Immobilization of acetylcholinesterase on new modified acrylonitrile copolymer membranes

• Published in: Journal of molecular catalysis. B, Enzymatic Enzymatic, 2008-11, Vol.55 (3), p.169-176
• Main Authors: Gabrovska, Katya, Nedelcheva, Teodora, Godjevargova, Tzonka, Stoilova, Olya, Manolova, Nevena, Rashkov, Iliya
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase; Bioconversions. Hemisynthesis; Biological and medical sciences; Biosensor; Biotechnology; Chitosan; Fundamental and applied biological sciences. Psychology; Immobilization; Membrane; Methods. Procedures. Technologies; Modification; Properties
• ISSN: 1381-1177; 1873-3158
• DOI: 10.1016/j.molcatb.2008.03.009

The three new dual-layer matrices (polyacrylonitrile (PAN) membranes coated with physically bound chitosan (CHI)—PANCHI-A and chemically bound chitosan—PANCHI-B and PANCHI-C) for immobilization of acetylcholinesterase (AChE) were obtained. The chemical-modified PAN membrane (PAN-NaOH + ethylenediamine (EDA)) was used as a base for the prepared dual-layer membranes. For chemical chitosan bound membrane, chitosan was tethered onto the membrane surface to form a dual-layer biomimetic membrane in the presence of glutaraldehyde (GA). The basic characteristics (amount of amino groups, hydrophilicity and transport characteristics) of the chitosan-modified membranes were investigated. The SEM analyses were shown essential morphology change in the different chitosan membranes. The relative activities and V max of the covalently immobilized enzyme on PANCHI-B and PANCHI-C membranes were higher than that on PANCHI-A membrane and chemical-modified membrane with NaOH + EDA. K m values for the different modified membranes are lower for the chitosan-treated membranes. The pH and temperature optimum of immobilized enzyme were determined. The bound enzymes on PANCHI-B and PANCHI-C have higher thermal and storage stability in comparison with AChE on PANCHI-A membrane and free enzyme.