Enzymatic sulfation of mucus glycoprotein in rat submandibular salivary gland.
1. The enzymic activity which catalyzes transfer of sulfate ester group from 3'-phosphoadenosine-5'-phosphosulfate to mucus glycoprotein was found associated with Golgi-rich membrane fraction of rat submandibular salivary gland. 2. Optimum enzyme activity was obtained with 0.5% Triton X-100, 4 mM MgCl2 and 25 mM NaF at a pH of 6.8 using desulfated submandibular salivary mucus glycoprotein. The apparent Km of the enzyme for mucus glycoprotein was 11.1 mg/ml. 3. Alkaline borohydride reductive cleavage of the synthesized 35S-labeled glycoprotein led to the liberation of the label into reduced oligosaccharides. A 75.4% of the label was found incorporated in four oligosaccharides. These were identified in order of abundance as sulfated penta-, tri-, hepta- and nonsaccharides. 4. Based on the results of chemical and enzymatic analyses of the intact and desulfated compounds the pentasaccharide was characterized as SO3H----GlcNAc beta----Gal beta----GlcNAc(NeuAc alpha----)GalNAc-ol and the trisaccharide as SO3H----GlcNAc beta----Gal beta----GalNAc-ol.
Slomiany
B L
BL
Dental Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark 07103-2425.
Murty
V L
VL
Sarosiek
J
J
Slomiany
A
A
D000818:Animals; D002855:Chromatography, Thin Layer; D006023:Glycoproteins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008297:Male; D009093:Mucus / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013363:Submandibular Gland / Q000201:enzymology* / Q000378:metabolism; D013379:Substrate Specificity; D013431:Sulfates / Q000378:metabolism
D006023:Glycoproteins; D013431:Sulfates; C047874:gastric mucus glycoproteins