RESUMEN
Whey and casein proteins representing the first and second halves of the early lactation phase in the common brushtail possum (Trichosurus vulpecula) have been compared by two dimensional gel electrophoresis. Nine components of whey were differentially expressed during early lactation, including proteins identified as cathepsin B, clusterin, late lactation protein, lysozyme, ganglioside M2 activator and neutrophil gelatinase-associated lipocalin. A major novel protein, termed very early lactation protein (VELP), was identified in whey. Partial amino acid sequence data obtained from VELP did not appear to match any other reported protein sequence. VELP was shown to be an acidic glycoprotein of 20-30 kDa which exists as a homodimer. In the casein fraction, kappa-casein appeared to be differentially post-translationally modified during early lactation and fragments of beta-casein were relatively more abundant at the earlier lactation stage.
RESUMEN
Previous investigations of bovine seminal plasma (BSP) have revealed the identities of the three major proteins, BSP-PDC109, BSP-A3 and BSP-30 kDa, which together constitute about half of the total protein, as well as about 30 of the minor proteins. Analyses of BSP by 2-DE have revealed about 250 protein spots, suggesting that much of the BSP proteome remains undescribed. In this study, BSP has been analyzed by 2-D LC-based and SDS-PAGE-based proteomic methods. Ninety-nine proteins were identified, including 49 minor proteins that have not previously been described in seminal plasma of any species.
Asunto(s)
Proteoma/análisis , Proteómica/métodos , Semen/química , Proteínas de Plasma Seminal/química , Animales , Bovinos , Cromatografía Liquida , Bases de Datos Factuales , Bases de Datos de Proteínas , Electroforesis en Gel Bidimensional , Electroforesis en Gel de Poliacrilamida , Masculino , Peso Molecular , Proteínas de Plasma Seminal/metabolismo , Coloración y EtiquetadoRESUMEN
Human colostrum is an important source of protective, nutritional and developmental factors for the newborn. We have investigated the low abundance proteins in the aqueous phase of human colostrum, after depletion of the major proteins secretory IgA, lactoferrin, alpha-lactalbumin and HSA by immunoabsorption, using 2-D LC and gel-based proteomic methods. One hundred and fifty-one proteins were identified, 83 of which have not been previously reported in human colostrum, or milk. This is the first comprehensive proteomic analysis of human colostrum produced during the first 48 h of lactation.