Purification of 6-phosphogluconolactonase from bass (Dicentrarchus labrax L.)liver.

The enzyme 6-phosphogluconolactonase (EC 3.1.1.31) is present at high levels in bass liver. The enzyme has been purified 1253-fold with an overall yield of 78% in a procedure involving dye-ligand and gel filtration chromatographies. The purified enzyme which is homogenous by all the usual criteria has a molecular weight of about 30,000. It exhibits a considerably high catalytic efficiency with Kcat/Km of 8.5 x 10(7) M-1.s-1 at 22 degrees C. Its activity illustrates the importance of glucose oxidation via the pentose phosphate pathway relative to glycolysis in this organism.