Association of steroid sulfatase with one of the arylsulfatase C isozymes in human fibroblasts.
When arylsulfatase C, a microsomal membrane-bound enzyme, is assayed with its natural substrates, the 3-beta-hydroxysteroid sulfates, it is also known as steroid sulfatase. Whether arylsulfatase C and steroid sulfatase are identical enzymes or not, however, has long been disputed. We now report that two electrophoretic variants of arylsulfatase C occur in normal human fibroblasts: one has a single anodic band of activity, "s," and the other has an additional faster migrating band, "f". The two types, s and "f + s", occur in cells from either sex. When fibroblast strains with the f + s forms of arylsulfatase C were cloned, two types of primary clones were always obtained: s and f + s. A single f band was never seen. When these primary clones were subcloned, however, the arylsulfatase C phenotype remained unchanged: primary s clones gave rise to s subclones and f + s clones to f + s subclones only. Therefore, these forms were clonal in origin and demonstrated a novel inheritance pattern in human cultured cells. The appearance of increasing amounts of the f band was correlated with up to 4-fold increase of arylsulfatase C activity, whereas the steroid sulfatase activity remained constant, thus demonstrating that arylsulfatase C was not identical with steroid sulfatase activity. Polyclonal antibodies raised against the s form immunoprecipitated activities of the s form of arylsulfatase C and steroid sulfatase but not the f form of arylsulfatase C. Therefore, we conclude that only the s form of arylsulfatase C is immunologically related to steroid sulfatase so that arylsulfatase C per se is not necessarily identical with steroid sulfatase. In addition, a novel form of genetic heterogeneity of isozymes in human fibroblasts is demonstrated.
Chang
P L
PL
Varey
P A
PA
Rosa
N E
NE
Ameen
M
M
Davidson
R G
RG
D000936:Antigen-Antibody Complex; D001192:Arylsulfatases / Q000302:isolation & purification / Q000378:metabolism*; D002478:Cells, Cultured; D002999:Clone Cells / Q000201:enzymology; D005260:Female; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D007106:Immune Sera; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D012867:Skin / Q000201:enzymology; D043266:Steryl-Sulfatase; D013429:Sulfatases / Q000302:isolation & purification / Q000378:metabolism*
D000936:Antigen-Antibody Complex; D007106:Immune Sera; D007527:Isoenzymes; D013429:Sulfatases; D001192:Arylsulfatases; D043266:Steryl-Sulfatase