A comparative study of brain arylsulfatases B1 and B2: the difference between the two forms in rates of uptake by multiple sulfatase deficient (MSD) disorder fibroblasts.

Arylsulfatases B1 and B2 isolated from human brain were introduced into neonatal type MSD fibroblast culture. Arylsulfatase B2 was linearly taken up into MSD fibroblasts with respect to time and the dose of enzyme, whereas arylsulfatase B1 enzyme was practically not taken up into cells. Uptake of arylsulfatase B2 was inhibited in the presence of mannose 6-phosphate. These data suggest that the biological functional difference between arylsulfatases B1 and B2 is due to the presence of a phosphorylated residue acting as a recognition marker on one of the enzymes.