title: An efficient method for 15N-labeling of chitin in fungi.
abstract: To permit facile (15)N solid-state NMR (ssNMR) analysis of the degree of acetylation (DA) of chitinous materials in fungi a method for the introduction of a (15)N isotopic label has been developed. Using Penicillium chrysogenum as a model system, a series of (15)N-based media were surveyed for their abilities to support mycelial growth, and a rich medium supplemented with ((15)NH(4))(2)SO(4) supported good growth. Uptake of label into chitin extracted from mycelia grown in the rich ((15)NH(4))(2)SO(4)-based media was monitored by mass spectrometry, with approximately 1 g/L of ((15)NH(4))(2)SO(4) leading to approximately 65% incorporation. The labeled chitin was studied by ssNMR to determine its DA, and the (15)N label permitted measurement of DA to within 0.5% with acquisition times of on the order of half an hour. Similar studies validated the method for DA measurements on chitin from cultures of Aspergillus niger and Mucor rouxii.
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, United Kingdom.
authors.forename: Helen R
authors.initials: HR
authors.lastname: Watson
authors.forename: David C
authors.initials: DC
authors.lastname: Apperley
authors.forename: David P
authors.initials: DP
authors.lastname: Dixon
authors.forename: Robert
authors.initials: R
authors.lastname: Edwards
authors.forename: David R W
authors.initials: DR
authors.lastname: Hodgson
mesh_terms: D000107:Acetylation; D001234:Aspergillus niger / Q000378:metabolism; D002686:Chitin / Q000737:chemistry* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D009089:Mucor / Q000378:metabolism; D009587:Nitrogen Isotopes; D010408:Penicillium chrysogenum / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D009587:Nitrogen Isotopes; D002686:Chitin