Louis A I, Fluharty A L
University of California at Los Angeles School of Medicine, Mental Retardation Research Group, Lanterman Developmental Center, Pomona.
Dev Neurosci. 1991;13(1):41-6. doi: 10.1159/000112139.
A purified myelin preparation containing [35S]-labeled cerebroside sulfate (CS) was biosynthesized in developing rat brain and tested as a model of a physiological substrate for CS hydrolysis by arylsulfatase A. Particular attention was directed to the involvement of the CS sulfatase activator protein in facilitating the catabolic process. Although arylsulfatase A alone was incapable of desulfating CS in either purified CS suspensions or the physiological membrane, activator-induced hydrolysis of myelin CS exhibited concentration dependency, pH optimum, and relative insensitivity to salts in a manner similar to purified lipid suspensions. Exogenous protein demonstrated concentration-dependent inhibition. Slower rates of hydrolysis observed for the myelin membrane substrate are proposed to be a consequence of myelin membrane configuration and competition for activator by other lipoidal constituents.
