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Sample records for milk protein synthesis

  1. Identification of lipid synthesis and secretion proteins in bovine milk.

    PubMed

    Lu, Jing; van Hooijdonk, Toon; Boeren, Sjef; Vervoort, Jacques; Hettinga, Kasper

    2014-02-01

    Lactation physiology is a process that is only partly understood. Proteomics techniques have shown to be useful to help advance the knowledge on lactation physiology in human and rodent species but have not been used as major tools for dairy cows, except for mastitis. In this paper, advanced non-targeted proteomics techniques (Filter aided sample preparation and NanoLC-Orbitrap-MS/MS) were applied to study the milk fat globule membrane and milk serum fraction, resulting in the identification of 246 proteins. Of these, 23 transporters and enzymes were related to lipid synthesis and secretion in mammary gland and their functions are discussed in detail. The identification of these intracellular transporters and enzymes in milk provides a possibility of using milk itself to study lipid synthesis and secretion pathways. This full-scale scan of milk proteins by using non-targeted proteomic analysis helps to reveal the important proteins involved in lipid synthesis and secretion for further examination in targeted studies.

  2. Effects of Whey, Caseinate, or Milk Protein Ingestion on Muscle Protein Synthesis after Exercise.

    PubMed

    Kanda, Atsushi; Nakayama, Kyosuke; Sanbongi, Chiaki; Nagata, Masashi; Ikegami, Shuji; Itoh, Hiroyuki

    2016-06-03

    Whey protein (WP) is characterized as a "fast" protein and caseinate (CA) as a "slow" protein according to their digestion and absorption rates. We hypothesized that co-ingestion of milk proteins (WP and CA) may be effective for prolonging the muscle protein synthesis response compared to either protein alone. We therefore compared the effect of ingesting milk protein (MP) to either WP or CA alone on muscle protein synthesis after exercise in rats. We also compared the effects of these milk-derived proteins to a control, soy protein (SP). Male Sprague-Dawley rats swam for two hours. Immediately after exercise, one of the following four solutions was administered: WP, CA, MP, or SP. Individual rats were euthanized at designated postprandial time points and triceps muscle samples collected for measurement of the protein fractional synthesis rate (FSR). FSR tended to increase in all groups post-ingestion, although the initial peaks of FSR occurred at different times (WP, peak time = 60 min, FSR = 7.76%/day; MP, peak time = 90 min, FSR = 8.34%/day; CA, peak time = 120 min, FSR = 7.85%/day). Milk-derived proteins caused significantly greater increases (p < 0.05) in FSR compared with SP at different times (WP, 60 min; MP, 90 and 120 min; CA, 120 min). Although statistical analysis could not be performed, the calculated the area under the curve (AUC) values for FSR following this trend were: MP, 534.61; CA, 498.22; WP, 473.46; and SP, 406.18. We conclude that ingestion of MP, CA or WP causes the initial peak time in muscle protein synthesis to occur at different times (WP, fast; MP, intermediate; CA, slow) and the dairy proteins have a superior effect on muscle protein synthesis after exercise compared with SP.

  3. Effects of Whey, Caseinate, or Milk Protein Ingestion on Muscle Protein Synthesis after Exercise

    PubMed Central

    Kanda, Atsushi; Nakayama, Kyosuke; Sanbongi, Chiaki; Nagata, Masashi; Ikegami, Shuji; Itoh, Hiroyuki

    2016-01-01

    Whey protein (WP) is characterized as a “fast” protein and caseinate (CA) as a “slow” protein according to their digestion and absorption rates. We hypothesized that co-ingestion of milk proteins (WP and CA) may be effective for prolonging the muscle protein synthesis response compared to either protein alone. We therefore compared the effect of ingesting milk protein (MP) to either WP or CA alone on muscle protein synthesis after exercise in rats. We also compared the effects of these milk-derived proteins to a control, soy protein (SP). Male Sprague-Dawley rats swam for two hours. Immediately after exercise, one of the following four solutions was administered: WP, CA, MP, or SP. Individual rats were euthanized at designated postprandial time points and triceps muscle samples collected for measurement of the protein fractional synthesis rate (FSR). FSR tended to increase in all groups post-ingestion, although the initial peaks of FSR occurred at different times (WP, peak time = 60 min, FSR = 7.76%/day; MP, peak time = 90 min, FSR = 8.34%/day; CA, peak time = 120 min, FSR = 7.85%/day). Milk-derived proteins caused significantly greater increases (p < 0.05) in FSR compared with SP at different times (WP, 60 min; MP, 90 and 120 min; CA, 120 min). Although statistical analysis could not be performed, the calculated the area under the curve (AUC) values for FSR following this trend were: MP, 534.61; CA, 498.22; WP, 473.46; and SP, 406.18. We conclude that ingestion of MP, CA or WP causes the initial peak time in muscle protein synthesis to occur at different times (WP, fast; MP, intermediate; CA, slow) and the dairy proteins have a superior effect on muscle protein synthesis after exercise compared with SP. PMID:27271661

  4. Proteomic and functional analyses reveal MAPK1 regulates milk protein synthesis.

    PubMed

    Lu, Li-Min; Li, Qing-Zhang; Huang, Jian-Guo; Gao, Xue-Jun

    2012-12-27

    L-Lysine (L-Lys) is an essential amino acid that plays fundamental roles in protein synthesis. Many nuclear phosphorylated proteins such as Stat5 and mTOR regulate milk protein synthesis. However, the details of milk protein synthesis control at the transcript and translational levels are not well known. In this current study, a two-dimensional gel electrophoresis (2-DE)/MS-based proteomic technology was used to identify phosphoproteins responsible for milk protein synthesis in dairy cow mammary epithelial cells (DCMECs). The effect of L-Lys on DCMECs was analyzed by CASY technology and reversed phase high performance liquid chromatography (RP-HPLC). The results showed that cell proliferation ability and β-casein expression were enhanced in DCMECs treated with L-Lys. By phosphoproteomics analysis, six proteins, including MAPK1, were identified up-expressed in DCMECs treated with 1.2 mM L-Lys for 24 h, and were verified by quantitative real-time PCR (qRT-PCR) and western blot. Overexpression and siRNA inhibition of MAPK1 experiments showed that MAPK1 upregulated milk protein synthesis through Stat5 and mTOR pathway. These findings that MAPK1 involves in regulation of milk synthesis shed new insights for understanding the mechanisms of milk protein synthesis.

  5. Porcine colostrum and milk stimulate visceral organ and skeletal muscle protein synthesis in neonatal piglets.

    PubMed

    Burrin, D G; Shulman, R J; Reeds, P J; Davis, T A; Gravitt, K R

    1992-06-01

    Our objective was to determine the relative contributions of protein synthesis and protein absorption in the rapid accretion of gastrointestinal protein in suckling piglets during the early neonatal period. We measured the rates of tissue protein synthesis using a flooding dose of L-[4-3H]phenylalanine in various visceral and peripheral tissues of neonatal piglets fed water, mature milk or colostrum for 6 h. The jejunal and ileal protein synthesis rates in piglets fed either colostrum or milk were three- to fourfold higher than in piglets fed water. The increased jejunal and ileal protein synthesis could not, however, account for the differences in protein mass between the colostrum-fed and water-fed groups. The relative abundance of IgG, a major porcine colostral protein, in jejunal tissue was markedly higher in piglets fed colostrum than in piglets fed either milk or water. The fractional protein synthesis rates in liver, kidney, spleen and skeletal muscle and the absolute protein synthesis rates in liver and spleen were also greater in piglets fed colostrum than in those fed milk or water. Increased endogenous protein synthesis made only a minor contribution to the increased intestinal protein accretion in neonatal piglets fed colostrum. A much larger proportion of this increase seemed to be a result of absorption and retention of ingested immunoglobulins.

  6. Consumption of Milk Protein or Whey Protein Results in a Similar Increase in Muscle Protein Synthesis in Middle Aged Men

    PubMed Central

    Mitchell, Cameron J.; McGregor, Robin A.; D’Souza, Randall F.; Thorstensen, Eric B.; Markworth, James F.; Fanning, Aaron C.; Poppitt, Sally D.; Cameron-Smith, David

    2015-01-01

    The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring 13C6 phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h−1 in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p < 0.001) to 0.057% ± 0.018% and 0.052% ± 0.024% h−1 in the milk and whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein. PMID:26506377

  7. Consumption of Milk Protein or Whey Protein Results in a Similar Increase in Muscle Protein Synthesis in Middle Aged Men.

    PubMed

    Mitchell, Cameron J; McGregor, Robin A; D'Souza, Randall F; Thorstensen, Eric B; Markworth, James F; Fanning, Aaron C; Poppitt, Sally D; Cameron-Smith, David

    2015-10-21

    The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring (13)C₆ phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h(-1) in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p < 0.001) to 0.057% ± 0.018% and 0.052% ± 0.024% h(-1) in the milk and whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein.

  8. Effect of dietary protein quality and feeding level on milk secretion and mammary protein synthesis in the rat

    SciTech Connect

    Sampson, D.A.; Jansen, G.R.

    1985-04-01

    Protein synthesis was studied in mammary tissue of rats fed diets deficient in protein quality and/or restricted in food intake throughout gestation and lactation. Diets containing 25% wheat gluten (WG), wheat gluten plus lysine and threonine (WGLT), or casein (C) were pair-fed from conception until day 15 of lactation at 100% or 85% of WG ad libitum consumption (PF100 and PF85, respectively). A seventh group was fed C ad libitum. Rates of protein synthesis were measured in vivo at day 15 of lactation from incorporation of (3-/sup 3/H)phenylalanine. At both PF100 and PF85, fractional and absolute rates of mammary gland protein synthesis were two- to three-fold higher in rats fed C than in those fed WG. Pup weights showed similar treatment effects. Both mammary protein synthesis rates and pup weights were significantly higher in rats fed C at PF85 than rats fed WG ad libitum. Food restriction from PF100 to PF85 depressed pup weights and mammary protein synthesis rates in rats fed WGLT, but had no effect in rats fed WG. These results demonstrate that when food intake is restricted, improvement of protein quality of the maternal diet increases milk output in the rat in association with increased rates of mammary protein synthesis.

  9. Effects of dietary forage sources on rumen microbial protein synthesis and milk performance in early lactating dairy cows.

    PubMed

    Zhu, W; Fu, Y; Wang, B; Wang, C; Ye, J A; Wu, Y M; Liu, J-X

    2013-03-01

    The objective of this study was to evaluate the effects of dietary forage sources on milk performance, rumen microbial protein synthesis, and N utilization in early lactation dairy cows. Twelve primiparous Chinese Holstein dairy cows (45 ± 6.0 DIM) were used in a 3 × 3 Latin square design. Diets were isonitrogenous and isocaloric, with a forage-to-concentrate ratio of 45:55 [dry matter (DM) basis] and contained similar concentrate mixtures. Different forage sources were then added (on a DM basis): 21% corn silage, 19% corn stover, and 5% alfalfa hay (CS); 19% corn silage, 21% Chinese wild rye hay and 5% alfalfa hay (CWR); or 19% corn silage, 9% Chinese wild rye hay, and 17% alfalfa hay (AH). Each period lasted for 21 d, with the first 14 d for an adaptation period. Dry matter intake was not affected by the source of dietary forage. Milk yield was higher for cows fed AH than those fed CS, with an intermediate value for CWR. Milk protein content was higher in the cows fed AH compared with CWR (3.02 vs. 2.92%), with CS (2.95%) at an intermediate position. The contents of milk fat and lactose were not different among the treatments. However, milk efficiency (milk yield/DM intake) was higher for cows fed AH than those fed CS, with those fed CWR intermediate. Cows fed AH had higher microbial protein yield and metabolizable protein than those fed CS or CWR. The concentrations of urea N in the urine, blood, and milk were decreased for cows fed AH, indicating an increased N conversion. The results indicated that corn stover could replace Chinese wild rye grass in the diets for lactating cows and that a high proportion of alfalfa hay in the diet is beneficial for milk protein production by increasing microbial protein yield. This can be attributed to the improving the supply of rumen-available energy.

  10. Influence of Nrf2 activators on subcellular skeletal muscle protein and DNA synthesis rates after 6 weeks of milk protein feeding in older adults.

    PubMed

    Konopka, Adam R; Laurin, Jaime L; Musci, Robert V; Wolff, Christopher A; Reid, Justin J; Biela, Laurie M; Zhang, Qian; Peelor, Fredrick F; Melby, Christopher L; Hamilton, Karyn L; Miller, Benjamin F

    2017-04-01

    In older adults, chronic oxidative and inflammatory stresses are associated with an impaired increase in skeletal muscle protein synthesis after acute anabolic stimuli. Conjugated linoleic acid (CLA) and Protandim have been shown to activate nuclear factor erythroid-derived 2-like 2 (Nrf2), a transcription factor for the antioxidant response element and anti-inflammatory pathways. This study tested the hypothesis that compared to a placebo control (CON), CLA and Protandim would increase skeletal muscle subcellular protein (myofibrillar, mitochondrial, cytoplasmic) and DNA synthesis in older adults after 6 weeks of milk protein feeding. CLA decreased oxidative stress and skeletal muscle oxidative damage with a trend to increase messenger RNA (mRNA) expression of a Nrf2 target, NAD(P)H dehydrogenase quinone 1 (NQO1). However, CLA did not influence other Nrf2 targets (heme oxygenase-1 (HO-1), glutathione peroxidase 1 (Gpx1)) or protein or DNA synthesis. Conversely, Protandim increased HO-1 protein content but not the mRNA expression of downstream Nrf2 targets, oxidative stress, or skeletal muscle oxidative damage. Rates of myofibrillar protein synthesis were maintained despite lower mitochondrial and cytoplasmic protein syntheses after Protandim versus CON. Similarly, DNA synthesis was non-significantly lower after Protandim compared to CON. After Protandim, the ratio of protein to DNA synthesis tended to be greater in the myofibrillar fraction and maintained in the mitochondrial and cytoplasmic fractions, emphasizing the importance of measuring both protein and DNA synthesis to gain insight into proteostasis. Overall, these data suggest that Protandim may enhance proteostatic mechanisms of skeletal muscle contractile proteins after 6 weeks of milk protein feeding in older adults.

  11. [Cow's milk protein allergy through human milk].

    PubMed

    Denis, M; Loras-Duclaux, I; Lachaux, A

    2012-03-01

    Cow's milk protein allergy (CMPA) is the first allergy that affects infants. In this population, the incidence rate reaches 7.5%. The multiplicity and aspecificity of the symptoms makes its diagnosis sometimes complicated, especially in the delayed type (gastrointestinal, dermatological, and cutaneous). CMPA symptoms can develop in exclusively breastfed infants with an incidence rate of 0.5%. It, therefore, raises questions about sensitization to cow's milk proteins through breast milk. Transfer of native bovine proteins such as β-lactoglobulin into the breast milk is controversial: some authors have found bovine proteins in human milk but others point to cross-reactivity between human milk proteins and cow's milk proteins. However, it seems that a small percentage of dietary proteins can resist digestion and become potentially allergenic. Moreover, some authors suspect the transfer of some of these dietary proteins from the maternal bloodstream to breast milk, but the mechanisms governing sensitization are still being studied. Theoretically, CMPA diagnosis is based on clinical observations, prick-test or patch-test results, and cow's milk-specific IgE antibody concentration. A positive food challenge test usually confirms the diagnosis. No laboratory test is available to make a certain diagnosis, but the detection of eosinophil cationic protein (ECP) in the mother's milk, for example, seems to be advantageous since it is linked to CMA. Excluding cow's milk from the mother's diet is the only cure when she still wants to breastfeed. Usually, cow's milk proteins are reintroduced after 6 months of exclusion. Indeed, the prognosis for infants is very good: 80% acquire a tolerance before the age of 3 or 4 years. Mothers should not avoid dairy products during pregnancy and breastfeeding as preventive measures against allergy.

  12. Ingestion of Casein in a Milk Matrix Modulates Dietary Protein Digestion and Absorption Kinetics but Does Not Modulate Postprandial Muscle Protein Synthesis in Older Men.

    PubMed

    Churchward-Venne, Tyler A; Snijders, Tim; Linkens, Armand M A; Hamer, Henrike M; van Kranenburg, Janneau; van Loon, Luc J C

    2015-07-01

    The slow digestion and amino acid absorption kinetics of isolated micellar casein have been held responsible for its relatively lower postprandial muscle protein synthetic response compared with rapidly digested proteins such as isolated whey. However, casein is normally consumed within a milk matrix. We hypothesized that protein digestion and absorption kinetics and the subsequent muscle protein synthetic response after micellar casein ingestion are modulated by the milk matrix. The aim of this study was to determine the impact of a milk matrix on casein protein digestion and absorption kinetics and postprandial muscle protein synthesis in older men. In a parallel-group design, 32 healthy older men (aged 71 ± 1 y) received a primed continuous infusion of L-[ring-(2)H5]-phenylalanine, L-[ring-3,5-(2)H2]-tyrosine, and L-[1-(13)C]-leucine, and ingested 25 g intrinsically L-[1-(13)C]-phenylalanine and L-[1-(13)C]-leucine labeled casein dissolved in bovine milk serum (Cas+Serum) or water (Cas). Plasma samples and muscle biopsies were collected in the postabsorptive state and for 300 min in the postprandial period to examine whole-body and skeletal muscle protein metabolism. Casein ingestion increased plasma leucine and phenylalanine concentrations and L-[1-(13)C]-phenylalanine enrichments, with a more rapid rise after Cas vs. Cas+Serum. Nonetheless, dietary protein-derived phenylalanine availability did not differ between Cas+Serum (47 ± 2%, mean ± SEM) and Cas (46 ± 3%) when assessed over the 300-min postprandial period (P = 0.80). The milk matrix did not modulate postprandial myofibrillar protein synthesis rates from 0 to 120 min (0.038 ± 0.005 vs. 0.031 ± 0.007%/h) or from 120 to 300 min (0.052 ± 0.004 vs. 0.067 ± 0.005%/h) after Cas+Serum vs. Cas. Similarly, no treatment differences in muscle protein-bound L-[1-(13)C]-phenylalanine enrichments were observed at 120 min (0.003 ± 0.001 vs. 0.002 ± 0.001) or 300 min (0.015 ± 0.002 vs. 0.016 ± 0.002 mole

  13. Effect of dietary energy source and level on nutrient digestibility, rumen microbial protein synthesis, and milk performance in lactating dairy cows.

    PubMed

    Zhou, X Q; Zhang, Y D; Zhao, M; Zhang, T; Zhu, D; Bu, D P; Wang, J Q

    2015-10-01

    This study was conducted to examine the effects of dietary energy source and level on intake, digestion, rumen microbial protein synthesis, and milk production in lactating dairy cows, using corn stover as a forage source. Eight multiparous Holstein cows, 4 of which were fitted with rumen cannulas, were evaluated in a replicated 4 × 4 Latin square design, with each period lasting 21 d. The cows were randomly assigned into 4 treatment groups: low-energy (LE) ground corn (GC), LE steam-flaked corn (SFC), high-energy (HE) GC, and HE SFC. Changes to ruminal energy degradation rates were induced by feeding the cows diets of either finely ground corn or SFC as components of diets with the same total energy level. Milk yield, milk protein content and yield, and milk lactose yield all increased in response to higher levels of dietary energy, whereas contents of milk fat and lactose were unaffected. Cows fed HE diets had a higher crude microbial protein yield and total-tract apparent digestibility than those receiving LE diets. Milk yield, milk protein yield, and microbial protein yield were also higher when SFC replaced GC as the main energy source for lactating cows fed LE diets. These results suggest that an increased dietary energy level and ruminal degradation rate are beneficial to milk protein production, which we suggest is due to increased yields of microbial proteins, when cows are fed corn stover as a dietary forage source.

  14. Recombinant human milk proteins.

    PubMed

    Lönnerdal, Bo

    2006-01-01

    Human milk provides proteins that benefit newborn infants. They not only provide amino acids, but also facilitate the absorption of nutrients, stimulate growth and development of the intestine, modulate immune function, and aid in the digestion of other nutrients. Breastfed infants have a lower prevalence of infections than formula-fed infants. Since many women in industrialized countries choose not to breastfeed, and an increasing proportion of women in developing countries are advised not to breastfeed because of the risk of HIV transmission, incorporation of recombinant human milk proteins into infant foods is likely to be beneficial. We are expressing human milk proteins known to have anti-infective activity in rice. Since rice is a normal constituent of the diet of infants and children, limited purification of the proteins is required. Lactoferrin has antimicrobial and iron-binding activities. Lysozyme is an enzyme that is bactericidal and also acts synergistically with lactoferrin. These recombinant proteins have biological activities identical to their native counterparts. They are equally resistant to heat processing, which is necessary for food applications, and to acid and proteolytic enzymes which are needed to maintain their biological activity in the gastrointestinal tract of infants. These recombinant human milk proteins may be incorporated into infant formulas, baby foods and complementary foods, and used with the goal to reduce infectious diseases.

  15. Prion protein in milk.

    PubMed

    Franscini, Nicola; El Gedaily, Ahmed; Matthey, Ulrich; Franitza, Susanne; Sy, Man-Sun; Bürkle, Alexander; Groschup, Martin; Braun, Ueli; Zahn, Ralph

    2006-12-20

    Prions are known to cause transmissible spongiform encephalopathies (TSE) after accumulation in the central nervous system. There is increasing evidence that prions are also present in body fluids and that prion infection by blood transmission is possible. The low concentration of the proteinaceous agent in body fluids and its long incubation time complicate epidemiologic analysis and estimation of spreading and thus the risk of human infection. This situation is particularly unsatisfactory for food and pharmaceutical industries, given the lack of sensitive tools for monitoring the infectious agent. We have developed an adsorption matrix, Alicon PrioTrap, which binds with high affinity and specificity to prion proteins. Thus we were able to identify prion protein (PrP(C))--the precursor of prions (PrP(Sc))--in milk from humans, cows, sheep, and goats. The absolute amount of PrP(C) differs between the species (from microg/l range in sheep to ng/l range in human milk). PrP(C) is also found in homogenised and pasteurised off-the-shelf milk, and even ultrahigh temperature treatment only partially diminishes endogenous PrP(C) concentration. In view of a recent study showing evidence of prion replication occurring in the mammary gland of scrapie infected sheep suffering from mastitis, the appearance of PrP(C) in milk implies the possibility that milk of TSE-infected animals serves as source for PrP(Sc).

  16. In vivo effect of growth hormone on DNA synthesis and expression of milk protein genes in the rabbit mammary gland.

    PubMed

    Zebrowska, T; Siadkowska, E; Zwierzchowski, L; Gajewska, A; Kochman, K

    1997-12-01

    The aim of this work was to show whether growth hormone (GH) is able to directly induce growth and functional differentiation of the mammary gland. We have shown that i.m. injections of prolactin and to lesser extent injections of growth hormone increased DNA synthesis in the mammary gland of pregnant rabbits. Injections of pituitary and recombinant bovine growth hormone (GH), similarly to prolactin, could also induce the expression of milk protein genes--caseins alpha S1 and beta and whey acidic protein (WAP). However, in contrast to prolactin, growth hormone failed to induce the synthesis of casein proteins. Lactogenic hormones act through binding to receptors in target tissues. Prolactin receptors were shown to be abundant in the rabbit mammary glands but no specific binding sites for 125I-labelled GH have been found in membranes isolated from mammary glands of pregnant or lactating rabbits. The specificity of hormone binding was examined using unlabelled hormones as competitive inhibitors of 125I-labelled prolactin. Bovine and recombinant bovine growth hormone did not displace prolactin from its receptors, thus excluding the possibility of action of GH through lactogenic receptors. Our results support the hypothesis that GH may act directly on the mammary gland and independently from prolactin; however, the mechanism of its action is still unknown.

  17. Cow's milk proteins in human milk.

    PubMed

    Coscia, A; Orrù, S; Di Nicola, P; Giuliani, F; Rovelli, I; Peila, C; Martano, C; Chiale, F; Bertino, E

    2012-01-01

    Cow's milk proteins (CMPs) are among the best characterized food allergens. Cow's milk contains more than twenty five different proteins, but only whey proteins alpha-lactalbumin, beta-lactoglobulin, bovine serum albumin (BSA), and lactoferrin, as well as the four caseins, have been identified as allergens. Aim of this study was to investigate by proteomics techniques cow's milk allergens in human colostrum of term and preterm newborns' mothers, not previously detected, in order to understand if such allergens could be cause of sensitization during lactation. Term colostrum samples from 62 healthy mothers and preterm colostrum samples from 11 healthy mothers were collected for this purpose. The most relevant finding was the detection of the intact bovine alpha-S1-casein in both term and preterm colostrum. Using this method, which allows direct proteins identification, beta-lactoglobulin was not detected in any of colostrum samples. According to our results bovine alpha 1 casein that is considered a major cow's milk allergen is readily secreted in human milk: further investigations are needed in order to clarify if alpha-1-casein has a major role in sensitization or tolerance to cow's milk of exclusively breastfed predisposed infants.

  18. Protein composition of rhesus monkey milk: comparison to human milk.

    PubMed

    Kunz, C; Lönnerdal, B

    1993-04-01

    1. Proteins in human milk and Rhesus monkey milk have been compared by FPLC gel filtration and anion exchange chromatography, SDS-Polyacrylamide gel electrophoresis, nitrogen and protein determination. 2. Mature Rhesus milk is higher in protein concentration (15-20 mg/ml) than human milk (8-9 mg/ml). 3. Non-Protein nitrogen is 6-13% in Rhesus milk but 25-30% in human milk. 4. Secretory IgA, lactoferrin, serum albumin, alpha-lactalbumin and lysozyme are present in Rhesus milk, but at a lower concentration than in human milk. 5. The casein subunit pattern is more complex in Rhesus milk compared to human milk. 6. The ratio of whey proteins to casein is similar in both milks (approximately 60/40). 7. A protein with a M(r) of 21,600 is a major component in monkey whey but is not found in human milk.

  19. Synthesis and characterization of functionalized CNTs using soya and milk protein

    NASA Astrophysics Data System (ADS)

    saxena, Sanjay; ranu, Rachana; Hait, Chandan; Priya, Shruti

    2014-10-01

    Nanotechnology is the study of the phenomenon and manipulation of matter at atomic and molecular scale to enhance their older property and generate several new properties. Carbon nanotubes (CNTs) are one of the most commonly mentioned building blocks of nanotechnology. CNTs are very prevalent in today's world of medical research and are being highly researched in the fields of efficient drug delivery and bio sensing methods for disease treatment and health monitoring. There are number of methods for synthesizing CNTs. This is a biological method for synthesis of CNTs in which protein is used as carbon source and amino acids present in protein form complex with metal salt. The CNTs synthesized are then characterized and functionalized using techniques such as transmission electron microscopy, Fourier transform infra-red, nuclear magnetic resonance, ultra-violet visible spectroscopy, X-ray diffraction, etc. The properties of the synthesized CNTs are studied with the help of techniques such as thermo-gravimetric analysis, differential thermal analysis, and vibrating sample magnetometer, etc.

  20. Optimization and characterization of an in vitro bovine mammary cell culture system to study regulation of milk protein synthesis and mammary differentiation

    SciTech Connect

    Talhouk, R.S.

    1988-01-01

    A long term bovine mammary cell culture system that maintains normal mammary cell function was established and optimized to study milk protein synthesis and secretion and mammary differentiation. This culture system used bovine mammary acini isolated from developing or lactating mammary gland by enzymatic dissociation, and cryopreserved until thawed and plated for growth in vitro for these studies. Cells in M199 with lactogenic hormones {plus minus} fetal calf serum (FCS) were cultured on plastic, 100ul and 500ul type I collagen, and Matrigel, or embedded within type I collagen. Cell morphology, cell number, and total TCA-precipitable {sup 35}S-labelled proteins were monitored. Milk protein ({alpha}{sub s,1}-casein, lactoferrin (LF), {alpha}-lactalbumin, and {beta}-lactoglobulin) secretion and intracellular levels were determined by an ELISA assay.

  1. The effect of heat stress on gene expression and synthesis of heat-shock and milk proteins in bovine mammary epithelial cells.

    PubMed

    Hu, Han; Zhang, Yangdong; Zheng, Nan; Cheng, Jianbo; Wang, Jiaqi

    2016-01-01

    In this study, bovine mammary epithelial cells were used to study stress responses after cells were exposed to 42°C for 0.5, 1, 3, 5, 8 or 12 h, and 38°C as control. The transcription of the genes (HSP27, HSP70 and HSP90) of heat shock protein (Hsp) was significantly enhanced under heat stress (HS). The peak transcription of HSP70 was 14 times the control at 1 h. Expression of proteins Hsp27 and Hsp70 was gradually increased under HS, with rapid deposition of Hsp70 in epithelial cells. The major milk protein genes of β-casein (CSN2) and butyrophilin (BTN1A1) were down-regulated and the synthesis of total caseins was decreased. After the cells were under HS (42°C) for 1 or 5 h, the cells were cultured at 38°C for 1, 6, 12 or 24 h for recovery. When the cells were cultured at 38°C for 24 h after HS for 1 h, the transcription of HSP70, HSP90, CSN2 and BTN reached normal levels. Our results suggest that HS initiated Hsp synthesis and decreased the milk protein synthesis. Hsp70 is extremely sensitive to HS and mainly responsible for mammary cell protection from HS. © 2015 Japanese Society of Animal Science.

  2. Milk protein concentrations in galactorrhoeic mammary secretions.

    PubMed

    Yap, P L; Pryde, E A; McClelland, D B

    1980-02-01

    Milk protein concentrations were determined either by double antibody radioimmunoassay (IgA) or single radial immunodiffusion (IgG, lactoferrin, lysozyme and albumin) in the mammayr secretions of one nulliparous and three parous female patients with galactorrhoea due to hyperprolactinaemia. Concentrations of all the proteins studied were found to be similar to the concentrations observed in post-partum colostrum. In particular, secretory IgA was the only form of IgA detected in galactorrhoeic secretions. It is suggested that hyperprolactinaemia alone can result in increased mammary synthesis of the milk proteins since the steroid changes associated with a full-term pregnancy and delivery of the placenta did not immediately precede the galactorrhoea in three of the four patients studied.

