| http://purl.uniprot.org/citations/18847231 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/18847231 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/18847231 | http://www.w3.org/2000/01/rdf-schema#comment | "Mammalian breast milk contains an array of proteins and other nutrients essential for the development of the newborn. In human milk, the caseins (alpha S1, beta and kappa) are a major class of proteins; however, the dynamic range of concentrations in which the various isoforms of each casein exist presents challenges in their characterization. To study human milk casein phosphoforms, we applied traditional two-dimensional polyacrylamide gel electrophoretic (2-DE) separation combined with matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) tandem mass spectroscopic analysis. The abundant beta-casein was resolved as a train of 6 spots differing in phosphorylation level with 0-5 phosphates attached. To study the less abundant alpha S1-casein, a cysteine-tagging enrichment treatment was used prior to 2-DE. A train of 9 spots with 4.4 < p I < 5.3 were identified as alpha S1-casein. This included five previously uncharacterized phosphoforms with up to 8 phosphate groups located in two serine-rich tryptic phosphopeptides ( (27)L-R (51), (69)N-K (98)) consistent with alpha-caseins from various ruminant species. MS/MS analysis of the phosphopeptides released by tryptic digestion enabled identification of the residue-specific order of phosphorylation among the 6 beta-casein and 9 alpha S1-casein phosphoforms. Deamidation of N (47) of alpha S1-casein was also a feature of the MS analysis. This study represents the first comprehensive analysis of the human casein phosphoproteome and reveals a much higher level of phosphorylation than previously recognized. It also highlights the advantages of 2-DE for examining the global pattern of protein phosphoforms and the limitations of attempting to estimate phosphorylation site occupancies from "bottom-up" studies."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.org/dc/terms/identifier | "doi:10.1021/pr800387s"xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.org/dc/terms/identifier | "doi:10.1021/pr800387s"xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/author | "Alewood P.F."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/author | "Alewood P.F."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/author | "Poth A.G."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/author | "Poth A.G."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/author | "Deeth H.C."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/author | "Deeth H.C."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/author | "Holland J.W."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/author | "Holland J.W."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/date | "2008"xsd:gYear |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/date | "2008"xsd:gYear |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/name | "J. Proteome Res."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/name | "J. Proteome Res."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/pages | "5017-5027"xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/pages | "5017-5027"xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/title | "Analysis of the human casein phosphoproteome by 2-D electrophoresis and MALDI-TOF/TOF MS reveals new phosphoforms."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/title | "Analysis of the human casein phosphoproteome by 2-D electrophoresis and MALDI-TOF/TOF MS reveals new phosphoforms."xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/volume | "7"xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://purl.uniprot.org/core/volume | "7"xsd:string |
| http://purl.uniprot.org/citations/18847231 | http://www.w3.org/2004/02/skos/core#exactMatch | http://purl.uniprot.org/pubmed/18847231 |
| http://purl.uniprot.org/citations/18847231 | http://www.w3.org/2004/02/skos/core#exactMatch | http://purl.uniprot.org/pubmed/18847231 |