beta-galactosidase loading resulted in a consistent increase in membrane activity from 3.3 x 10(-2) to 17.8 x 10(-2) U cm(-2) pHEMA membranes. The K-m values for both immobilized beta-galactosidase (adsorbed 0.32 mM and entrapped 0.81 mM) were higher than that of the free enzyme (0.26 mM). The optimum reaction temperature of the adsorbed enzyme was 5 degrees C higher than that of both the free and the entrapped enzyme. The optimum reaction pH was 7.5 for free and both immobilized preparations. After 15 successive uses the retained activity of the adsorbed and the entrapped enzymes was 80% and 95%, respectively. The storage stability of the enzyme was found to increase upon immobilization.


ARICA, MY; Hasırcı, Vasıf Nejat (1993-01-01)
Glucose oxidase was immobilized onto poly(2-hydroxyethyl methacrylate) (pHEMA) membranes by two methods: by covalent bonding through epichlorohydrin and by entrapment between pHEMA membranes. The highest immobilization efficiency was found to be 17.4% and 93.7% for the covalent bonding and entrapment, respectively. The K(m) values were 5.9 mmol dm-3, 8.8 mmol dm-3 and 12.4 mmol dm-3 for free, bound and entrapped enzyme, respectively. The V(max) values were 0.071 mmol dm-3 min-1, 0.067 mmol dm-3 min-1 and 0....
Immobilization of glucose oxidase in conducting graft copolymers and determination of glucose amount in orange juices with enzyme electrodes
Yildiz, HB; Kiralp, S; Toppare, Levent Kamil; Yagci, Y (Elsevier BV, 2005-12-15)
Glucose oxidase was immobilized in conducting copolymers of three different types of poly(methyl methacrylate-co-thienyl methacrylate). Immobilization of enzyme was carried out by the entrapment in conducting polymers during electrochemical polymerization of pyrrole on the copolymer electrodes. Maximum reaction rate, Michaelis-Menten constants, temperature, pH and operational stabilities were determined for immobilized enzyme. The amount of glucose in orange juices of Turkey was investigated by using enzyme...
Dye derived and metal incorporated affinity poly(2-hydroxyethyl methacrylate) membranes for use in enzyme immobilization
Arica, MY; Denizli, A; Baran, T; Hasırcı, Vasıf Nejat (1998-08-01)
Microporous poly(2-hydroxyethyl methacrylate) (PHEMA) membranes were prepared by W-initiated photopolymerization of HEMA in the presence of an initiator (alpha,alpha'-azobisisobutyronitrile, AIBN). An affinity dye Cibacron Blue F3GA (CB) was attached covalently and then Fe3+ ions incorporated. The PHEMA-CB and PHEMA-CB-Fe3+ membranes derived were used for adsorption of glucose oxidase (GOD). The adsorption capacities of these membranes were determined under conditions of different pH and with different conc...
Immobilization of invertase and glucose oxidase in poly 2-methylbutyl-2-(3-thienyl) acetate/polypyrrole matrices
Isik, S; Alkan, S; Toppare, Levent Kamil; Cianga, I; Yagci, Y (Elsevier BV, 2003-12-01)
Immobilization of invertase and glucose oxidase in conducting polypyrrole and copolymers of poly 2-methylbutyl-2-(3-thienyl) acetate with pyrrole were achieved via electrochemical method. Sodium dodecyl sulphate was found to be the most suitable supporting electrolyte. Maximum reaction rate, Michaelis-Menten constant and optimum temperatures were determined for native and immobilized enzymes. Storage and operational stabilities of enzyme electrodes were also investigated.
EROGLU, I; ZUBAT, BM; Yücel, Ayşe Meral (1991-09-01)
Purple membrane fragments isolated from the cell membrane of the photosynthetic bacteria Halobacterium halobium S.9 strain are incorporated into egg yolk phosphatidylcholine liposomes. Purple membrane contains crystalline patches of a retinal protein called bacteriorhodopsin. Upon illumination, bacteriorhodopsin undergoes a reversible photoreaction in which a proton is released on one side of the membrane and a proton is bound on the other side, thus resulting in an electro-chemical gradient across the me...
Citation Formats
T. Baran, M. Arica, A. Denizli, and V. N. Hasırcı, “Comparison of beta-galactosidase immobilization by entrapment in and adsorption on poly(2-hydroxyethylmethacrylate) membranes,” POLYMER INTERNATIONAL, pp. 530–536, 1997, Accessed: 00, 2020. [Online]. Available: