CHARACTERISTICS OF THE BINDING BETWEEN THE ENZYME PREPARATION RAPHANUS SATIVUS L. AND NATURAL LAYERED ALUMOSILICA IN THE PRESENCE OF IRON OXIDES

Abstract

IR and X-ray analyses of bentonite modified with magnetite and enzyme established the dependence of enzyme immobilization on the presence of iron oxides. IR studies have proven that the binding of the enzyme to the carrier is adsorption in nature without stable chemical interactions. This type of binding does not significantly affect the change in the structure of the enzyme module. Characte­ristic bands of vibrations of amide groups of proteins were detected at 1637 cm-1 ( ν-vibrations of C=O bonds (amide I)), 713 cm-1 (δ – vibrations of O=C-N in the plane (amide IV)), which can participate in the sorption binding of the enzyme to bentonite and the SiO2 group, which is characterized by a weak connection of the outer part of protein with the formation of a surface structure, which disappears over time due to the diffusion of molecules into the pores of the mineral. Comparison of the basal distances in the samples established the following dependence: 12.43 Å bentonite+ Fe3O4+enz (48 h) > 12.38; Å natural bentoni­te> 12.31; Å bentonite+ Fe3O4+enz (2 hours) > 11.91; Å bentonite+ Fe3O4 , which indicates a high probability of iron compounds entering the interlayer space due to the hydrolysis of magnetite with the formation of Fe-(OH)n bonds and unstable compounds. According to the research results, a scheme of the interaction of the enzyme with modified layered iron aluminosilicate is proposed: 1 – transport of the enzyme to the surface (phase distribution boundaries); 2 – deformation of the enzyme under the action of the surface as a result of a polycondensation reaction with the formation of water molecules; 3 – entry of water molecules into the interlayer space; 4 – hydrolysis of magnetite particles; 5 – extraction of iron hydroxide from the interlayer space due to the formation of aggregates with an enzyme molecule that has a related adsorption center.