Uridine – Cytidine Kinase from Foetal and Adult Rat Liver

Abstract

Partial purification of uridine-cytidine kinase (EC 2.7.1.48) from fetal rat liver by chromatography on DEAE-cellulose gives 2 active fractions. The 1st in order of elution was identified as a form specific for fetal liver. It was purified 300-fold. The 2nd fraction was common to fetal, and adult rat liver and spleen and was purified 20-fold. The fetal fraction of the enzyme was heat-sensitive and protected against inactivation by .**GRAPHIC**. anions. The 2 isolated forms have different apparent Km for uridine, respectively, 410 .mu.M for the fetal form and 52 .mu.M for the adult form.