- Title
- A novel dimeric exoglucanase (GH5_38)
- Creator
- Mafa, Mpho S, Dirr, Heinrich W, Malgas, Samkelo, Krause, Rui W M, Pletschke, Brett I
- Subject
- To be catalogued
- Date
- 2020
- Type
- text
- Type
- article
- Identifier
- http://hdl.handle.net/10962/193976
- Identifier
- vital:45412
- Identifier
- xlink:href="https://doi.org/10.3390/molecules25030746"
- Description
- An exoglucanase (Exg-D) from the glycoside hydrolase family 5 subfamily 38 (GH5_38) was heterologously expressed and structurally and biochemically characterised at a molecular level for its application in alkyl glycoside synthesis. The purified Exg-D existed in both dimeric and monomeric forms in solution, which showed highest activity on mixed-linked β-glucan (88.0 and 86.7 U/mg protein, respectively) and lichenin (24.5 and 23.7 U/mg protein, respectively). They displayed a broad optimum pH range from 5.5 to 7 and a temperature optimum from 40 to 60 °C. Kinetic studies demonstrated that Exg-D had a higher affinity towards β-glucan, with a Km of 7.9 mg/mL and a kcat of 117.2 s−1, compared to lichenin which had a Km of 21.5 mg/mL and a kcat of 70.0 s−1. The circular dichroism profile of Exg-D showed that its secondary structure consisted of 11% α-helices, 36% β-strands and 53% coils. Exg-D performed transglycosylation using p-nitrophenyl cellobioside as a glycosyl donor and several primary alcohols as acceptors to produce methyl-, ethyl- and propyl-cellobiosides. These products were identified and quantified via thin-layer chromatography (TLC) and liquid chromatography–mass spectrometry (LC-MS). We concluded that Exg-D is a novel and promising oligomeric glycoside hydrolase for the one-step synthesis of alkyl glycosides with more than one monosaccharide unit.
- Format
- computer, online resource, application/pdf, 1 online resource (20 pages), pdf
- Publisher
- MDPI
- Language
- English
- Relation
- Molecules, Mafa, M.S., Dirr, H.W., Malgas, S., Krause, R.W., Rashamuse, K. and Pletschke, B.I., 2020. A novel dimeric exoglucanase (GH5_38): Biochemical and structural characterisation towards its application in alkyl cellobioside synthesis. Molecules, 25(3), p.746, Molecules volume 25 number 3 p. 746 2020 1420-3049
- Rights
- Publisher
- Rights
- Use of this resource is governed by the terms and conditions of the MDPI Open Access Statement (https://www.int-res.com/journals/terms-of-use/)
- Rights
- Open Access
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Krause, Rui Werner Maçedo (Prof)
Pletschke, Brett (Prof)
RU Department of Chemistry
SDG 15. Life On Land
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