  3. Antihypertensive Peptides from Milk Proteins

    PubMed Central

    Jäkälä, Pauliina; Vapaatalo, Heikki

    2010-01-01

    Dietary proteins possess a wide range of nutritional and functional properties. They are used as a source of energy and amino acids, which are needed for growth and development. Many dietary proteins, especially milk proteins, contain physiologically active peptides encrypted in the protein sequence. These peptides may be released during gastrointestinal digestion or food processing and once liberated, cause different physiological functions. Milk-derived bioactive peptides are shown to have antihypertensive, antimicrobial, immunomodulatory, antioxidative and mineral-binding properties. During the fermentation of milk with certain lactobacilli, two interesting tripeptides Ile-Pro-Pro and Val-Pro-Pro are released from casein to the final product. These lactotripeptides have attenuated the development of hypertension in several animal models and lowered blood pressure in clinical studies. They inhibit ACE in vitro at micromolar concentrations, protect endothelial function in vitro and reduce arterial stiffness in humans. Thus, milk as a traditional food product can after certain processing serve as a functional food and carry specific health-promoting effects, providing an option to control blood pressure. PMID:27713251

  4. Bioactive proteins in human milk: mechanisms of action.

    PubMed

    Lönnerdal, Bo

    2010-02-01

    Human milk contains a multitude of bioactive proteins, with very diverse functions. Some of these proteins are involved in the synthesis and expression of milk, but the majority appears to have evolved to provide physiological activities in the breast-fed infant. These activities are exerted by a wide variety of mechanisms and have largely been unraveled by in vitro studies. To be active in the gastrointestinal tract, these proteins must be able to resist proteolytic degradation, at least for some time. We have evaluated the human milk proteins lactoferrin, haptocorrin, alpha(1)-antitrypsin, and transforming growth factor -beta in an in vitro digestion model, mimicking the conditions of the infant gastrointestinal milieu. These bioactive proteins are resistant against proteolysis and can remain intact or as larger fragments through passage of the gastrointestinal tract. In vitro digestibility assays can be helpful to assess which human milk proteins can resist proteolysis and to what extent.

  5. Relationships between milks differentiated on native milk fat globule characteristics and fat, protein and calcium compositions.

    PubMed

    Couvreur, S; Hurtaud, C

    2017-03-01

    Many studies have shown that milk fat globule (MFG) diameter varies in dairy cows in relation to diet and/or breed. However, the mechanisms governing the size of the fat globules remain hypothetical. Our objective was to determine the variable biochemical characteristics (fat, protein, fatty acids (FA), casein and calcium (Ca) contents) between individual milk which differed in both MFG diameter and membrane content, in order to speculate about the links between milk synthesis and MFG secretion. With this aim, we built five databases of individual milk samples from 21 experiments performed between 2003 and 2011. Three of them grouped data from trials dealing with breed/diet effects and included information about: (i) MFG size/membrane, fat and protein contents (n=982), (ii) previous parameters plus FA profile (n=529) and (iii) previous parameters plus true protein composition and calcium contents (n=101). A hierarchical clustering analysis performed on these three databases yielded four groups differing in the MFG characteristics. We observed significant differences among groups for the following parameters: (i) fat content and fat : protein ratio; (ii) de novo and polyunsaturated FA contents; (iii) Ca contents. These relationships could result from potential process regulating the synthesis and secretion of MFG: (i) the apical membrane turnover for MFG secretion and (ii) cytoplasmic lipid droplet formation in the lactocyte during its migration from the basal to the apical pole. The two other databases grouped data from trials dealing with milking frequency (n=211), milking kinetics and milk type (residual v. cisternal) (n=224). They were used to study the relationships between the size of the MFG and milk composition for high native fat contents (from 60 up to 100 g/kg in residual milks). We observed curvilinear relationships between the size of the MFG and fat content, as well as with the fat : protein ratio. This result suggests that MFG diameter reaches a

  6. Solubility of commercial milk protein concentrates and milk protein isolates.

    PubMed

    Sikand, V; Tong, P S; Roy, S; Rodriguez-Saona, L E; Murray, B A

    2011-12-01

    High-protein milk protein concentrate (MPC) and milk protein isolate (MPI) powders may have lower solubility than low-protein MPC powders, but information is limited on MPC solubility. Our objectives in this study were to (1) characterize the solubility of commercially available powder types with differing protein contents such as MPC40, MPC80, and MPI obtained from various manufacturers (sources), and (2) determine if such differences could be associated with differences in mineral, protein composition, and conformational changes of the powders. To examine possible predictors of solubility as measured by percent suspension stability (%SS), mineral analysis, Fourier transform infrared (FTIR) spectroscopy, and quantitative protein analysis by HPLC was performed. After accounting for overall differences between powder types, %SS was found to be strongly associated with the calcium, magnesium, phosphorus, and sodium content of the powders. The FTIR score plots were in agreement with %SS results. A principal component analysis of FTIR spectra clustered the highly soluble MPC40 separately from the rest of samples. Furthermore, 2 highly soluble MPI samples were clustered separately from the rest of the MPC80 and MPI samples. We found that the 900 to 1,200 cm⁻¹ region exhibited the highest discriminating power, with dominant bands at 1,173 and 968 cm⁻¹, associated with phosphate vibrations. The 2 highly soluble MPI powders were observed to have lower κ-casein and α-(S1)-casein contents and slightly higher whey protein contents than the other powders. The differences in the solubility of MPC and MPI were associated with a difference in mineral composition, which may be attributed to differences in processing conditions. Additional studies on the role of minerals composition on MPC80 solubility are warranted. Such a study would provide a greater understanding of factors associated with differences in solubility and can provide insight on methods to improve

  7. Health-Related Aspects of Milk Proteins

    PubMed Central

    Davoodi, Seyed Hossein; Shahbazi, Roghiyeh; Esmaeili, Saeideh; Sohrabvandi, Sara; Mortazavian, AmirMohamamd; Jazayeri, Sahar; Taslimi, Aghdas

    2016-01-01

    Milk is an important component of a balanced diet and contains numerous valuable constituents. Considerable acclaimed health benefits of milk are related to its proteins, not only for their nutritive value but also for their biological properties. Scientific evidence suggests that anticarcinogenic activities, antihypertensive properties, immune system modulation, and other metabolic features of milk, are affiliated with its proteins (intact proteins or its derivatives). In this article, the main health-related aspects of milk proteins, such as anticarcinogenic, immunomodulatory, antimicrobial, anticariogenic, antihypertensive, and hypocholesterolemic effects are reviewed. Collectively, the findings indicate the effectiveness of milk proteins on reduction of risk factors for cancer, cardiovascular diseases and overall improvement of health aspects. PMID:27980594

  8. Effects of extruding wheat dried distillers grains with solubles with peas or canola meal on ruminal fermentation, microbial protein synthesis, nutrient digestion, and milk production in dairy cows.

    PubMed

    Claassen, R M; Christensen, D A; Mutsvangwa, T

    2016-09-01

    Our objective was to examine the effects of feeding coextruded and nonextruded supplements consisting of wheat dried distillers grains with solubles with peas (WDDGS-peas) or canola meal (WDDGS-CM) on ruminal fermentation, omasal flow, and production performance in Holstein cows. Eight cows (4 ruminally cannulated) were used in a replicated 4×4 Latin square with 28-d periods and a 2×2 factorial arrangement of dietary treatments. Dietary treatments were coextruded or nonextruded mixtures of WDDGS-peas and WDDGS-CM that were included in total mixed rations at 15.1% [dry matter (DM) basis]. Diet had no effect on DM intake. Milk yield was greater in cows fed coextruded diets compared with those fed nonextruded diets. Milk fat content was greater in cows fed nonextruded diets compared with those fed coextruded diets, but milk fat yield was greater in cows fed coextruded diets compared with those fed nonextruded diets. Milk yield tended to be greater and milk protein yield was greater in cows fed WDDGS-peas compared with those fed WDDGS-CM. Cows fed nonextruded diets had a greater milk urea-N concentration compared with those fed coextruded diets. Cows fed coextruded diets had greater ruminal digestion of DM and tended to have greater ruminal digestion of organic matter compared with those fed nonextruded diets. Total-tract digestibilities of organic matter, crude protein, ether extract, and starch were greater, whereas that of acid detergent fiber and neutral detergent fiber tended to be greater in cows fed coextruded compared with those fed nonextruded diets. Total-tract digestibility of ether extract was lower whereas that of starch was greater and that of crude protein tended to be greater in cows fed WDDGS-peas compared with those fed WDDGS-CM. Total N excretion and milk N efficiency were unaffected by diet. Ruminal NH3-N concentration tended to be greater in cows fed WDDGS-CM compared with those fed WDDGS-peas. Ruminal propionate concentration was greater whereas

  9. STAT6-Dependent Collagen Synthesis in Human Fibroblasts Is Induced by Bovine Milk.

    PubMed

    Kippenberger, Stefan; Zöller, Nadja; Kleemann, Johannes; Müller, Jutta; Kaufmann, Roland; Hofmann, Matthias; Bernd, August; Meissner, Markus; Valesky, Eva

    2015-01-01

    Since the domestication of the urus, 10.000 years ago, mankind utilizes bovine milk for different purposes. Besides usage as a nutrient also the external application of milk on skin has a long tradition going back to at least the ancient Aegypt with Cleopatra VII as a great exponent. In order to test whether milk has impact on skin physiology, cultures of human skin fibroblasts were exposed to commercial bovine milk. Our data show significant induction of proliferation by milk (max. 2,3-fold, EC50: 2,5% milk) without toxic effects. Surprisingly, bovine milk was identified as strong inducer of collagen 1A1 synthesis at both, the protein (4-fold, EC50: 0,09% milk) and promoter level. Regarding the underlying molecular pathways, we show functional activation of STAT6 in a p44/42 and p38-dependent manner. More upstream, we identified IGF-1 and insulin as key factors responsible for milk-induced collagen synthesis. These findings show that bovine milk contains bioactive molecules that act on human skin cells. Therefore, it is tempting to test the herein introduced concept in treatment of atrophic skin conditions induced e.g. by UV light or corticosteroids.

  10. STAT6-Dependent Collagen Synthesis in Human Fibroblasts Is Induced by Bovine Milk

    PubMed Central

    Kippenberger, Stefan; Zöller, Nadja; Kleemann, Johannes; Müller, Jutta; Kaufmann, Roland; Hofmann, Matthias; Bernd, August; Meissner, Markus; Valesky, Eva

    2015-01-01

    Since the domestication of the urus, 10.000 years ago, mankind utilizes bovine milk for different purposes. Besides usage as a nutrient also the external application of milk on skin has a long tradition going back to at least the ancient Aegypt with Cleopatra VII as a great exponent. In order to test whether milk has impact on skin physiology, cultures of human skin fibroblasts were exposed to commercial bovine milk. Our data show significant induction of proliferation by milk (max. 2,3-fold, EC50: 2,5% milk) without toxic effects. Surprisingly, bovine milk was identified as strong inducer of collagen 1A1 synthesis at both, the protein (4-fold, EC50: 0,09% milk) and promoter level. Regarding the underlying molecular pathways, we show functional activation of STAT6 in a p44/42 and p38-dependent manner. More upstream, we identified IGF-1 and insulin as key factors responsible for milk-induced collagen synthesis. These findings show that bovine milk contains bioactive molecules that act on human skin cells. Therefore, it is tempting to test the herein introduced concept in treatment of atrophic skin conditions induced e.g. by UV light or corticosteroids. PMID:26134630

  11. [Bioactive peptides derived from milk proteins].

    PubMed

    Torres-Llanez, María de Jesús; Vallejo-Cordoba, Belinda; González-Córdova, Aaron Fernando

    2005-06-01

    Milk proteins are known for having a wide range of nutritional, functional and biological properties that make them important ingredients in functional or health promoting foods. These properties are partly attributed to bioactive peptides coded in the different milk proteins. Bioactive peptides are inactive within the protein sequence but may be released by the action of native proteolitic enzymes from milk, enzymes from lactic acid bacteria or from exogenous sources or may be produced during gastrointestinal digestion or processing of foods. Peptides derived from caseins and whey proteins were shown to present several bioactive properties such as opioid, antihypertensive, antimicrobial, immunodulatory, mineral carrier and antithrombotic. This overview presents a perspective of the importance of dairy proteins in the production of bioactive peptides and their biological activities, as well as the main analytical tecniques that have been used for the isolation and identification of these peptides.

  12. Milk metabolome relates enteric methane emission to milk synthesis and energy metabolism pathways.

    PubMed

    Antunes-Fernandes, E C; van Gastelen, S; Dijkstra, J; Hettinga, K A; Vervoort, J

    2016-08-01

    Methane (CH4) emission of dairy cows contributes significantly to the carbon footprint of the dairy chain; therefore, a better understanding of CH4 formation is urgently needed. The present study explored the milk metabolome by gas chromatography-mass spectrometry (milk volatile metabolites) and nuclear magnetic resonance (milk nonvolatile metabolites) to better understand the biological pathways involved in CH4 emission in dairy cattle. Data were used from a randomized block design experiment with 32 multiparous Holstein-Friesian cows and 4 diets. All diets had a roughage:concentrate ratio of 80:20 (dry matter basis) and the roughage was grass silage (GS), corn silage (CS), or a mixture of both (67% GS, 33% CS; 33% GS, 67% CS). Methane emission was measured in climate respiration chambers and expressed as CH4 yield (per unit of dry matter intake) and CH4 intensity (per unit of fat- and protein-corrected milk; FPCM). No volatile or nonvolatile metabolite was positively related to CH4 yield, and acetone (measured as a volatile and as a nonvolatile metabolite) was negatively related to CH4 yield. The volatile metabolites 1-heptanol-decanol, 3-nonanone, ethanol, and tetrahydrofuran were positively related to CH4 intensity. None of the volatile metabolites was negatively related to CH4 intensity. The nonvolatile metabolites acetoacetate, creatinine, ethanol, formate, methylmalonate, and N-acetylsugar A were positively related to CH4 intensity, and uridine diphosphate (UDP)-hexose B and citrate were negatively related to CH4 intensity. Several volatile and nonvolatile metabolites that were correlated with CH4 intensity also were correlated with FPCM and not significantly related to CH4 intensity anymore when FPCM was included as covariate. This suggests that changes in these milk metabolites may be related to changes in milk yield or metabolic processes involved in milk synthesis. The UDP-hexose B was correlated with FPCM, whereas citrate was not. Both metabolites were

  13. Milk secretion: The role of SNARE proteins.

    PubMed

    Truchet, Sandrine; Chat, Sophie; Ollivier-Bousquet, Michèle

    2014-03-01

    During lactation, polarized mammary epithelial secretory cells (MESCs) secrete huge quantities of the nutrient molecules that make up milk, i.e. proteins, fat globules and soluble components such as lactose and minerals. Some of these nutrients are only produced by the MESCs themselves, while others are to a great extent transferred from the blood. MESCs can thus be seen as a crossroads for both the uptake and the secretion with cross-talks between intracellular compartments that enable spatial and temporal coordination of the secretion of the milk constituents. Although the physiology of lactation is well understood, the molecular mechanisms underlying the secretion of milk components remain incompletely characterized. Major milk proteins, namely caseins, are secreted by exocytosis, while the milk fat globules are released by budding, being enwrapped by the apical plasma membrane. Prolactin, which stimulates the transcription of casein genes, also induces the production of arachidonic acid, leading to accelerated casein transport and/or secretion. Because of their ability to form complexes that bridge two membranes and promote their fusion, SNARE (Soluble N-ethylmaleimide-Sensitive Factor Attachment Protein Receptor) proteins are involved in almost all intracellular trafficking steps and exocytosis. As SNAREs can bind arachidonic acid, they could be the effectors of the secretagogue effect of prolactin in MESCs. Indeed, some SNAREs have been observed between secretory vesicles and lipid droplets suggesting that these proteins could not only orchestrate the intracellular trafficking of milk components but also act as key regulators for both the coupling and coordination of milk product secretion in response to hormones.

  14. Molecular aspects of viviparous reproductive biology of the tsetse fly (Glossina morsitans morsitans): Regulation of yolk and milk gland protein synthesis

    PubMed Central

    Attardo, Geoffrey M.; Guz, Nurper; Strickler-Dinglasan, Patricia; Aksoy, Serap

    2006-01-01

    Tsetse fly (Diptera: Glossinidae) viviparous reproductive physiology remains to be explored at the molecular level. Adult females carry their young in utero for the duration of embryonic and larval development, all the while supplying their offspring with nutrients in the form of a “milk” substance secreted from a modified accessory gland. Flies give birth to fully developed third instar larvae that pupariate shortly after birth. Here, we describe the spatial and temporal expression dynamics of two reproduction-associated genes and their products synthesized during the first and second gonotrophic cycles. The proteins studied include a putative yolk protein, Glossina morsitans morsitans yolk protein 1 (GmmYP1) and the major protein found in tsetse “milk” secretions (Glossina morsitans morsitans milk gland protein, GmmMGP). Developmental stage and tissue-specific expression of GmmYP1 show its presence exclusively in the reproductive tract of the fly during oogenesis, suggesting that GmmYP1 acts as a vitellogenic protein. Transcripts for GmmMGP are present only in the milk gland tissue and increase in coordination with the process of larvigenesis. Similarly, GmmMGP can be detected at the onset of larvigenesis in the milk gland, and is present during the full duration of pregnancy. Expression of GmmMGP is restricted to the adult stage and is not detected in the immature developmental stages. These phenomena indicate that the protein is transferred from mother to larvae as nourishment during its development. These results demonstrate that both GmmYP1 and GmmMGP are involved in tsetse reproductive biology, the former associated with the process of oogenesis and the latter with larvigenesis. PMID:17046784

  15. ALMOND MILK: A POTENTIAL THERAPEUTIC WEAPON AGAINST COW’S MILK PROTEIN ALLERGY.

    PubMed

    Cuppari, C; Manti, S; Salpietro, A; Dugo, G; Gitto, E; Arrigo, T; Sturiale, M; Salpietro, C

    2015-01-01

    Food allergy is defined as an adverse health effect arising from a specific immune response that occurs reproducibly following exposure to a given food. Cow’s milk protein allergy results from an immunological reaction to one or more milk proteins. The principle key in the treatment of cow’s milk protein allergy is the dietary elimination of cow’s milk protein. Although hydrolyzed and elemental formulas are appropriate replacements, other milk products, including almond milk adequately integrated, could be administered. Here, in the light of encouraging results from our study, we focused on the anti-inflammatory and anti-oxidant properties of almond milk and we also believe that almond milk might be considered as a potential alternative in cow’s milk protein allergy treatment.

  16. Regulation of peroxisome proliferator-activated receptor gamma on milk fat synthesis in dairy cow mammary epithelial cells.

    PubMed

    Liu, Lili; Lin, Ye; Liu, Lixin; Wang, Lina; Bian, Yanjie; Gao, Xuejun; Li, Qingzhang

    2016-12-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) participates in lipogenesis in rats, goats, and humans. However, the exact mechanism of PPARγ regulation on milk fat synthesis in dairy cow mammary epithelial cells (DCMECs) remains largely unexplored. The aim of this study was to investigate the role of PPARγ regarding milk fat synthesis in DCMECs and to ascertain whether milk fat precursor acetic acid and palmitic acid could interact with PPARγ signaling to regulate milk fat synthesis. For this study, we examined the effects of PPARγ overexpression and gene silencing on cell growth, triacylglycerol synthesis, and the messenger RNA (mRNA) and protein expression levels of genes involved in milk fat synthesis in DCMECs. In addition, we investigated the influences of acetic acid and palmitic acid on the mRNA and protein levels of milk lipogenic genes and triacylglycerol synthesis in DCMECs transfected with PPARγ small interfering RNA (siRNA) and PPARγ expression vector. The results showed that when PPARγ was silenced, cell viability, proliferation, and triacylglycerol secretion were obviously reduced. Gene silencing of PPARγ significantly downregulated the expression levels of milk fat synthesis-related genes in DCMECs. PPARγ overexpression improved cell viability, proliferation, and triacylglycerol secretion. The expression levels of milk lipogenic genes were significantly increased when PPARγ was overexpressed. Acetic acid and palmitic acid could markedly improve triacylglycerol synthesis and upregulate the expression levels of PPARγ and other lipogenic genes in DCMECs. These results suggest that PPARγ is a positive regulator of milk fat synthesis in DCMECs and that acetic acid and palmitic acid could partly regulate milk fat synthesis in DCMECs via PPARγ signaling.

  17. Nitrogen and protein components of human milk.

    PubMed

    Hambraeus, L; Lönnerdal, B; Forsum, E; Gebre-Medhin, M

    1978-09-01

    The true protein content of human milk is 0.9%, in well-nourished as well as malnourished mothers. Casein constitutes only about 20% of the protein nitrogen in human milk. The remaining 80% is derived from the whey proteins, the three dominant components being alpha-lactalbumin, lactoferrin and secretory IgA. alpha-lactalbumin is a subunit of lactose synthetase. Lactoferrin is an iron-binding glycoprotein which plays a role in the defence against gastro-intestinal infections and is probably also involved in iron transport in the gut. Secretory IgA is comparatively stable at low pH; it is resistant to proteolytic enzymes and plays an essential role in the immunological defence against gastro-intestinal infections. Lysozyme is a minor component of the whey proteins and represents an active enzyme with a bactericidal effect. The nutritional and immunological significance of the marked differences with respect to the nitrogen and protein compositions of human milk and cow's milk should not be underestimated, but need further elucidation.

  18. Proteins of human milk. I. Identification of major components

    SciTech Connect

    Anderson, N.G.; Powers, M.T.; Tollaksen, S.L.

    1982-04-01

    Traditionally, human milk proteins are identified largely by reference to bovine milk. Hence, to identify the major proteins in human milk, we subjected human and bovine milk, in parallel, to high-resolution two-dimensional electrophoresis. Isoelectric precipitation at pH 4.6 was our criterion for distinguishing whey proteins from those of the casein complex. The ..cap alpha..- and..beta..-caseins were identified on the basis of relative abundance, relative molecular mass, and relative isoelectric points. No protein disappeared from ISO-DALT patterns of human milk after rennin treatment, and no new protein comparable to bovine para K-casein appeared in the BASO-DALT patterns; this suggests that K-casein is absent from human milk. The proteins identified in human milk patterns include the ..cap alpha.. and ..beta.. casein families, lactalbumin, albumin, transferrin, IgA, and lactoferrin. Numerous additional proteins seen in patterns for human milk remain to be identified.

  19. Transcriptional enhancer from milk protein genes

    DOEpatents

    Casperson, Gerald F.; Schmidhauser, Christian T.; Bissell, Mina J.

    1999-01-01

    The invention relates to novel enhancer nucleotide sequences which stimulate transcription of heterologous DNA in cells in culture. The enhancers are derived from major milk protein genes by the process of deletion mapping and functional analysis. The invention also relates to expression vectors containing the novel enhancers.

  20. Transcriptional enhancer from milk protein genes

    SciTech Connect

    Casperson, G.F.; Schmidhauser, C.T.; Bissell, M.J.

    1999-12-21

    The invention relates to novel enhancer nucleotide sequences which stimulate transcription of heterologous DNA in cells in culture. The enhancers are derived from major milk protein genes by the process of deletion mapping and functional analysis. The invention also relates to expression vectors containing the novel enhancers.

  1. Use of Donkey Milk in Children with Cow’s Milk Protein Allergy

    PubMed Central

    Polidori, Paolo; Vincenzetti, Silvia

    2013-01-01

    Human breast milk is the best nutritional support that insures the right development and influences the immune status of the newborn infant. However, when it is not possible to breast feed, it may be necessary to use commercial infant formulas that mimic, where possible, the levels and types of nutrients present in human milk. Despite this, some formula-fed infant develops allergy and/or atopic disease compared to breast-fed infants. Cow’s milk allergy can be divided into immunoglobulin IgE mediated food allergy and non-IgE-mediated food allergy. Most infants with cow’s milk protein allergy (CMPA) develop symptoms before 1 month of age, often within 1 week after introduction of cow’s milk-based formula. Donkey milk may be considered a good substitute for cow’s milk in feeding children with CMPA since its composition is very similar to human milk. Donkey milk total protein content is low (1.5–1.8 g/100 g), very close to human milk. A thorough analysis of the donkey milk protein profile has been performed in this study; the interest was focused on the milk proteins considered safe for the prevention and treatment of various disorders in humans. The content of lactoferrin, lactoperoxidase and lysozyme, peptides with antimicrobial activity, able to stimulate the development of the neonatal intestine, was determined. Donkey milk is characterized by a low casein content, with values very close to human milk; the total whey protein content in donkey milk ranges between 0.49 and 0.80 g/100 g, very close to human milk (0.68–0.83 g/100 g). Among whey proteins, α-lactalbumin average concentration in donkey milk is 1.8 mg/mL. The results of this study confirmed the possibility of using donkey milk in feeding children with CMPA. PMID:28239105

  2. Use of Donkey Milk in Children with Cow's Milk Protein Allergy.

    PubMed

    Polidori, Paolo; Vincenzetti, Silvia

    2013-05-06

    Human breast milk is the best nutritional support that insures the right development and influences the immune status of the newborn infant. However, when it is not possible to breast feed, it may be necessary to use commercial infant formulas that mimic, where possible, the levels and types of nutrients present in human milk. Despite this, some formula-fed infant develops allergy and/or atopic disease compared to breast-fed infants. Cow's milk allergy can be divided into immunoglobulin IgE mediated food allergy and non-IgE-mediated food allergy. Most infants with cow's milk protein allergy (CMPA) develop symptoms before 1 month of age, often within 1 week after introduction of cow's milk-based formula. Donkey milk may be considered a good substitute for cow's milk in feeding children with CMPA since its composition is very similar to human milk. Donkey milk total protein content is low (1.5-1.8 g/100 g), very close to human milk. A thorough analysis of the donkey milk protein profile has been performed in this study; the interest was focused on the milk proteins considered safe for the prevention and treatment of various disorders in humans. The content of lactoferrin, lactoperoxidase and lysozyme, peptides with antimicrobial activity, able to stimulate the development of the neonatal intestine, was determined. Donkey milk is characterized by a low casein content, with values very close to human milk; the total whey protein content in donkey milk ranges between 0.49 and 0.80 g/100 g, very close to human milk (0.68-0.83 g/100 g). Among whey proteins, α-lactalbumin average concentration in donkey milk is 1.8 mg/mL. The results of this study confirmed the possibility of using donkey milk in feeding children with CMPA.

  3. Mild protein hydrolysation of lactose-free milk further reduces milk-related gastrointestinal symptoms.

    PubMed

    Turpeinen, Anu; Kautiainen, Hanna; Tikkanen, Marja-Leena; Sibakov, Timo; Tossavainen, Olli; Myllyluoma, Eveliina

    2016-05-01

    Gastrointestinal symptoms associated with milk are common. Besides lactose, milk proteins may cause symptoms in sensitive individuals. We have developed a method for mild enzymatic hydrolysation of milk proteins and studied the effects of hydrolysed milk on gastrointestinal symptoms in adults with a self-diagnosed sensitive stomach. In a double blind, randomised placebo-controlled study, 97 subjects consumed protein-hydrolysed lactose-free milk or commercially available lactose-free milk for 10 d. Frequency of gastrointestinal symptoms during the study period was reported and a symptom score was calculated. Rumbling and flatulence decreased significantly in the hydrolysed milk group (P < 0·05). Also, the total symptom score was lower in subjects who consumed hydrolysed milk (P < 0·05). No difference between groups was seen in abdominal pain (P = 0·47) or bloating (P = 0·076). The results suggest that mild enzymatic protein hydrolysation may decrease gastrointestinal symptoms in adults with a sensitive stomach.

  4. Chemical Synthesis of Proteins

    PubMed Central

    Nilsson, Bradley L.; Soellner, Matthew B.; Raines, Ronald T.

    2010-01-01

    Proteins have become accessible targets for chemical synthesis. The basic strategy is to use native chemical ligation, Staudinger ligation, or other orthogonal chemical reactions to couple synthetic peptides. The ligation reactions are compatible with a variety of solvents and proceed in solution or on a solid support. Chemical synthesis enables a level of control on protein composition that greatly exceeds that attainable with ribosome-mediated biosynthesis. Accordingly, the chemical synthesis of proteins is providing previously unattainable insight into the structure and function of proteins. PMID:15869385

  5. A novel preparation of milk protein/polyethylene terephthalate fabric

    NASA Astrophysics Data System (ADS)

    Zhou, J. F.; Zheng, D. D.; Zhong, L.; Zhang, F. X.; Zhang, G. X.

    2016-07-01

    In this work, -NH2 groups were introduced to polyethylene terephthalate (PET) fibers by nitration and reduction method, and then milk protein was grafted on the nitrated and reduced PET (NR PET) fibers by sucrose glycidyl ether crosslinking agent. FTIR suggested the milk protein was successfully grafted on PET fiber surface. SEM images showed a layer of substance covered on the PET fiber surface. DSC demonstrated an excellent thermal stability of milk protein/PET fiber. The moisture regain was improved by milk protein/PET fiber. Moreover, the crease recovery angle and stiffness were retained by the milk protein/PET fabric.

  6. Commercial Milk Enzyme-Linked Immunosorbent Assay (ELISA) Kit Reactivities to Purified Milk Proteins and Milk-Derived Ingredients.

    PubMed

    Ivens, Katherine O; Baumert, Joseph L; Taylor, Steve L

    2016-07-01

    Numerous commercial enzyme-linked immunosorbent assay (ELISA) kits exist to quantitatively detect bovine milk residues in foods. Milk contains many proteins that can serve as ELISA targets including caseins (α-, β-, or κ-casein) and whey proteins (α-lactalbumin or β-lactoglobulin). Nine commercially-available milk ELISA kits were selected to compare the specificity and sensitivity with 5 purified milk proteins and 3 milk-derived ingredients. All of the milk kits were capable of quantifying nonfat dry milk (NFDM), but did not necessarily detect all individual protein fractions. While milk-derived ingredients were detected by the kits, their quantitation may be inaccurate due to the use of different calibrators, reference materials, and antibodies in kit development. The establishment of a standard reference material for the calibration of milk ELISA kits is increasingly important. The appropriate selection and understanding of milk ELISA kits for food analysis is critical to accurate quantification of milk residues and informed risk management decisions.

  7. Proteomic analysis to unravel the effect of heat stress on gene expression and milk synthesis in bovine mammary epithelial cells.

    PubMed

    Li, Lian; Wang, Yiru; Li, Chengmin; Wang, Genlin

    2017-08-14

    Heat stress can play a negative effect on milk yield and composition of dairy cattle, leading to immeasurable economic loss. The basic components of the mammary gland are the alveoli; these alveolar mammary epithelial cells reflect the milk producing ability of dairy cows. In this study, we exposed bovine mammary epithelial cells to heat stress and compared them to a control group using isobaric tags for relative and absolute quantitation combined with liquid chromatography coupled with tandem mass spectrometry. Compared with a control group, 104 differentially elevated proteins (>1.3-fold) and 167 decreased proteins (<0.77-fold) were identified in the heat treatment group. Gene Ontology analysis identified a majority of the differentially expressed proteins are associated in cell-substrate junction assembly, catabolic processes and metabolic processes. Some of these significantly regulated proteins were related to the synthesis and secretion of milk, such as milk protein and fat. This finding was further supported by the results obtained from the reduced β-casein expression through the system of plasminogen activator - plasminogen - plasmin and decreased fatty acid synthase could partly explain why milk fat synthesis ability of dairy cows decreased under heat stress. Our results highlight the effects of heat stress on synthesis of milk protein and fat, thus providing additional clues for further studies of heat stress on dairy milk production. © 2017 Japanese Society of Animal Science.

