A MOLECULAR-WEIGHT STUDY OF ADENOSINE-DEAMINASE

Adenosine deaminase exists in its smallest molecular form (ADA-S) of < 42 kDa in primate and rodent brain, intestine and liver, human erythr ocytes, avian liver and in bovine spleen and intestine. The enzyme exh ibits molecular heterogeneity in monkey and chicken liver and human er ythrocytes. The large form of adenosine deaminase is seen in monkey Li ver and intermediary forms of the enzyme in chicken liver and human er ythrocytes. Large forms of the enzyme predominate in rabbit intestine. Molecular weights of adenosine deaminase molecular forms were determi ned by gel filtration and by non denaturing gel electrophoresis with c onstruction of Ferguson plots. Anomalous migration of the enzyme on SD S-PAGE possibly due to charge, disulfide bonds and proline content, di d not allow for molecular weight determination on denaturing gels.