Tyrosine O-sulfate ester in proteoglycans.
Tyrosine O-sulfate residues were detected in the protein core of sulfated proteoglycans. When cultured skin fibroblasts and arterial smooth muscle cells were incubated in the presence of [35S]sulfate, dermatan sulfate proteoglycan and chondroitin sulfate proteoglycan isolated from the culture medium contained tyrosine [35S]sulfate ester which accounted for 0.03%-0.82% of total 35S radioactivity incorporated into the sulfated proteoglycans. This corresponds to a tyrosine sulfation of every second (fibroblasts) and every 10th (smooth muscle cells) dermatan sulfate proteoglycan molecule. [3H]Tyrosine labeling of fibroblast dermatan sulfate proteoglycan gave a similar stoichiometry. However, the relative proportion of tyrosine [35S]sulfate in proteoglycans from arterial tissue was about 10 times higher than in that from cultured arterial cells. Pulse chase experiments with [35S]sulfate revealed that tyrosine sulfation is a late event in the biosynthesis of dermatan sulfate proteoglycan from fibroblasts and occurs immediately prior to secretion. Cultured skin fibroblasts from a patient with a progeroid variant (Kresse et al. 1987, Am. J. Hum. Gen. 41, 436-453) which exhibit a partial deficiency to synthesize dermatan sulfate proteoglycan were shown to form and to secrete a tyrosine-sulfated but glycosaminoglycan-free protein core, thus confirming a selective and independent [35S]sulfate labeling of the protein core.
Rauch
U
U
Institut für Physiologische Chemie und Pathobiochemie, Universität Münster.
Hollmann
J
J
Schmidt
A
A
Buddecke
E
E
Kresse
H
H
D000818:Animals; D001158:Arteries / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D002807:Chondroitin / Q000031:analogs & derivatives*; D011508:Chondroitin Sulfate Proteoglycans / Q000096:biosynthesis* / Q000302:isolation & purification; D003871:Dermatan Sulfate / Q000096:biosynthesis* / Q000302:isolation & purification; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D011509:Proteoglycans / Q000096:biosynthesis*; D012867:Skin / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D013462:Sulfur Radioisotopes; D014316:Tritium; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism
D011508:Chondroitin Sulfate Proteoglycans; D011509:Proteoglycans; D013431:Sulfates; D013462:Sulfur Radioisotopes; C032649:dermatan sulfate proteoglycan; D014316:Tritium; D003871:Dermatan Sulfate; C005662:tyrosine O-sulfate; D014443:Tyrosine; D002807:Chondroitin