Kinetic Study of Phosphorolysis of Dextrin by Potato Phosphorylase

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Masaru Sakata³  Takashi Kawai²  Hiroshi Ooshima³  Shigeto Kayane¹ 

[1] Reserch & Development Division, Kao Corp.;Processing Development Research Laboratories, Kao Corp.;Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University

关键词: Phosphorylase;    G-1-P;    Dextrin;    Phosphate;    Substrate Inhibition;   

DOI  :  10.1252/jcej.40.441

来源: Maruzen Company Ltd

【 摘 要 】

References(16)Cited-By(3)A lot of physiological activities are expected from glucose-1-phosphate (G-1-P) and its derivatives. From the viewpoint that enzymatic phosphorolysis of dextrin is promising as an industrial production of G-1-P, kinetics of the enzymatic reaction in high concentration of substrate was investigated. Phosphorylase with a specific activity of 22.5 U·mg–1-protein was purified from potato. Linear chain dextrin and branched dextrin were used as substrate. For inorganic phosphate (Pi), a mixture of KH2PO4 and K2HPO4 was used. The initial rate of phosphorolysis was a function of the non-reducing-end concentration of α-1,4-glucan, regardless of the chain length and branch ratio of α-1,4-glucan. The inhibitory effects of both dextrin and phosphate were observed. From these experimental results, a possible kinetic model of the enzymatic reaction under high concentration of substrate was proposed. This model could well explain the experimental data obtained up to 18 mM of non-reducing-end of dextrin and 1000 mM of Pi.

【 授权许可】

Unknown