ABSTRACT
Background: Enzyme engineering by immobilization techniques has proven to be well compatible with the other chemical or biological approaches aiming to improve enzyme's functions and stability. Zeolites are porous alumino-silicates with a wide range of porosity and particle size along with the other remarkable properties such as high surface area, high stability against a wide range temperatures, pHs, as well as organic solvents
Objectives: Nano-zeolites are a class of advanced materials that have special properties that has made them ideal candidate for a wide range of applications
Materials and Methods: In this study, a nano-zeolite which has been synthesized and characterized in our previous work, was used to immobilize alpha-amylase and activated with glutaraldehyde as a bi-functional agent to improve enzyme properties
Results: Studies have shown an increased stability of the immobilized enzyme compared to the free enzyme against a range of temperature change and pHs as well. Also the stability of the immobilized enzyme was increased with respect to storage. The calculated binding efficiency shows that the immobilized alpha-amylase conserved 58.44% of its native activity
Conclusions: Using nano pore zeolite for covalent attachment of the alpha-amylase resulted in an increased resistance of this enzyme against denaturation. The immobilized enzyme demonstrated higher stability compared to the free enzyme at higher temperatures and pH variations. Immobilization also caused an increase in the enzyme stability during storage
ABSTRACT
Background: collagen, the most abundant protein in the human body, and as an extracellular matrix protein, has an important role in the fiber formation. This feature of the collagen renders establishment of the structural skeleton in tissues. Regarding specific features associated with the collagen, such as, formation of the porous structure, permeability and hydrophilicity, it can also be used as a biocompatible matrix in the enzyme engineering
Objectives: the aim of the present study was to investigate the application of the type I collagen as a matrix for alkaline phosphatase immobilization using cross-linking method
Material and Methods: the Alkaline phosphatase was covalently immobilized on collagen matrix by using 1-ethyl-3-[dimethylaminopropyl] carbodiimide hydrochloride [EDC]. The source of the alkaline phosphatase was from the bovine intestinal mucous. After that, the activity of the immobilized enzyme was assayed under different experimental conditions
Results: the optimum pH was similar to that of the free enzyme, whereas the optimum temperature and thermal stability were shown some increments. The surface topography of the collagen matrix containing immobilized enzyme and ALP [Alkaline phosphatase] deficient was investigated by Atomic-force microscopy [AFM]. Images that have been obtained applying AFM show significant differences between uncovered and immobilized enzyme- matrix surface topography
Conclusions: our findings suggest that type I collagen can be utilized as a matrix for alkaline phosphatase immobilization via cross-linking method