Immobilization of proteins on highly activated glyoxyl supports: dramatic increase of the enzyme stability via multipoint immobilization on pre-existing carriers

摘要

The binding of enzymes on carriers with a high degree of activation with glyoxyl groups is an excellent method for improving enzyme stability by multipoint covalent attachment on a pre-existing carrier. Glyoxyl groups are short aliphatic aldehyde groups (Support – O-CH2 – CHO) that can be obtained by periodate oxidation of glyceryl groups (Support –O-CH2-CHOH-CH2OH). The unique features of glyoxyl groups are as follows: a.- The immobilization of enzymes through their amino groups has to occur via multipoint attachment. b.- The glyoxyl groups are stable at pH 10, which allows for the participation of Lys in the immobilization process. c.- The glyoxyl groups are very stable at pH 10, which allows for a long-term incubation between the immobilized enzyme and the activated support to promote a very intense enzyme-support multipoint covalent attachment. Using this protocol, more than 100 industrial enzymes were highly stabilized. In many cases, stabilizations of greater than 1000-fold compared with immobilized derivatives generated by conventional methods were obtained. Although dramatic stabilization was achieved, the immobilized enzymes maintained only 50 to 90 % of the catalytic activity of the corresponding soluble enzyme. Stabilization of industrial enzymes is a key step in immobilization protocols. Enzymes are immobilized for use at industrial scales for a number of reaction cycles.