title: Assessing the extent of bone degradation using glutamine deamidation in collagen.
abstract: Collagen peptides are analyzed using a low-cost, high-throughput method for assessing deamidation using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). For each chosen peptide, the theoretical distribution is calculated and the measured distribution for each sample compared with this to determine the extent of glutamine deamidation. The deamidation of glutamine (Q) to glutamic acid (E) results in a mass shift of +0.984 Da. Thus, from the resolution of our data, the second peak in the isotope distribution for a peptide containing one glutamine residue coincides with the first peak of the isotope distribution for the peptide in which the residue is deamidated. A genetic algorithm is used to determine the extent of deamidation that gives the best fit to the measured distribution. The method can be extended to peptides containing more than one glutamine residue. The extent of protein degradation assessed in this way could be used, for example, to assess the damage of collagen, and screen samples for radiocarbon dating and DNA analysis.
authors.affiliation: Department of Mathematics, University of York, York YO10 5YW, UK. julie.wilson@york.ac.uk
authors.forename: Julie
authors.initials: J
authors.lastname: Wilson
authors.forename: Nienke L
authors.initials: NL
authors.lastname: van Doorn
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Collins
mesh_terms: D000595:Amino Acid Sequence; D001842:Bone and Bones / Q000378:metabolism*; D003094:Collagen / Q000737:chemistry* / Q000378:metabolism*; D003641:Deamination; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D010446:Peptide Fragments; D005973:Glutamine; D003094:Collagen