Threonine Deaminase from Bacillus subtilis I. PURIFICATION OF THE ENZYME

摘要: Abstract Threonine deaminase (l-threonine hydro-lyase (deaminating), EC 4.2.1.16) has been purified from crude extracts of Bacillus subtilis. The enzyme in and after crystallization yielded substrate saturation curves which were hyperbolic unless the inhibitor, isoleucine, was present. Sigmoid obtained presence isoleucine. In extracts, stabilized phosphate buffer at room temperature by pyridoxal phosphate. Under these conditions, however, cold labile. After treatment with brushite during purification procedure stable. had a molecular weight about 200,000 could be dissociated into half-molecules urea, guanidine, sodium lauryl sulfate. Electron microscopy suggested dimeric structure.