Cyclodextrin glucanotransferase (EC 2.4.1.19) from the alkaliphilic Bacillus sp. G-825-6 converts starch mainly to c-cyclodextrin (CD8). A combination of error-prone PCR and DNA shuffling was used to obtain variants of this enzyme with higher product specificity for CD8 and a broad pH activity range. The variant S54 with seven amino acid substitutions showed a 1.2-fold increase in CD8-synthesizing activity and the product ratio of CD7:CD8 was shifted to 1:7 compared to 1:3 of
the wild-type enzyme. Nine amino acid substitutions of the cyclodextrin glucanotransferase were performed to generate the variant S35 active in a pH range 4.0–10.0. Compared to the wild-type enzyme which is inactive below pH 6.0, S35 retained 70% of its CD8-synthesizing activity at pH 4.0.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa.de:bsz:15-qucosa-172353 |
| Date | 29 June 2015 |
| Creators | Melzer, Susanne, Sonnendecker, Christian, Föllner, Christina, Zimmermann, Wolfgang |
| Contributors | Universität Leipzig, Institut für Biochemie, Elsevier, |
| Publisher | Universitätsbibliothek Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:article |
| Format | application/pdf |
| Source | FEBS Open Bio 2015, 5, S. 528–534 |
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