  8. Donkey milk-based formula: A substitute for patients with cow’s milk protein allergy

    PubMed Central

    2011-01-01

    Cow’s milk protein allergy affects 2-7% of children using cow’s milk formulae. Fifty to eighty percent of them develop allergy to other food items and substitutes. On the search for a safe and affordable substitute, we reviewed the composition of milks of the domestic mammals in close contact with man. Milk constituents studied included fat, protein, lactose, minerals, water, pH, specific gravity and caloric value. Compared to others, donkey milk was found to be closest to breast milk when the amount of 16ml of sunflower is added to one liter of this milk. To our knowledge, no allergy to donkey milk has been reported yet. PMID:27493315

  9. Short-term administration of rhGH increases markers of cellular proliferation, but not milk protein gene expression in normal lactating women.

    USDA-ARS?s Scientific Manuscript database

    Growth hormone is one of few pharmacologic agents known to augment milk production in humans. We hypothesized that recombinant human GH (rhGH) increases the expression of cell proliferation and milk protein synthesis genes. Sequential milk and blood samples collected over four days were obtained fro...

  10. Rapid sensing of melamine in milk by interference green synthesis of silver nanoparticles.

    PubMed

    Varun, S; Kiruba Daniel, S C G; Gorthi, Sai Siva

    2017-05-01

    A highly sensitive, selective, and rapid interference green synthesis based determination of potential milk adulterant melamine has been reported here. Melamine is a nitrogenous compound added to milk for mimicking proteins, consumption of which leads to kidney stones and renal failures. Melamine interacts with ascorbic acid (AA) through strong hydrogen-bonding interactions, thus resulting in an interference/interruption in the formation of silver (Ag) nanoparticles which was confirmed by UV-Vis spectroscopy and Transmission Electron Microscopy (TEM). The corresponding benchmark validations for melamine spiked milk samples were performed using High Performance Liquid Chromatography (HPLC). This interference in the formation of Ag nanoparticles resulted in color change that varies with concentration of melamine, thereby enabling in-situ rapid sensing of melamine from milk to a lower limit of 0.1ppm with a linear correlation coefficient of 0.9908. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Relationships between milk protein composition, milk protein variants, and cow fertility traits in Dutch Holstein-Friesian cattle.

    PubMed

    Demeter, R M; Markiewicz, K; van Arendonk, J A M; Bovenhuis, H

    2010-11-01

    Selective breeding can change milk protein composition to improve the manufacturing properties of milk. However, the effects of such breeding strategies on other economically important traits should be investigated before implementation. The objectives of this study were to examine the association between cow fertility traits and (1) milk protein composition and (2) milk protein variants (β-lactoglobulin, β-casein, κ-casein, and β-κ-casein) in commercial Dutch Holstein-Friesian cattle. Data on 1,644 first-lactation cows were analyzed by fitting linear mixed models. Greater relative concentration of α(S1)-casein within total milk protein had a positive phenotypic relationship with nonreturn rates and calving rate after first insemination. Furthermore, results showed virtually no significant relationship between cow fertility and concentration of other milk proteins or milk protein variants. Results of this study can be used to assess the correlated effects of breeding for improved milk protein composition on reproduction, thereby allowing for better evaluation of breeding programs before implementation. Our findings suggest that selecting cows based on milk protein composition or milk protein variants for improved manufacturing properties would have no negative influence on reproductive performance. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Modification of the analysis of parathyroid hormone-related protein in milk and concentrations of this protein in commercial milk and milk products in Japan.

    PubMed

    Onda, K; Yamaguchi, M; Ohashi, M; Sato, R; Ochiai, H; Iriki, T; Wada, Y

    2010-05-01

    Parathyroid hormone-related protein (PTHrP), which causes hypercalcemia associated with malignant tumors, is known to be present in milk. Gene expression of PTHrP in the mammary gland increases markedly during parturition and with the onset of lactation. Even when circulating PTHrP levels are extremely low or below the detection limit, milk PTHrP levels are remarkably high. Parathyroid hormone-related protein derived from the mammary gland is assumed to play a role in maintaining the maternal calcium homeostasis and calcium transport from blood to milk. In previous studies that determined the PTHrP concentrations in milk, the pretreatments and diluent composition were not standardized. Here, we investigated the effect of various pretreatment procedures and diluent constitutions and the consequent PTHrP concentrations in commercial milk and milk products in Japan. Significant differences were found in PTHrP concentrations in raw milk samples subjected to different combinations of pretreatments (mixing, centrifugation, acidification, and heating) and diluents (0pM standard solution of PTHrP, plasma treated with protease inhibitors, and original diluent). We measured the PTHrP concentrations in normal liquid milk, processed milk, milk drinks, formulated milk powders, and skim milk powder by using the appropriate combination of pretreatment (acidification) and diluent (plasma treated with protease inhibitors). The PTHrP concentration in normal liquid milk, processed milk, and skim milk powder was as high as that in raw milk (>5nM), whereas that in milk drinks differed considerably. The PTHrP concentration in infant formulas (<2nM) was lower than that in the other milk products. These results indicate that a certain amount of PTHrP is ingested when milk and milk products are consumed.

  13. Milk, revealed "silent" chemistry: new mode of cycloretinal synthesis.

    PubMed

    Bench, Bennie J; Foulke-Abel, Jennifer; Watanabe, Coran M H

    2011-01-01

    Bovine milk is by far the most commonly consumed milk in the western world. The protein composition in milk consists of casein and whey proteins, of which β-lactoglobulin (BLG) is the principal constituent of the latter. Here we provide biochemical evidence that this milk protein, in purified form and in pasteurized store-bought milk, promotes the formation of cycloretinal (all-trans retinal dimer), and a variety of other cycloterpenals of biological relevance [Fishkin et al., Proc. Natl. Acad. Sci. U. S. A., 2005, 102, 7091-7096; Fishkin et al., Chirality, 2004, 16, 637-641; Kim et al., Proc. Natl. Acad. Sci. U. S. A., 2007, 104, 19273-19278]. Cycloretinal is an eye metabolite and among several toxic byproducts of the visual cycle firmly established to cause age-related macular degeneration. Experiments in rabbits further demonstrate that BLG/milk can survive the digestive system and promote this reaction in vivo [Caillard et al., Am. J. Physiol., 1994, 266(6), G1053-G1059]. Proteomic studies on age-related macular degeneration patients have detected BLG in the eye of these patients further suggesting that this milk protein could contribute to disease progression [Crabb et al., Proc. Natl. Acad. Sci. U. S. A., 2002, 99(23), 14682-14687].

  14. [Proteins of human milk involved in immunological processes].

    PubMed

    Lis, Jolanta; Orczyk-Pawiłowicz, Magdalena; Kątnik-Prastowska, Iwona

    2013-05-31

    Human milk contains a lot of components (i.e. proteins, carbohydrates, lipids, inorganic elements) which provide basic nutrients for infants during the first period of their lives. Qualitative composition of milk components of healthy mothers is similar, but their levels change during lactation stages. Colostrum is the fluid secreted during the first days postpartum by mammary epithelial cells. Colostrum is replaced by transitional milk during 5-15 days postpartum and from 15 days postpartum mature milk is produced. Human milk, apart from nutritional components, is a source of biologically active molecules, i.e. immunoglobulins, growth factors, cytokines, acute phase proteins, antiviral and antibacterial proteins. Such components of human milk are responsible for specific biological activities of human milk. This secretion plays an important role in growth and development of newborns. Bioactive molecules present in the milk support the immature immune system of the newborn and also protect against the development of infection. In this article we describe the pathways involved in the production and secretion of human milk, the state of knowledge on the proteome of human milk, and the contents of components of milk during lactation. Moreover, some growth factors and proteins involved in innate and specific immunity, intercellular communication, immunomodulation, and inflammatory processes have been characterized.

  15. Composition and Variation of Macronutrients, Immune Proteins, and Human Milk Oligosaccharides in Human Milk From Nonprofit and Commercial Milk Banks.

    PubMed

    Meredith-Dennis, Laura; Xu, Gege; Goonatilleke, Elisha; Lebrilla, Carlito B; Underwood, Mark A; Smilowitz, Jennifer T

    2017-06-01

    When human milk is unavailable, banked milk is recommended for feeding premature infants. Milk banks use processes to eliminate pathogens; however, variability among methods exists. Research aim: The aim of this study was to compare the macronutrient (protein, carbohydrate, fat, energy), immune-protective protein, and human milk oligosaccharide (HMO) content of human milk from three independent milk banks that use pasteurization (Holder vs. vat techniques) or retort sterilization. Randomly acquired human milk samples from three different milk banks ( n = 3 from each bank) were analyzed for macronutrient concentrations using a Fourier transform mid-infrared spectroscopy human milk analyzer. The concentrations of IgA, IgM, IgG, lactoferrin, lysozyme, α-lactalbumin, α antitrypsin, casein, and HMO were analyzed by mass spectrometry. The concentrations of protein and fat were significantly ( p < .05) less in the retort sterilized compared with the Holder and vat pasteurized samples, respectively. The concentrations of all immune-modulating proteins were significantly ( p < .05) less in the retort sterilized samples compared with vat and/or Holder pasteurized samples. The total HMO concentration and HMOs containing fucose, sialic acid, and nonfucosylated neutral sugars were significantly ( p < .05) less in retort sterilized compared with Holder pasteurized samples. Random milk samples that had undergone retort sterilization had significantly less immune-protective proteins and total and specific HMOs compared with samples that had undergone Holder and vat pasteurization. These data suggest that further analysis of the effect of retort sterilization on human milk components is needed prior to widespread adoption of this process.

  16. Role of milk protein-based products in some quality attributes of goat milk yogurt.

    PubMed

    Gursel, A; Gursoy, A; Anli, E A K; Budak, S O; Aydemir, S; Durlu-Ozkaya, F

    2016-04-01

    Goat milk yogurts were manufactured with the fortification of 2% (wt/vol) skim goat milk powder (SGMP), sodium caseinate (NaCn), whey protein concentrate (WPC), whey protein isolate (WPI), or yogurt texture improver (YTI). Yogurts were characterized based on compositional, microbiological, and textural properties; volatile flavor components (with gas chromatography); and sensory analyses during storage (21d at 5 °C). Compared with goat milk yogurt made by using SGMP, the other goat milk yogurt variants had higher protein content and lower acidity values. Goat milk yogurts with NaCn and WPC, in particular, had better physical characteristics. Using WPI caused the hardest structure in yogurt, leading to higher syneresis values. Acetaldehyde and ethanol formation increased with the incorporation of WPI, WPC, or YTI to yogurt milk. The tyrosine value especially was higher in the samples with NaCn and YTI than in the samples with WPC and WPI. Counts of Streptococcus thermophilus were higher than the counts of Lactobacillus delbrueckii ssp. bulgaricus, possibly due to a stimulatory effect of milk protein-based ingredients other than SGMP on the growth of S. thermophilus. Yogurt with NaCn was the best accepted among the yogurts. For the parameters used, milk protein-based products such as NaCn or WPC have promising features as suitable ingredients for goat milk yogurt manufacture.

  17. Nutrigenomics, rumen-derived bioactive fatty acids, and the regulation of milk fat synthesis.

    PubMed

    Bauman, Dale E; Harvatine, Kevin J; Lock, Adam L

    2011-08-21

    Mammary synthesis of milk fat continues to be an active research area, with significant advances in the regulation of lipid synthesis by bioactive fatty acids (FAs). The biohydrogenation theory established that diet-induced milk fat depression (MFD) in the dairy cow is caused by an inhibition of mammary synthesis of milk fat by specific FAs produced during ruminal biohydrogenation. The first such FA shown to affect milk fat synthesis was trans-10, cis-12 conjugated linoleic acid, and its effects have been well characterized, including dose-response relationships. During MFD, lipogenic capacity and transcription of key mammary lipogenic genes are coordinately down-regulated. Results provide strong evidence for sterol response element-binding protein-1 (SREBP1) and Spot 14 as biohydrogenation intermediate responsive lipogenic signaling pathway for ruminants and rodents. The study of MFD and its regulation by specific rumen-derived bioactive FAs represents a successful example of nutrigenomics in present-day animal nutrition research and offers several potential applications in animal agriculture.

  18. Effect of protein degradability on milk production of dairy ewes.

    PubMed

    Mikolayunas-Sandrock, C; Armentano, L E; Thomas, D L; Berger, Y M

    2009-09-01

    The objective of this experiment was to determine the effect of protein degradability of dairy sheep diets on milk yield and protein utilization across 2 levels of milk production. Three diets were formulated to provide similar energy concentrations and varying concentrations of rumen-degradable protein (RDP) and rumen-undegradable protein (RUP): 12% RDP and 4% RUP (12-4) included basal levels of RDP and RUP, 12% RDP and 6% RUP (12-6) included additional RUP, and 14% RDP and 4% RUP (14-4) included additional RDP. Diets were composed of alfalfa-timothy cubes, whole and ground corn, whole oats, dehulled soybean meal, and expeller soybean meal (SoyPlus, West Central, Ralston, IA). Estimates of RDP and RUP were based on the Small Ruminant Nutrition System model (2008) and feed and orts were analyzed for Cornell N fractions. Eighteen multiparous dairy ewes in midlactation were divided by milk yield (low and high) into 2 blocks of 9 ewes each and were randomly assigned within block (low and high) to 3 pens of 3 ewes each. Dietary treatments were arranged in a 3 x 3 Latin square within each block and applied to pens for 14-d periods. We hypothesized that pens consuming high-RUP diets (12-6) would produce more milk and milk protein than the basal diet (12-4) and pens consuming high-RDP diets (14-4) would not produce more milk than the basal diet (12-4). Ewes in the high-milk-yield square consumed more dry matter and produced more milk, milk fat, and milk protein than ewes in the low-milk-yield square. There was no effect of dietary treatment on dry matter intake. Across both levels of milk production, the 12-6 diet increased milk yield by 14%, increased milk fat yield by 14%, and increased milk protein yield by 13% compared with the 14-4 and 12-4 diets. Gross N efficiency (milk protein N/intake protein N) was 11 and 15% greater in the 12-6 and 12-4 diets, respectively, compared with the 14-4 diet. Milk urea N concentration was greater in the 12-6 diet and tended to be

  19. Short-term effects of milking frequency on milk yield, milk composition, somatic cell count and milk protein profile in dairy goats.

    PubMed

    Torres, Alexandr; Hernández-Castellano, Lorenzo-Enrique; Morales-delaNuez, Antonio; Sánchez-Macías, Davinia; Moreno-Indias, Isabel; Castro, Noemi; Capote, Juan; Argüello, Anastasio

    2014-08-01

    Goats in Canary Islands are milked once a day by tradition, but in most countries with high technology on farms, goats are milked twice a day, which is known to improve milk yield. Therefore it is important to know whether the increase of milking frequency can improve the production without impairing milk quality. The objective of this study was to investigate the short term effects of three milking frequencies on milk yield, milk composition, somatic cell count (SCC) and milk protein profile in dairy goats traditionally milked once a day. Twelve Majorera goats in early lactation (48±4 d in milk) were used. During a 5-week period, goats were milked once a day (X1) in weeks 1 and 5, twice a day (X2) in weeks 2 and 4, and three times a day (X3) in week 3. Milk recording and sampling were done on the last day of each experimental week. Milk yield increased by 26% from X1 to X2. No differences were obtained when goats were switched from X2 to X3, and from X3 to X2. The goats recovered the production level when they returned to X1. Different patterns of changes in the milk constituents due to the milking frequency effect were observed. Fat percentage increased when switched from X1 to X2, then decreased from X2 to X3, and from X3 to X2, whereas it did not show significant differences from X2 to X1. Milking frequency did not affect the protein and lactose percentages. SCC values were unaffected when goats were milked X1, X2 and X3, but then they increased slightly when milking frequency was returned to X2 and X1. Finally, quantitative analysis showed an increase in intensities of milk protein bands from X1 to X2, but the intensities of casein bands (α(S1)-CN, α(S2)-CN, β-CN, κ-CN) and major whey proteins (α-La, β-Lg) decreased from X2 to X3.

  20. Physical properties of ice cream containing milk protein concentrates.

    PubMed

    Alvarez, V B; Wolters, C L; Vodovotz, Y; Ji, T

    2005-03-01

    Two milk protein concentrates (MPC, 56 and 85%) were studied as substitutes for 20 and 50% of the protein content in ice cream mix. The basic mix formula had 12% fat, 11% nonfat milk solids, 15% sweetener, and 0.3% stabilizer/emulsifier blend. Protein levels remained constant, and total solids were compensated for in MPC mixes by the addition of polydextrose. Physical properties investigated included apparent viscosity, fat globule size, melting rate, shape retention, and freezing behavior using differential scanning calorimetry. Milk protein concentrate formulations had higher mix viscosity, larger amount of fat destabilization, narrower ice melting curves, and greater shape retention compared with the control. Milk protein concentrates did not offer significant modifications of ice cream physical properties on a constant protein basis when substituted for up to 50% of the protein supplied by nonfat dry milk. Milk protein concentrates may offer ice cream manufacturers an alternative source of milk solids non-fat, especially in mixes reduced in lactose or fat, where higher milk solids nonfat are needed to compensate other losses of total solids.

  1. Chocolate milk and endurance exercise recovery: protein balance, glycogen, and performance.

    PubMed

    Lunn, William R; Pasiakos, Stefan M; Colletto, Megan R; Karfonta, Kirstin E; Carbone, John W; Anderson, Jeffrey M; Rodriguez, Nancy R

    2012-04-01

    This study examined effects of fat-free chocolate milk (MILK) consumption on kinetic and cellular markers of protein turnover, muscle glycogen, and performance during recovery from endurance exercise. Male runners participated in two trials separated by 1 wk and consumed either MILK or a nonnitrogenous isocaloric carbohydrate (CHO) control beverage (CON) after a 45-min run at 65% of V˙O(2peak). Postexercise muscle protein fractional synthetic rate (FSR) and whole-body protein turnover were determined during 3 h of recovery using muscle biopsies and primed constant infusions of L-[ring-²H₅]phenylalanine and L-[1-¹³C]leucine, respectively. Phosphorylation of translational signaling proteins and activity of proteolytic molecules were determined using Western blotting and enzymatic activity assays. Muscle glycogen was quantified, and treadmill time to exhaustion was determined after the recovery period. Consuming MILK after exercise resulted in higher mixed muscle FSR with lower whole-body proteolysis and synthesis compared with CON (P ≤ 0.05). Phosphorylation of eIF4E-BP1 and FOXO3a was higher for MILK (P < 0.01), whereas Akt phosphorylation was lower during recovery regardless of dietary treatment (P < 0.05). Enzymatic activity assays indicated lower caspase-3 activity during recovery for MILK (P < 0.01) and higher 26S proteasome activity for CON (P < 0.01). Muscle glycogen was not affected by either dietary treatment; however, time to exhaustion was greater for MILK than for CON (P < 0.05). The effects of consumption of MILK after endurance exercise on FSR, signaling molecules of skeletal muscle protein turnover, leucine kinetics, and performance measures suggest unique benefits of milk compared with a CHO-only beverage.

  2. Synthesis of Lipidated Proteins.

    PubMed

    Mejuch, Tom; Waldmann, Herbert

    2016-08-17

    Protein lipidation is one of the major post-translational modifications (PTM) of proteins. The attachment of the lipid moiety frequently determines the localization and the function of the lipoproteins. Lipidated proteins participate in many essential biological processes in eukaryotic cells, including vesicular trafficking, signal transduction, and regulation of the immune response. Malfunction of these cellular processes usually leads to various diseases such as cancer. Understanding the mechanism of cellular signaling and identifying the protein-protein and protein-lipid interactions in which the lipoproteins are involved is a crucial task. To achieve these goals, fully functional lipidated proteins are required. However, access to lipoproteins by means of standard expression is often rather limited. Therefore, semisynthetic methods, involving the synthesis of lipidated peptides and their subsequent chemoselective ligation to yield full-length lipoproteins, were developed. In this Review we summarize the commonly used methods for lipoprotein synthesis and the development of the corresponding chemoselective ligation techniques. Several key studies involving full-length semisynthetic lipidated Ras, Rheb, and LC3 proteins are presented.

  3. Detection of cow's milk proteins and minor components in human milk using proteomics techniques.

    PubMed

    Coscia, A; Orrù, S; Di Nicola, P; Giuliani, F; Varalda, A; Peila, C; Fabris, C; Conti, A; Bertino, E

    2012-10-01

    Cow's milk proteins (CMPs) are the best characterized food allergens. The aim of this study was to investigate cow's milk allergens in human colostrum of term and preterm newborns' mothers, and other minor protein components by proteomics techniques, more sensitive than other techniques used in the past. Sixty-two term and 11 preterm colostrum samples were collected, subjected to a treatment able to increase the concentration of the most diluted proteins and simultaneously to reduce the concentration of the proteins present at high concentration (Proteominer Treatment), and subsequently subjected to the steps of proteomic techniques. The most relevant finding in this study was the detection of the intact bovine alpha-S1-casein in human colostrum, then bovine alpha-1-casein could be considered the cow's milk allergen that is readily secreted in human milk and could be a cause of sensitization to cow's milk in exclusively breastfed predisposed infants. Another interesting result was the detection, at very low concentrations, of proteins previously not described in human milk (galectin-7, the different isoforms of the 14-3-3 protein and the serum amyloid P-component), probably involved in the regulation of the normal cell growth, in the pro-apoptotic function and in the regulation of tissue homeostasis. Further investigations are needed to understand if these families of proteins have specific biological activity in human milk.

  4. Manufacture of nonfat yogurt from a high milk protein powder.

    PubMed

    Mistry, V V; Hassan, H N

    1992-04-01

    Nonfat yogurts were manufactured from skim milk fortified with a new high milk protein powder. The powder, containing approximately 84% milk protein, was added to skim milk to obtain 5.2 to 11.3% total protein, 11.1 to 15% total solids, and 1.6 to 7.9% lactose in the yogurt mix. Mixes were homogenized, pasteurized at 90 degrees C for 10 min, and fermented with a yogurt culture at 42 degrees C to pH 4.6. Controls were made from the same skim milk fortified with NDM to approximately 14% total solids. Yogurts made with the protein powder and containing 5.6% protein were similar in firmness to the control and had good flavor when fresh and after 2 wk of storage. Yogurts with more than 5.6% protein were too firm and had an astringent flavor. Acetaldehyde content of all yogurts was comparable with that of the control, and fat content ranged from .18 to .33%. As the protein content of yogurts increased, the porosity of yogurts, as seen by scanning electron microscopy, decreased. Good quality nonfat yogurts can be produced by supplementing skim milk with a high milk protein powder up to 5.6% protein. The added protein assists in providing a firm body and minimal whey separation without the use of stabilizers.

  5. Tudor-SN Regulates Milk Synthesis and Proliferation of Bovine Mammary Epithelial Cells

    PubMed Central

    Ao, Jinxia; Wei, Chengjie; Si, Yu; Luo, Chaochao; Lv, Wei; Lin, Ye; Cui, Yingjun; Gao, Xuejun

    2015-01-01

    Tudor staphylococcal nuclease (Tudor-SN) is a highly conserved and ubiquitously expressed multifunctional protein, related to multiple and diverse cell type- and species-specific cellular processes. Studies have shown that Tudor-SN is mainly expressed in secretory cells, however knowledge of its role is limited. In our previous work, we found that the protein level of Tudor-SN was upregulated in the nucleus of bovine mammary epithelial cells (BMEC). In this study, we assessed the role of Tudor-SN in milk synthesis and cell proliferation of BMEC. We exploited gene overexpression and silencing methods, and found that Tudor-SN positively regulates milk synthesis and proliferation via Stat5a activation. Both amino acids (methionine) and estrogen triggered NFκB1 to bind to the gene promoters of Tudor-SN and Stat5a, and this enhanced the protein level and nuclear localization of Tudor-SN and p-Stat5a. Taken together, these results suggest the key role of Tudor-SN in the transcriptional regulation of milk synthesis and proliferation of BMEC under the stimulation of amino acids and hormones. PMID:26694361

  6. Short-term administration of rhGH increases markers of cellular proliferation but not milk protein gene expression in normal lactating women

    PubMed Central

    Maningat, Patricia D.; Sen, Partha; Rijnkels, Monique; Hadsell, Darryl L.; Bray, Molly S.

    2011-01-01

    Growth hormone is one of few pharmacologic agents known to augment milk production in humans. We hypothesized that recombinant human GH (rhGH) increases the expression of cell proliferation and milk protein synthesis genes. Sequential milk and blood samples collected over four days were obtained from five normal lactating women. Following 24 h of baseline milk and blood sampling, rhGH (0.1 mg/kg/day) was administered subcutaneously once daily for 3 days. Gene expression changes were determined by microarray studies utilizing milk fat globule RNA isolated from each milk sample. Following rhGH administration, DNA synthesis and cell cycle genes were induced, while no significant changes were observed in the expression of milk synthesis genes. Expression of glycolysis and citric acid cycle genes were increased by day 4 compared with day 1, while lipid synthesis genes displayed a circadian-like pattern. Cell cycle gene upregulation occurred after a lag of ∼2 days, likely explaining the failure to increase milk production after only 3 days of rhGH treatment. We conclude that rhGH induces expression of cellular proliferation and metabolism genes but does not induce milk protein gene expression, as potential mechanisms for increasing milk production and could account for the known effect of rhGH to increase milk production following 7–10 days. PMID:21205870

  7. Regulation of lipid synthesis genes and milk fat production in human mammary epithelial cells during secretory activation.

    PubMed

    Mohammad, Mahmoud A; Haymond, Morey W

    2013-09-15

    Expression of genes for lipid biosynthetic enzymes during initiation of lactation in humans is unknown. Our goal was to study mRNA expression of lipid metabolic enzymes in human mammary epithelial cell (MEC) in conjunction with the measurement of milk fatty acid (FA) composition during secretory activation. Gene expression from mRNA isolated from milk fat globule (MFG) and milk FA composition were measured from 6 h to 42 days postpartum in seven normal women. Over the first 96 h postpartum, daily milk fat output increased severalfold and mirrored expression of genes for all aspects of lipid metabolism and milk FA production, including lipolysis at the MEC membrane, FA uptake from blood, intracellular FA transport, de novo FA synthesis, FA and glycerol activation, FA elongation, FA desaturation, triglyceride synthesis, cholesterol synthesis, and lipid droplet formation. Expression of the gene for a key lipid synthesis regulator, sterol regulatory element-binding transcription factor 1 (SREBF1), increased 2.0-fold by 36 h and remained elevated over the study duration. Expression of genes for estrogen receptor 1, thyroid hormone-responsive protein, and insulin-induced 2 increased progressively to plateau by 96 h. In contrast, mRNA of peroxisome proliferator-activated receptor-γ decreased severalfold. With onset of lactation, increased de novo synthesis of FA was the most prominent change in milk FA composition and mirrored the expression of FA synthesis genes. In conclusion, milk lipid synthesis and secretion in humans is a complex process requiring the orchestration of a wide variety of pathways of which SREBF1 may play a primary role.

  8. De novo synthesis of milk triglycerides in humans

    PubMed Central

    Mohammad, Mahmoud A.; Sunehag, Agneta L.

    2014-01-01

    Mammary gland (MG) de novo lipogenesis contributes significantly to milk fat in animals but little is known in humans. Objective: To test the hypothesis that the incorporation of 13C carbons from [U-13C]glucose into fatty acids (FA) and glycerol in triglycerides (TG) will be greater: 1) in milk than plasma TG, 2) during a high-carbohydrate (H-CHO) diet than high-fat (H-FAT) diet, and 3) during feeding than fasting. Seven healthy, lactating women were studied on two isocaloric, isonitrogenous diets. On one occasion, subjects received diets containing H-FAT or H-CHO diet for 1 wk. Incorporation of 13C from infused [U-13C]glucose into FA and glycerol was measured using GC-MS and gene expression in RNA isolated from milk fat globule using microarrays. Incorporation of 13C2 into milk FA increased with increased FA chain length from C2:0 to C12:0 but progressively declined in C14:0 and C16:0 and was not detected in FA>C16. During feeding, regardless of diets, enrichment of 13C2 in milk FA and 13C3 in milk glycerol were ∼3- and ∼7-fold higher compared with plasma FA and glycerol, respectively. Following an overnight fast during H-CHO and H-FAT diets, 25 and 6%, respectively, of medium-chain FA (MCFA, C6–C12) in milk were derived from glucose but increased to 75 and 25% with feeding. Expression of genes involved in FA or glycerol synthesis was unchanged regardless of diet or fast/fed conditions. The human MG is capable of de novo lipogenesis of primarily MCFA and glycerol, which is influenced by the macronutrient composition of the maternal diet. PMID:24496312

  9. The daily rhythm of milk synthesis is dependent on the timing of feed intake in dairy cows

    PubMed Central

    Rottman, L. Whitney; Ying, Yun; Zhou, Kan; Bartell, Paul A.; Harvatine, Kevin J.

    2014-01-01

    Abstract Regulation of the daily rhythm of milk synthesis is important to production animals and breastfeeding, but is difficult to observe in nursing animals. The rate of food intake varies over the day and is expected to create a daily rhythm of nutrient absorption. The objective of this study was to determine if the timing of food intake entrains a daily pattern of milk synthesis. Seventeen Holstein cows were used in a crossover design. Treatments were ad libitum feeding of a total mixed ration once daily (1× fed) or fed in four equal meals every 6 h (4× fed). Cows were milked every 6 h the last 7 days of each period. There was a treatment by time of day interaction for milk and milk component yield and concentration. Milk fat and protein concentration and yield exhibited a daily rhythm and the amplitude of the rhythm was reduced in 4× fed. In addition, milk fat percent was higher in 4× fed than 1× fed at three of the four milking intervals (0.22–0.45% higher) and 4× fed increased daily milk fat yield. Treatment by time of day interactions were detected for plasma glucose, insulin, and blood urea nitrogen. These variables also fit a cosine function with a 24 h period and the amplitudes of plasma glucose, insulin, and blood urea nitrogen rhythms were decreased by 4× feeding. In conclusion, there is a circadian pattern of milk synthesis in the dairy cow that is responsive to the timing of food intake. PMID:24963033

  10. Trace elements and their distribution in protein fractions of camel milk in comparison to other commonly consumed milks.

