Abstract:

“Bottom Up” analysis strategy, combined with HPLC and nanospray Fourier transfrom ion cyclotron resonance mass spectrometry(FT-ICR-MS) technology, was applied to the fragmentation of different proteins separated and purified from human milk. With the high sensitivity and dynamic range of FT-ICR-MS, the detection of different peptide fragmentations in proteins at lowlevels could be fulfilled. Taking advantage of the protein database in the Mascot search engine, the compositions of the major proteins in the fat, whey and pellet parts can be determined efficiently on the basis of complementary relationship of fragmented polypeptides by collisional activated dissociation(CAD) and electron capture dissociation(ECD) techniques. The result shows that keratin, albumin(ALB) protein and lactotransferrin were contained in all the three parts but with different types and quantities, suggesting the nutrition difference among these three parts in human milk.

Key words: human milk, protein, composition