title: Gel-free shotgun proteomic analysis of human milk.
abstract: The composition of milk has adapted during the evolution of the species to fulfill the specific nutritional needs of the offspring. Currently, it is widely recognized that milk benefits go beyond mere nutrition and serve as a source of a number of functional components to the newborn, particularly host defense effectors. However, the human milk proteome description is still incomplete, primarily because the detection of low-abundance proteins remains challenging. To overcome the limitations of the classical electrophoresis-based approach, previously separated milk fat globule membrane (MFGM) and whey protein fractions were analyzed by nanoflow-high performance liquid chromatography (HPLC)/Fourier Transform-Ion Cyclotron Resonance (FT-ICR) mass spectrometry (MS). This shotgun strategy showed an as yet unmatched potential to profile low-abundance proteins in human milk. Proteins associated with 301 different gene products were identified, some of which could be clustered into subsets of protein isoforms, thus providing one of the largest protein inventories of human milk. The identified proteins, which were derived from multiple metabolic pathways, are involved in different physiological functions, such as membrane trafficking, cell signaling, fat metabolism and transport, metabolite delivery, protein synthesis/proteolysis or folding, and immunity-related actions. Nevertheless, it appears clear from this study that the overall picture of the human milk proteome is still incomplete, although several protein signatures of milk evolution are emerging.
authors.affiliation: Istituto di Scienze dell'Alimentazione-Consiglio Nazionale delle Ricerche (CNR), Via Roma 64, 83100 Avellino, Italy. picariello@isa.cnr.it
authors.forename: Gianluca
authors.initials: G
authors.lastname: Picariello
authors.forename: Pasquale
authors.initials: P
authors.lastname: Ferranti
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Mamone
authors.forename: Iveta
authors.initials: I
authors.lastname: Klouckova
authors.forename: Yehia
authors.initials: Y
authors.lastname: Mechref
authors.forename: Milos V
authors.initials: MV
authors.lastname: Novotny
authors.forename: Francesco
authors.initials: F
authors.lastname: Addeo
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006017:Glycolipids; D006023:Glycoproteins; D006801:Humans; D066292:Lipid Droplets; D013058:Mass Spectrometry / Q000379:methods; D008894:Milk Proteins / Q000032:analysis*; D008895:Milk, Human / Q000737:chemistry*; D010449:Peptide Mapping / Q000379:methods*; D020543:Proteome / Q000032:analysis; D040901:Proteomics / Q000379:methods*
chemical_list: D006017:Glycolipids; D006023:Glycoproteins; D008894:Milk Proteins; D020543:Proteome; C110367:milk fat globule