Separation and analysis of arylsulfatase isoenzymes in body fluids of man

Abstract

Soluble arylsulfatase (EC 3.1.6.1) is present in the body fluids of man in the form of two isoenzymes, arylsulfatase A and B, which reportedly are useful biochemical markers for certain types of malignancy. However, rapid assay of the individual isoenzymes is extremely difficult; procedures based on differential inhibition or activation of the isoenzymes in a mixture yield only semiquantitative results. A feature of these isoenzymes is their inhibition by some common anions (notably phosphate) at physiologic concentrations. The isoenzymes can be separated by anion-exchange chromatography, the B isoenzyme being eluted in the void volume and the A isoenzyme and the anionic inhibitors retarded. Lead is used to sequester phosphate, enabling measurement of A in the salt-eluted fraction. Using this technique, we have found significant elevations of B in the sera of patients with colorectal cancer. The potential of rapid, chromatographic separation coupled with continuous monitoring for arylsulfatase activity is discussed.