Arylamidase from human renal cancer tissue in comparison with normal kidney and placental enzymes.

Arylamidase (E.C. 3.4.11.2) was solubilized from renal cancer tissues by bromelain treatment, and its properties were compared with those of normal kidney and placental enzymes after partial purification. Their column chromatograms on TEAE-cellulose revealed a slight, but constant difference in the negative charge, namely, in normal kidney, renal cancer tissue, and placental enzymes in increasing order. An electrophoretic study on polyacrylamide gel showed comparable results. On the other hand, when treated with neuraminidase prior to electrophoresis, the renal cancer tissue and kidney enzymes came to have an identical mobility, while the placental enzyme still had a faster mobility than the others. The renal cancer tissue arylamidase was not clearly distinguished from the kidney and placental enzymes with respect to molecular weight, Michaelis constant, pH optimum, heat stability, behavior to divalent cations or chelating agents, susceptibility to urea or amino acids, inhibition by sulfhydryl agents, and immunological properties. These results suggest that renal cancer tissue and kidney enzymes are similar glycoproteins, simply different in sialic acid content, and that these two enzymes are different from the placental enzyme in the structure of the peptide portion and/or carbohydrate portions other than sialic acid residues.