Presence of activator proteins for the enzymic hydrolysis of G(M1) and G(M2) gangliosides in normal human urine

Normal human urine has been found to contain activator proteins that stimulate the enzymic hydrolysis of G(M1) and G(M2) gangliosides. These two activators were partially purified by Sephadex G-200 filtration and DEAE-Sephadex A-50 chromatography. The presence of these two activators was assayed by demonstrating the stimulation of the in vitro hydrolysis of G(M1) and G(M2) gangliosides. As litle as 50 ml of urine is sufficient to detect the presence of these two activators. The crude activator preparation from normal urine was also found to stimulate the hydrolysis of galactosylceramide sulfate by arylsulfatase A.