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THE CHARACTERISTICS OF SOYBEAN PHYTASE
Author(s) -
BUCKLE K. A.
Publication year - 1986
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/j.1745-4514.1986.tb00100.x
Subject(s) - phytase , chemistry , phytic acid , fractionation , substrate (aquarium) , chelation , hydrolysis , mole , enzyme , ammonium , chromatography , tris , nuclear chemistry , sodium , sodium fluoride , fluoride , inorganic chemistry , biochemistry , organic chemistry , oceanography , geology
Soybean phytase was extracted with 2% CaCl 2 and partially purified by ammonium sulphate fractionation followed by dialysis in 0.01 M tris‐maleate buffer, pH 6.5. The enzyme showed an optimum pH of 4.8 and optimum temperature of 60°C. The phytase was partially inhibited at high substrate concentration, with an optimum substrate concentration at 20 mM and a K m value of 2.4 × 10 ‐3 M. V max was 0.22 μmole P i liberated/min/mL enzyme. The inactivation and activation energies for the hydrolysis of phytic acid were approximately 47,000 cal/mole and 11,100 cal/mole, respectively. Enzyme activity was inhibited by about 25%, 23% and 22% in the presence of 10 ‐3 M Zn ++ , Cu ++ and Hg ++ , respectively, and was also decreased by about 85% in the presence of 10 ‐1 M N‐ethylmaleimide and sodium fluoride. Reducing and chelating agents at concentrations up to 10 ‐1 M inhibited activity by about 50% and by more than 90%, respectively.