[Biosynthesis of glycoproteins in pulmonary parenchyma. II. Galactosyltransferase activity in pneumocyte subcellular fractions].
A soluble galactosyltransferase exists in the cell sap of the alveolar cells of the lung. The optimal conditions of galactosyltransferase are: pH 6, 20 DEGREES C, 10 mM Mn2+, 1 mM Mg2+. Michaelis constant for substrate UDP-galactose is 390 nM. By electrofocusing on Ampholine column, galactosyltransferase appears in a unique peak, at pHi 4.8. The parameters of the purified enzyme are the same as that of the crude enzyme. UDP is a noncompetitive inhibitor for the purified enzyme.
D000818:Animals; D004789:Enzyme Activation; D005700:Galactosyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008168:Lung / Q000166:cytology / Q000201:enzymology*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008345:Manganese / Q000494:pharmacology; D051381:Rats; D013347:Subcellular Fractions / Q000201:enzymology; D013696:Temperature
D008345:Manganese; D005700:Galactosyltransferases; D008274:Magnesium
Biosynthèse des glycoprotéines dans le parenchyme pulmonaire. II. Activité galactosyltransférase dans les fractions subcellulaires des pneumocytes