PARTIAL PURIFICATION OF THYROID PEROXIDASE TPO FROM BLOOD SERUM AND STUDY IT'S KINETIC PROPERTIES AND MOLECULAR WEIGHT

This study was done to partially purification of thyroid peroxidase TPO from blood serum using Gel filtration technique, by using Sephadex G100 gel. A single peak in fraction four has been obtained, and the degree of purification (4.28) fold, enzyme yield (25.5%) and specific activity (0.00036 ng/mg). Kinetics studies for the partial purified enzyme were carried out which showed optimal concentration of substrate which was (0.1ng/ml), Michael's - Menten constant (Km=4 mM) and maximum velocity (Vmax=0.0435 IU/L), while optimum Temperature was (37 C°) and optimum pH was (7.4). The molecular weight of the partial purified enzyme has been determined by gel electrophoresis method, in presence of polyacrylamide gel and sodium dodecyl sulphate (SDS-PAGE) which showed that the approximated molecular weight was (31.5 kD).