Both Chemical and Non-Chemical Steps Limit the Catalytic Efficiency of Family 4 Glycoside Hydrolases
| العنوان: | Both Chemical and Non-Chemical Steps Limit the Catalytic Efficiency of Family 4 Glycoside Hydrolases |
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| المؤلفون: | Fahimeh S. Shidmoossavee, Saeideh Shamsi Kazem Abadi, Chloe A. N. Gerak, Natalia Sannikova, Andrew J. Bennet, Dustin T. King, Andrew R. Lewis |
| المصدر: | Biochemistry. 57:3378-3386 |
| بيانات النشر: | American Chemical Society (ACS), 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | 0301 basic medicine, Glycoside Hydrolases, Stereochemistry, Molecular Conformation, Biochemistry, Cofactor, 03 medical and health sciences, Hydrolysis, Kinetic isotope effect, Glycoside hydrolase, biology, Chemistry, Leaving group, Galactose, NAD, biology.organism_classification, Citrobacter freundii, Kinetics, 030104 developmental biology, Deuterium, 13. Climate action, Biocatalysis, biology.protein, NAD+ kinase |
| الوصف: | The glycoside hydrolase family 4 (GH4) α-galactosidase from Citrobacter freundii (MelA) catalyzes the hydrolysis of fluoro-substituted phenyl α-d-galactopyranosides by utilizing two cofactors, NAD+ and a metal cation, under reducing conditions. In order to refine the mechanistic understanding of this GH4 enzyme, leaving group effects were measured with various metal cations. The derived βlg value on V/K for strontium activation is indistinguishable from zero (0.05 ± 0.12). Deuterium kinetic isotope effects (KIEs) were measured for the activated substrates 2-fluorophenyl and 4-fluorophenyl α-d-galactopyranosides in the presence of Sr2+, Y3+, and Mn2+, where the isotopic substitution was on the carbohydrate at C-2 and/or C-3. To determine the contributing factors to the virtual transition state (TS) on which the KIEs report, kinetic isotope effects on isotope effects were measured on these KIEs using doubly deuterated substrates. The measured DV/K KIEs for MelA-catalyzed hydrolysis of 2-fluorophenyl α-d-gal... |
| تدمد: | 1520-4995 0006-2960 |
| DOI: | 10.1021/acs.biochem.8b00117 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4e5cc0b371c3bfccc5851ee6ab8d4997 https://doi.org/10.1021/acs.biochem.8b00117 |
| رقم الانضمام: | edsair.doi.dedup.....4e5cc0b371c3bfccc5851ee6ab8d4997 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15204995 00062960 |
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| DOI: | 10.1021/acs.biochem.8b00117 |