Determination of the molecular weights of ribonuclease isozymes in a cell-free crude extract of Dictyostelium discoideum, by activity-staining of gels after SDS-PAGE

Comp Biochem Physiol B. 1992 Jun;102(2):343-7. doi: 10.1016/0305-0491(92)90132-b.


1. In a previous report we described three isozymes of intracellular ribonuclease in Dictyostelium discoideum, which were found in vegetative cells. Here we report that the molecular weights of the three isozymes from vegetative cells. 2. They are 14.3 kDa, 60 kDa and 80 kDa, as determined by activity-staining of gels after SDS-PAGE. 3. For renaturation of ribonucleolytic activity from D. discoideum cells after SDS-PAGE, fibrinogen-containing gels were used and gels were washed in aqueous isopropanol to remove detergent. Results of studies by this method suggest that each of these isozymes is composed of only a single polypeptide. 4. The effect of the buffer system on this technique is discussed.

MeSH terms

  • Animals
  • Cell-Free System
  • Dictyostelium / enzymology*
  • Electrophoresis, Polyacrylamide Gel
  • Isoenzymes / chemistry*
  • Molecular Weight
  • Protein Denaturation
  • Ribonucleases / chemistry*
  • Staining and Labeling


  • Isoenzymes
  • Ribonucleases