| 摘要 |
<p>Aβ-lactam acylase enzyme covalently immobilised on a resin of the polyacrylic type containing from 35 to 650μM of free primary amine groups per gram of resin is prepared by a procedure which comprises: a) modifying a resin of the polyacrylic ester type having a porosity between 50 and 600 angstrom and a particle size of between 1 and 0.05 mm by the aminolysis of the ester groups with an aliphatic diamine having the formula: H2N-(CH2)n-NH2 where n has a value between 2 and 12, in order to obtain a resin having free primary amine functional groups, b) activating the resin as modified in stage a) with an aliphatic dialdehyde in order to obtain a resin having free aldehyde functional groups, c) mixing the resin as activated in stage b) with an aqueous solution ofβ-lactam acylase enzyme buffered to a pH between 7.0 and 8.5, and finally d) recovering the resin with the immobilised enzyme by filtration or settling. The immobilised enzyme can be stabilised by reducing the double bonds of the Schiff base type which form as a result of activation with the dialdehyde using a reducing agent selected from NaBH4 and NaCNBH3. The enzymes immobilised in this way show improved operational stability and are used in a process for the preparation of 6-amino penicillanic acid (6-APA) and 7- amino cefalosporanic acid (7-ACA).</p> |
