Irregularity of interaction between homologous ω-aminated 1-methoxyalkyl β-d-glucopyranosides and β-d-glucosidase from sweet almond emulsin
✍ Scribed by Jochen Lehmann; Lothar Ziser
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- English
- Weight
- 608 KB
- Volume
- 188
- Category
- Article
- ISSN
- 0008-6215
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✦ Synopsis
A number of homologous (R)-and (S)-1-methoxyalkyl
P-D-glUCO-
pyranosides, carrying at the wend of the C,_, atom alkyl chain either an azido-or an amino group, were used as substrates or competitive inhibitors of p-D-glucosidase from sweet almond emulsin. All azides were cleaved at comparatively high rates, whereas the amines required extremely high enzyme concentrations and incubation times for only partial hydrolysis. Kinetic parameters were determined as far as possible. The influence of the amino group in the glycoside on Ki values or cleavage rates did not change in the expected regular way. Exceptional behavior was found with (R)-3-amino-1-methoxypropyl P-D-glucopyranoside (4). As compared to its diastereomer and to its smaller or larger homologues, compound 4 had a much higher affinity to the enzyme and was almost totally resistant to enzymecatalyzed cleavage. Considering a likely three-dimensional structure of the enzymebound glycoside, a certain spatial orientation of interacting groups in the active site is discussed.