Isoelectric enzyme patterns of leukocyte peroxidase in normal controls and patients with neuronal ceroid-lipofuscinoses.

Using macro- and microanalytical isoelectric focussing techniques for separation of the soluble leukocytic peroxidase (hydrogen donor: p-phenylenediamine) we found 4 main isoenzyme components with pI at 9.6 (9.0), 7.6 (7.5), 6.2 (6.2) and 4.2 (4.7), which exhibited additional heterogeneities. The isoenzymes of the membrane-bound peroxidase displayed a similar pattern. The isoelectric subfractions of peroxidase in controls and patients with late-infantile (Jansky-Bielschowsky), juvenile (Spielmeyer-Sjögren) and adult (Kufs) types of neuronal ceroid-lipofuscinosis did not reveal any significant differences. Based on these findings, a deficiency of an isoenzyme component cannot be held responsible for producing neuronal ceroid-lipofuscinoses, neither in patients with normal nor in patients with reduced total activity of leukocyte peroxidase.