    PubMed

    Al-Awadi, F M; Srikumar, T S

    2001-08-01

    Studies on camels' milk, whether with respect to concentration or bioavailability of trace elements from this milk, are limited and warrant further investigation. The object of this study was to analyse the concentration and distribution of zinc, copper, selenium, manganese and iron in camel milk compared to those in human milk, cows' milk and infant formula under similar experimental conditions. Camels' milk and cows' milk were collected from local farms, human milk samples were obtained from healthy donors in Kuwait and infant formula was purchased locally. Milk fractionation was performed by ultra-centrifugation and gelcolumn chromatography. The concentration of trace elements was analysed by atomic absorption spectrometry and that of protein was determined spectrophotometrically. The concentration of manganese and iron in camels' milk was remarkably higher (7-20-fold and 4-10-fold, respectively) than in human milk, cows' milk and infant formula. The zinc content of camels' milk was higher than that of human milk but slightly lower than in cows' milk and infant formula. The concentration of copper in camels' milk was similar to that of cows' milk but lower than in human milk and infant formula. The selenium content of camels' milk was comparable to those of other types of milk, Approximately 50-80% of zinc, copper and manganese in camels' milk were associated with the casein fraction, similar to that of cows' milk, The majority of selenium and iron in camels' milk was in association with the low molecular weight fraction, It is recommended that camels' milk be considered as a potential source of manganese, selenium and iron, perhaps not only for infants, but also for other groups suspected of mild deficiency of these elements. Further investigations are required to confirm this proposal.

  11. Following the digestion of milk proteins from mother to baby.

    PubMed

    Holton, Thérèse A; Vijayakumar, Vaishnavi; Dallas, David C; Guerrero, Andrés; Borghese, Robyn A; Lebrilla, Carlito B; German, J Bruce; Barile, Daniela; Underwood, Mark A; Shields, Denis C; Khaldi, Nora

    2014-12-05

    Little is known about the digestive process in infants. In particular, the chronological activity of enzymes across the course of digestion in the infant remains largely unknown. To create a temporal picture of how milk proteins are digested, enzyme activity was compared between intact human milk samples from three mothers and the gastric samples from each of their 4-12 day postpartum infants, 2 h after breast milk ingestion. The activities of 7 distinct enzymes are predicted in the infant stomach based on their observed cleavage pattern in peptidomics data. We found that the same patterns of cleavage were evident in both intact human milk and gastric milk samples, demonstrating that the enzyme activities that begin in milk persist in the infant stomach. However, the extent of enzyme activity is found to vary greatly between the intact milk and gastric samples. Overall, we observe that milk-specific proteins are cleaved at higher levels in the stomach compared to human milk. Notably, the enzymes we predict here only explain 78% of the cleavages uniquely observed in the gastric samples, highlighting that further investigation of the specific enzyme activities associated with digestion in infants is warranted.

  12. Following the Digestion of Milk Proteins from Mother to Baby

    PubMed Central

    2015-01-01

    Little is known about the digestive process in infants. In particular, the chronological activity of enzymes across the course of digestion in the infant remains largely unknown. To create a temporal picture of how milk proteins are digested, enzyme activity was compared between intact human milk samples from three mothers and the gastric samples from each of their 4–12 day postpartum infants, 2 h after breast milk ingestion. The activities of 7 distinct enzymes are predicted in the infant stomach based on their observed cleavage pattern in peptidomics data. We found that the same patterns of cleavage were evident in both intact human milk and gastric milk samples, demonstrating that the enzyme activities that begin in milk persist in the infant stomach. However, the extent of enzyme activity is found to vary greatly between the intact milk and gastric samples. Overall, we observe that milk-specific proteins are cleaved at higher levels in the stomach compared to human milk. Notably, the enzymes we predict here only explain 78% of the cleavages uniquely observed in the gastric samples, highlighting that further investigation of the specific enzyme activities associated with digestion in infants is warranted. PMID:25385259

  13. A conjugated linoleic acid supplement containing trans-10, cis-12 reduces milk fat synthesis in lactating sheep.

    PubMed

    Lock, A L; Teles, B M; Perfield, J W; Bauman, D E; Sinclair, L A

    2006-05-01

    The efficacy of conjugated linoleic acid (CLA) supplements containing trans-10, cis-12 for reducing milk fat synthesis has been well documented in dairy cows, but studies with other ruminant species are less convincing, and there have been no investigations of this in sheep. Therefore, the current study was designed to determine whether trans-10, cis-12 CLA would inhibit milk fat synthesis in sheep. Twenty multiparous ewes in early lactation were paired and randomly allocated to 2 treatments: grass hay plus concentrate either unsupplemented (control) or supplemented with lipid-encapsulated CLA to provide 2.4 g/d of trans-10, cis-12 CLA. The CLA dose was based on published responses of dairy cows extrapolated to ewes on a metabolic body weight basis. The experimental design was a 2-period crossover with 10-d treatment periods separated by a 10-d interval. Compared with the control, CLA supplementation reduced milk fat content from 6.4 to 4.9% and reduced fat yield from 95 to 80 g/d. The CLA treatment also increased milk yield from 1,471 to 1,611 g/d and increased protein yield from 68 to 73 g/d. Milk protein content and DMI were unaffected by treatment. The reduction in milk fat yield was due to decreases in both de novo fatty acid synthesis and uptake of preformed fatty acids. Milk fat content of trans-10, cis-12 CLA was < 0.01 and 0.12 g/100 g of fatty acids for the control and CLA treatments, respectively. The transfer efficiency of trans-10, cis-12 CLA from the dietary supplement into milk fat was 3.8%. Results of the present study demonstrate that a CLA supplement containing trans-10, cis-12 CLA reduces milk fat synthesis in lactating sheep in a manner similar to dairy cows when fed at an equivalent dose (metabolic body weight basis). Furthermore, the nutrients spared by the reduction in milk fat coincided with an increase in milk and milk protein yield.

  14. Milk proteins interact with goat Binder of SPerm (BSP) proteins and decrease their binding to sperm.

    PubMed

    de Menezes, Erika Bezerra; van Tilburg, Mauricio; Plante, Geneviève; de Oliveira, Rodrigo V; Moura, Arlindo A; Manjunath, Puttaswamy

    2016-11-01

    Seminal plasma Binder of SPerm (BSP) proteins bind to sperm at ejaculation and promote capacitation. When in excess, however, BSP proteins damage the sperm membrane. It has been suggested that milk components of semen extenders associate with BSP proteins, potentially protecting sperm. Thus, this study was conducted to investigate if milk proteins interact with BSP proteins and reduce BSP binding to goat sperm. Using gel filtration chromatography, milk was incubated with goat seminal plasma proteins and loaded onto columns with and without calcium. Milk was also fractionated into parts containing mostly whey proteins or mostly caseins, incubated with seminal plasma proteins and subjected to gel filtration. Eluted fractions were evaluated by immunoblot using anti-goat BSP antibodies, confirming milk protein-BSP protein interactions. As determined by ELISA, milk proteins coated on polystyrene wells bound to increasing of goat BSP proteins. Far-western dot blots confirmed that BSP proteins bound to caseins and β-lactoglobulin in a concentration-dependent manner. Then, cauda epididymal sperm from five goats was incubated with seminal plasma; seminal plasma followed by milk; and milk followed by seminal plasma. Sperm membrane proteins were extracted and evaluated by immunoblotting. The pattern of BSP binding to sperm membrane proteins was reduced by 59.3 % when epididymal sperm were incubated with seminal plasma and then with skimmed milk (p < 0.05). When epididymal sperm were treated with milk followed by seminal plasma, coating of sperm with BSP proteins was not significantly reduced (57.6 %; p > 0.05). In conclusion, goat BSP proteins have an affinity for caseins and whey proteins. Milk reduces BSP binding to goat sperm, depending whether or not sperm had been previously exposed to seminal plasma. Such events may explain the protective effect of milk during goat sperm preservation.

  15. Evaluation of milk powder quality by protein oxidative modifications.

    PubMed

    Scheidegger, Dana; Radici, Paola M; Vergara-Roig, Víctor A; Bosio, Noelia S; Pesce, Silvia F; Pecora, Rolando P; Romano, José C P; Kivatinitz, Silvia C

    2013-06-01

    The objective of the present research was to evaluate commercially available milk powders according to their protein oxidative modifications and antioxidant capacity, and to evaluate if these characteristics are related to physical quality parameters such as dispersibility or stability during storage. Fifteen commercially processed spray-dried milk powders were evaluated: 6 whole milk powders (WMP), 4 skim milk powders (SMP), and 5 infant formula powders (IFP). Protein oxidative status was measured as protein carbonyl (PC) content, dityrosine content, and extent of protein polymerization. The level of PC was slightly lower in SMP than in WMP, whereas IFP had more than twice as much PC as WMP (2.8 ± 0.4, 2.1 ± 0.2, and 6.5 ± 1.3 nmol/mg of protein for WMP, SMP, and IFP, respectively). No differences were detected in dityrosine accumulation. Although all the possible pairs of parameters were tested for correlations, we found that 4 parameters were linked: PC, whey content, protein aggregate level, and dispersibility. After 9 mo of storage at -20°C or room temperature, all milk samples were analyzed to evaluate changes in protein oxidative status (PC, dityrosine, and protein integrity) and related parameters. Compared with the initial condition, PC increased in all tested samples after 9 mo of storage at -20°C or at room temperature. Stored milk powders had increased PC and decreased dispersibility compared with prestorage levels. Our results highlight the importance of protein oxidative status in milk powder and its relationship to other related quality parameters, such as protein integrity and dispersibility. Our findings suggest that the understanding of such relationships could help in developing quality differentiation for different types of milk powders in the product market.

  16. Protein carbonylation sites in bovine raw milk and processed milk products.

    PubMed

    Milkovska-Stamenova, Sanja; Mnatsakanyan, Ruzanna; Hoffmann, Ralf

    2017-08-15

    During thermal treatment of milk, proteins are oxidized, which may reduce the nutritional value of milk, abolish protein functions supporting human health, especially important for newborns, and yield potentially harmful products. The side chains of several amino acids can be oxidized to reactive carbonyls, which are often used to monitor oxidative stress in organisms. Here we mapped protein carbonylation sites in raw milk and different brands of pasteurized, ultra high temperature (UHT) treated milk, and infant formulas (IFs) after digesting the precipitated proteins with trypsin. Reactive carbonyls were derivatized with O-(biotinylcarbazoylmethyl)hydroxylamine to enrich the modified peptides by avidin-biotin affinity chromatography and analyze them by nanoRP-UPLC-ESI-MS. Overall, 53 unique carbonylated peptides (37 carbonylation sites, 15 proteins) were identified. Most carbonyls were derived from dicarbonyls (mainly glyoxal). The number of carbonylation sites increased with the harsher processing from raw milk (4) to pasteurized (16) and UHT milk (16) and to IF (24). Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. [Quantitative determination of the protein content of milk by ultraviolet spectrophotometry. 3. The protein content of whole milk].

    PubMed

    Reichardt, W; Schüler, E

    1987-01-01

    It is possible to determine the protein content of unskimmed milk after dilution with a detergent solution by measuring of absorbance at 210 and 220 nm. If milk samples are not elder than 36 h the difference A210-A220 shows a high correlation to the values of Kjeldahl nitrogen analysis (r = 0.97). Similar coincidence was found to the values of absorbance measurements in skimmed milk (A210: r = 0.98; A235-A280: r = 0.96). With decreasing age of unskimmed milk samples the coincidence diminished. Absorbance data measured at 210, 215, 220, 225, 235 and 280 nm as well as the differences A215-A225 and A235-A280 do not much agree with analogous results from skimmed milk. Elderly creamed milk samples allow the determination of protein content from milk plasma. It could be proved by Kjeldahl nitrogen analysis, that differences in the nitrogen content of unskimmed and skimmed milk depend on the nitrogen-loss during centrifugation, on the protein content and the protein-fat-ratio.

  18. Host-defence-related proteins in cows' milk.

    PubMed

    Wheeler, T T; Smolenski, G A; Harris, D P; Gupta, S K; Haigh, B J; Broadhurst, M K; Molenaar, A J; Stelwagen, K

    2012-03-01

    Milk is a source of bioactive molecules with wide-ranging functions. Among these, the immune properties have been the best characterised. In recent years, it has become apparent that besides the immunoglobulins, milk also contains a range of minor immune-related proteins that collectively form a significant first line of defence against pathogens, acting both within the mammary gland itself as well as in the digestive tract of the suckling neonate. We have used proteomics technologies to characterise the repertoire of host-defence-related milk proteins in detail, revealing more than 100 distinct gene products in milk, of which at least 15 are known host-defence-related proteins. Those having intrinsic antimicrobial activity likely function as effector proteins of the local mucosal immune defence (e.g. defensins, cathelicidins and the calgranulins). Here, we focus on the activities and biological roles of the cathelicidins and mammary serum amyloid A. The function of the immune-related milk proteins that do not have intrinsic antimicrobial activity is also discussed, notably lipopolysaccharide-binding protein, RNase4, RNase5/angiogenin and cartilage-glycoprotein 39 kDa. Evidence is shown that at least some of these facilitate recognition of microbes, resulting in the activation of innate immune signalling pathways in cells associated with the mammary and/or gut mucosal surface. Finally, the contribution of the bacteria in milk to its functionality is discussed. These investigations are elucidating how an effective first line of defence is achieved in the bovine mammary gland and how milk contributes to optimal digestive function in the suckling calf. This study will contribute to a better understanding of the health benefits of milk, as well as to the development of high-value ingredients from milk.

  19. Evidence that growth hormone stimulates milk synthesis by direct action on the mammary gland and that prolactin exerts effects on milk secretion by maintenance of mammary deoxyribonucleic acid content and tight junction status.

    PubMed

    Flint, D J; Gardner, M

    1994-09-01

    Both PRL and GH play a role in maintaining lactation in the rat, although GH can only maintain pup weight gain at around 50% of the control value, whereas PRL can maintain weight gain close to 90% in the absence of GH. In this study we examined the effects of PRL and GH deficiency (using bromocriptine and an antiserum to rat GH) on milk yield and composition in lactating rats. Treatment with bromocriptine to suppress PRL secretion for 48 h led to a 57% decrease in milk yield with a concomitant decrease in milk protein and lactose yields, but no decrease in fat output. This led to the production of milk with a lower lactose concentration but increased concentrations of protein and particularly fat (increased 100%), which suggests that GH serves an auxiliary role by maintaining an energy-rich milk for the neonate when PRL secretion is reduced. This decrease in milk synthesis was accompanied by decreases in total mammary DNA content and increased milk sodium concentrations. The latter indicates the opening of tight junctions between mammary epithelial cells, which normally occurs during dedifferentiation and involution of the mammary gland. This suggests that PRL maintains milk synthesis at least in part by inhibiting epithelial cell loss and maintaining cellular differentiation. A deficiency in GH, by contrast, caused only a small decrease (24%) in milk yield and had no effect on the major constituents of milk or on milk sodium concentrations or total mammary DNA content. When animals were made deficient in both PRL and GH, however, there was a further marked decrease (88%) in milk volume along with the yields of all major milk constituents, confirming our previous findings that PRL and GH are the major regulators of milk synthesis. Recent studies have indicated that GH exerts direct effects on mammary gland growth, but its actions on milk secretion have been proposed to be mediated indirectly via insulin-like growth factor-I (IGF-I). We, therefore, inhibited

  20. The binding of drugs to major human milk whey proteins.

    PubMed Central

    Atkinson, H C; Begg, E J

    1988-01-01

    The binding of nine drugs of diverse physicochemical characteristics to major human milk whey proteins is reported. This group included acids, bases and neutral drugs. No drug bound to alpha-lactalbumin, which is the protein present in greatest concentrations in mature milk. Four drugs, diclofenac, phenytoin, prednisolone and warfarin, bound to albumin but to a much lesser extent than in plasma, consistent with quantitatively less albumin in milk. None of the basic drugs studied bound to albumin. Five drugs, atenolol, diclofenac, prednisolone, propranolol and warfarin, bound to lactoferrin though the extent was minimal except for diclofenac. This group included acids, bases and neutral drugs. PMID:3203054

  1. Complementary transcriptomic and proteomic analyses reveal regulatory mechanisms of milk protein production in dairy cows consuming different forages

    PubMed Central

    Dai, Wenting; Chen, Qiong; Wang, Quanjuan; White, Robin R.; Liu, Jianxin; Liu, Hongyun

    2017-01-01

    Forage plays a critical role in the milk production of dairy cows; however, the mechanisms regulating bovine milk synthesis in dairy cows fed high forage rations with different basal forage types are not well-understood. In the study, rice straw (RS, low-quality) and alfalfa hay (AH, high-quality) diets were fed to lactating cows to explore how forage quality affected the molecular mechanisms regulating milk production using RNA-seq transcriptomic method with iTRAQ proteomic technique. A total of 554 transcripts (423 increased and 131 decreased) and 517 proteins (231 up-regulated and 286 down-regulated) were differentially expressed in the mammary glands of the two groups. The correlation analysis demonstrated seven proteins (six up-regulated and one down-regulated) had consistent mRNA expression. Functional analysis of the differentially expressed transcripts/proteins suggested that enhanced capacity for energy and fatty acid metabolism, increased protein degradation, reduced protein synthesis, decreased amino acid metabolism and depressed cell growth were related to RS consumption. The results indicated cows consuming RS diets may have had depressed milk protein synthesis because these animals had decreased capacity for protein synthesis, enhanced proteolysis, inefficient energy generation and reduced cell growth. Additional work evaluating RS- and AH-based rations may help better isolate molecular adaptations to low nutrient availability during lactation. PMID:28290485

  2. Sensitization to cow's milk protein in a dairy worker.

    PubMed

    Quirantes Sierra, B; Lara Jiménez, A; Skodova, M

    2017-09-02

    Repeated skin exposure and inhalation of milk proteins may lead to IgE-mediated sensitization, normally manifested at the site of contact. Although this is a phenomenon predominantly found in children, it has also been observed in adults. To describe a case of a worker who, after being exposed to milk proteins for many years, eventually experienced episodes of anaphylaxis. A 62-year-old worker experienced severe episodes of anaphylaxis following the intake of dairy products. He had worked in the dairy industry for 17 years, where he was exposed to dried milk every day. This case report illustrates how continued exposure to milk proteins, either by skin contact or inhalation, may lead to sensitization which could result in severe manifestations of anaphylaxis.

  3. Milk proteins as a source of tryptophan-containing bioactive peptides.

    PubMed

    Nongonierma, Alice B; FitzGerald, Richard J

    2015-07-01

    Tryptophan (W) is an essential amino acid which is primarily required for protein synthesis. It also acts as a precursor of key biomolecules for human health (serotonin, melatonin, tryptamine, niacin, nicotinamide adenine dinucleotide (NAD), phosphorylated NAD (NADP), quinolinic acid, kynureric acid, etc.). Among dietary proteins, milk proteins are particularly rich in W. W residues within milk proteins may be released by proteolytic/peptidolytic enzymes either as a free amino acid or as part of peptide sequences. Different W-containing peptides originating from milk proteins have been shown in vitro to display a wide range of bioactivities such as angiotensin converting enzyme (ACE) inhibition along with antioxidant, antidiabetic and satiating related properties. Free W has been shown in certain instances to have an effect on cognition and the aforementioned bioactive properties. However, a higher bioactive potency has generally been observed with specific W-containing peptides compared to free W. Since W is thermolabile, the impact of processing on the stability of W-containing peptides needs to be considered. Milk protein-derived W-containing peptides may have significant potential as natural health promoting agents in humans.

  4. Hydrolysis by Alcalase Improves Hypoallergenic Properties of Goat Milk Protein

    PubMed Central

    Yun, Sung-Seob; Lee, Won-Jae; Kim, Jin-Wook; Ha, Ho-Kyung; Yoo, Michelle

    2016-01-01

    Goat milk is highly nutritious and is consumed in many countries, but the development of functional foods from goat milk has been slow compared to that for other types of milk. The aim of this study was to develop a goat milk protein hydrolysate (GMPH) with enhanced digestibility and better hypoallergenic properties in comparison with other protein sources such as ovalbumin and soy protein. Goat milk protein was digested with four commercial food-grade proteases (separately) under various conditions to achieve the best hydrolysis of αs -casein and β-lactoglobulin. It was shown that treatment with alcalase (0.4%, 60℃ for 30 min) effectively degraded these two proteins, as determined by SDS-PAGE, measurement of nonprotein nitrogen content, and reverse-phase high-performance liquid chromatography. Hydrolysis with alcalase resulted in a significant decrease in β-lactoglobulin concentration (almost to nil) and a ~40% reduction in the level of αs-casein. Quantification of histamine and TNF-α released from HMC-1 cells (human mast cell line) showed that the GMPH did not induce an allergic response when compared to the control. Hence, the GMPH may be useful for development of novel foods for infants, the elderly, and convalescent patients, to replace cow milk. PMID:27621693

  5. Rapid resolution of milk protein intolerance in infancy.

    PubMed

    Lazare, Farrah B; Brand, Donald A; Marciano, Tuvia A; Daum, Fredric

    2014-08-01

    Infants with milk protein intolerance are usually switched to a casein hydrolysate or amino acid-based formula, which they continue to receive until 1 year of age, when they are rechallenged with a cow's-milk or soy protein formula. To investigate whether some of these infants actually become tolerant sooner, this study gathered preliminary data for establishing an empirical timetable for the resolution of milk protein intolerance. This prospective, longitudinal cohort study enrolled infants <4 months of age receiving either breast milk or a cow's-milk or casein hydrolysate formula who presented to a pediatric subspecialty practice during an 18-month period and had a positive stool guaiac test. After having been successfully switched to a casein hydrolysate or amino acid formula, infants who had guaiac-negative stools for at least 2 consecutive months were rechallenged with the formula that had necessitated the most recent switch. Of the 25 patients enrolled in the study, 16 completed the food challenge and data collection protocol. Negative stool guaiac tests following rechallenge indicated resolution of milk protein intolerance by the time subjects reached an average age of 6.7 ± 1.0 months (mean ± standard deviation). By the age of 7 months, milk protein intolerance was resolved in 12 of the 16 infants, the remainder having resolved by 10 months. It may be reasonable to treat infants with milk protein intolerance for 2 to 3 months with a hypoallergenic formula, then rechallenge them at 6 months of age, usually without causing recurrence of the hematochezia. Rechallenging before 12 months old could result in cost savings to families and insurers.

  6. Apoptosis induced by a human milk protein.

    PubMed

    Håkansson, A; Zhivotovsky, B; Orrenius, S; Sabharwal, H; Svanborg, C

    1995-08-15

    To the breast-fed infant, human milk is more than a source of nutrients; it furnishes a wide array of molecules that restrict microbes, such as antibodies, bactericidins, and inhibitors of bacterial adherence. However, it has rarely been considered that human milk may also contain substances bioactive toward host cells. While investigating the effect of human milk on bacterial adherence to a human lung cancer cell line, we were surprised to discover that the milk killed the cells. Analysis of this effect revealed that a component of milk in a particular physical state--multimeric alpha-lact-albumin--is a potent Ca(2+)-elevating and apoptosis-inducing agent with broad, yet selective, cytotoxic activity. Multimeric alpha-lactalbumin killed all transformed, embryonic, and lymphoid cells tested but spared mature epithelial elements. These findings raise the possibility that milk contributes to mucosal immunity not only by furnishing antimicrobial molecules but also by policing the function of lymphocytes and epithelium. Finally, analysis of the mechanism by which multimeric alpha-lactalbumin induces apoptosis in transformed epithelial cells could lead to the design of antitumor agents.

  7. Veterinary Medicine and Omics (Veterinomics): Metabolic Transition of Milk Triacylglycerol Synthesis in Sows from Late Pregnancy to Lactation.

    PubMed

    Lv, Yantao; Guan, Wutai; Qiao, Hanzhen; Wang, Chaoxian; Chen, Fang; Zhang, Yinzhi; Liao, Zhichao

    2015-10-01

    Mammalian milk is a key source of lipids, providing not only important calories but also essential fatty acids. Veterinary medicine and omics systems sciences intersection, termed as "veterinomics" here, has received little attention to date but stands to offer much promise for building bridges between human and animal health. We determined the changes in porcine mammary genes and proteomics expression associated with milk triacylglycerol (TAG) synthesis and secretion from late pregnancy to lactation. TAG content and fatty acid (FA) composition were determined in porcine colostrum (the 1st day of lactation) and milk (the 17th day of lactation). The mammary transcriptome for 70 genes and 13 proteins involved in TAG synthesis and secretion from six sows, each at d -17(late pregnancy), d 1(early lactation), and d 17 (peak lactation) relative to parturition were analyzed using quantitative real-time PCR and Western blot analyses. The TAG content and the concentrations of de novo synthesized FAs, saturated FAs, and monounsaturated FAs were higher in milk than in colostrum (p<0.05). Robust upregulation with high relative mRNA abundance was evident during lactation for genes associated with FA uptake (VLDLR, LPL, CD36), FA activation (ACSS2, ACSL3), and intracellar transport (FABP3), de novo FA synthesis (ACACA, FASN), FA elongation (ELOVL1), FA desaturation (SCD, FADS1), TAG synthesis (GPAM, AGPAT1, LPIN1, DGAT1), lipid droplet formation (BTN2A1, XDH, PLIN2), and transcription factors and nuclear receptors (SREBP1, SCAP, INSIG1/2). In conclusion, a wide variety of lipogenic genes and proteins regulate the channeling of FAs towards milk TAG synthesis and secretion in porcine mammary gland tissue. These findings inform future omics strategies to increase milk fat production and lipid profile and attest to the rise of both veterinomics and lipidomics in postgenomics life sciences.

  8. A conjugated linoleic acid supplement containing trans-10, cis-12 conjugated linoleic acid reduces milk fat synthesis in lactating goats.

    PubMed

    Lock, A L; Rovai, M; Gipson, T A; de Veth, M J; Bauman, D E

    2008-09-01

    The effect of conjugated linoleic acid (CLA) supplements containing trans-10, cis-12 for reducing milk fat synthesis has been well described in dairy cows and sheep. Studies on lactating goats, however, remain inconclusive. Therefore, the current study investigated the efficacy of a lipid-encapsulated trans-10, cis-12 CLA supplement (LE-CLA) on milk production and milk fatty acid profile in dairy goats. Thirty multiparous Alpine lactating goats in late lactation were used in a 3 x 3 Latin square design (14-d treatment periods separated by 14-d intervals). Does were fed a total mixed ration of Bermuda grass hay, dehydrated alfalfa pellets, and concentrate. Does were randomly allocated to 3 treatments: A) unsupplemented (control), B) supplemented with 30 g/d of LE-CLA (low dose; CLA-1), and C) supplemented with 60 g/d of LE-CLA (high dose; CLA-2). Milk yield, dry matter intake, and milk protein content and yield were unaffected by treatment. Compared with the control, milk fat yield was reduced 8% by the CLA-1 treatment and 21% by the CLA-2 treatment, with milk fat content reduced 5 and 18% by the CLA-1 and CLA-2 treatments, respectively. The reduction in milk fat yield was due to decreases in both de novo fatty acid synthesis and uptake of preformed fatty acids. Milk fat content of trans-10, cis-12 CLA was 0.03, 0.09, and 0.19 g/100 g of fatty acids for the control, CLA-1, and CLA-2 treatments, respectively. The transfer efficiency of trans-10, cis-12 CLA from the 2 levels of CLA supplement into milk fat was not different between treatments and averaged 1.85%. In conclusion, trans-10, cis-12 CLA reduced milk fat synthesis in lactating dairy goats in a manner similar to that observed for lactating dairy cows and dairy sheep. Dose-response comparisons, however, suggest that the degree of reduction in milk fat synthesis is less in dairy goats compared with dairy cows and dairy sheep.

  9. Correlation between skin prick test using commercial extract of cow's milk protein and fresh milk and food challenges.

    PubMed

    Calvani, Mauro; Mauro, Calvani; Alessandri, Claudia; Claudia, Alessandri; Frediani, Tullio; Tullio, Frediani; Lucarelli, Sandra; Sandra, Lucarelli; Miceli Sopo, Stefano; Stefano, Miceli Sopo; Panetta, Valentina; Valentina, Panetta; Zappalã, Daniela; Daniela, Zappala'; Zicari, Anna Maria; Maria, Zicari Anna

    2007-11-01

    The skin prick test (SPT) is regarded as an important diagnostic measure in the diagnostic work-up of cow's milk protein allergy. It is not known whether commercial extracts have any advantage over fresh milk. The aims of the study were to (i) compare the diagnostic capacity of SPTs for the three main cow's milk proteins (alpha-lactalbumin, casein and beta-lactoglobulin) with fresh milk and (ii) determine a cut-off that discriminates between allergic and tolerant children in a controlled food challenge. A study was carried out on 104 children consecutively attending two paediatric allergy clinics for suspected cow's milk allergy. A clinical history, SPTs with fresh cow's milk and commercial extracts of its three main proteins and a challenge test were performed on all the children. A study of the validity of the prick test was also performed by taking different cut-off points for fresh milk and its proteins. Twenty-eight of 104 challenge tests (26.9%) were positive. At a cut-off point of 3 mm, fresh milk showed the greatest negative predictive value (98%), whereas casein showed the greatest positive predictive value (PPV, 85%). Calculation of 95% predicted probabilities using logistic regression revealed predictive decision points of 12 mm for lactalbumin, 9 mm for casein, 10 mm for beta-lactoglobulin and 15 mm for fresh cow's milk. We found that the greater the number of positive SPTs for milk proteins, the more likely the positive response to challenge. Having a positive SPT for all three milk proteins had PPV of 92.3% and would seem more clinically useful than any cut-off. Both fresh milk and cow's milk extract of the three main proteins could be useful in the diagnostic work-up of cow's milk allergy. Finding positivity to all three cow's milk proteins seems to be a simpler and more useful way of avoiding oral food challenges.

  10. Human milk proteins: an interactomics and updated functional overview.

    PubMed

    D'Alessandro, Angelo; Scaloni, Andrea; Zolla, Lello

    2010-07-02

    Milk and milk fractions are characterized by a wide array of proteins, whose concentration spans across several orders of magnitude. By exploiting a combined approach based on functional gene ontology enrichment (FatiGO/Babelomics), hierarchical clustering, and pathway and network analyses, we merged data from literature dealing with protein-oriented studies on human milk. A total of 285 entries defined a nonredundant list upon comparison with the Ingenuity Knowledge Base from the Ingenuity Pathway Analysis software. Results were compared with an inventory of bovine milk proteins gathered from dedicated proteomic studies. A protein core of 106 proteins was found, with most of the entries associated to three main biological functions, namely nutrient transport/lipid metabolism, concretization of the immune system response and cellular proliferation processes. Our analyses confirm and emphasize that the biological role of the human milk proteins is not only limited to the provision of external nutrients and defense molecules against pathogens to the suckling but also to the direct stimulation of the growth of neonate tissues/organs and to the development of a proper independent immune system, both through the induction of a number of molecular cascades associated with cell proliferation/differentiation. The latter aspects were previously investigated by single-molecule dedicated studies, missing the holistic view that results from our analysis.

