Updated project metadata. Col1 from the skins of 4 animals (cow, deer, goat and sheep) were purified, then used mass spectrometry and proteomic techniques to identify lysines that were oxidised, galactosylated, glucosylgalactosylated, or glycated in its ma-ture sequence. We found 18 out of the 38 lysines in collagen type 1α1, (Col1A1) and 7 of the 30 lysines in collagen type 1α2 (Col1A2) were glycosylated. Six of these modifications had not been reported before, and included a lysine involved in cross linking collagen molecules. Mapping the positions of these modifications on the ColA1 and Col1A2 sequences showed they were complimentary and resembled a lock and key arrangement.