Identification of Specific Peptides in Digested Gelatins by High Performance Liquid Chromatography/Mass Spectrometry

Sequence analysis of bovine and porcine collagen type I indicates that some partial sequences are specific for bovine or porcine collagen type I, which can be used as marker peptides for gelatin differentiation. Bovine and porcine gelatins were digested with trypsin. The digest mixtures were analyzed with high performance liquid chromatography/mass spectrometry ( HPLC/MS ). Marker peptides were identified by the method of peptide sequence tag. The results indicated that the bovine and porcine. gelatins could be differentiated according to the sequences of marker peptides. Further analysis indicated that some prolines in the marker peptides were hydroxylated, which should be taken into account to increase the confidence in peptide identification. The relative abundance of marker peptides in gelatin of different molecular weight range was also investigated. The results indicate that identification of the marker peptides in the digested gelatins by HPLC/MS is an alternative method for differentiation of bovine and porcine gelatins.