Multi-Point Immobilization of Penicillin G Acylase on Silica-Glyoxyl: Influence of the Degree of Activation

Abstract

Multi-point immobilization, by an intense enzyme-support attachment, may increase the operational stability of a biocatalyst. Penicillin G acylase has many applications, from the hydrolysis of penicillin G (production of 6-aminopenicillanic acid) to the synthesis of semi-synthetic antibiotics. The application of this technique in macroporous silica involves support activation with 3-glycidyloxypropyltrimetoxysilane, followed by acidic hydrolysis and oxidation with sodium periodate. The aldehyde-glyoxyl groups so formed react subsequently with the enzyme. The degree of activation affects the yield and stability of the enzyme immobilization. For 20 UI of enzyme, the results show an immobilization yield equal to 100%, whenever there are more than 140 <FONT FACE="Symbol">m</FONT> Eq of aldehyde groups/g of dry silica. The immobilized enzyme half-life is 23 minutes at 60ºC; under the same conditions, the soluble enzyme has no residual activity after a few minutes. The increase in the degree of activation does not lead to higher stability, which indicates the negative influence of sub-products, formed during the activation of the suppor

Delaminated Zeolites: An Efficient Support for Enzymes

“…[14] The results shown in Figure 5 indicate that the stability of the enzyme is substantially improved when it is covalently bonded to the surface of the G-ITQ-6, in such a way that, while the activity of the unsupported enzyme was zero after 6 h of incubation, the remaining activity of the supported enzyme was close to 90 %. The enhancement of enzyme stability suggests a multipoint grafting between the enzyme and the support, perhaps involving the most reactive groups of the protein surface.…”

Methods and Supports for Immobilization and Stabilization of Cyclomaltodextrin Glucanotransferase from Thermoanaerobacter

“…The glyoxyl-silica support with high concentration of aldehyde groups was prepared as described by Pereira et al [11] with slightly modifications.…”

“…For example, Pereira et al [11] immobilized Penicillin G acylase on glyoxyl-silica (140 μmol of aldehyde groups per gram of silica) and obtained 100% activity recovery. Silica is an adequate support because it is inexpensive and easily regenerated.…”

“…Finally, the aldehyde groups are formed by oxidation with sodium periodate. The degree of activation of the support (i.e., the number of aldehyde groups on the silica surface) is related to the intensity of the multi-interaction between enzyme and support [11].…”

Immobilization of Candida antarctica lipase B by covalent attachment to green coconut fiber

“…It was cut and sieved to obtain particles between 32 and 35 mesh, washed with distilled water, and dried at 60°C before being used as an immobilization matrix. Before immobilization, activated fiber was dried under vacuum (18). The support was first protonated with nitric acid (10%, [v/v]) under low stirring for 30 min at 30°C.…”