Purification and some particular kinetic properties of rat spleen cytosolic deoxynucleotidase.
1. Rat spleen cytosolic deoxynucleotidase was purified 40,000-fold to almost homogeneity and had a specific activity of 3000 mumols/min per mg. 2. Molecular mass of the native enzyme was 45 kDa. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis indicated that the native enzyme comprises two identical 27-kDa subunits. 3. Specific enzyme activity increases with increasing concentration of enzyme protein and approaches a plateau at high enzyme concentrations. 4. Enzyme activity increases gradually and nonlinearly with increasing concentration of enzyme in the low concentration range. Above a certain concentration the increase attains a maximal and constant slope. 5. The kinetic properties can be explained by assuming dissociation of the enzyme into subunits with low or no activity.
Fritzson
P
P
Institute of Medical Biochemistry, University of Oslo, Norway.
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D007700:Kinetics; D008970:Molecular Weight; D009708:Nucleotidases / Q000302:isolation & purification* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000201:enzymology*
D009708:Nucleotidases; C028331:deoxynucleotidase