  11. Biofunctional peptides from milk proteins: mineral binding and cytomodulatory effects.

    PubMed

    Meisel, H; FitzGerald, R J

    2003-01-01

    The protein fraction of milk contains many valuable components and biologically active substances. Moreover, milk proteins are precursors of many different biologically active peptides which are inactive within the sequence of the precursor protein but can be released by enzymatic proteolysis. Many milk protein-derived peptides, such as caseinophosphopeptides, reveal multi-functional bioactivities. Caseinophosphopeptides can form soluble organophosphate salts and may function as carriers for different minerals, especially calcium. Furthermore, they have been shown to exert cytomodulatory effects. Cytomodulatory peptides inhibit cancer cell growth or they stimulate the activity of immunocompetent cells and neonatal intestinal cells, respectively. Several bioactive peptides derived from milk proteins are potential modulators of various regulatory processes in the body and thus may exert beneficial physiological effects. Caseinophosphopeptides are already produced on an industrial-scale and as a consequence these peptides have been considered for application as ingredients in both 'functional foods' and pharmaceutical preparations. Although the physiological significance as exogenous regulatory substances is not yet fully understood, both mineral binding and cytomodulatory peptides derived from bovine milk proteins are claimed to be health enhancing components that can be used to reduce the risk of disease or to enhance a certain physiological function.

  12. Specific antibodies to cow's milk proteins in infants: effect of early feeding and diagnosis of cow's milk allergy.

    PubMed

    Savilahti, Emma Merike; Saarinen, Kristiina Mertta; Savilahti, Erkki

    2010-12-01

    To investigate whether specific IgA, IgG, IgG1 and IgG4 responses to cow's milk proteins differ between infants with cow's milk allergy and infants with cow's milk related symptoms (control subjects), and whether early feeding affects these responses as well as specific IgE. A cohort of 6,209 healthy, full-term infants in a double-blind randomized trial received, as supplementary feeding at maternity hospitals (mean duration 4 days), either cow's milk formula, extensively hydrolyzed whey formula or donor breast milk. Infants who developed cow's milk associated symptoms (n = 223) underwent an open oral cow's milk challenge (mean age 7 months), which confirmed cow's milk allergy in 111 and was negative in 112. We measured in sera cow's milk specific IgE levels with UniCAP (Phadia, Uppsala, Sweden), and β-lactoglobulin and α-casein specific IgA, IgG1, IgG4 and IgG levels with enzyme-linked immunosorbent assay. Infants with IgE-mediated cow's milk allergy had lower β-lactoglobulin and α-casein specific IgG1, IgG4 and IgG levels (p < 0.05) than infants with non-IgE-mediated cow's milk allergy or control subjects. Within the group of infants with cow's milk allergy, exposure to cow's milk during the first few days after birth led to higher β-lactoglobulin and α-casein specific IgG4 levels (p < 0.005) compared to infants fed with either breast milk or extensively hydrolyzed formula. Subdued IgG class responses to cow's milk proteins characterized IgE-mediated cow's milk allergy. In infants who developed cow's milk allergy early exposure to cow's milk resulted in a heightened specific IgG4 response.

  13. Rheological properties of rennet gels containing milk protein concentrates.

    PubMed

    Ferrer, M A; Hill, A R; Corredig, M

    2008-03-01

    Different milk protein concentrates (MPC), with protein concentrations of 56, 70, and 90%, were dispersed in water under different treatments (hydration, shear, heat, and overnight storage at 4 degrees C), as well as in a combination of all the treatments in a factorial design. The particle size distribution of the dispersions was then measured to determine the optimal conditions for the dispersion. Heating at 60 degrees C for 30 min with 5 min of shear was chosen as the best condition to dissolve MPC powders. The samples were also characterized for composition, presence of protein aggregates, and ratio of calcium to protein. The total calcium present in MPC increased with increasing concentration of protein; however, the total calcium-to-protein ratio was lower in MPC90 than in MPC56 and MPC70. The level of whey protein denaturation, the presence of kappa-casein-whey protein aggregates in the supernatant after centrifugation, and the amount of caseins dissociated from the micelle increased as the protein concentration in the powder increased. The total amount of casein macropeptide released was lower in samples from powders with a higher protein concentration than for MPC56 or the skim milk control. The gelation behavior of reconstituted MPC was tested in systems dispersed in water (5% protein) as well as in systems dispersed in skim milk (6% protein). The gelation time of MPC dispersions was considerably lower and the gel modulus was higher than those of reconstituted skim milk with the same protein concentration. When MPC dispersions were dialyzed against skim milk, a significant decrease in the gelation time and modulus were shown, with a complete loss of gelling functionality in MPC90 dispersed in water. This demonstrated that the ionic equilibrium was key to the functionality of MPC.

  14. Short communication: Effects of nanofiltration and evaporation on the physiochemical properties of milk protein during processing of milk protein concentrate.

    PubMed

    Cao, Jialu; Zhang, Wei; Wu, Shaozong; Liu, Chang; Li, Yan; Li, Haimei; Zhang, Liebing

    2015-01-01

    The aim of this work was to evaluate the effects of nanofiltration and evaporation concentration technologies on the physiochemical properties of milk protein concentrate (MPC) during processing. Skim milk, ultrafiltered milk, evaporated milk, nanofiltered milk, evaporated MPC, and nanofiltered MPC samples were collected at different processing stages. Chemical composition, microstructure of casein micelles, free sulfhydryl content, and surface hydrophobicity of the samples were determined. The insolubility index of MPC was also determined. Casein micelles aggregated compactly after evaporation while surface hydrophobicity increased and free sulfhydryl content decreased in evaporated milk compared with skim milk. However, the microstructure of the casein micelles was relatively undisturbed after nanofiltration, with reduced surface hydrophobicity and free sulfhydryl content. No significant difference was found in chemical composition between the 2 MPC preparations: approximately 61.40% protein and 28.49% lactose. In addition, the particulate microstructures of both MPC were similar. However, the insolubility index of evaporated MPC was significantly (0.58mL) higher than that of nanofiltered MPC. Nanofiltration may be an effective way to improve the solubility of MPC products.

  15. The effects of cell death-inducing DNA fragmentation factor-α-like effector C on milk lipid synthesis in mammary glands of dairy cows.

    PubMed

    Yang, Yang; Lin, Ye; Duan, Xiaoyu; Lv, He; Xing, Weinan; Li, Qingzhang; Gao, Xuejun; Hou, Xiaoming

    2017-03-08

    Adequate lipid synthesis by the mammary gland during lactation is essential for the survival of mammalian offspring. Cell death-inducing DNA fragmentation factor-α-like effector C (CIDEC) is a lipid droplet-associated protein and functions to promote lipid accumulation and inhibit lipolysis in mice and human adipocytes. However, the function of CIDEC in regulation of milk lipid synthesis in dairy cow mammary gland remains largely unknown. In this study, 6 multiparous Holstein cows (parity = 3) in early lactation were allocated to high-fat milk (milk yield 33.9 ± 2.1 kg/d, milk fat >3.5%, n = 3) and low-fat milk (milk yield 33.7 ± 0.5 kg/d, milk fat <3.5%, n = 3) groups according to their milk fat content. Lactating cows were slaughtered at 90 d in milk and mammary tissues were collected to detect CIDEC localization. Immunofluorescence staining of sections of lactating mammary glands with high- and low-fat milk showed that CIDEC was expressed in the cytoplasm of epithelial cells and localized to lipid droplets. Lipid droplets and CIDEC protein were also detected in isolated lactating mammary epithelial cells of dairy cows. Immunostaining of CIDEC in isolated mammary epithelial cells also confirmed its presence in the nucleus. The knockdown of CIDEC in cultured bovine mammary epithelial cells decreased milk lipid content and reduced expression of genes associated with mammary de novo fatty acid synthesis, short- and long-chain intracellular fatty acid activation, triacylglycerol synthesis, and transcription regulation. These genes included those for acetyl-CoA carboxylase (ACC, -60%), fatty acid synthase (FASN, -65%), acyl-CoA synthetase short-chain family member 2 (ACSS2, -50%), acyl-CoA synthetase long-chain family member 1 (ACSL1, -30%), diacylglycerol acyltransferase 1 (DGAT1, -60%), sterol regulatory element-binding protein 1 (SREBP1, -45%), and SREBP cleavage activating protein (SCAP, -66%). Conversely, in cells overexpressing CIDEC, triacylglycerol content

  16. Amino acid supplementation of calf milk replacers containing plasma protein.

    PubMed

    Morrison, S Y; Campbell, J M; Drackley, J K

    2017-03-22

    We determined the effects of calf milk replacers containing 0, 5, or 10% bovine plasma protein (PP), either without or with the supplemental amino acids (AA) Ile and Thr, on growth and health of male Holstein calves (n = 104) for 56 d. Milk replacers were formulated to contain 22% crude protein (CP), 20% fat, and 2.0% Lys. Milk replacers (12.5% solids) were fed at a rate of 1.5% of body weight (BW) on a dry matter basis during wk 1 and 1.75% of BW beginning on d 8. Starter was introduced on d 36 so that effects of PP and AA balance in milk replacers could be isolated. Intake, respiratory scores, and fecal scores were measured daily. Body weight and stature were measured weekly and blood serum samples were obtained during wk 4. Treatments had no effects on intakes of dry matter, CP, or metabolizable energy. During wk 6 and 8, BW was less as PP inclusion increased without AA supplementation compared with the other treatments. In wk 7, calves fed the higher level of PP without AA had lower BW than calves fed either the lower level of PP without supplemented AA or the higher inclusion of PP with supplemented AA. Average daily gain and gain:feed were lowest for calves fed the higher inclusion of PP without supplemented AA; heart girth in wk 7 was smallest for those calves. During the first 21 d, occurrence of scours was greater in calves fed the control milk replacer than in calves fed milk replacers containing the higher inclusion of PP either without or with supplemental AA. Occurrence of scours was also greater for the lower inclusion of PP compared with the higher inclusion of PP when AA were supplemented. Throughout the 56-d experiment, the chance of antibiotic treatment was greater for calves fed the control milk replacer than for all other treatments except the higher inclusion of PP without supplemental AA. Additionally, chance of antibiotic treatment was greater for the higher inclusion of PP without supplemental AA than for other milk replacers with PP. Calves

  17. Milk proteins-derived bioactive peptides in dairy products: molecular, biological and methodological aspects.

    PubMed

    Dziuba, Bartłomiej; Dziuba, Marta

    2014-01-01

    Proteins are one of the primary components of the food, both in terms of nutrition and function. They are main source of amino acids, essential for synthesis of proteins, and also source of energy. Additionally, many proteins exhibit specific biological activities, which may have effect on functional or pro-health properties of food products. These proteins and their hydrolysis products, peptides, may influence the properties of food and human organism. The number of commercially available food products containing bioactive peptides is very low, apart from that milk proteins are their rich source. It could be supposed that number of available products with declared activity will rise in near future because of observed strong uptrend on interest in such products. Molecular and biological properties of milk proteins, as precursors of bioactive peptides was characterised in the work. Therefore, the strategy of research and obtaining of such peptides both in laboratory and industrial scale, as well as the range of their commercial application, was presented. Several examples of research efforts presenting high potential to develop new products containing bioactive peptides from milk proteins and predetermined as nutraceuticals was described.

  18. Colostrum enhances the nutritional stimulation of vital organ protein synthesis in neonatal pigs.

    PubMed

    Burrin, D G; Davis, T A; Ebner, S; Schoknecht, P A; Fiorotto, M L; Reeds, P J

    1997-07-01

    Our objective was to determine the relative importance of the macronutrient components of colostrum in the stimulation of vital organ protein synthesis in neonatal pigs. We studied colostrum-deprived newborn pigs within 4-6 h after birth (unfed) and three groups fed for 24 h mature milk, colostrum, or a formula containing a macronutrient composition comparable to that of colostrum. We measured protein synthesis in vivo using a flooding dose of 3H-phenylalanine. The fractional rates of protein synthesis (Ks) in the brain, heart, lung, kidney and spleen were significantly higher in all fed groups than in the unfed newborns. Among the three fed groups, brain and heart protein synthesis rates were greater in colostrum-fed than in either milk- or formula-fed pigs. Kidney and spleen protein synthesis rates in colostrum- and formula-fed pigs were not significantly different, but both were higher than in milk-fed pigs. The stimulation of kidney protein synthesis in response to feeding was primarily a consequence of greater protein synthetic efficiency; however, protein synthetic capacity in the heart, lung and spleen was generally greater in colostrum- and formula-fed pigs than in unfed newborns. Our results suggest that the predominant stimulus for vital organ protein synthesis in colostrum-fed neonatal pigs is nutrient intake. However, there was a specific stimulation of both brain and heart protein synthesis in colostrum-fed pigs that cannot be attributed to macronutrients.

  19. Differences of protein fractions among fresh, frozen and powdered donkey milk.

    PubMed

    Polidori, Paolo; Vincenzetti, Silvia

    2010-01-01

    Recently donkey milk has been the focus of several studies because of its special nutritional properties and composition, which is very close to human milk. When a mother cannot breastfeed, or chooses not to breastfeed, the use of a milk substitute must provide the best option to meet the nutritional and health needs of the infant. Donkey milk has been widely used in the past to replace human milk, because chemical composition and protein content are close to that of human milk, and also because the allergenicity of donkey milk is low. The recent studies of the paediatric scientists have demonstrated that infant formulae, which are based on dairy cows milk, are less adapted than donkey milk. In fact, donkey's milk digestibility is higher than cows' milk and similar to human milk, because of the high whey proteins content and the few casein content. Since donkey milk supply is related to its seasonal availability during the year, in this study were evaluated the effects of a specific technological treatment (spray-dryer) and a particular storage temperature (-20 degrees C) on the protein fractions of donkey milk. The results obtained in fresh, frozen and powdered donkey milk showed different values in total proteins, caseins, whey proteins and lysozyme content. The article presents some promising patents on protein fractions among fresh, frozen and powdered donkey milk.

  20. Short communication: interaction of bovine milk protein with chlorpyrifos.

    PubMed

    Lv, Ying; Li, Xuefen; Wang, Zongyi; Zheng, Han; Zhang, Qi; Huo, Ran; Chen, Xiangning; Han, Tao

    2014-01-01

    Dairy products are considered as nutrient-dense foods and consumed by many people in western countries, as well as an increasing number of Asian people. Excessive and frequent application of pesticides on vegetables and fruits leads to a potential health hazard to consumers. The organophosphate insecticide chlorpyrifos has been reported to bind with human and bovine serum albumin. Thus, it is necessary to explore the interaction between food protein and chlorpyrifos. In this study, equilibrium dialysis and fluorescence spectra were used to demonstrate binding of milk proteins to chlorpyrifos. The amount of milk protein bound was 0.03±0.01mg/g. Moreover, the milk protein-chlorpyrifos complexes were stable at pH 3.5to 9.5 and ion concentrations from 0.1 to 1.0M. The amount of chlorpyrifos bound to milk proteins decreased to 50% after being in vitro digested by pepsin and trypsin. The results showed that the interaction between food proteins and the pesticide might partially remove the insecticide and reduce the concentration of pesticide absorbed into the blood and, thus, alleviate the corresponding toxicity.

  1. Protein profile of mature soybean seeds and prepared soybean milk.

    PubMed

    Capriotti, Anna Laura; Caruso, Giuseppe; Cavaliere, Chiara; Samperi, Roberto; Stampachiacchiere, Serena; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2014-10-08

    The soybean (Glycine max (L.) Merrill) is economically the most important bean in the world, providing a wide range of vegetable proteins. Soybean milk is a colloidal solution obtained as water extract from swelled and ground soybean seeds. Soybean proteins represent about 35-40% on a dry weight basis and they are receiving increasing attention with respect to their health effects. However, the soybean is a well-recognized allergenic food, and therefore, it is urgent to define its protein components responsible for the allergenicity in order to develop hypoallergenic soybean products for sensitive people. The main aim of this work was the characterization of seed and milk soybean proteome and their comparison in terms of protein content and specific proteins. Using a shotgun proteomics approach, 243 nonredundant proteins were identified in mature soybean seeds.

  2. Proteomic tools to characterize the protein fraction of Equidae milk.

    PubMed

    Miranda, Guy; Mahé, Marie-Françoise; Leroux, Christine; Martin, Patrice

    2004-08-01

    The principal components of the protein fraction in pony mare's milk have been successfully identified and partially characterized using proteomic tools. Skimmed pony mare's milk was fractionated by either reversed phase-high-performance liquid chromatography (RP-HPLC) on a C4 column or a bi-dimensional separation technique coupling RP-HPLC in the first dimension and sodium dodecyl sulfate-polyacrylamide electrophoresis (SDS-PAGE) in the second dimension (two-dimensional RP-HPLC/SDS-PAGE). The fractions thus obtained were analyzed by Edman N-terminal microsequencing and mass determination, with or without tryptic digestion, on a matrix-assisted laser desorption/ionization-time of flight spectrometer. Based on the sequence and molecular mass information obtained, identifications were achieved through a protein database search using homology or pattern research algorithms. This methodological approach was shown to be rapid, efficient and reliable in identifying the principal proteins in pony mare's milk. kappa-, alpha(s1)-, alpha(s2)-, and beta-casein, lysozyme C, alpha-lactalbumin and beta-lactoglobulin I and II were thus identified. alpha(s1) and beta-caseins displayed polymorphic patterns, probably due to alternative splicing processes leading to casual exon skipping events involving exons 7 and 14 in alpha(s1)-casein and exon 5 in beta-casein. Edman N-terminal microsequencing over 35 amino acid residues, for pony alpha(s1)-casein, clearly demonstrated the occurrence, in Equidae, of a splicing pattern similar to that reported in rodents, characterized by the constitutive outsplicing of exon 5. Pony mare's milk SDS-PAGE and RP-HPLC patterns were compared with those obtained for other milks (cow, goat and human), as were the relative levels of caseins and major whey proteins in these milks. Our results provide further evidence to support the notion that Equidae milk is closer to human breast milk than milk from bovine and caprine with respect to the casein and

  3. Twinfilin 1 enhances milk bio-synthesis and proliferation of bovine mammary epithelial cells via the mTOR signaling pathway.

    PubMed

    Li, Lu; Liu, Lijie; Qu, Bo; Li, Xueying; Gao, Xuejun; Zhang, Minghui

    2017-10-21

    Twinfilin1 (TWF1) is an actin monomer-binding protein, which biological function has not yet been fully uncovered. In our previous study, we found by mass spectrometry analysis that TWF1 might be one of the major proteins responsible for milk bio-synthesis and proliferation of bovine mammary epithelial cells (BMECs). The purpose of this study was to explore the possible mechanism by which TWF1 regulates signaling pathways that enhance milk bio-synthesis and proliferation of BMECs. We first explored the effects of TWF1 on milk bio-synthesis and cell proliferation, and analyzed the role of TWF1 on the protein levels of signaling molecules (mTOR, SREBP-1c and Cyclin D1) related to milk bio-synthesis and cell proliferation. Then we determinate the impacts of amino acids (methionine and leucine) and hormones (estrogen and prolactin) on the expressions of TWF1. These results reveal that TWF1 is highly induced by the stimulation of amino acids and hormones and involved in regulation of milk bio-synthesis and cell proliferation via the mTOR pathway in BMECs. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The use of radiolabelled milk proteins to study thermally-induced interactions in milk systems

    SciTech Connect

    Noh, B.

    1988-01-01

    Heat induced complexes between milk proteins are of considerable importance in determining the heat stability and rennin clottability of milk products. Thiol-disulfide interchange reactions have been suggested as the principal reaction mechanism for complex formation. Studies to data have not adequately established the mechanism and stoichiometry of complex formation in situ in total milk system. Tracer amounts of {sup 14}C-{beta}-lactoglobulin and {alpha}-lactalbumin were heated under various conditions. After clotting with rennet, radioactivity retained in the curd was counted to estimate extent of interaction of {beta}-lactoglobulin with casein. {sup 14}C- and {sup 3}H-Methyl labelled proteins were used for the preparation of radiolabelled artificial casein micelles. These micelles with radiolabelled whey proteins were heated and heat-induced complexes were separated on Sephacryl S-300 eluting with 6 M guanidine hydrochloride to break all non-covalent bonds. Further separation of the protein complexes was obtained using CPG-10 or Sephacryl S-1000. The ratios of {sup 3}H to {sup 14}C labelled proteins in the protein complexes suggested that the stoichiometries of k-, {alpha}{sub s2}-casein, {beta}-lactoglobulin and {alpha}-lactalbumin in the heat-induced complexes varied as a function of the heat treatment.

  5. Rapid turbidimetric detection of milk powder adulteration with plant proteins.

    PubMed

    Scholl, Peter F; Farris, Samantha M; Mossoba, Magdi M

    2014-02-19

    Development of assays to screen milk for economically motivated adulteration with foreign proteins has been stalled since 2008 due to strong international reactions to the melamine poisoning incident in China and the surveillance emphasis placed on low molecular weight nitrogen-rich adulterants. New screening assays are still needed to detect high molecular weight foreign protein adulterants and characterize this understudied potential risk. A rapid turbidimetric method was developed to screen milk powder for adulteration with insoluble plant proteins. Milk powder samples spiked with 0.03-3% by weight of soy, pea, rice, and wheat protein isolates were extracted in 96-well plates, and resuspended pellet solution absorbance was measured. Limits of detection ranged from 100 to 200 μg, or 0.1-0.2% of the sample weight, and adulterant pellets were visually apparent even at ∼0.1%. Extraction recoveries ranged from 25 to 100%. Assay sensitivity and simplicity indicate that it would be ideally suitable to rapidly screen milk samples in resource poor environments where adulteration with plant protein is suspected.

  6. Identification of potent antioxidant bioactive peptides from goat milk proteins.

    PubMed

    Ahmed, Ahmed S; El-Bassiony, Tawfik; Elmalt, Laila M; Ibrahim, Hisham R

    2015-08-01

    Goat milk proteins have gained increasing attention especially the bioactive peptides released from the parent proteins by digestive enzymes. Specifically, the interest in bioactives of goat milk is intensifying due to its reduced allergenicity compared to bovine milk. In this study, proteins of goat milk were fractionated into caseins (GCP) and whey proteins (GWP), hydrolyzed by pepsin and the generated peptides were examined for radical scavenging activities. The hydrolysates of whey (P-GWP) and casein (P-GCP) proteins exhibited potent superoxide anion (O2(・-)) scavenging activity in a dose-dependent manner, as investigated using the natural xanthine/xanthine oxidase (X/XOD) system. The P-GWP and P-GCP dramatically quenched the O2(・-) flux but had negligible effect on the catalytic function of the enzyme, indicating specificity to scavenge O2(・-) but not oxidase inhibition. Further, both P-GWP and P-GCP were able to remarkably quench the chemical DPPH radical. Fractionation of hydrolysates by size-exclusion chromatography produced four fractions (F1-F4) from both hydrolysates, with variable O2(・-) scavenging activities. However, the slow eluting fractions (F4) of both hydrolysates and fast eluting fraction (F2) of P-GCP contained peptides with the highest scavenging activities. Peptides in the active fractions of P-GWP and P-GCP, isolated by reversed phase-HPLC, exhibited significantly strong O2(・-) scavenging activities. MALDI-TOF-MS allowed the identification of several antioxidant peptides derived from both caseins and whey proteins, with β-casein and β-lactoglobulin being the major contributors, respectively. The results demonstrate that digestion with pepsin generates multiple soluble peptides from goat milk protein fractions with remarkable ability to scavenge superoxide radicals and thus providing a fascinating opportunity for their potential candidacy as antioxidant bioactive peptides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Milk protein and the restoration of fluid balance after exercise.

    PubMed

    James, Lewis

    2012-01-01

    Sweat is produced during exercise to help dissipate some of the extra heat produced due to an increase in metabolic rate. Inadequate drink ingestion during exercise means athletes finish exercise hypohydrated and when the time between exercise bouts is short, effective rehydration strategies will be necessary to prevent subsequent performance impairment. For complete rehydration, drink volume must be sufficient to replace sweat losses as well as the additional water losses during recovery. Once a sufficient volume of drink is ingested it is the drink composition that dictates the rehydration success of the drink. It is well known that addition of sodium and some other nutrients to rehydration drinks enhances fluid balance restoration after exercise, but the effects of milk proteins have been less well documented. Skimmed milk is an effective post-exercise rehydration solution and enhances the restoration of fluid balance after exercise-induced dehydration to a greater extent than a carbohydrate-electrolyte sports drink. Whilst there are a number of factors in skimmed milk that might be responsible for this enhancement of rehydration, it appears that some of the effect is due to the milk protein, as milk protein has been shown to be more effective for post-exercise rehydration than an isoenergetic amount of carbohydrate. Whilst the effects of whey protein on post-exercise rehydration are equivocal, whey protein addition to a carbohydrate-electrolyte rehydration solution certainly does not impair rehydration. Therefore, in situations where protein ingestion after exercise might be advantageous for the athlete, this protein might also enhance restoration of fluid balance.

  8. Amino acid nutrition beyond methionine and lysine for milk protein

    USDA-ARS?s Scientific Manuscript database

    Amino acids are involved in many important physiological processes affecting the production, health, and reproduction of high-producing dairy cows. Most research and recommendations for lactating dairy cows has focused on methionine and lysine for increasing milk protein yield. This is because these...

  9. Functional and technological properties of camel milk proteins: a review.

    PubMed

    Hailu, Yonas; Hansen, Egon Bech; Seifu, Eyassu; Eshetu, Mitiku; Ipsen, Richard; Kappeler, Stefan

    2016-11-01

    This review summarises current knowledge on camel milk proteins, with focus on significant peculiarities in protein composition and molecular properties. Camel milk is traditionally consumed as a fresh or naturally fermented product. Within the last couple of years, an increasing quantity is being processed in dairy plants, and a number of consumer products have been marketed. A better understanding of the technological and functional properties, as required for product improvement, has been gained in the past years. Absence of the whey protein β-LG and a low proportion of к-casein cause differences in relation to dairy processing. In addition to the technological properties, there are also implications for human nutrition and camel milk proteins are of interest for applications in infant foods, for food preservation and in functional foods. Proposed health benefits include inhibition of the angiotensin converting enzyme, antimicrobial and antioxidant properties as well as an antidiabetogenic effect. Detailed investigations on foaming, gelation and solubility as well as technological consequences of processing should be investigated further for the improvement of camel milk utilisation in the near future.

  10. Methods for improving enzymatic trans-glycosylation for synthesis of human milk oligosaccharide biomimetics.

    PubMed

    Zeuner, Birgitte; Jers, Carsten; Mikkelsen, Jørn Dalgaard; Meyer, Anne S

    2014-10-08

    Recently, significant progress has been made within enzymatic synthesis of biomimetic, functional glycans, including, for example, human milk oligosaccharides. These compounds are mainly composed of N-acetylglucosamine, fucose, sialic acid, galactose, and glucose, and their controlled enzymatic synthesis is a novel field of research in advanced food ingredient chemistry, involving the use of rare enzymes, which have until now mainly been studied for their biochemical significance, not for targeted biosynthesis applications. For the enzymatic synthesis of biofunctional glycans reaction parameter optimization to promote "reverse" catalysis with glycosidases is currently preferred over the use of glycosyl transferases. Numerous methods exist for minimizing the undesirable glycosidase-catalyzed hydrolysis and for improving the trans-glycosylation yields. This review provides an overview of the approaches and data available concerning optimization of enzymatic trans-glycosylation for novel synthesis of complex bioactive carbohydrates using sialidases, α-l-fucosidases, and β-galactosidases as examples. The use of an adequately high acceptor/donor ratio, reaction time control, continuous product removal, enzyme recycling, and/or the use of cosolvents may significantly improve trans-glycosylation and biocatalytic productivity of the enzymatic reactions. Protein engineering is also a promising technique for obtaining high trans-glycosylation yields, and proof-of-concept for reversing sialidase activity to trans-sialidase action has been established. However, the protein engineering route currently requires significant research efforts in each case because the structure-function relationship of the enzymes is presently poorly understood.

  11. Effects of postexercise milk consumption on whole body protein balance in youth.

    PubMed

    Volterman, Kimberly A; Obeid, Joyce; Wilk, Boguslaw; Timmons, Brian W

    2014-11-15

    In adults, adding protein to a postexercise beverage increases muscle protein turnover and replenishes amino acid stores. Recent focus has shifted toward the use of bovine-based milk and milk products as potential postexercise beverages; however, little is known about how this research translates to the pediatric population. Twenty-eight (15 girls) pre- to early pubertal (PEP, 7-11 yr) and mid- to late-pubertal (MLP, 14-17 yr) children consumed an oral dose of [(15)N]glycine prior to performing 2 × 20-min cycling bouts at 60% V̇O(2 peak) in a warm environment (34.5°C, 47.3% relative humidity). Following exercise, participants consumed either water (W), a carbohydrate-electrolyte solution (CES), or skim milk (SM) in a randomized, cross-over fashion in a volume equal to 100% of their body mass loss during exercise. Whole body nitrogen turnover (Q), protein synthesis (S), protein breakdown (B), and whole body protein balance (WBPB) were measured over 16 h. Protein intake from SM was 0.40 ± 0.10 g/kg. Over 16 h, Q and S were significantly greater (P < 0.01) with SM than W and CES. B demonstrated a trend for a main effect for beverage (P = 0.063). WBPB was more negative (P < 0.01) with W and CES than with SM. In the SM trial, WBPB was positive in PEP, although it remained negative in MLP. Boys exhibited significantly more negative WBPB than girls (P < 0.05). Postexercise milk consumption enhances WBPB compared with W and CES; however, additional protein intake may be required to sustain a net anabolic environment over 16 h.

  12. Longitudinal evolution of true protein, amino acids and bioactive proteins in breast milk: a developmental perspective.

    PubMed

    Lönnerdal, Bo; Erdmann, Peter; Thakkar, Sagar K; Sauser, Julien; Destaillats, Frédéric

    2017-03-01

    The protein content of breast milk provides a foundation for estimating protein requirements of infants. Because it serves as a guideline for regulatory agencies issuing regulations for infant formula composition, it is critical that information on the protein content of breast milk is reliable. We have therefore carried out a meta-analysis of the protein and amino acid contents of breast milk and how they evolve during lactation. As several bioactive proteins are not completely digested in the infant and therefore represent "non-utilizable" protein, we evaluated the quantity, mechanism of action and digestive fate of several major breast milk proteins. A better knowledge of the development of the protein contents of breast milk and to what extent protein utilization changes with age of the infant will help improve understanding of protein needs in infancy. It is also essential when designing the composition of infant formulas, particularly when the formula uses a "staging" approach in which the composition of the formula is modified in stages to reflect changes in breast milk and changing requirements as the infant ages.

  13. Proteomic analysis of cow, yak, buffalo, goat and camel milk whey proteins: quantitative differential expression patterns.

    PubMed

    Yang, Yongxin; Bu, Dengpan; Zhao, Xiaowei; Sun, Peng; Wang, Jiaqi; Zhou, Lingyun

    2013-04-05

    To aid in unraveling diverse genetic and biological unknowns, a proteomic approach was used to analyze the whey proteome in cow, yak, buffalo, goat, and camel milk based on the isobaric tag for relative and absolute quantification (iTRAQ) techniques. This analysis is the first to produce proteomic data for the milk from the above-mentioned animal species: 211 proteins have been identified and 113 proteins have been categorized according to molecular function, cellular components, and biological processes based on gene ontology annotation. The results of principal component analysis showed significant differences in proteomic patterns among goat, camel, cow, buffalo, and yak milk. Furthermore, 177 differentially expressed proteins were submitted to advanced hierarchical clustering. The resulting clustering pattern included three major sample clusters: (1) cow, buffalo, and yak milk; (2) goat, cow, buffalo, and yak milk; and (3) camel milk. Certain proteins were chosen as characterization traits for a given species: whey acidic protein and quinone oxidoreductase for camel milk, biglycan for goat milk, uncharacterized protein (Accession Number: F1MK50 ) for yak milk, clusterin for buffalo milk, and primary amine oxidase for cow milk. These results help reveal the quantitative milk whey proteome pattern for analyzed species. This provides information for evaluating adulteration of specific specie milk and may provide potential directions for application of specific milk protein production based on physiological differences among animal species.

  14. Review: Milk Proteins as Nanocarrier Systems for Hydrophobic Nutraceuticals.

    PubMed

    Kimpel, Florian; Schmitt, Joachim J

    2015-11-01

    Milk proteins and milk protein aggregates are among the most important nanovehicles in food technology. Milk proteins have various functional properties that facilitate their ability to carry hydrophobic nutraceutical substances. The main functional transport properties that were examined in the reviewed studies are binding of molecules or ions, surface activity, aggregation, gelation, and interaction with other polymers. Hydrophobic binding has been investigated using caseins and isolated β-casein as well as whey proteins. Surface activity of caseins has been used to create emulsion-based carrier systems. Furthermore, caseins are able to self-assemble into micelles, which can incorporate molecules. Gelation and interaction with other polymers can be used to encapsulate molecules into protein networks. The release of transported substances mainly depends on pH and swelling behavior of the proteins. The targeted use of nanocarrier systems requires specific knowledge about the binding mechanisms between the proteins and the carried substances in a certain food matrix. © 2015 Institute of Food Technologists®

  15. Proteome Analysis of Streptococcus thermophilus Grown in Milk Reveals Pyruvate Formate-Lyase as the Major Upregulated Protein

    PubMed Central

    Derzelle, Sylviane; Bolotin, Alexander; Mistou, Michel-Yves; Rul, Françoise

    2005-01-01

    We investigated the adaptation to milk of Streptococcus thermophilus LMG18311 using a proteomic approach. Two-dimensional electrophoresis of cytosolic proteins were performed after growth in M17 medium or in milk. A major modification of the proteome concerned proteins involved in the supply of amino acids, like the peptidase PepX, and several enzymes involved in amino acid biosynthesis. In parallel, we observed the upregulation of the synthesis of seven enzymes directly involved in the synthesis of purines, as well as formyl-tetrahydrofolate (THF) synthetase and serine hydroxy-methyl transferase, two enzymes responsible for the synthesis of compounds (THF and glycine, respectively) feeding the purine biosynthetic pathway. The analysis also revealed a massive increase in the synthesis of pyruvate formate-lyase (PFL), the enzyme which converts pyruvate into acetyl coenzyme A and formate. PFL has been essentially studied for its role in mixed-acid product formation in lactic acid bacteria during anaerobic fermentation. However, formate is an important methyl group donor for anabolic pathway through the formation of folate derivates. We hypothesized that PFL was involved in purine biosynthesis during growth in milk. We showed that PFL expression was regulated at the transcriptional level and that pfl transcription occurred during the exponential growth phase in milk. The complementation of milk with formate or purine bases was shown to reduce pfl expression, to suppress PFL synthesis, and to stimulate growth of S. thermophilus. These results show a novel regulatory mechanism controlling the synthesis of PFL and suggest an unrecognized physiological role for PFL as a formate supplier for anabolic purposes. PMID:16332852

  16. Identification of lipopolysaccharide-binding proteins in porcine milk

    PubMed Central

    Shahriar, Farshid; Gordon, John R.; Simko, Elemir

    2006-01-01

    Septicemia and endotoxemia initiated by bacterial lipopolysaccharide (LPS) are relatively common in suckling and weaned piglets. Maternal milk is a source of both nutrition and immune protection for piglets. Passive transfer of colostral antibodies is necessary for protection of neonatal piglets against diseases, but the concentration of immunoglobulins in milk rapidly declines during the 1st wk of lactation in all mammals. We hypothesized, therefore, that nonimmunoglobulin substances in milk contribute to the innate protection of neonates against septicemia during the suckling period. Using LPS-affinity chromatography for isolation of LPS-binding proteins and liquid chromatography–mass spectrometry for their identification, we identified in porcine milk the following proteins with LPS-binding capacity: lactoferrin, soluble CD14, serum amyloid A, α-S1 casein, β-casein, and κ-casein. For lactoferrin, α-S1 casein, and κ-casein, in vitro pepsin digestion did not inhibit LPS-binding activity, whereas combined digestion with pepsin and pancreatin abolished it. The biologic functions of these LPS-binding proteins and peptides were not determined. PMID:17042375

  17. Circulating antibodies to cow's milk proteins in ulcerative colitis

    PubMed Central

    Jewell, D. P.; Truelove, S. C.

    1972-01-01

    Sera from patients with ulcerative colitis (51), Crohn's disease (30), hypolactasia (13), untreated adult coeliac disease (11), irritable colon syndrome (24), and sera from 38 healthy control subjects were tested for antibodies to the principal cow's milk proteins—casein, α-lactalbumin, and β-lactoglobulin. The red-cell-linked antigen-antiglobulin reaction was used to determine the titres of direct agglutinating antibodies and IgA and IgG incomplete antibodies. Apart from patients with coeliac disease, direct agglutinating antibodies were found infrequently and then in low titres. Approximately 50% of subjects had low titres of IgA and IgG antibodies. However, the titres found in sera from patients with ulcerative colitis did not differ from those found in the control subjects or in patients with Crohn's disease, hypolactasia, or irritable colon syndrome. Patients with untreated coeliac disease frequently had high antibody titres to the milk proteins. In all subjects tested, incomplete antibodies of IgA or IgG immunoglobulin class occurred with equal frequency. The frequent occurrence in adults of low titres of antibodies to the milk proteins may be due to continued absorption of minute amounts of protein. Absorption of allergens may be facilitated by mucosal damage, such as that of coeliac disease, with stimulation of antibody production. At the present time, however, there is little evidence to suggest that milk allergy is a factor in the aetiology of ulcerative colitis. PMID:5087069

  18. Deciphering the genetic blueprint behind Holstein milk proteins and production.

    PubMed

    Lee, Hyun-Jeong; Kim, Jaemin; Lee, Taeheon; Son, Jun Kyu; Yoon, Ho-Baek; Baek, Kwang-Soo; Jeong, Jin Young; Cho, Yong-Min; Lee, Kyung-Tai; Yang, Byoung-Chul; Lim, Hyun-Joo; Cho, Kwanghyeon; Kim, Tae-Hun; Kwon, Eung Gi; Nam, Jungrye; Kwak, Woori; Cho, Seoae; Kim, Heebal

    2014-05-14

    Holstein is known to provide higher milk yields than most other cattle breeds, and the dominant position of Holstein today is the result of various selection pressures. Holstein cattle have undergone intensive selection for milk production in recent decades, which has left genome-wide footprints of domestication. To further characterize the bovine genome, we performed whole-genome resequencing analysis of 10 Holstein and 11 Hanwoo cattle to identify regions containing genes as outliers in Holstein, including CSN1S1, CSN2, CSN3, and KIT whose products are likely involved in the yield and proteins of milk and their distinctive black-and-white markings. In addition, genes indicative of positive selection were associated with cardiovascular disease, which is related to simultaneous propagation of genetic defects, also known as inbreeding depression in Holstein.

  19. Deciphering the Genetic Blueprint behind Holstein Milk Proteins and Production

    PubMed Central

    Lee, Hyun-Jeong; Kim, Jaemin; Lee, Taeheon; Son, Jun Kyu; Yoon, Ho-Baek; Baek, Kwang-Soo; Jeong, Jin Young; Cho, Yong-Min; Lee, Kyung-Tai; Yang, Byoung-Chul; Lim, Hyun-Joo; Cho, Kwanghyeon; Kim, Tae-Hun; Kwon, Eung Gi; Nam, Jungrye; Kwak, Woori; Cho, Seoae; Kim, Heebal

    2014-01-01

    Holstein is known to provide higher milk yields than most other cattle breeds, and the dominant position of Holstein today is the result of various selection pressures. Holstein cattle have undergone intensive selection for milk production in recent decades, which has left genome-wide footprints of domestication. To further characterize the bovine genome, we performed whole-genome resequencing analysis of 10 Holstein and 11 Hanwoo cattle to identify regions containing genes as outliers in Holstein, including CSN1S1, CSN2, CSN3, and KIT whose products are likely involved in the yield and proteins of milk and their distinctive black-and-white markings. In addition, genes indicative of positive selection were associated with cardiovascular disease, which is related to simultaneous propagation of genetic defects, also known as inbreeding depression in Holstein. PMID:24920005

  20. A meta-analysis of the effects of dietary protein concentration and degradability on milk protein yield and milk N efficiency in dairy cows.

    PubMed

    Huhtanen, P; Hristov, A N

    2009-07-01

    Data sets from North American (NA, 739 diets) and North European (NE, 998 diets) feeding trials with dairy cows were evaluated to investigate the effects of dietary crude protein (CP) intake and ruminal degradability on milk protein yield (MPY) and efficiency of N utilization for milk protein synthesis (MNE; milk N / N intake) in dairy cows. The NA diets were based on corn silage, alfalfa silage and hay, corn and barley grains, and soybean meal. The NE diets were based on grass silage, barley and oats grains, and soybean and rapeseed meals. Diets were evaluated for rumen-degradable and undegradable protein (RDP and RUP, respectively) concentrations according to NRC (2001). A mixed model regression analysis with random study effect was used to evaluate relationships between dietary CP concentration and degradability and MPY and MNE. In both data sets, CP intake alone predicted MPY reasonably well. Addition of CP degradability to the models slightly improved prediction. Models based on metabolizable protein (MP) intake predicted MPY better than the CP or the CP-CP degradability models. The best prediction models were based on total digestible nutrients (TDN) and CP intakes. Similar to the MPY models, inclusion of CP degradability in the CP (intake or concentration) models only slightly improved prediction of MNE in both data sets. Concentration of dietary CP was a better predictor of MNE than CP intake. Compared with the CP models, prediction of MNE was improved by inclusion of TDN intake or concentration. Milk yield alone was a poor predictor of MNE. The models developed from one data set were validated using the other data set. The MNE models based on TDN and CP intake performed well as indicated by small mean and slope bias. This meta-analysis demonstrated that CP concentration is the most important dietary factor influencing MNE. Ruminal CP degradability as predicted by NRC (2001) does not appear to be a significant factor in predicting MPY or MNE. Data also

  1. Differentiating Milk and Non-milk Proteins by UPLC Amino Acid Fingerprints Combined with Chemometric Data Analysis Techniques.

    PubMed

    Lu, Weiying; Lv, Xiaxia; Gao, Boyan; Shi, Haiming; Yu, Liangli Lucy

    2015-04-22

    Amino acid fingerprinting combined with chemometric data analysis was used to differentiate milk and non-milk proteins in this study. Microwave-assisted hydrolysis and ultraperformance liquid chromatography (UPLC) were used to obtain the amino acid fingerprints. Both univariate and multivariate chemometrics methods were applied for differentiation. The confidence boundary of amino acid concentration, principal component analysis (PCA), and partial least-squares-discriminant analysis (PLS-DA) of the amino acid fingerprints demonstrated that there were significant differences between milk proteins and inexpensive non-milk protein powders from other biological sources including whey, peanut, corn, soy, fish, egg yolk, beef extract, collagen, and cattle bone. The results indicate that the amino acid compositions with the chemometric techniques could be applied for the detection of potential protein adulterants in milk.

  2. TGF beta suppresses casein synthesis in mouse mammary explants and may play a role in controlling milk levels during pregnancy

    PubMed Central

    1993-01-01

    Mammary explants from 14-15-d-pregnant mice synthesize and secrete milk proteins in culture in response to insulin, hydrocortisone, and prolactin. Here we demonstrate that transforming growth factor beta (TGF beta) treatment suppresses, in a dose dependent and reversible manner, the ability of explants to synthesize and secrete milk caseins. TGF beta does not affect the level of casein mRNA within explants but inhibits casein synthesis posttranscriptionally. We also show increased expression of TGF beta 2 and TGF beta 3 in intact mammary gland as pregnancy progresses, with reduced expression of all three TGF betas at the onset of lactation. These findings suggest that endogenously produced TGF beta may limit the accumulation of milk caseins that are produced in the mammary gland during pregnancy. PMID:8416990

  3. Evaluation of a rapid protein analyzer for determination of protein in milk and cream.

    PubMed

    Amamcharla, J K; Metzger, L E

    2010-08-01

    Accurate and rapid measurement of the protein content of milk is important from both a product quality and an economic standpoint. The Sprint rapid protein analyzer (CEM Corporation, Matthews, NC) is a commercial system based on a dye-binding technique and can be used for rapid measurement of protein in foods. The objective of the present study was to compare the Sprint method with the reference method (Kjeldahl method). Milk and cream samples were analyzed in duplicate for true protein and crude protein (CP) using the reference method as well as the rapid method. Method comparison statistics (regression analysis, graphical representation, standard deviation of residuals, repeatability, and so on) were used to evaluate the agreement between the 2 methods. Regression coefficients and the intercepts were not significantly different from 1 and zero for CP measurement in milk and cream, respectively. The average coefficient of variance between the duplicate CP measurements for the Sprint method was found to be 0.40, 0.49, and 0.76 for milk, light cream, and heavy cream, respectively. True protein measurement in milk and cream also followed a similar trend. Overall, there exists a sufficient level of agreement between the Sprint rapid protein analyzer and Kjeldahl method for true protein and CP measurement of milk and cream samples.

  4. The balance between caseins and whey proteins in cow's milk determines its allergenicity.

    PubMed

    Lara-Villoslada, F; Olivares, M; Xaus, J

    2005-05-01

    Cow's milk allergy is quite common in the first years of human life. Protein composition plays an important role in this pathology, particularly the casein/whey protein ratio. It is known that milks from different species have different sensitization capacities although their protein sources are quite similar. Thus, the objective of this work was to compare the allergenicity of native cow's milk and milk with a modified ratio of casein and whey proteins in a murine model of atopy. Twenty-four Balb/c mice were orally sensitized to native cow's milk or modified cow's milk with a casein/whey protein ratio of 40:60. During the sensitization period, the number of mice suffering from diarrhea was significantly higher in the native cow's milk-sensitized group than in the modified milk-sensitized group. Once mice were killed, plasma histamine levels were shown to be significantly higher in native cow's milk-sensitized mice. In addition, cow's milk proteins induced a higher lymphocyte sensitization in the native milk-sensitized mice, with a significant increase in the specific proliferation ratio of these cells. These results suggest that the balance between caseins and whey proteins plays an important role in the sensitization capacity of cow's milk, and its modification might be a way to reduce the allergenicity of cow's milk.

  5. In vivo digestomics of milk proteins in human milk and infant formula using a suckling rat pup model.

    PubMed

    Wada, Yasuaki; Phinney, Brett S; Weber, Darren; Lönnerdal, Bo

    2017-02-01

    Human milk is the optimal mode of infant feeding for the first several months of life, and infant formulas serve as an alternative when breast-feeding is not possible. Milk proteins have a balanced amino acid composition and some of them provide beneficial bioactivities in their intact forms. They also encrypt a variety of bioactive peptides, possibly contributing to infant health and growth. However, there is limited knowledge of how milk proteins are digested in the gastrointestinal tract and bioactive peptides are released in infants. A peptidomic analysis was conducted to identify peptides released from milk proteins in human milk and infant formula, using a suckling rat pup model. Among the major milk proteins targeted, α-lactalbumin and β-casein in human milk, and β-lactoglobulin and β-casein in infant formula were the main sources of peptides, and these peptides covered large parts of the parental proteins' sequences. Release of peptides was concentrated to specific regions, such as residues 70-92 of β-casein in human milk, residues 39-55 of β-lactoglobulin in infant formula, and residues 57-96 and 145-161 of β-CN in infant formula, where resistance to gastrointestinal digestion was suggested. In the context of bioactive peptides, release of fragments containing known bioactive peptides was confirmed, such as β-CN-derived opioid and antihypertensive peptides. It is therefore likely that these fragments are of biological significance in neonatal health and development.

  6. Disorder in milk proteins: caseins, intrinsically disordered colloids.

    PubMed

    Redwan, Elrashdy M; Xue, Bin; Almehdar, Hussein A; Uversky, Vladimir N

    2015-01-01

    This article opens a series of reviews on the abundance and roles of intrinsic disorder in milk proteins. The focus of this introductory article on caseins is symbolic, since caseins were among the first recognized functional unfolded proteins and since they are definitely the most disordered, the most abundant, and the most studied of all milk proteins. In eutherian milks, the casein family includes at least three and usually four major members (αs1-, αs2-, β-, and κ-caseins) that are unrelated in sequence. However, in some species, two different αS2-casein genes are active, and therefore the total number of caseins can be as high as five. These proteins have found a number of uses in food industry. The functional repertoire of caseins ranges from nutritional function to involvement in the improving and/or maintaining cardiovascular health, to crucial contribution to the milk capacity to transport calcium phosphate, to serve as molecular chaperones, and to protect the mother's mammary gland against amyloidoses and ectopic calcification. An intricate feature of caseins is their ability to assemble to colloidal protein particles, casein micelles, serving to sequester and transport amorphous calcium phosphate. These and many other functions of caseins are obviously dependent on their intrinsically disordered nature and are controlled by various posttranslational modifications. Since various aspects of casein structure and function are rather well studied and since several recent reviews emphasized the functional roles of caseins' intrinsic disorder, the major goal of this article is to show how intrinsic disorder is encoded in the amino acid sequences of these proteins.

  7. Associations between individual cow factors and milk-protein production.

    PubMed

    Sargeant, J M; Martin, S W; Lissemore, K D; Leslie, K E; Gibson, J P; Scott, H M; Kelton, D F

    1998-02-06

    Associations between stage of lactation, cow characteristics, and protein production were evaluated using data from a 2-year period on 75 Ontario, 5 Alberta, and 3 Nova Scotia dairy farms. Individual-cow protein production was defined by 305-day protein yield and by the estimated breeding value for protein yield. Lactation curves for average daily protein yield were computed by parity, breed, and season of calving. Mean protein yield was highest in early lactation. However, there was no pronounced peak in daily protein yield. Parity was positively associated with 305-day protein yield and negatively associated with the estimated breeding values for protein yield. First-calf heifers had lower protein yields in early lactation and a slower rate of decline in protein yield in late lactation, as compared to later parity cows. Holstein cows had higher unadjusted protein yields and lower protein yields after adjusting for milk yield than other breeds. Holstein cows had significantly higher protein yields early in lactation compared to other breeds, but the rate of decline in protein production in late lactation was also greater. Season was associated with 305-day protein yield; the highest protein yields occurred in cows calving in the fall and winter months, but these cows had the greatest rate of decline in protein production in late lactation.

  8. Protein-Linked Glycan Degradation in Infants Fed Human Milk

    PubMed Central

    Dallas, David C.; Sela, David; Underwood, Mark A.; German, J. Bruce; Lebrilla, Carlito

    2014-01-01

    Many human milk proteins are glycosylated. Glycosylation is important in protecting bioactive proteins and peptide fragments from digestion. Protein-linked glycans have a variety of functions; however, there is a paucity of information on protein-linked glycan degradation in either the infant or the adult digestive system. Human digestive enzymes can break down dietary disaccharides and starches, but most of the digestive enzymes required for complex protein-linked glycan degradation are absent from both human digestive secretions and the external brush border membrane of the intestinal lining. Indeed, complex carbohydrates remain intact throughout their transit through the stomach and small intestine, and are undegraded by in vitro incubation with either adult pancreatic secretions or intact intestinal brush border membranes. Human gastrointestinal bacteria, however, produce a wide variety of glycosidases with regio- and anomeric specificities matching those of protein-linked glycan structures. These bacteria degrade a wide array of complex carbohydrates including various protein-linked glycans. That bacteria possess glycan degradation capabilities, whereas the human digestive system, perse, does not, suggests that most dietary protein-linked glycan breakdown will be of bacterial origin. In addition to providing a food source for specific bacteria in the colon, protein-linked glycans from human milk may act as decoys for pathogenic bacteria to prevent invasion and infection of the host. The composition of the intestinal microbiome may be particularly important in the most vulnerable humans-the elderly, the immunocompromised, and infants (particularly premature infants). PMID:24533224

  9. Feeding Unprotected CLA Methyl Esters Compared to Sunflower Seeds Increased Milk CLA Level but Inhibited Milk Fat Synthesis in Cows

    PubMed Central

    Dohme-Meier, F.; Bee, G.

    2012-01-01

    An experiment was conducted to compare the effect of the same amount of 18:2 offered either as 18:2n-6 or as a mixture of unprotected 18:2c9t11 and 18:2t10c12 on feed intake, milk components as well as plasma and milk fatty acid profile. Fifteen cows were blocked by milk yield and milk fat percentage and within block assigned randomly to 1 of 3 treatments (n = 5). Each cow passed a 12-d adjustment period (AP) on a basal diet. After the AP cows received 1 of 3 supplements during an 18-d experimental period (EP). The supplements contained either 1.0 kg ground sunflower seeds (S), 0.5 kg conjugated linoleic acid (CLA)-oil (C) or 0.75 kg of a mixture of ground sunflower seeds and CLA-oil (2:1; SC). All 3 supplements contained the same amount of 18:2 either as CLA (∑18:2c9t11+18:2t10c12, 1:1) or as 18:2c9c12. During the last 2 d of AP and the last 4 d of EP feed intake and milk yield were recorded daily and milk samples were collected at each milking. Blood samples were collected from the jugular vein on d 11 of AP and d 15 and 18 of EP. The 18:2 intake increased in all treatments from AP to EP. Regardless of the amount of supplemented CLA, the milk fat percentage decreased by 2.35 and 2.10%-units in treatment C and SC, respectively, whereas in the treatment S the decrease was with 0.99%-unit less pronounced. Thus, C and SC cows excreted daily a lower amount of milk fat than S cows. The concentration of trans 18:1 in the plasma and the milk increased from AP to EP and increased with increasing dietary CLA supply. While the concentration of 18:2c9t11 and 18:2t10c12 in the plasma and that of 18:2t10c12 in the milk paralleled dietary supply, the level of 18:2c9t11 in the milk was similar in C and CS but still lower in S. Although the dietary concentration of CLA was highest in treatment C, the partial replacement of CLA by sunflower seeds had a similar inhibitory effect on milk fat synthesis. Comparable 18:2c9t11 levels in the milk in both CLA treatments implies that

  10. Feeding Unprotected CLA Methyl Esters Compared to Sunflower Seeds Increased Milk CLA Level but Inhibited Milk Fat Synthesis in Cows.

    PubMed

    Dohme-Meier, F; Bee, G

    2012-01-01

    An experiment was conducted to compare the effect of the same amount of 18:2 offered either as 18:2n-6 or as a mixture of unprotected 18:2c9t11 and 18:2t10c12 on feed intake, milk components as well as plasma and milk fatty acid profile. Fifteen cows were blocked by milk yield and milk fat percentage and within block assigned randomly to 1 of 3 treatments (n = 5). Each cow passed a 12-d adjustment period (AP) on a basal diet. After the AP cows received 1 of 3 supplements during an 18-d experimental period (EP). The supplements contained either 1.0 kg ground sunflower seeds (S), 0.5 kg conjugated linoleic acid (CLA)-oil (C) or 0.75 kg of a mixture of ground sunflower seeds and CLA-oil (2:1; SC). All 3 supplements contained the same amount of 18:2 either as CLA (∑18:2c9t11+18:2t10c12, 1:1) or as 18:2c9c12. During the last 2 d of AP and the last 4 d of EP feed intake and milk yield were recorded daily and milk samples were collected at each milking. Blood samples were collected from the jugular vein on d 11 of AP and d 15 and 18 of EP. The 18:2 intake increased in all treatments from AP to EP. Regardless of the amount of supplemented CLA, the milk fat percentage decreased by 2.35 and 2.10%-units in treatment C and SC, respectively, whereas in the treatment S the decrease was with 0.99%-unit less pronounced. Thus, C and SC cows excreted daily a lower amount of milk fat than S cows. The concentration of trans 18:1 in the plasma and the milk increased from AP to EP and increased with increasing dietary CLA supply. While the concentration of 18:2c9t11 and 18:2t10c12 in the plasma and that of 18:2t10c12 in the milk paralleled dietary supply, the level of 18:2c9t11 in the milk was similar in C and CS but still lower in S. Although the dietary concentration of CLA was highest in treatment C, the partial replacement of CLA by sunflower seeds had a similar inhibitory effect on milk fat synthesis. Comparable 18:2c9t11 levels in the milk in both CLA treatments implies that

  11. The regulation of glucose on milk fat synthesis is mediated by the ubiquitin-proteasome system in bovine mammary epithelial cells.

    PubMed

    Liu, Lily; Jiang, Li; Ding, Xiang-dong; Liu, Jian-feng; Zhang, Qin

    2015-09-11

    Glucose as one of the nutrition factors plays a vital role in the regulation of milk fat synthesis. Ubiquitin-proteasome system (UPS) is a vital proteolytic pathway in all eukaryotic cells through timely marking, recognizing and degrading the poly-ubiquitinated protein substrates. Previous studies indicated that UPS plays a considerable role in controlling the triglyceride (TG) synthesis. Therefore, the aim of this study is to confirm the link between high-glucose and UPS and its regulation mechanism on milk fat synthesis in BMEC (bovine mammary epithelial cells). We incubated BMEC with normal (17.5 mm/L) and high-glucose (25 mm/L) with and without proteasome inhibitor epoxomicin and found that, compared with the control (normal glucose and without proteasome inhibitor), both high-glucose concentration and proteasome inhibitor epoxomicin could increase the accumulation of TG and poly-ubiquitinated proteins, and reduce significantly three proteasome activities (chymotrypsin-like, caspase-like, and trypsin-like). In addition, high-glucose concentration combined with proteasome inhibitor further enhanced the increase of the poly-ubiquitinated protein level and the decrease of proteasome activities. Our results suggest that the regulation of high-glucose on milk fat synthesis is mediated by UPS in BMEC, and high-glucose exposure could lead to a hypersensitization of BMEC to UPS inhibition which in turn results in increased milk fat synthesis.

  12. Milk-derived proteins and peptides in clinical trials.

    PubMed

    Artym, Jolanta; Zimecki, Michał

    2013-08-06

    Clinical trials are reviewed, involving proteins and peptides derived from milk (predominantly bovine), with the exception of lactoferrin, which will be the subject of another article. The most explored milk fraction is α-lactalbumin (LA), which is often applied with glycomacropeptide (GMP) - a casein degradation product. These milk constituents are used in health-promoting infant and adult formulae as well as in a modified form (HAMLET) to treat cancer. Lactoperoxidase (LCP) is used as an additive to mouth hygiene products and as a salivary substitute. Casein derivatives are applied, in addition, in the dry mouth syndrome. On the other hand, casein hydrolysates, containing active tripeptides, found application in hypertension and in type 2 diabetes. Lysozyme is routinely used for food conservation and in pharmaceutical products. It was successfully used in premature infants with concomitant diseases to improve health parameters. When used as prophylaxis in patients with scheduled surgery, it significantly reduced the incidence of hepatitis resulting from blood transfusion. Lysozyme was also used in infected children as an antimicrobial agent showing synergistic effects in combination with different antibiotics. Proline-rich polypeptide (PRP) was introduced to therapy of Alzheimer's disease patients. The therapeutic value of PRP was proved in several clinical trials and supported by studies on its mechanism of action. Concentrated immunoglobulin preparations from colostrum and milk of hyperimmunized cows showed efficacy in prevention of infections by bacteria, viruses and protozoa. A nutrition formula with milk-derived TGF-β2 (Modulen IBD®) found application in treatment of pediatric Crohn's disease. In conclusion, the preparations containing milk-derived products are safe and effective measures in prevention and treatment of infections as well as autoimmune and neoplastic diseases.

  13. Prolactin receptor and signal transduction to milk protein genes

    SciTech Connect

    Djiane, J.; Daniel, N.; Bignon, C.

    1994-06-01

    After cloning of the mammary gland prolactin (PRL) receptor cDNA, a functional assay was established using co-transfection of PRL receptor cDNA together with a milk protein promoter/chloramphenicol acetyl transferase (CAT) construct in Chinese hamster ovary (CHO) cells. Different mutants of the PRL receptor were tested in this CAT assay to delimit the domains in the receptor necessary for signal transduction to milk protein genes. In CHO cells stably transfected with PRL receptor cDNA, high numbers of PRL receptor are expressed. By metabolic labeling and immunoprecipitation, expressed PRL receptor was identified as a single species of 100 kDa. Using these cells, we analyzed the effects of PRL on intracellular free Ca{sup ++} concentration. PRL stimulates Ca{sup ++} entry and induces secondary Ca{sup ++} mobilization. The entry of Ca{sup ++} is a result of an increase in K{sup +} conductance that hyperpolarizes the membranes. We have also analyzed tyrosine phosphorylation induced by PRL. In CHO cells stably transfected with PRL receptor cDNA, PRL induced a very rapid and transient tyrosine phosphorylation of a 100-kDa protein which is most probably the PRL receptor. The same finding was obtained in mammary membranes after PRL injection to lactating rabbits. Whereas tyrosine kinase inhibitors genistein and lavendustin were without effect, PRL stimulation of milk protein gene promoters was partially inhibited by 2 {mu}M herbimycin in CHO cells co-transfected with PRL receptor cDNA and the {Beta} lactoglobulin CAT construct. Taken together these observations indicate that the cytoplasmic domain of the PRL receptor interacts with one or several tyrosine kinases, which may represent early postreceptor events necessary for PRL signal transduction to milk protein genes. 14 refs., 4 figs.

