Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae

Abstract

α-Glucosidase from S. cerevisiae was covalently immobilized onto Sepabeads EC-EA by the glutaraldehyde method. An analysis of the variables controlling the immobilization process is first presented and it is shown that the highest coupling of α-glucosidase occurred within 24 h. Also, a loading of 30 mg/g support proved to be effective, resulting in a rather high activity of around 45 U g -1 with a satisfactory degree of enzyme fixed. Both free and immobilized enzymes were then characterized by determining the activity profile as a function of pH, temperature and thermal stability. The obtained immobilized preparation showed the same optimum pH, but a higher optimum temperature compared with the soluble one. In addition, the immobilized enzyme treated at 45 ºC for 1 h still retained an activity of around 20 %, whereas the free enzyme completely lost its original activity under this condition. In conclusion, the developed immobilization procedure is quite simple, easily reproducible and provides a promising solution for the application of immobilized α-glucosidase.

A Novel α-Glucosidase Inhibitor Protein from the Rhizomes of Zingiber ottensii Valeton

“…The optimal pH for the S. cerevisiae α-glucosidase used was 6.8 (supplier's information sheet). In agreement with this, the optimum pH for baker's yeast (S. cerevisiae) α-glucosidase has been reported to be about pH 6.0 and 5.8-7.0, respectively [31,32]. Thus, at pH at 7.0, the concentration of F50 used (50 μg/ml) might be too limited to overcome the strongest activities of the α-glucosidase enzyme.…”

“…The maximal inhibition at 65°C may, therefore, be regarded as the optimum temperature for this system. The baker's yeast enzyme used in this system had a poor activity at 65°C, in common with other S. cerevisiae-derived α-glucosidases which are reported to have a maximal optima at close 30°C [31], preventing co-incubations of enzyme and inhibitor together. However, that the F50 α-glucosidase inhibitor could be used at a rather high temperature means that α-glucosidases from other sources that are more thermotolerant should be applied in future studies.…”

Study of the covalently immobilized amyloglucosidase on macroporous polymer by mathematical modeling of the pH optima

“…Immobilization is often accompanied by some changes of the conditions for optimum enzymatic activity such as temperature, pH and substrate concentration. 11 Enzymes are usually covalently immobilized on support through their different groups (amino, sulfhydryl, hydroxyl, phenolic ones) that could be essential for their catalytic action. 9 The oriented immobilization of glycoenzymes through their carbohydrate moieties is a very useful technique because enzyme active sites are less likely to be involved in covalent interactions.…”

Development of immobilized systems with penicillin acylase from Esherichia coli for production of semisyntetic penicillins

“…Ovi rezultati ukazuju na neophodnost optimizacije postupka imobilizacije na neki nosač u slučaju svakog pojedinačnog enzima, pa čak i istog enzima različitog mikrobiološkog porekla. Sepabeads EC-EA, redom [216,223]. Isto tako, masa vezane PAC na Sepabeads EC-HA postignuta u ovom radu veća je od vrednosti P g u slučaju lipaze imobilisane na isti nosač koja je iznosila 90,9 mg/g [216].…”

“…Sa ovog aspekta imobilizacija PAC na Sepabeads EC-EP je pogodnija jer nakon imobilizacije dolazi do pomeranja pH optimuma ka alkalnoj sredini. U slučaju imobilizacije -glukozidaze na Sepabeads EC-EA pH optimum imobilisanog i slobodnog enzima je ostao isti dok u slučaju imobilizacije lipaze dolazi do pomeranja optimuma ka baznoj sredini [216,223]. Sa druge strane, PAC imobilisana na Sepabeads EC-HA ima isti pH optimum kao i slobodna PAC, dok je profil nešto uži nego kod slobodnog enzima.…”