Invertase immobilized on spacer-arm attached poly(hydroxyethyl methacrylate) membrane: Preparation and properties

Arica, MY
Senel, S
Alaeddinoglu, NG
Patir, S
Denizli, A
Microporous poly(2-hydroxyethyl methacrylate) (pHEMA) membrane was prepared by UV-initiated photopolymerization. The spacer arm (i.e., hexamethylene diamine) was attached covalently and then invertase was immobilized by the condensation reaction of the amino groups of the spacer arm with carboxyl groups of the enzyme in the presence of carbodiimides. The values of the Michael's constant K-m of invertase were significantly larger (ca. 2.5 times) upon immobilization, indicating decreased affinity by the enzyme for its substrate, whereas V-max was smaller for the immobilized invertase. Immobilization improved the pH stability of the enzyme as well as its temperature stability. Thermal stability was found to increase with immobilization and at 70 degrees C the half times for the activity decay were 12 min for the free enzyme and 41 min for the immobilized enzyme. The immobilized enzyme activity was found to be quite stable in repeated experiments. (C) 2000 John Wiley & Sons, Inc.


Conduction mechanism in H-type polysiloxane-polypyrrole block copolymers
BOZKURT, AYHAN; Parlak, Mehmet; Ercelebi, C; Toppare, Levent Kamil (Wiley, 2002-07-05)
Conducting polymers of polysiloxane-polypyrrole were Synthesized by electropolymerization of the pyrrole monomer through pyrrole moieties in N-pyrrole-terminated polysiloxanes. Sodium paratoluene sulfonate was used as the electrolyte. Scanning electron microscopy (SEM) was used to determine the surface morphology of the films. The room-temperature conductivity values of the films were found to be in the range of 1.9-4.4 x 10(-4) (Omega cm)(-1), depending on the supporting electrolyte concentration. The temp...
Synthesis and Spectroelectrochemistry of Dithieno(3,2-b:2 ',3 '-d)pyrrole Derivatives
Udum, Yasemin Arslan; Yildiz, Huseyin Bekir; Azak, Hacer; Sahin, Elif; Talaz, Oktay; Çırpan, Ali; Toppare, Levent Kamil (Wiley, 2014-09-05)
New pi-conjugated polymers containing dithieno(3,2-b: 2',3'-d) pyrrole (DTP) were successfully synthesized via electropolymerization. The effect of structural differences on the electrochemical and optoelectronic properties of the 4-[4H-dithieno(3,2-b: 2',3'-d) pyrrol-4-yl] aniline (DTP-aryl-NH2), 10-[4H-dithiyeno(3,2-b: 2',3'-d) pirol-4-il] dekan-1-amine (DTP-alkyl-NH2), and 1,10-bis[4H-dithieno(3,2-b:2',3'-d) pyrrol-4-yl] decane (DTP-alkyl-DTP) were investigated. The corresponding polymers were characteri...
Immobilization of invertase in conducting polypyrrole/PMMA-co-PMTM graft copolymers
Yildiz, HB; Kiralp, S; Toppare, Levent Kamil; Yagci, Y (Wiley, 2005-04-15)
In this study, invertase was immobilized in copolymer electrodes constructed. Three different types of polymethyl methacrylate-co-polymethyl thienyl methacrylate matrices were used to obtain copolymers that were characterized by FT-IR spectroscopy. Immobilization of enzymes was carried out by the entrapment of the enzyme in conducting polymer matrices during electrochemical polymerization of pyrrole through thiophene moieties of polymers. Immobilization of the enzyme was achieved by application of 1.0 V con...
Synthesis and Characterization of a New Conducting Polymer Based on 4-(2,5-di-2-thiophen-2-yl-pyrrol-1-yl)-phthalonitrile
Yavuz, Arzu; Bezgin, Buket; Önal, Ahmet Muhtar (Wiley, 2009-12-05)
A new conducting polymer was synthesized by electrochemical polymerization of 4-(2,5-di-2-thiophen-2-yl-pyrrol-1-yl)-2-phthalonitrile (SNS-PN). Electrochemical polymerization of SNS-PN was performed in acetonitrile/0.2M LiClO4 solvent/electrolyte couple. Characterizations of the resulting polymer P(SNS-PN) were carried out by cyclic voltammetry, UV-vis, and Fourier transform infrared (FTIR) spectroscopic techniques. Spectroelectrochemical studies revealed that P(SNS-PN) has an electronic band gap of 2.45 eV...
Effect of ZnO type and concentration on the mophology, thermal, and mechanical properties of poly(ether ester)/ZnO composites
ÇELEBİ, HANDE; Bayram, Göknur; DOĞAN, AYDIN (Wiley, 2013-09-15)
Poly(ether ester) (PEE) copolymers were synthesized in a two-stage process involving transesterification and polycondensation. The synthesized copolymer and the zinc oxide (ZnO) were used in composite preparation by melt compounding. The influence of ZnO type and concentration on the morphology, thermal and mechanical properties of the composites were studied. DSC and XRD analyses indicated that crystallinity of composites was slightly reduced with ZnO content. Homogeneous dispersion of fillers in the polym...
Citation Formats
M. Arica, S. Senel, N. Alaeddinoglu, S. Patir, and A. Denizli, “Invertase immobilized on spacer-arm attached poly(hydroxyethyl methacrylate) membrane: Preparation and properties,” JOURNAL OF APPLIED POLYMER SCIENCE, pp. 1685–1692, 2000, Accessed: 00, 2020. [Online]. Available: