Endogenous human milk Peptide release is greater after preterm birth than term birth
Dallas, D.C. ; Smink, C.J. ; Robinson, R.C. ; Tian, T. ; Guerrero, A. ; Parker, E.A. ; Smilowitz, J.T. ; Hettinga, K.A. ; Underwood, M.A. ; Lebrilla, C.B. ; German, J.B. ; Barile, D. - \ 2015
The Journal of Nutrition 145 (2015)3. - ISSN 0022-3166 - p. 425 - 433.
breast-milk - bioactive peptides - plasmin activity - early lactation - casein - enzyme - proteins - infants - trypsin - carboxypeptidase
Background: Hundreds of naturally occurring milk peptides are present in term human milk. Preterm milk is produced before complete maturation of the mammary gland, which could change milk synthesis and secretion processes within the mammary gland, leading to differences in protein expression and enzymatic activity, thereby resulting in an altered peptide profile. Objective: This study examined differences in peptides present between milk from women delivering at term and women delivering prematurely.
Peptidomic analysis of healthy and subclinically mastitic bovine milk
Guerrero, A. ; Dallas, D.C. ; Contreras, S. ; Bhandari, A. ; Canovas, A. ; Islas-Trejo, A. ; Medrano, J.F. ; Parker, E.A. ; Wang, M. ; Hettinga, K.A. ; Chee, S. ; German, J.B. ; Barile, D. ; Lebrilla, C.B. - \ 2015
International Dairy Journal 46 (2015). - ISSN 0958-6946 - p. 46 - 52.
enzyme inhibitory peptides - globule-membrane proteome - somatic-cell count - casein - proteolysis - hydrolysate - lactation - antibacterial - colostrum - casecidin
A variety of proteases release hundreds of endogenous peptide fragments from intact bovine milk proteins. Mass spectrometry-based peptidomics allows for high throughput sequence assignment of a large number of these peptides. Mastitis is known to result in increased protease activity in the mammary gland. Therefore, we hypothesized that subclinically mastitic milks would contain higher concentrations of released peptides. In this work, milks were sampled from three cows and, for each, one healthy and one subclinically mastitic teat were sampled for milk. Peptides were analyzed by nano-liquid chromatography quadrupole time of flight tandem mass spectrometry and identified with database searching. In total, 682 peptides were identified. The total number of released peptides increased 146% from healthy to subclinically mastitic milks (p <0.05), and the total abundance of released peptides also increased significantly (p <0.05). Bioinformatic analysis of enzyme cleavage revealed increases in activity of cathepsin D and elastase (p <0.05) with subclinical mastitis.
Comprehensive peptidomic and glycomic evaluation reveals that sweet whey permeate from colostrum is a source of milk protein-derived peptides and oligosaccharides
Dallas, D.C. ; Weinborn, V. ; Moura Bell, J.M.L.N. de; Wang, M. ; Parker, E.A. ; Guerrero, A. ; Hettinga, K.A. ; Lebrilla, C.B. ; German, J.B. ; Barile, D. - \ 2014
Food Research International 63 (2014)part B. - ISSN 0963-9969 - p. 203 - 209.
holstein-friesian colostrum - globule-membrane proteome - bovine-milk - mass-spectrometry - peptone fraction - beta-casein - chromatography - proteolysis - components - system
Whey permeate is a co-product obtained when cheese whey is passed through an ultrafiltration membrane to concentrate whey proteins. Whey proteins are retained by the membrane, whereas the low-molecular weight compounds such as lactose, salts, oligosaccharides and peptides pass through the membrane yielding whey permeate. Research shows that bovine milk from healthy cows contains hundreds of naturally occurring peptides – many of which are homologous with known antimicrobial and immunomodulatory peptides – and nearly 50 oligosaccharide compositions (not including structural isomers). As these endogenous peptides and oligosaccharides have low-molecular weight and whey permeate is currently an under-utilized product stream of the dairy industry, we hypothesized that whey permeate may serve as an inexpensive source of naturally occurring functional peptides and oligosaccharides. Laboratory fractionation of endogenous peptides and oligosaccharides from bovine colostrum sweet whey was expanded to pilot-scale. The membrane fractionation methodology used was similar to the methods commonly used industrially to produce whey protein concentrate and whey permeate. Pilot-scale fractionation was compared to laboratory-scale fractionation with regard to the identified peptides and oligosaccharide compositions. Results were interpreted on the basis of whether industrial whey permeate could eventually serve as a source of functional peptides and oligosaccharides. The majority (96%) of peptide sequences and the majority (96%) of oligosaccharide compositions found in the laboratory-scale process were mirrored in the pilot-scale process. Moreover, the pilot-scale process recovered an additional 33 peptides and 1 oligosaccharide not identified from the laboratory-scale extraction. Both laboratory- and pilot-scale processes yielded peptides deriving primarily from the protein ß-casein. The similarity of the laboratory- and pilot-scale's resulting peptide and oligosaccharide profiles demonstrates that whey permeate can serve as an industrial-scale source of bovine milk peptides and oligosaccharides.