Phosphorolytic Reaction ofCellvibrio gilvusCellobiose Phosphorylase
| Autor: | Takashi Sasaki, Motomitsu Kitaoka, Hajime Taniguchi |
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| Rok vydání: | 1992 |
| Předmět: |
Chemistry
Stereochemistry Organic Chemistry Sucrose phosphorylase Cellvibrio gilvus Fructose General Medicine Applied Microbiology and Biotechnology Biochemistry Analytical Chemistry chemistry.chemical_compound Cellobiose phosphorylase Ping pong Molecular Biology Equilibrium constant Biotechnology Phosphorolysis |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 56:652-655 |
| ISSN: | 1347-6947 0916-8451 |
| DOI: | 10.1271/bbb.56.652 |
| Popis: | Cellobiose phosphorylase was purified from Cellvibrio gilvus cells by the method reported previously with some modifications, and its kinetic properties were studied in detail. The initial velocity of the synthetic reaction was 1.4 times as fast as that of the phosphorolytic one. The equilibrium constant of the phosphorolysis was 0.32 at 37°C and pH 7.0. No D-[U-(14)C]glucose exchange reaction was observed in the absence of Pi. Kinetic studies on the phosphorolytic reaction showed that the reaction follows an ordered bi bi mechanism. These results make a sharp contrast to those of sucrose phosphorylase, which catalyzes fructose exchange reaction and follows a ping pong bi bi mechanism. Kinetic parameters were calculated as KmA = 2.6 mM, KmB = 0.61mM, and KiA = 6.8 mw (A, D-cellobiose; B, Pi). |
| Databáze: | OpenAIRE |
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