Immobilization of some enzymes onto some polymeric materials
Ahmad EI-Sayed Atia;
Abstract
Immobilized enzymes bound to polymeric supports are prepared for the purpose of repeated use and the possibilities of continuous reaction systems. One of the most important properties is the stability of proteins when they are used in some medical and industrial applications. Immobilization of enzymes improves this property as well as many other properties. In the present study three enzymes were immobilized, namely ADA Adenosine Deaminase [EC
3.5.4.4, Type IV; from Bovine Spleen], Pullulanase [EC 3.2.1.4.1, from Klebsiella pneumoniae] and 13-Amylase [EC 3.2.1.2., Type 11-B from Barley). The immobilization of these enzymes was carried out onto three different polymeric materials: agarose, casein and butylacrylate/ acrylic acid (BuA/ AAc) copolymer. The factors affecting the amount of enzyme attachment onto the polymeric supports such as incubation pH, enzyme concentration and incubation time was investigated. Some physico-chemical properties of the free and immobilized enzymes such as reuse efficiency, optimum temperature and thermal stability, pH optimum and stability, storage stability and the effect of y-radiation were studied. For the immobilization process, chemical and radiation methods were used. The results of this study may be summarized as follows:
• The maximum amount of enzyme immobilized onto the different polymeric supports occurred at incubation pH values of 7.5, 5 and 7 for Adenosine Deaminase (cone. 42 units/ gm), Pullulanase (cone. 16 units/gm) and J3-amylase (86 units/ gm), respectively. The incubation time needed for the three enzymes was found to be
8, 10 and 11 hours, respectively. An optimum concentration of the enzymes and optimum incubation time were determined
3.5.4.4, Type IV; from Bovine Spleen], Pullulanase [EC 3.2.1.4.1, from Klebsiella pneumoniae] and 13-Amylase [EC 3.2.1.2., Type 11-B from Barley). The immobilization of these enzymes was carried out onto three different polymeric materials: agarose, casein and butylacrylate/ acrylic acid (BuA/ AAc) copolymer. The factors affecting the amount of enzyme attachment onto the polymeric supports such as incubation pH, enzyme concentration and incubation time was investigated. Some physico-chemical properties of the free and immobilized enzymes such as reuse efficiency, optimum temperature and thermal stability, pH optimum and stability, storage stability and the effect of y-radiation were studied. For the immobilization process, chemical and radiation methods were used. The results of this study may be summarized as follows:
• The maximum amount of enzyme immobilized onto the different polymeric supports occurred at incubation pH values of 7.5, 5 and 7 for Adenosine Deaminase (cone. 42 units/ gm), Pullulanase (cone. 16 units/gm) and J3-amylase (86 units/ gm), respectively. The incubation time needed for the three enzymes was found to be
8, 10 and 11 hours, respectively. An optimum concentration of the enzymes and optimum incubation time were determined
Other data
| Title | Immobilization of some enzymes onto some polymeric materials | Other Titles | ثبيت بعض الانزيمات علي بعض المواد البوليمرية | Authors | Ahmad EI-Sayed Atia | Keywords | ADA) Adenosine Deaminase - Pullulanase - -Amylase - Agarose - ButylacrylateJ Acrylic Acid (BuAI AAc) copolymer - Casein - Trichlorotriazine - Epichlorohyrdine - Glutaric dialdehyde. | Issue Date | 1999 | Description | In the present study three enzymes were immobilized, namely ADA Adenosine Deaminase, Pullulanase and 13-Amylase. The immobilization of these enzymes was carried out onto three different polymeric materials: agarose, casein and butylacrylate/ acrylic acid (BuAI AAc) copolymer. The factors affecting the amount of enzyme attachment onto the polymeric supports such as incubation pH, enzyme concentration and incubation time was investigated. The maximum amount of enzyme immobilized onto the different polymeric supports occurred at incubation pH values of 7.5, 5 and 7 for Adenosine Deaminase (cone. 42 units/ gm), Pullulanase (cone. 16 units/gm) and P-amylase (86 units/ gm), respectively. The incubation time needed for the three enzymes was found to be 8, 10 and ll hours, respectively. Some physico-<:hemical properties of the free and immobilized enzymes such as reuse efficiency, optimum temperature and thermal stability, pH optimum and stability, storage stability and the effect of y-radiation were studied. For the immobilization process, chemical and radiation methods were used. The reuse efficiency of the free and immobilized enzymes showed that the enzymes immobilized by a crosslinking technique using gultaric dialdehyde (GA) showed poor durability and the relative activity decreased sharply due to the leakage after repeated washing, while the enzymes immobilized by covalent bonds to the carriers showed in most cases a slight decrease in relative activity (around 20%) after being used l 0 times. Temperature optimum and thermal inactivation as well as pH optimum and stability showed a severe loss in the activity of the free enzymes, while the temperature and pH profiles of the immobilized enzymes was much broader at higher temperatures demonstrating the effectiveness of the carriers protecting the enzymes. Storage of the free and immobilized enzymes at 4°C in the dry and wet states for 4-6 months, showed that the free enzyme lost most of its activity after storage. The storage of the immobilized enzymes in the dry state was much better than in the wet state, which may be due to the prevention of autodigestion and thermal denaturation. Storage at room temperature (25°C) showed much less stability of the immobilized enzyme. Subjecting the immobilized enzymes to doses of y-radiation 0.5-10 Mrad showed complete loss in the activity of the free enzyme at a dose of 5 Mrad, while the immobilized enzymes showed relatively high resistance to y-radiation up to a dose of 5 Mrad. Also, Nuclear Magnetic Resonance CH-NMR), FTIR, DSC measurement were carried out to confirm the structure and the immobilization process of the enzymes onto the polymeric carriers. |
Attached Files
| File | Size | Format | |
|---|---|---|---|
| KHALID SALAH ATIA.pdf | 1.42 MB | Adobe PDF | View/Open |
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