| Autor: |
Pavlína Nekvasilová, Natalia Kulik, Michael Kotik, Lucie Petrásková, Kristýna Slámová, Vladimír Křen, Pavla Bojarová |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
International Journal of Molecular Sciences; Volume 23; Issue 20; Pages: 12456 |
| ISSN: |
1422-0067 |
| DOI: |
10.3390/ijms232012456 |
| Popis: |
β-N-Acetylhexosaminidase from Talaromyces flavus (TfHex; EC 3.2.1.52) is an exo-glycosidase with dual activity for cleaving N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) units from carbohydrates. By targeting a mutation hotspot of the active site residue Glu332, we prepared a library of ten mutant variants with their substrate specificity significantly shifted towards GlcNAcase activity. Suitable mutations were identified by in silico methods. We optimized a microtiter plate screening method in the yeast Pichia pastoris expression system, which is required for the correct folding of tetrameric fungal β-N-acetylhexosaminidases. While the wild-type TfHex is promiscuous with its GalNAcase/GlcNAcase activity ratio of 1.2, the best single mutant variant Glu332His featured an 8-fold increase in selectivity toward GlcNAc compared with the wild-type. Several prepared variants, in particular Glu332Thr TfHex, had significantly stronger transglycosylation capabilities than the wild-type, affording longer chitooligomers – they behaved like transglycosidases. This study demonstrates the potential of mutagenesis to alter the substrate specificity of glycosidases. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
|
Nepřihlášeným uživatelům se plný text nezobrazuje |
K zobrazení výsledku je třeba se přihlásit.
|