  14. Chloroplast ribosomes and protein synthesis.

    PubMed Central

    Harris, E H; Boynton, J E; Gillham, N W

    1994-01-01

    Consistent with their postulated origin from endosymbiotic cyanobacteria, chloroplasts of plants and algae have ribosomes whose component RNAs and proteins are strikingly similar to those of eubacteria. Comparison of the secondary structures of 16S rRNAs of chloroplasts and bacteria has been particularly useful in identifying highly conserved regions likely to have essential functions. Comparative analysis of ribosomal protein sequences may likewise prove valuable in determining their roles in protein synthesis. This review is concerned primarily with the RNAs and proteins that constitute the chloroplast ribosome, the genes that encode these components, and their expression. It begins with an overview of chloroplast genome structure in land plants and algae and then presents a brief comparison of chloroplast and prokaryotic protein-synthesizing systems and a more detailed analysis of chloroplast rRNAs and ribosomal proteins. A description of the synthesis and assembly of chloroplast ribosomes follows. The review concludes with discussion of whether chloroplast protein synthesis is essential for cell survival. PMID:7854253

  15. Variation in the bovine FABP4 gene affects milk yield and milk protein content in dairy cows

    PubMed Central

    Zhou, H.; Cheng, L.; Azimu, W.; Hodge, S.; Edwards, G. R.; Hickford, J. G. H.

    2015-01-01

    Fatty acid binding proteins (FABPs) bind long-chain fatty acids and are involved in their intracellular transport. Of the known bovine FABP genes, FABP4 has been mapped to a region on chromosome 14 that contains quantitative trait loci for milk traits. This study investigated the association of FABP4 haplotypes with milk production traits in 719 Holstein-Friesian × Jersey cows. Polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis of a variable region of the gene revealed three haplotypes (A, B and C). Five single nucleotide polymorphisms (SNPs) were identified: two in exon 3 and three in intron 3. A was associated (P = 0.032) with increased milk protein percentage (present: 4.00 ± 0.02%; absent: 3.95 ± 0.02%) and B was associated (P = 0.009) with increased milk yield (present: 23.81 ± 0.23 kg/d; absent: 23.06 ± 0.21 kg/d), but tended to be associated with a decrease in protein percentage and an increase in protein yield. Cows with genotypes AA, AB and AC produced less milk, but with a higher protein percentage than BC cows. This suggest that FABP4 affects milk yield and milk protein content, both economically important traits, and that further study of this gene is warranted. PMID:26067182

  16. Heat stability of reconstituted, protein-standardized skim milk powders.

    PubMed

    Sikand, V; Tong, P S; Walker, J

    2010-12-01

    We determined the effects of standardization material, protein content, and pH on the heat stability of reconstituted milk made from low-heat (LH) and medium-heat (MH) nonfat dry milk (NDM). Low-heat and MH NDM were standardized downward from 35.5% to 34, 32, and 30% protein by adding either edible lactose powder (ELP) or permeate powder (PP) from skim milk ultrafiltration. These powders were called standardized skim milk powders (SSMP). The LH and MH NDM and SSMP were reconstituted to 9% total solids. Furthermore, subsamples of reconstituted NDM and SSMP samples were set aside to measure heat stability at native (unadjusted) pH, and the rest were adjusted to pH 6.3 to 7.0. Heat stability is defined as heat coagulation time at 140°C of the reconstituted LH or MH NDM and SSMP samples. The entire experiment was replicated 3 times at unadjusted pH values and 2 times at adjusted pH values. At an unadjusted pH, powder type, standardization material, and protein content influenced the heat stability of the samples. Heat stability for reconstituted LH NDM and SSMP was higher than reconstituted MH NDM and SSMP. Generally, decreased heat stability was observed in reconstituted LH or MH SSMP as protein content was decreased by standardization. However, adding ELP to MH SSMP did not significantly change its heat stability. When pH was adjusted to values between 6.3 and 7.0, powder type, standardization material, and pH had a significant effect on heat stability, whereas protein content did not. Maximum heat stability was noted at pH 6.7 for both reconstituted LH NDM and SSMP samples, and at pH 6.6 for both reconstituted MH NDM and SSMP samples. Furthermore, for samples with adjusted pH, higher heat stability was observed for reconstituted LH SSMP containing PP compared with reconstituted milk from LH SSMP containing ELP. However, no statistical difference was observed in the heat stability of reconstituted milk from MH NDM and MH SSMP samples. We conclude that powder type

  17. Identification of major milk fat globule membrane proteins from pony mare milk highlights the molecular diversity of lactadherin across species.

    PubMed

    Cebo, C; Rebours, E; Henry, C; Makhzami, S; Cosette, P; Martin, P

    2012-03-01

    Although several studies have been devoted to the colloidal and soluble protein fractions of mare milk (caseins and whey proteins), to date little is known about the milk fat globule membrane (MFGM) protein fraction from mare milk. The objective of this study was thus to describe MFGM proteins from Equidae milk and to compare those proteins to already described MFGM proteins from cow and goat milk. Major MFGM proteins (namely, xanthine oxidase, butyrophilin, lactadherin, and adipophilin) already described in cow or goat milk were identified in mare milk using mass spectrometry. However, species-specific peculiarities were observed for 2 MFGM proteins: butyrophilin and lactadherin. A highly glycosylated 70-kDa protein was characterized for equine butyrophilin, whereas proteins of 64 and 67 kDa were characterized for cow and goat butyrophilin, respectively. Prominent differences across species were highlighted for lactadherin. Indeed, whereas 1 or 2 polypeptide chains were identified, respectively, by peptide mass fingerprinting matrix-assisted laser desorption/ionization-time of flight analysis for caprine and bovine lactadherin, 4 isoforms (60, 57, 48, and 45 kDa) for lactadherin from mare milk were identified by 10% sodium dodecyl sulfate-PAGE. Polymerase chain reaction experiments on lactadherin transcripts isolated from milk fat globules revealed the existence of 2 distinct lactadherin transcripts in the horse mammary gland. Cloning and sequencing of both transcripts encoding lactadherin showed an alternative use of a cryptic splice site located at the end of intron 5 of the equine lactadherin-encoding gene. This event results in the occurrence of an additional alanine (A) residue in the protein that disrupts a putative atypical N-glycosylation site (VNGC/VNAGC) described in human lactadherin. Liquid chromatography coupled with tandem mass spectrometry analyses confirmed the existence of both lactadherin variants in mare MFGM. We show here that lactadherin from

  18. Considerations in meeting protein needs of the human milk-fed preterm infant.

    PubMed

    Wagner, Julie; Hanson, Corrine; Anderson-Berry, Ann

    2014-08-01

    Preterm infants provided with sufficient nutrition to achieve intrauterine growth rates have the greatest potential for optimal neurodevelopment. Although human milk is the preferred feeding for preterm infants, unfortified human milk provides insufficient nutrition for the very low-birth-weight infant. Even after fortification with human milk fortifier, human milk often fails to meet the high protein needs of the smallest preterm infants, and additional protein supplementation must be provided. Although substantial evidence exists to support quantitative protein goals for human milk-fed preterm infants, the optimal type of protein for use in human milk fortification remains uncertain. This question was addressed through a PubMed literature search of prospective clinical trials conducted since 1990 in preterm or low-birth-weight infant populations. The following 3 different aspects of protein quality were evaluated: whey-to-casein ratio, hydrolyzed versus intact protein, and bovine milk protein versus human milk protein. Because of a scarcity of current studies conducted with fortified human milk, studies examining protein quality using preterm infant formulas were included to address certain components of the clinical question. Twenty-six studies were included in the review study. No definite advantage was found for any specific whey-to-casein ratio. Protein hydrolyzate products with appropriate formulations can support adequate growth and biochemical indicators of nutrition status and may reduce gastrointestinal transit time, gastroesophageal reflux events, and later incidence of atopic dermatitis in some infants. Plasma amino acid levels similar to those of infants fed exclusive human milk-based diets can be achieved with products composed of a mixture of bovine proteins, peptides, and amino acids formulated to replicate the amino acid composition of human milk. Growth and biochemical indicators of nutrition status are similar for infants fed human milk

  19. [Cow milk protein allergies: primary prevention. Nutritional aspects].

    PubMed

    Dalmau Serra, J; Martorell Aragonés, A

    2008-03-01

    In 2001 the Nutrition Committee of the Spanish Association of Pediatrics, published a position paper on "Recommendations on the use of formulae for the treatment and prevention of adverse reactions to cow milk proteins" (An Esp Pediatr. 2001;54:372-9). Since most of the recommendations given in this report still remain effective, the Nutrition Committee of the Spanish Association of Pediatrics reaffirms its support of the data expressed in it. In the present publication we only approach the aspects that have changed due to new knowledge and the accumulated clinical experience, especially on the primary prevention of allergy to cow milk proteins, and on the basis of it, the present recommendations for this prevention are set out. In addition, the importance of the nutritional aspects in all infants and small children receiving special nutritional formulae and exclusion diets are reviewed.

  20. Influence of processing on functionality of milk and dairy proteins.

    PubMed

    Augustin, Mary Ann; Udabage, Punsandani

    2007-01-01

    The inherent physical functionality of dairy ingredients makes them useful in a range of food applications. These functionalities include their solubility, water binding, viscosity, gelation, heat stability, renneting, foaming, and emulsifying properties. The suitability of dairy ingredients for an application can be further tailored by altering the structure of the proteins using appropriate processes. The processes discussed include physical modification (heat treatment, acidification, addition of mineral slats, homogenization, and shear), enzymatic modification (renneting, hydrolysis, and transglutamination), and chemical modification (use of chemical agents and the Maillard reaction). Emerging food processes (high pressure and ultrasound) are also discussed. The challenges for using dairy ingredients for the delivery of nutrients and bioactive components, while maintaining physical functionality, are also highlighted. There is a need for continued research into the fundamental aspects of milk proteins and their responses to various stresses for further differentiation of milk products and for the delivery of ingredients with consistent quality for target applications.

  1. Towards proteomic analysis of milk proteins in historical building materials

    NASA Astrophysics Data System (ADS)

    Kuckova, S.; Crhova, M.; Vankova, L.; Hnizda, A.; Hynek, R.; Kodicek, M.

    2009-07-01

    The addition of proteinaceous binders to mortars and plasters has a long tradition. The protein additions were identified in many sacral and secular historical buildings. For this method of peptide mass mapping, three model mortar samples with protein additives were prepared. These samples were analysed fresh (1-2 weeks old) and after 9 months of natural ageing. The optimal duration of tryptic cleavage (2 h) and the lowest amount of material needed for relevant analysis of fresh and weathered samples were found; the sufficient amounts of weathered and fresh mortars were set to 0.05 and 0.005 g. The list of main tryptic peptides coming from milk additives (bovine milk, curd, and whey), their relative intensities and theoretical amino acid sequences assignment is presented. Several sequences have been "de novo" confirmed by mass spectrometry.

  2. Distribution of Animal Drugs among Curd, Whey, and Milk Protein Fractions in Spiked Skim Milk and Whey.

    PubMed

    Shappell, Nancy W; Shelver, Weilin L; Lupton, Sara J; Fanaselle, Wendy; Van Doren, Jane M; Hakk, Heldur

    2017-02-01

    It is important to understand the partitioning of drugs in processed milk and milk products, when drugs are present in raw milk, in order to estimate the potential consumer exposure. Radioisotopically labeled erythromycin, ivermectin, ketoprofen, oxytetracycline, penicillin G, sulfadimethoxine, and thiabendazole were used to evaluate the distribution of animal drugs among rennet curd, whey, and protein fractions from skim cow milk. Our previous work reported the distribution of these same drugs between skim and fat fractions of milk. Drug distribution between curd and whey was significantly correlated (R(2) = 0.70) to the drug's lipophilicity (log P), with improved correlation using log D (R(2) = 0.95). Distribution of drugs was concentration independent over the range tested (20-2000 nM). With the exception of thiabendazole and ivermectin, more drug was associated with whey protein than casein on a nmol/g protein basis (oxytetracycline experiment not performed). These results provide insights into the distribution of animal drug residues, if present in cow milk, among milk fractions, with possible extrapolation to milk products.

  3. Cow's milk protein allergy in children: a practical guide

    PubMed Central

    2010-01-01

    A joint study group on cow's milk allergy was convened by the Emilia-Romagna Working Group for Paediatric Allergy and by the Emilia-Romagna Working Group for Paediatric Gastroenterology to focus best practice for diagnosis, management and follow-up of cow's milk allergy in children and to offer a common approach for allergologists, gastroenterologists, general paediatricians and primary care physicians. The report prepared by the study group was discussed by members of Working Groups who met three times in Italy. This guide is the result of a consensus reached in the following areas. Cow's milk allergy should be suspected in children who have immediate symptoms such as acute urticaria/angioedema, wheezing, rhinitis, dry cough, vomiting, laryngeal edema, acute asthma with severe respiratory distress, anaphylaxis. Late reactions due to cow's milk allergy are atopic dermatitis, chronic diarrhoea, blood in the stools, iron deficiency anaemia, gastroesophageal reflux disease, constipation, chronic vomiting, colic, poor growth (food refusal), enterocolitis syndrome, protein-losing enteropathy with hypoalbuminemia, eosinophilic oesophagogastroenteropathy. An overview of acceptable means for diagnosis is included. According to symptoms and infant diet, three different algorithms for diagnosis and follow-up have been suggested. PMID:20205781

  4. Cow's milk protein allergy in children: a practical guide.

    PubMed

    Caffarelli, Carlo; Baldi, Francesco; Bendandi, Barbara; Calzone, Luigi; Marani, Miris; Pasquinelli, Pamela

    2010-01-15

    A joint study group on cow's milk allergy was convened by the Emilia-Romagna Working Group for Paediatric Allergy and by the Emilia-Romagna Working Group for Paediatric Gastroenterology to focus best practice for diagnosis, management and follow-up of cow's milk allergy in children and to offer a common approach for allergologists, gastroenterologists, general paediatricians and primary care physicians.The report prepared by the study group was discussed by members of Working Groups who met three times in Italy. This guide is the result of a consensus reached in the following areas. Cow's milk allergy should be suspected in children who have immediate symptoms such as acute urticaria/angioedema, wheezing, rhinitis, dry cough, vomiting, laryngeal edema, acute asthma with severe respiratory distress, anaphylaxis. Late reactions due to cow's milk allergy are atopic dermatitis, chronic diarrhoea, blood in the stools, iron deficiency anaemia, gastroesophageal reflux disease, constipation, chronic vomiting, colic, poor growth (food refusal), enterocolitis syndrome, protein-losing enteropathy with hypoalbuminemia, eosinophilic oesophagogastroenteropathy. An overview of acceptable means for diagnosis is included. According to symptoms and infant diet, three different algorithms for diagnosis and follow-up have been suggested.

  5. Milk C-reactive protein in canine mastitis.

    PubMed

    Vasiu, Iosif; Dąbrowski, Roman; Martinez-Subiela, Silvia; Ceron, Jose J; Wdowiak, Anna; Pop, Raul Alexandru; Brudaşcă, Florinel Gheorghe; Pastor, Josep; Tvarijonaviciute, Asta

    2017-04-01

    Presence of mastitis in lactating bitches can become life threatening for both the bitch and pups. The aim of the present study was to evaluate a possible utility of C-reactive protein (CRP) in both milk and serum for canine mastitis diagnosis. Our study showed that milk CRP levels ranged between 0.1 and 4.9μg/mL and from 0.3 to 40.0μg/mL in healthy and diseased bitches (P<0.01), respectively, while serum CRP levels ranged between 2.0 and 8.6μg/mL and between 0.3 and 162.3μg/mL in healthy and diseased bitches (P<0.01), respectively. Milk and serum CRP levels were higher in both clinical and subclinical mastitis when compared with healthy controls (P<0.05 in all cases). However, no significant differences were recorded in CRP concentrations between clinical and subclinical cases. Based on these results, it could be concluded that serum and milk CRP could be useful in order to diagnose canine mastitis. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. The Future of Milk Protein Texturization

    USDA-ARS?s Scientific Manuscript database

    Extrusion processing and texturization of soy and other vegetable proteins developed in the 1970’s paved the way for the benefits the food industry is reaping now in their ability to deliver multi-functional products such as meat and seafood analogues. Our work at the USDA Agricultural Research Ser...

  7. Histopathologic findings in children diagnosed with cow's milk protein allergy.

    PubMed

    Cervantes-Bustamante, R; Pedrero-Olivares, I; Toro-Monjaraz, E M; Murillo-Márquez, P; Ramírez-Mayans, J A; Montijo-Barrios, E; Zárate-Mondragón, F; Cadena-León, J; Cazares-Méndez, M; López-Ugalde, M

    2015-01-01

    Cow's milk protein allergy is the most common cause of food allergy. The challenge test, either open or doubled-blind with a placebo control, is regarded as the criterion standard. Endoscopy and histologic findings are considered a method that can aid in the diagnosis of this entity. The aim of this study was to describe the histopathologic findings in children suspected of cow's milk protein allergy that were seen at our hospital. A descriptive, observational study was conducted on 116 children clinically suspected of presenting with cow's milk protein allergy that were seen at the Department of Gastroenterology and Nutrition of the Instituto Nacional de Pediatría. Upper endoscopy and rectosigmoidoscopy with biopsies were performed and the findings were described. Of the 116 patients, 64 (55.17%) were girls and 52 (44.83%) were boys. The rectum was the site with the greatest presence of eosinophils per field in both groups, followed by the duodenum. In general, more than 15 eosinophils were found in 46% of the patients. Between 40 and 45% of the cases had the histologic criterion of more than 15 to 20 eosinophils per field and the rectosigmoid colon was the most affected site. Therefore, panendoscopy and rectosigmoidoscopy with biopsy and eosinophil count are suggested. Copyright © 2014 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.

  8. Claudins, dietary milk proteins, and intestinal barrier regulation.

    PubMed

    Kotler, Belinda M; Kerstetter, Jane E; Insogna, Karl L

    2013-01-01

    The family of claudin proteins plays an important role in regulating the intestinal barrier by modulating the permeability of tight junctions. The impact of dietary protein on claudin biology has not been studied extensively. Whey proteins have been reported to improve intestinal barrier function, but their mechanism of action is not clear. Recent studies, however, have demonstrated increased intestinal claudin expression in response to milk protein components. Reviewed here are new findings suggesting that whey-protein-derived transforming growth factor β transcriptionally upregulates claudin-4 expression via a Smad-4-dependent pathway. These and other data, including limited clinical studies, are summarized below and, in the aggregate, suggest a therapeutic role for whey protein in diseases of intestinal barrier dysfunction, perhaps, in part, by regulating claudin expression. © 2013 International Life Sciences Institute.

  9. Prevalence of soy protein hypersensitivity in cow's milk protein-sensitive children in Korea.

    PubMed Central

    Ahn, Kang-Mo; Han, Young-Shin; Nam, Seung-Yeon; Park, Hwa-Young; Shin, Mee-Yong; Lee, Sang-Il

    2003-01-01

    This study was aimed to evaluate the prevalence of soy protein hypersensitivity in cow's milk protein-sensitive children in Korea. A total of 1,363 patients with atopic dermatitis, urticaria, enterocolitis syndrome, bronchial asthma or allergic rhinitis were recruited. First, we estimated the prevalence of sensitization to soy in children sensitized to cow's milk. Specific IgE levels > 0.7 kU/L by CAP assay were considered positive. Next, the prevalence of soy allergy in cow's milk allergy (CMA) patients was investigated. Those children whose parents agreed to participate the open challenge test with soy had a convincing history of allergic reactions elicited by cow's milk and these symptoms were relieved by elimination. All of them had negative soy-specific IgE. Patients with positive soy-specific IgE accounted for 18.3% of 224 children sensitized to cow's milk protein. The prevalence of sensitization to soy decreased with age (36.8% in the first year of life, 16.4% in the second year, and 13.7% in the third year). Of 21 CMA patients, 42.9% (n=9) were determined to have soy allergy (mean age 10.3 months). Our results suggest that soy protein formula should be carefully used as a substitute for cow's milk in CMA patients, especially during infancy. PMID:12923320

  10. 14-3-3γ regulates cell viability and milk fat synthesis in lipopolysaccharide-induced dairy cow mammary epithelial cells

    PubMed Central

    LIU, LIXIN; ZHANG, LI; LIN, YE; BIAN, YANJIE; GAO, XUEJUN; QU, BO; LI, QINGZHANG

    2016-01-01

    Our previous study demonstrated that 14-3-3γ overexpression was able to inhibit the production of lipopolysaccharide (LPS)-induced cytokines in dairy cow mammary epithelial cells (DCMECs) by inhibiting the activation of nuclear factor-κB (NF-κB) signaling pathways. However, the association between 14-3-3γ overexpression and milk fat synthesis in LPS-induced DCMECs remains unclear. Therefore, the present study investigated the effect of 14-3-3γ on cell viability and milk fat synthesis in LPS-induced DCMECs. The results of the MTT assay and lactate dehydrogenase activity assay demonstrated that 14-3-3γ overexpression was able to attenuate LPS-induced cytotoxicity in DCMECs, and increase the viability of the cells. In addition, the results of reverse transcription-quantitative polymerase chain reaction suggested that mRNA expression levels of genes associated with milk fat synthesis, including sterol regulatory element binding protein (SREBP1), peroxisome proliferator-activated receptor-γ (PPARG), cluster of differentiation 36, acetyl-coA carboxylase (ACC), fatty acid synthase (FAS) and fatty acid binding protein-3, were significantly upregulated in cells overexpressing the 14-3-3γ protein. In addition, as compared with the LPS-treated group, the activities of FAS and ACC were significantly increased. Furthermore, western blotting demonstrated that 14-3-3γ overexpression enhanced the protein expression levels of phosphorylated SREBP1 and PPARG. These results suggested that high levels of 14-3-3γ protein were able to attenuate LPS-induced cell damage and promote milk fat synthesis in LPS-induced DCMECs by increasing the cell viability and upregulating the expression levels of transcription factors associated with milk fat synthesis. PMID:27073437

  11. Dietary carbohydrate composition modifies the milk N efficiency in late lactation cows fed low crude protein diets.

    PubMed

    Cantalapiedra-Hijar, G; Peyraud, J L; Lemosquet, S; Molina-Alcaide, E; Boudra, H; Nozière, P; Ortigues-Marty, I

    2014-02-01

    Nitrogen emissions from dairy cows can be readily decreased by lowering the dietary CP concentration. The main objective of this work was to test whether the milk protein yield reduction associated with low N intakes could be partially compensated for by modifying the dietary carbohydrate composition (CHO). The effects of CHO on digestion, milk N efficiency (milk N/N intake; MNE) and animal performance were studied in four Jersey cows fed 100% or 80% of the recommended protein requirements using a 4×4 Latin square design. Four iso-energetic diets were formulated to two different CHO sources (starch diets with starch content of 34.3% and NDF at 32.5%, and fiber diets with starch content of 5.5% and NDF at 49.1%) and two CP levels (Low=12.0% and Normal=16.5%). The apparent digestible organic matter intake (DOMI) and the protein supply (protein digestible in the small intestine; PDIE) were similar between starch and fiber diets. As planned, microbial N flow (MNF) to the duodenum, estimated from the urinary purine derivatives (PD) excretion, was similar between Low and Normal CP diets. However, the MNF and the efficiency of microbial synthesis (g of microbial N/kg apparently DOMI) were higher for starch v. fiber diets. Milk and milk N fractions (CP, true protein, non-protein N (NPN)) yield were higher for starch compared with fiber diets and for Normal v. Low CP diets. Fecal N excretion was similar across dietary treatments. Despite a higher milk N ouput with starch v. fiber diets, the CHO modified neither the urinary N excretion nor the milk urea-N (MUN) concentration. The milk protein yield relative to both N and PDIE intakes was improved with starch compared with fiber diets. Concentrations of β-hydroxybutyrate, urea and Glu increased and those of glucose and Ala decreased in plasma of cows fed starch v. fiber diets. On the other hand, plasma concentration of albumin, urea, insulin and His increased in cows fed Normal compared with Low CP diets. This study showed

  12. Secretion of Human Protein C in Mouse Milk

    PubMed Central

    Park, Chae-Won; Kang, Myung-Hwa; Min, Kwan-Sik

    2015-01-01

    To determine the production of recombinant human protein C (rec-hPC) in milk, we created two homozygous mice lines for the goat β-casein/hPC transgene. Females and males of both lines (#10 and #11) displayed normal growth, fertility, and lactated normally. The copy number of the transgene was about fivefold higher in #10 line as compared to #11 line. mRNA expression of the transgene was only detected in the mammary glands of both lines. Furthermore, mRNA expression was fourfold higher on day 7 than on day 1 during lactation. Northern blot analysis of mRNA expression in the #10 line of transgenic (Tg) mice indicated a strong expression of the transgene in the mammary glands after seven days of lactation. Comparison of rec-hPC protein level with that of mRNA in the mammary glands showed a very similar pattern. A 52-kDa band corresponding to the hPC protein was strongly detected in mammary glands of the #10 line during lactation. We also detected two bands of heavy chain and one weak band of light chain in the milk of the #10 and #11 lines. One single band at 52 kDa was detected from CHO cells transfected with hPC cDNA. hPC was mainly localized in the alveolar epithelial cell of the mammary glands. The protein is strongly expressed in the cytoplasm of the cultured mammary gland tissue. hPC protein produced in milk ranged from 2 to 28 ng/mL. These experiments indicated that rec-hPC can be produced at high levels in mice mammary glands. PMID:25749471

  13. Bioactive Proteins in Human Milk-Potential Benefits for Preterm Infants.

    PubMed

    Lönnerdal, Bo

    2017-03-01

    Human milk contains many bioactive proteins that are likely to be involved in the better outcomes of breast-fed infants compared with those fed infant formula. Bovine milk proteins or protein fractions may be able to provide some of these benefits and may, therefore, be used for preterm infants. Recombinant human milk proteins are likely to exert bioactivities similar to those of the native human milk proteins, but considerable research is needed before they can be used in routine care of preterm infants.

  14. Acetate Dose-Dependently Stimulates Milk Fat Synthesis in Lactating Dairy Cows.

    PubMed

    Urrutia, Natalie L; Harvatine, Kevin J

    2017-03-22

    Background: Acetate is a short-chain fatty acid (FA) that is especially important to cows because it is the major substrate for de novo FA synthesis. However, the effect of acetate supply on mammary lipid synthesis is not clear.Objective: The objective of this experiment was to determine the effect of increasing acetate supply on milk fat synthesis in lactating dairy cows.Methods: Six multiparous lactating Holstein cows were randomly assigned to treatments in a replicated design to investigate the effect of acetate supply on milk fat synthesis. Treatments were 0 (control), 5, 10, and 15 mol acetate/d continuously infused into the rumen for 4 d. Rumen short-chain FAs, plasma hormones and metabolites, milk fat concentration, and milk FA profile were analyzed on day 4 of each treatment. Polynomial contrasts were used to test the linear and quadratic effects of increasing acetate supply.Results: Acetate increased milk fat yield quadratically (P < 0.01) by 7%, 16%, and 14% and increased milk fat concentration linearly (P < 0.001) by 6%, 9%, and 11% for 5, 10, and 15 mol acetate/d, respectively, compared with the control treatment. Increased milk fat yield predominantly was due to a linear increase in 16-carbon FAs (P < 0.001) and a quadratic increase in de novo synthesized FAs (<16-carbon FAs; P < 0.01), indicating that there was stimulation of de novo synthesis pathways. Apparent transfer of acetate to milk fat was 33.4%, 36.2%, and 20.6% for 5, 10, and 15 mol/d, respectively. Acetate infusion linearly increased the relative concentration of rumen acetate (P < 0.001) before feeding, but not after feeding. Acetate linearly increased plasma ß-hydroxybutyric acid by 29%, 50%, and 78%, respectively, after feeding compared with the control treatment (P < 0.01).Conclusions: Increasing acetate supply to lactating cows increases milk fat synthesis, suggesting that nutritional strategies that increase ruminal acetate absorption would be expected to increase milk fat by

  15. Identification and quantification of bovine protein lactosylation sites in different milk products.

    PubMed

    Milkovska-Stamenova, Sanja; Hoffmann, Ralf

    2016-02-16

    The microbiological safety of milk is typically guaranteed by thermal treatments, such as pasteurization and ultra high temperature (UHT) treatment, whereas infant formula (IF) is often produced at even harsher conditions including a drying process. Thermal treatments have raised concerns, as they may denature proteins and initiate protein modifications. Previous studies identified already many lactosylation sites in milk and showed that the lactosylation degree of some proteins correlates to thermal treatment conditions. Here, we studied the glycation degrees of 124 lactosylation sites in 28 bovine milk proteins in raw milk, three brands of pasteurized milk, three brands of UHT milk, and five brands of IF. Whereas, the glycation degree of many lactosylation sites increased from raw milk, to pasteurized milk, UHT milk, and IF, several modification sites showed a different behavior indicating that global measures do not correctly reflect the reactivity of distinct sites. Interestingly, the glycation degrees varied considerably among the brands of UHT milk and IF indicating that specific production processes of a company have to be considered and not only the classification of milk as pasteurized or UHT. Thus, proper adjustments of the technical processes should allow reducing the lactosylation levels in both UHT milk and IF. It is well established that thermal treatment of milk triggers protein modifications, such as lactosylation of lysine residues in several proteins, although the extent of lactosylation has not been quantitatively compared for a broad panel of protein lactosylation sites among different commercial products. The current study extends previous reports by relatively quantifying 124 confirmed lactosylation sites in 28 bovine milk proteins including several low abundant proteins. Whereas, glycation is generally assumed to be an unspecific chemical reaction with the modification degrees depending on the protein and sugar concentrations, we could show

  16. [Intensity of lipid peroxidation and protein oxidative modification of goat and cow milk].

    PubMed

    Vysokogorskiĭ, V E; Gavrilova, N B; Arkhipenko, Iu A

    2014-01-01

    Indices of free-radical peroxidation have been estimated: intensity of lipid per- oxidation and protein oxidative modification of goat and cow milk of specific breeds of forest-steppe zone of Omsk region. The obtained results indicate that processes of lipid peroxidation and protein oxidative destruction in goat and cow milk of different breeds occur with different gradation. The content of carbonile derivatives in goat milk of Saan breed 1.4 (0.95; 1.5) u/ml was lower than in cow's milk of black-and-white breed 4.6 (1.1; 6.0) u/ml (p = 0.005) what could be caused by large content of protein thiol groups of this kind of milk and lower quantity of amino acid residues that are available for carbonylation. This kind of milk is characterized by higher SH-group content than cow milk for 31% and Switzerland goat milk for 20% (p = 0.005). The content of cetodiens and attached triens in isopropanol phase of the lipid extract of goat milk of Swiss breed is lower by 30% than in cow milk. In isopropanol phase of the milk lipid extracts contain- ing phospholipids the level of Schiff grounding did not differ. The results obtained prove that goat milk contain less protein subjected to oxidative modification.

  17. Study of human allergic milk whey protein from different mammalian species using computational method

    PubMed Central

    Dixit, Shikha Jaiprakash; KK, Appu Kuttan; Singh, Kiran

    2012-01-01

    Nowadays, safety and quality assessment of food used for human consumption have to consider by its possible contribution to the maintenance or improvement of the consumer's health. Milk is an important food with many nutrients. Cow milk is an important source of energy, protein, vitamins and minerals for the growing child as well as adults. But, numerous cow milk proteins have been implicated in allergic responses and most of these have been shown to contain multiple allergic epitopes. The present study disclosed best alternatives to cow milk, which are not allergic and as good as cow milk in nutritional value. The in silico analysis of casein (alpha s1, alpha s2, beta and kappa) and beta-lactoglobulin, unveils that sheep milk is a more suitable alternate to cow milk for allergic infants and buffalo milk for allergic adult humans. PMID:23275703

  18. Associations between milk protein concentration at various stages of lactation and reproductive performance in dairy cows.

