CS256856B1 - A method for producing inorganic carriers for immobilizing enzymes - Google Patents

Abstract

A method for producing inorganic carriers for immobilizing enzymes by reacting glutaraldehyde with a surface-bound amino group, wherein the reacting amino group is a 3-aminopropyl group chemically bonded to a porous or non-porous ceramic carrier that has been previously exposed to hydrochloric, hydrobromic, or hydrofluoric acid. These carriers are suitable for immobilizing enzymes and other biologically active substances.

Description

The invention relates to a process for the production of inorganic carriers for the immobilization of enzymes.

For many enzymatic reactions, it is useful to immobilize the enzyme by binding to a carrier. In addition to the more commonly used organic carriers, inorganic carriers functionalized by suitable groups have recently been employed (eg, RA Messing: Immobilized enzymes for industrial reactors, Academic Press, New York 1975; M. Lynn: Biomaterial supports, Chim. Ind., Gen. Chim 106,601 (1973), H. H. Weetel, Methods in Enzymology 44, 135 (1976)). Most of the inorganic carriers, however, were very expensive because they used special porous glasses or modified silica modifications. However, the compounds according to the invention do not have this disadvantage since they are based on stable and readily available porous and non-porous ceramic materials.

SUMMARY OF THE INVENTION The present invention provides a process for the preparation of inorganic supports for the immobilization of enzymes resulting from the reaction of an amino group with glutaraldehyde, using a 3-aminopropyl group bound to a porous or non-porous ceramic support exposed to hydrochloric, hydrobromic or hydrofluoric acid.

The starting reactants for the carriers thus prepared are readily accessible since glutaraldehyde is a conventional commercial product, usually supplied as a 25% aqueous solution, and ceramic materials functionalized with a chemically bonded 3-aminopropyl group can be readily prepared by reacting the ceramic carrier with alkoxysilyl-substituted propylamine.

Although other temperatures may be used, it is preferable to carry out the actual reaction of glutaraldehyde with the amino group at temperatures of 15 to 35 ° C, it is also preferable to use a buffered aqueous solution having a pH of 5 to 8.0. Although the ratio of glutaraldehyde to amino groups is governed by the stoichiometry of the reaction, it is preferable to use a multiple excess of glutaraldehyde to accelerate and achieve high conversions. With this arrangement, the usual reaction time ranges from several hours to several tens of hours.

After completion of the reaction, the conditioned support is separated from the unreacted glutaraldehyde solution, for which filtration or decantation may advantageously be used and washed with water or buffer.

While the carrier can be dried, it is usually neither necessary nor expedient, and the wet carrier can be directly used to immobilize the enzymes.

The following examples characterize the inorganic carriers of the invention without limiting or limiting it.

Example 1 g of porous earthenware (Lachema Brno), which was first treated with hydrochloric acid according to U.S. Pat. 254 289 and then 3-aminopropyltrimethoxysilane containing 1.1 µmol of chemically bonded aminopropyl groups was suspended in 200 ml buffer pH 7.0 and 50 ml of a 25% glutaraldehyde solution was added and the mixture was stirred with stirring The treated carrier is then separated and washed with 2x200 ml buffer pH 6.0. In the carrier thus prepared, it was as described in J. Biol. Chem.

_2

195, 19 (1952) found a concentration of aldehyde groups of 0.5 µmol. 9.9 g of treated carrier were obtained.

Example 2

Example 1 was repeated except that ceramic beads pretreated with a mixture of hydrobromic acid and hydrofluoric acid according to U.S. Pat. No. 254,289 and their surface concentration of aminopropyl groups after reaction with (3-aminopropyl) -2 methyldimethoxysilane was 1.2 µmol. 10 g of a carrier having a surface concentration of aldehyde groups of 0.6 µmol was obtained

SUBJECT OF THE INVENTION

Claims (1)

SUBJECT OF THE INVENTION Process for the preparation of inorganic supports for the immobilization of enzymes by reaction of glutaraldehyde with a surface-bound amino group, characterized in that a 3-aminopropyl group chemically bonded to a porous or non-porous ceramic carrier exposed to hydrochloric, hydrobromic or hydrofluoric acid is used.