earticle

영어

Glutamate decarboxylase(GAD) has been purified from several brain tissues and it is generally accepted that the dimeric protein possesses a relative molecular mass of around 110,000. The stochiometry of binding of the cofactor to the protein has not been elucidated, though the presence of non-equivalent binding sites has been postulated to explain the catalytic behavior of the decarboxylase. The substrate L-glutamate, at concentrations slightly higher than Km value, promotes slow inactivation of the decarboxylase. This inactivation process has been attributed to a secondary reaction, i.e. decarboxylation-dependent transamination. Gamma-aminobutyric acid(GABA), a four-carbon non protein amino acid, acts as the major inhibitory neurotransmitter of the central nervous system. Other physiological functions of GABA　are induction of anti-hypertensive, prevention of diabetes, diuretic and tranquilizer effects. GABA is extensively used in pharmaceutical preparations and functional foods. In this study, the optimum temperature, pH, stability and reuse efficiency was studied for immobilized GAD. And For the increase productivity of GABA, investigated buffer concentration and reaction into cation exchange resin. As the results, free enzyme and immobilized enzymes were increased final GABA concentration by changed buffer concentration.