Isolation and biochemical characterization of δ-aminolevulinic acid dehydratase from Streptomyces yokosukanensis ATCC 25520

In this study, δ-aminolevulinic acid dehydratase (ALAD) fromStreptomyces yokosukanensis ATCC 25520, producer of an unusual purineriboside antibiotic called nebularine, was purified and characterized. Purificationprocuders involved with ammonium sulphate precipitation and following gelfiltration techniques by use of Sephacryl S-200. After Gel filtration a 90.76-foldpurification was obtained. According to the data obtained from investigation, theenzyme was found to be a single polypeptide having molecular mass around 34.8kDa. This was determined by SDS-PAGE. Its optimal temperature around 45 ºC,and optimal pH was found to be 8. Some heavy metals inhibited its activity ratioof Pb2+ %61, Mg2+ %26, Co2+ %20, Fe3+ %51, Mn2+ %26, Zn2+ %36. Surprisingly,Ni+2 increased its activity up to 15%. In Lineweaver-Burk plot, Vmax was found as30.3 µmol PBG/h/mg of protein and Km value 1.21 mmol/reaction mixture.Key words: ALAD, enzyme characterization, Streptomycete, Streptomycesyokosukanensis, purification.