Steady-state inhibitory kinetic studies on almond .BETA.-glucosidase-catalyzed reaction - Binding sites of monosaccharides
| Autor: | Takako Hotta, Mako Sugiura, Akiyoshi Tanaka, Yasuyuki Ishihara, Hiroshi Kurata |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
chemistry.chemical_classification
biology Stereochemistry Active site Mannose General Biochemistry Genetics and Molecular Biology Fucose chemistry.chemical_compound Non-competitive inhibition chemistry Glucosamine Galactose Galactosamine biology.protein Monosaccharide General Agricultural and Biological Sciences |
| Zdroj: | Agricultural and Biological Chemistry. 53:1401-1405 |
| ISSN: | 1881-1280 0002-1369 |
| Popis: | Steady-state inhibitory kinetic studies on almond β-glucosidase-catalyzed reactions were done to elucidate the binding subsite of several monosaccharides on this enzyme.Glucono-1,5-Iactone (a transition-state analog), glucose, 2-deoxy glucose, fucose, and methyl α-glucoside showed mixed-type inhibition, but galactose, galactosamine, mannose, N-acetyl glucosamine, and glucosamine showed pure competitive inhibition on the hydrolysis of P-nitrophenyl β-glucoside.These results are reasonably accounted for by assuming that the former monosaccharides (the mixed type inhibitors) bind to subsite 1 (the nonreducing-end side subsite to which the nonreducing-end glucose residue of a substrate binds in a productive binding mode), and that the latter (the competitive inhibitors) bind to subsite 2, the adjacent subsite to subsite 1.The binding affinity ( — ΔG°) of glucono-1,5-lactone (— ΔG° = 6.7 kcal mol 1 at pH 5.0, 25°C) was significantly greater than those of the others (0.3 ~ 1.6 kcal mol-1). |
| Databáze: | OpenAIRE |
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