title: Chitin biosynthesis in protoplasts and subcellular fractions of Aspergillus fumigatus.
abstract: The biosynthesis of chitin has been obtained in broken mycelia and protoplasts of the fungus Aspergillus fumigatus. The specific activity of chitin synthase (EC 2.4.1.16) in a membrane preparation from protoplasts derived from the hyphal tips of A. fumigatus was 26.8-fold greater than that of the chitin synthase in broken mycelia, indicating that the active chitin synthase is located primarily in a membrane-bound site at the hyphal tip. Polyoxin D was a potent competitive inhibitor of the enzyme, having Ki 5.2 +/- 0.8 micron with respect to the natural substrate UDP-N-acetyl-D-glucosamine, which has Km 1.58 mM.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001232:Aspergillus fumigatus / Q000201:enzymology / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology; D002686:Chitin / Q000096:biosynthesis*; D002687:Chitin Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D009705:Nucleosides / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D011523:Protoplasts / Q000201:enzymology / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D009705:Nucleosides; D010455:Peptides; D002686:Chitin; D002687:Chitin Synthase