Effect of neuraminidase on the chromatographic behaviour of eleven acid hydrolases from human liver and plasma.

1. The elution profiles of eleven acid hydrolases from human liver and plasma were directly compared using a system whereby a single salt gradient was simultaneously applied to two DEAE-cellulose chromatographic columns. 2. Plasma alpha-L-fucosidase, alpha-mannosidase, alpha-galactosidase and alpha-glucosidase isoenzymes were eluted at higher salt concentrations than the corresponding liver isoenzymes whereasbeta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase, exo-1,4-beta-xylosidase and alpha-L-arabinofuranosidase isoenzymes were eluted at lower salt concentrations. The elution profiles of beta-glucuronidase and acid phosphatase weremore complex. 3. After incubation with neuraminidase most plasma hydrolases were eluted at lower salt concentrations, however the elution patterns of beta-glucosidase, beta-xylosidase and acid phosphatase were not altered. 4. Preincubation with neuraminidase had no effect on the elution profiles of six liver hydrolases whereas the major isoenzymes of alpha-mannosidase, beta-galactosidase and alpha-L-arabinofuranosidase were eluted at markedly lower salt concentrations. Liver alpha-fucosidase and alpha-galactosidase were eluted at slightly lower salt concentrations afterincubation with neuraminidase. 5. The results are discussed in relation to thepathogenesis of Mucolipidosis II (I-cell disease), and the synthesis and packaging of lysosomal enzymes.