β-D -Xylosidase from Penicillium wortmanni: binding and hydrolysis of alkyl and aryl 1-oxygen and 1-thio-β-D -xylopyranosides
| Autor: | Francois Deleyn, Marc Claeyssens, C. K. De Bruyne |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
Steric effects
chemistry.chemical_classification Binding Sites Glycoside Hydrolases biology Stereochemistry Hydrolysis Aryl Penicillium Thio chemistry.chemical_element General Medicine biology.organism_classification Binding Competitive Oxygen Substrate Specificity chemistry.chemical_compound Xylosidases chemistry Thioglycosides Beta-D Allosteric Site Alkyl |
| Zdroj: | Canadian Journal of Biochemistry. 58:5-8 |
| ISSN: | 0008-4018 |
| DOI: | 10.1139/o80-002 |
| Popis: | The influence of the chain length in n-alkyl β-D-xylopyranosides and of the para substituents in aryl β-D-xylopyranosides on the kinetic parameters (Ka, V) for hydrolysis of these substrates by a β-D-xylosidase from Penicillium wortmanni, has been investigated. Binding of the corresponding 1-thio derivatives as competitive inhibitors (Ki) was studied for comparative purposes. For the n-alkyl substrates, a slight dependency of V on the chain length is noted, whereas the aryl β-D-xylopyranosides show nearly constant V values. The influence of the aglycon on Ka and Ki values is complex; for the n-alkyl derivatives the contribution of the hydrophobicity of the aliphatic chain seems predominant, although steric factors cannot be neglected. These results, together with previous observations, can tentatively be interpreted in terms of a double-displacement mechanism. |
| Databáze: | OpenAIRE |
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