    PubMed

    Morton, J M; Auldist, M J; Douglas, M L; Macmillan, K L

    2016-12-01

    Milk protein concentration has been positively associated with a range of measures of reproductive performance in dairy cows. These beneficial associations are most likely due to factors affecting both milk protein concentration and reproductive performance possibly being mediated, in part, by energy balance during early lactation. However, it is likely that factors other than energy balance are also involved in these relationships. A retrospective single cohort study was conducted using subsets of data collected from 74 dairy herds with seasonal or split calving patterns. Associations between milk protein concentration at various stages of lactation and reproductive performance in Holstein dairy cows were assessed using random effects logistic regression and survival analysis with milk protein concentration during the cow's breeding period fitted as a time-varying covariate. The beneficial associations between milk protein concentration and each of the 4 selected indices for measuring reproductive performance were evident when milk protein concentration was derived for each 30-d period from calving up to 300d in milk. For the first 150d of lactation the adjusted odds ratios were highest from 31 to 60d and only slightly lower for all periods up to 150d of lactation. Estimated associations for 31 to 60d were stronger than for 0 to 30d. In addition, milk protein concentration during a cow's breeding period was positively associated with the subsequent daily hazard of conception, even after adjusting for milk protein concentration in the cow's first or second month of lactation. Milk protein concentrations from 0 to 30d of lactation were less closely correlated with concentrations measured at subsequent 30-d intervals; correlations were closer between other periods in lactation. These results indicate that the association between milk protein concentration and reproductive performance is partly due to factors other than the extent of negative energy balance in early

  19. [Quantitative determination of the protein content of milk by ultraviolet spectrophotometry. 3. Determination of proteins in preserved milk samples].

    PubMed

    Reichardt, W; Schüler, E; Sieber, L; Schüler, E

    1987-01-01

    It is reported upon the results of the quantitative estimation of protein content from preserved milk by means of ultraviolet spectrophotometry. In addition to the preservation by boric acid, bronopol, copper sulphate, potassium dichromate and ammonium peroxodisulphate storage at temperatures below 0 degrees C and freeze drying were tested. Besides bronopol and copper sulphate especially physical preservation methods proves fit for the protein estimation by measurements of absorbance at 210 nm, 235 and 280 nm or 210 and 220 nm. It is recommended to use solutions and filters of quartz with evaluated absorbance in daily calibrating of the spectrophotometer.

  20. Differential digestion of human milk proteins in a simulated stomach model.

    PubMed

    Zhang, Qiang; Cundiff, Judy K; Maria, Sarah D; McMahon, Robert J; Wickham, Martin S J; Faulks, Richard M; van Tol, Eric A F

    2014-02-07

    A key element in understanding how human milk proteins support the health and development of the neonate is to understand how individual proteins are affected during digestion. In the present study, a dynamic gastric model was used to simulate infant gastric digestion of human milk, and a subsequent proteomic approach was applied to study the behavior of individual proteins. A total of 413 human milk proteins were quantified in this study. This approach demonstrated a high degree of variability in the susceptibility of human milk proteins to gastric digestion. Specifically this study reports that lipoproteins are among the class of slowly digested proteins during gastric processes. The levels of integral lysozyme C and partial lactadherin in milk whey increase over digestion. Mucins, ribonuclease 4, and macrophage mannose receptor 1 are also resistant to gastric digestion. The retention or enhancement in whey protein abundance can be ascribed to the digestive release of milk-fat-globule-membrane or immune-cell enclosed proteins that are not initially accessible in milk. Immunoglobulins are more resistant to digestion compared to total milk proteins, and within the immunoglobulin class IgA and IgM are more resistant to digestion compared to IgG. The gastric digestion of milk proteins becomes more apparent from this study.

  1. Associations of high and low milk protein concentrations with energy allocation, milk production, and concentrations of blood plasma metabolites and hormones in Holstein-Friesian cows.

    PubMed

    Douglas, M L; Marett, L C; Macmillan, K L; Morton, J M; Hannah, M C; Fisher, A D; Auldist, M J

    2016-12-01

    A positive association between milk protein concentration (MPC) and reproductive performance in dairy cows has been shown in several studies globally. This association may positively influence farm productivity and profitability, particularly in seasonally calving, pasture-based herds. However, the differences in milk production and energy allocation, physical characteristics, and blood plasma nutrient status between cows with differing MPC have not been examined, and the underlying mechanisms responsible for the association remain undefined. The objective of this study was to examine associations between MPC and nutrient partitioning in primiparous Holstein-Friesian cows managed under pasture-based dairying conditions, and to identify differences that may indicate the underlying mechanisms. Data were collected from 85 cows at regular intervals during the early part of the 2013 to 2014 seasonal lactation, including daily milk yield, weekly milk composition, weekly body condition score measurements, as well as weekly blood plasma metabolite and hormone concentrations. Cows were retrospectively separated into quartiles based on their average MPC during the first 120d of lactation, and comparisons were made between cows within the highest (high; 3.22 to 3.40%) and the lowest (low; 2.87 to 3.00%) MPC quartiles. The high-MPC cows had lower daily milk yields, yet did not differ in the daily yields of milk solids (protein + fat) compared with the low-MPC cows. After parturition, the high-MPC cows had greater blood plasma concentrations of glucose, insulin, insulin-like growth factor-1 and leptin compared with the low-MPC cows and maintained their body condition score, despite no differences in these variables prepartum. These results indicate an increased partitioning of nutrients toward milk synthesis at the expense of body condition for cows in the low MPC quartile. However, average daily energy outputs in milk were similar in the high- and low-MPC cows. The high

  2. Gene regulation of UDP-galactose synthesis and transport: Potential rate limiting processes in initiation of milk production in humans

    USDA-ARS?s Scientific Manuscript database

    Lactose synthesis is believed to be rate-limiting for milk production. However, understanding the molecular events controlling lactose synthesis in humans is still rudimentary. We have utilized our established model of the RNA isolated from breast milk fat globule from 7 healthy exclusively breastfe...

  3. Milk yield and milk composition responses to change in predicted net energy and metabolizable protein: a meta-analysis.

    PubMed

    Daniel, J B; Friggens, N C; Chapoutot, P; Van Laar, H; Sauvant, D

    2016-12-01

    Using a meta-analysis of literature data, this study aimed to quantify the dry matter (DM) intake response to changes in diet composition, and milk responses (yield, milk component yields and milk composition) to changes in dietary net energy for lactation (NEL) and metabolizable protein (MP) in dairy cows. From all studies included in the database, 282 experiments (825 treatments) with experimentally induced changes in either NEL or MP content were kept for this analysis. These treatments covered a wide range of diet characteristics and therefore a large part of the plausible NEL and MP contents and supplies that can be expected in practical situations. The average MP and NEL contents were, respectively (mean±SD), 97±12 g/kg DM and 6.71±0.42 MJ/kg DM. On a daily supply basis, there were high between-experiment correlations for MP and NEL above maintenance. Therefore, supplies of MP and NEL above maintenance were, respectively, centred on MP supply for which MP efficiency into milk protein is 0.67, and NEL above maintenance supply for which the ratio of NEL milk/NEL above maintenance is 1.00 (centred variables were called MP67 and NEL100). The majority of the selected studies used groups of multiparous Holstein-Friesian cows in mid lactation, milked twice a day. Using a mixed model, between- and within-experiment variation was split to estimate DM intake and milk responses. The use of NEL100 and MP67 supplies substantially improved the accuracy of the prediction of milk yield and milk component yields responses with, on average, a 27% lower root mean square error (RMSE) relative to using dietary NEL and MP contents as predictors. For milk composition (g/kg), the average RMSE was only 3% lower on a supply basis compared with a concentration basis. Effects of NEL and MP supplies on milk yield and milk component yields responses were additive. Increasing NEL supply increases energy partitioning towards body reserve, whereas increasing MP supply increases the

  4. De novo synthesis of milk triglycerides in humans

    USDA-ARS?s Scientific Manuscript database

    Mammary gland (MG) de novo lipogenesis contributes significantly to milk fat in animals but little is known in humans. Objective: To test the hypothesis that the incorporation of 13C carbons from [U-13C]glucose into fatty acids (FA) and glycerol in triglycerides (TG) will be greater: 1) in milk tha...

  5. Reducing dietary protein in dairy cow diets: implications for nitrogen utilization, milk production, welfare and fertility.

    PubMed

    Sinclair, K D; Garnsworthy, P C; Mann, G E; Sinclair, L A

    2014-02-01

    In light of increasing global protein prices and with the need to reduce environmental impact of contemporary systems of milk production, the current review seeks to assess the feasibility of reducing levels of dietary CP in dairy cow diets. At CP levels between 140 and 220 g/kg DM there is a strong positive relationship between CP concentration and dry matter intake (DMI). However, such effects are modest and reductions in DMI when dietary CP is below 180 g/kg DM can be at least partially offset by improving the digestibility and amino acid profile of the undegradable protein (UDP) component of the diet or by increasing rumen fermentable energy. Level and balance of intestinally absorbable amino acids, in particular methionine and lysine, may become limiting at lower CP concentrations. In general the amino acid composition of microbial protein is superior to that of UDP, so that dietary strategies that aim to promote microbial protein synthesis in the rumen may go some way to correcting for amino acid imbalances in low CP diets. For example, reducing the level of NDF, while increasing the proportion of starch, can lead to improvements in nitrogen (N) utilisation as great as that achieved by reducing dietary CP to below 150 g/kg. A systematic review and meta-analysis of responses to rumen protected forms of methionine and lysine was conducted for early/mid lactation cows fed diets containing ⩽150 g CP/kg DM. This analysis revealed a small but significant (P=0.002) increase in milk protein yield when cows were supplemented with these rumen protected amino acids. Variation in milk and milk protein yield responses between studies was not random but due to differences in diet composition between studies. Cows fed low CP diets can respond to supplemental methionine and lysine so long as DMI is not limiting, metabolisable protein (MP) is not grossly deficient and other amino acids such as histidine and leucine do not become rate limiting. Whereas excess dietary protein

  6. Effect of protein source on amino acid supply, milk production, and metabolism of plasma nutrients in dairy cows fed grass silage.

    PubMed

    Korhonen, M; Vanhatalo, A; Huhtanen, P

    2002-12-01

    This study conducted according to a 4 x 4 Latin square with 28 d periods and four ruminally cannulated Finnish Ayrshire cows investigated the effect of protein supplements differing in amino acid (AA) profile and rumen undegradable protein content on postruminal AA supply and milk production. Mammary metabolism of plasma AA and other nutrients were also studied. The basal diet (Control; 13.4% crude protein) consisted of grass silage and barley in a ratio of 55:45 on a dry matter basis. The other three isonitrogenous diets (17.0% crude protein) were control + fishmeal (FM), control + soybean meal (SBM), and control + corn gluten meal (CGM). The protein supplements replaced portions of dry matter of the control diet maintaining the silage to barley ratio constant for all diets. Dry matter intake was limited to 95% of the preexperimental ad libitum intake and was similar (mean 19.8 kg/d dry matter) across the diets. Protein supplements increased milk, lactose, and protein yields but did not affect yields of energy-corrected milk or milk fat. Milk protein yield response was numerically lowest for diet SBM. Protein supplements increased milk protein concentration but decreased milk fat and lactose concentrations. Microbial protein synthesis and rumen fermentation parameters were similar across the diets, except for an increased rumen ammonia concentration for diets supplemented with protein feeds. Protein supplements increased N intake, ruminal organic matter and N, and total tract organic matter, N, and neutral detergent fiber digestibilities. Protein supplements also increased N and AA flows into the omasum, with SBM giving the lowest and CGM the highest flows. This was associated with an unchanged microbial N flow and a higher undegraded dietary N flow. The omasal flows of individual AA reflected differences in total N flow and AA profile of the experimental diets. Differences in AA flows did not always reflect plasma AA concentrations. The results indicated that AA

  7. Effect of microparticulated whey proteins on milk coagulation properties.

    PubMed

    Sturaro, A; Penasa, M; Cassandro, M; Varotto, A; De Marchi, M

    2014-11-01

    The enhancement of milk coagulation properties (MCP) and the reuse of whey produced by the dairy industry are of great interest to improve the efficiency of the cheese-making process. Native whey proteins (WP) can be aggregated and denatured to obtain colloidal microparticulated WP (MWP). The objective of this study was to assess the effect of MWP on MCP; namely, rennet coagulation time (RCT), curd-firming time, and curd firmness 30 min after rennet addition. Six concentrations of MWP (vol/vol; 1.5, 3.0, 4.5, 6.0, 7.5, and 9.0%) were added to 3 bulk milk samples (collected and analyzed during 3 d), and a sample without MWP was used as control. Within each day of analysis, 6 replicates of MCP for each treatment were obtained, changing the position of the treatment in the rack. For control samples, 2 replicates per day were performed. In addition to MCP, WP fractions were measured on each treatment during the 3 d of analysis. Milk coagulation properties were measured on 144 samples by using a Formagraph (Foss Electric, Hillerød, Denmark). Increasing the amount of MWP added to milk led to a longer RCT. In particular, significant differences were found between RCT of the control samples (13.5 min) and RCT of samples with 3.0% (14.6 min) or more MWP. A similar trend was observed for curd-firming time, which was shortest in the control samples and longest in samples with 9.0% MWP (21.4 min). No significant differences were detected for curd firmness at 30 min across concentrations of MWP. Adjustments in cheese processing should be made when recycling MWP, in particular during the coagulation process, by prolonging the time of rennet activity before cutting the curd.

  8. [Therapeutic properties of proteins and peptides from colostrum and milk].

    PubMed

    Zimecki, Michał; Artym, Jolanta

    2005-01-01

    Colostrum and milk are rich in proteins and peptides which play a crucial role in innate immunity when transferred to the offspring and may accelerate maturation of the immune system in neonates. The immunotropic properties of these proteins prompted investigators research their potential application in prevention and therapy. Lactoferrin (LF) exhibits antibacterial, antifungal, antiviral, antiparasitice, and antitumoral activities. It is protective with regard to intestinal epithelium, promotes bone growth, and accelerates the recovery of immune system function in immunocompromised animals. LF was tried in the treatment of hepatitis C infection and the intestinal form of graft-versus-host disease (GvHD). A proline-rich polypeptide (PRP) demonstrated a variety of immunotropic functions, including the promotion of T-cell maturation and inhibition of autoimmune disorders. PRP, in the form of chewable tablets (Colostrinin) was recently found to improve or stabilize the health status of Alzheimer's disease patients. Casein and casein-derived peptides showed protective activities in enamel demineralization and as caries-preventing agents. The protein hydrolyzates were also protective in diabetic animals, reduced tumor growth, had antihypertensive activity and diminished colicky symptoms in infants. Glycomacropeptide (GMP), a peptide derived from kappa-casein, exhibited various antibacterial and antithrombotic activities. Alpha-lactalbumin (LA) demonstrated antiviral, antitumoral and anti-stress properties. LA-enriched diets were anxiolytic, lowered blood pressure in rats, prevented diarrhea, and led to a better weight gain in malnourished children. HAMLET, a complex of LA and oleic acid, was effective in patients with cutaneous papillomas. Lysozyme found application in infant formulas, the treatment of periodentitis, and the prevention of tooth decay. Milk enriched in lysozyme was used in feeding premature infants suffering from concomitant diseases. Interesting

  9. Proteomic characterization of human milk whey proteins during a twelve-month lactation period.

    PubMed

    Liao, Yalin; Alvarado, Rudy; Phinney, Brett; Lönnerdal, Bo

    2011-04-01

    Human milk is a rich source of bioactive proteins that support the early growth and development of the newborn. Although the major components of the protein fraction in human milk have been studied, the expression and relative abundance of minor components have received limited attention. We examined the expression of low-abundance proteins in the whey fraction of human milk and their dynamic changes over a twelve-month lactation period. The low-abundance proteins were enriched by ProteoMiner beads, and protein identification was performed by liquid chromatography tandem mass spectrometry. One hundred and fifteen proteins were identified, thirty-eight of which have not been previously reported in human colostrum or milk. We also for the first time described differences in protein patterns among the low-abundance proteins during lactation. These results enhance our knowledge about the complexity of the human milk proteome, which constitutes part of the advantages to the breast-fed infant.

  10. The aggregation behavior and interactions of yak milk protein under thermal treatment.

    PubMed

    Wang, T T; Guo, Z W; Liu, Z P; Feng, Q Y; Wang, X L; Tian, Q; Ren, F Z; Mao, X Y

    2016-08-01

    The aggregation behavior and interactions of yak milk protein were investigated after heat treatments. Skim yak milk was heated at temperatures in the range of 65 to 95°C for 10 min. The results showed that the whey proteins in yak milk were denatured after heat treatment, especially at temperatures higher than 85°C. Sodium dodecyl sulfate-PAGE analysis indicated that heat treatment induced milk protein denaturation accompanied with aggregation to a certain extent. When the heating temperature was 75 and 85°C, the aggregation behavior of yak milk proteins was almost completely due to the formation of disulfide bonds, whereas denatured α-lactalbumin and β-lactoglobulin interacted with κ-casein. When yak milk was heated at 85 and 95°C, other noncovalent interactions were found between proteins including hydrophobic interactions. The particle size distributions and microstructures demonstrated that the heat stability of yak milk proteins was significantly lowered by heat treatment. When yak milk was heated at 65 and 75°C, no obvious changes were found in the particle size distribution and microstructures in yak milk. When the temperature was 85 and 95°C, the particle size distribution shifted to larger size trend and aggregates were visible in the heated yak milk.

  11. Interaction of milk whey protein with common phenolic acids

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Yu, Dandan; Sun, Jing; Guo, Huiyuan; Ding, Qingbo; Liu, Ruihai; Ren, Fazheng

    2014-01-01

    Phenolics-rich foods such as fruit juices and coffee are often consumed with milk. In this study, the interactions of α-lactalbumin and β-lactoglobulin with the phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, and coumalic acid) were examined. Fluorescence, CD, and FTIR spectroscopies were used to analyze the binding modes, binding constants, and the effects of complexation on the conformation of whey protein. The results showed that binding constants of each whey protein-phenolic acid interaction ranged from 4 × 105 to 7 × 106 M-n and the number of binding sites n ranged from 1.28 ± 0.13 to 1.54 ± 0.34. Because of these interactions, the conformation of whey protein was altered, with a significant reduction in the amount of α-helix and an increase in the amounts of β-sheet and turn structures.

  12. Comparative proteomics of milk fat globule membrane in goat colostrum and mature milk.

    PubMed

    Lu, Jing; Liu, Lu; Pang, Xiaoyang; Zhang, Shuwen; Jia, Zhenhu; Ma, Changlu; Zhao, Lili; Lv, Jiaping

    2016-10-15

    As an important nutrient source in large area of world, the composition and nutritional value of goat milk are not well deliberated. Detailed annotation of protein composition is essential to address the physiological and nutritional value of goat milk. In the present study, 423 colostrum and mature goat milk fat globule membrane (MFGM) proteins were identified. The abundance of 189 proteins was significantly different between colostrums and mature milk MFGM. The acute phase proteins were higher in colostrums MFGM than those in mature milk MFGM which protected newborns at the beginning of life. Proteins related to synthesis and secretion were conserved through lactation to ensure the milk production. Of note, long term depression (LTD) proteins were observed in colostrum and mature milk MFGM. Milk LTD proteins could be potential biomarkers for diagnosis of lactation related depressive syndromes and should be taken into considerations of their effects on newborns. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Combining proteomic tools to characterize the protein fraction of llama (Lama glama) milk.

    PubMed

    Saadaoui, Besma; Bianchi, Leonardo; Henry, Céline; Miranda, Guy; Martin, Patrice; Cebo, Christelle

    2014-05-01

    Llamas belong to the Camelidae family along with camels. While dromedary camel milk has been broadly characterized, data on llama milk proteins are scarce. The objective of this study was thus to investigate the protein composition of llama milk. Skimmed llama milk proteins were first characterized by a 2D separation technique coupling RP-HPLC in the first dimension with SDS-PAGE in the second dimension (RP-HPLC/SDS-PAGE). Llama milk proteins, namely caseins (αs1 -, αs2 -, β-, and κ-caseins), α-lactalbumin, lactoferrin, and serum albumin, were identified using PMF. Llama milk proteins were also characterized by online LC-ESI-MS analysis. This approach allowed attributing precise molecular masses for most of the previously MS-identified llama milk proteins. Interestingly, α-lactalbumin exhibits distinct chromatographic behaviors between llama and dromedary camel milk. De novo sequencing of the llama α-lactalbumin protein by LC coupled with MS/MS (LC-MS/MS) showed the occurrence of two amino acid substitutions (R62L/I and K89L/I) that partly explained the higher hydrophobicity of llama α-lactalbumin compared with its dromedary counterpart. Taken together, these results provide for the first time a thorough description of the protein fraction of Lama glama milk.

  14. Comparison of the principal proteins in bovine, caprine, buffalo, equine and camel milk.

    PubMed

    Hinz, Katharina; O'Connor, Paula M; Huppertz, Thom; Ross, R Paul; Kelly, Alan L

    2012-05-01

    Proteomic analysis of bovine, caprine, buffalo, equine and camel milk highlighted significant interspecies differences. Camel milk was found to be devoid of β-lactoglobulin, whereas β-lactoglobulin was the major whey protein in bovine, buffalo, caprine, and equine milk. Five different isoforms of κ-casein were found in camel milk, analogous to the micro-heterogeneity observed for bovine κ-casein. Several spots observed in 2D-electrophoretograms of milk of all species could tentatively be identified as polypeptides arising from the enzymatic hydrolysis of caseins. The understanding gained from the proteomic comparison of these milks may be of relevance both in terms of identifying sources of hypoallergenic alternatives to bovine milk and detection of adulteration of milk samples and products.

  15. Detection and quantitation of pea and soy-derived proteins in calf milk replacers.

    PubMed

    Schoonderwoerd, M; Misra, V

    1989-01-01

    Preruminant calves on several farms had diarrhea nonresponsive to treatment and were doing poorly, despite being fed a high quality calf milk replacer. Because these reconstituted milk replacers always had a sediment, they were suspected of containing insoluble nonmilk-derived proteins. Microscopic examination of the milk replacer, however, did not show any evidence of starch granules. We therefore analyzed the samples by SDS PAGE. We were able to identify and quantitate pea protein in calf milk replacers in which all the protein was supposedly milk-derived. We were also able to differentiate polypeptides derived from pea and soy. We concluded that PAGE is a sensitive technique for detecting nonmilk-derived proteins in calf milk replacers.

  16. Invited review: milk protein polymorphisms in cattle: effect on animal breeding and human nutrition.

    PubMed

    Caroli, A M; Chessa, S; Erhardt, G J

    2009-11-01

    The 6 main milk proteins in cattle are encoded by highly polymorphic genes characterized by several nonsynonymous and synonymous mutations, with up to 47 protein variants identified. Such an extensive variation was used for linkage analysis with the description of the casein cluster more than 30 yr ago and has been applied to animal breeding for several years. Casein haplotype effects on productive traits have been investigated considering information on the whole casein complex. Moreover, mutations within the noncoding sequences have been shown to affect the specific protein expression and, as a consequence, milk composition and cheesemaking. Milk protein variants are also a useful tool for breed characterization, diversity, and phylogenetic studies. In addition, they are involved in various aspects of human nutrition. First, the occurrence of alleles associated with a reduced content of different caseins might be exploited for the production of milk with particular nutritional qualities; that is, hypoallergenic milk. On the other hand, the frequency of these alleles can be decreased by selection of sires using simple DNA tests, thereby increasing the casein content in milk used for cheesemaking. Furthermore, the biological activity of peptides released from milk protein digestion can be affected by amino acid exchanges or deletions resulting from gene mutations. Finally, the gene-culture coevolution between cattle milk protein genes and human lactase genes, which has been recently highlighted, is impressive proof of the nonrandom occurrence of milk protein genetic variation over the centuries.

  17. Composition of the non-protein nitrogen fraction of goat whole milk powder and goat milk-based infant and follow-on formulae.

    PubMed

    Prosser, Colin G; Mclaren, Robert D; Frost, Deborah; Agnew, Michael; Lowry, Dianne J

    2008-03-01

    The non-protein nitrogen fraction of goat whole milk powder and of infant and follow-on formulae made from goat milk was characterized and compared with cow milk powder and formulae. Goat milk infant formula contained 10% non-protein nitrogen, expressed as a proportion of total nitrogen, compared with 7.1% for cow milk formula. Goat follow-on formula contained 9.3% and cow 7.4% non-protein nitrogen. Urea, at 30%, was quantitatively the most abundant component of the non-protein nitrogen fraction of goat milk and formulae, followed by free amino acids at 7%. Taurine, glycine and glutamic acid were the most abundant free amino acids in goat milk powders. Goat milk infant formula contained 4 mg/100 ml total nucleotide monophosphates, all derived from the goat milk itself. Goat milk has a very different profile of the non-protein nitrogen fraction to cow milk, with several constituents such as nucleotides at concentrations approaching those in human breast milk.

  18. Peptidomic analysis reveals proteolytic activity of kefir microorganisms on bovine milk proteins

    PubMed Central

    Dallas, David C.; Citerne, Florine; Tian, Tian; Silva, Vitor L. M.; Kalanetra, Karen M.; Frese, Steven A.; Robinson, Randall C.; Mills, David A.; Barile, Daniela

    2015-01-01

    Scope The microorganisms that make up kefir grains are well known for lactose fermentation, but the extent to which they hydrolyze and consume milk proteins remains poorly understood. Peptidomics technologies were used to examine the proteolytic activity of kefir grains on bovine milk proteins. Methods and results Gel electrophoresis revealed substantial digestion of milk proteins by kefir grains, with mass spectrometric analysis showing the release of 609 protein fragments and alteration of the abundance of >1,500 peptides that derived from 27 milk proteins. Kefir contained 25 peptides identified from the literature as having biological activity, including those with antihypertensive, antimicrobial, immunomodulatory, opioid and anti-oxidative functions. 16S rRNA and shotgun metagenomic sequencing identified the principle taxa in the culture as Lactobacillus species. Conclusion The model kefir sample contained thousands of protein fragments released in part by kefir microorganisms and in part by native milk proteases. PMID:26616950

  19. Peptidomic analysis reveals proteolytic activity of kefir microorganisms on bovine milk proteins.

    PubMed

    Dallas, David C; Citerne, Florine; Tian, Tian; Silva, Vitor L M; Kalanetra, Karen M; Frese, Steven A; Robinson, Randall C; Mills, David A; Barile, Daniela

    2016-04-15

    The microorganisms that make up kefir grains are well known for lactose fermentation, but the extent to which they hydrolyze and consume milk proteins remains poorly understood. Peptidomics technologies were used to examine the proteolytic activity of kefir grains on bovine milk proteins. Gel electrophoresis revealed substantial digestion of milk proteins by kefir grains, with mass spectrometric analysis showing the release of 609 protein fragments and alteration of the abundance of >1500 peptides that derived from 27 milk proteins. Kefir contained 25 peptides identified from the literature as having biological activity, including those with antihypertensive, antimicrobial, immunomodulatory, opioid and anti-oxidative functions. 16S rRNA and shotgun metagenomic sequencing identified the principle taxa in the culture as Lactobacillus species. The model kefir sample contained thousands of protein fragments released in part by kefir microorganisms and in part by native milk proteases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Comparison of functional properties of 34% and 80% whey protein and milk serum protein concentrates.

    PubMed

    Luck, P J; Vardhanabhuti, B; Yong, Y H; Laundon, T; Barbano, D M; Foegeding, E A

    2013-09-01

    This study compared the functional properties of serum protein concentrate (SPC) with whey protein concentrate (WPC) made from the same milk and with commercial WPC. The experimental SPC and WPC were produced at 34% or 80% protein from the same lot of milk. Protein contents of WPC and SPC were comparable; however, fat content was much lower in SPC compared with WPC and commercial WPC. The effect of drying methods (freeze vs. spray drying) was studied for 34% WPC and SPC. Few differences due to drying method were found in turbidity and gelation; however, drying method made a large difference in foam formation for WPC but not SPC. Between pH 3 and 7, SPC was found to have lower turbidity than WPC; however, protein solubility was similar between SPC and WPC. Foaming and gelation properties of SPC were better than those of WPC. Differences in functional properties may be explained by differences in composition and extent of denaturation or aggregation.

  1. Immunological studies in cows' milk protein-sensitive enteropathy

    PubMed Central

    Yadav, M; Iyngkaran, N

    1981-01-01

    55 infants, aged between 1 and 13 months, who presented with persistent diarrhoea were placed on a diet free of cows' milk protein. The clinical condition of the infants improved and 6-8 weeks later each was challenged with low-lactose cows' milk. The following investigations were performed before and 24 hours after provocation: jejunal biopsy, serum and duodenal juice levels of complement C3 and C4, C3-activator, and immunoglobulins A, G, M, and D. Three groups were recognised on postchallenge clinical symptoms together with histological changes in the jejunal mucosa: group 1 (n=10 infants) with no clinical or mucosal abnormality, group 2 (n=18 infants) with mucosal abnormalities but lacking clinical symptoms, and group 3 (n=27 infants) with mucosal abnormalities and clinical symptoms; but in group 3 symptoms were delayed for over 24 hours in 7 infants, and in the remaining 20 infants symptoms appeared within 24 hours. After provocation the serum IgG levels were decreased in 3 infants in group 1, 12 in group 2, and 17 in group 3. The mean serum IgA and IgM levels were higher in group 1 compared with group 2 or 3; pre- and postchallenge mean serum immunoglobulin levels, complement, and complement activator levels were of equal magnitude in all three groups. A depletion of serum complement C3 level was observed in 4 (group 1), 4 (group 2), and 13 (group 3) infants 24 hours after provocation with cows' milk; the fall in serum IgG was often associated with depletion of complement in serum. This suggests the involvement in some infants of IgG-mediated complement-consuming immune reactions in the development of the damage in the intestinal mucosa. After challenge, exudation of IgG and IgA occurred irrespective of the presence or absence of mucosal damage and was not always associated with the decrease in serum IgG concentration. Because of the variable conditions present in the intestinal lumen it is suggested that the level of immunoglobulins in duodenal juice is not a

  2. Cheese production using kefir culture entrapped in milk proteins.

    PubMed

    Dimitrellou, Dimitra; Kandylis, Panagiotis; Kourkoutas, Yiannis; Koutinas, Athanasios A; Kanellaki, Maria

    2015-05-01

    The aim of the present study was to evaluate the use of kefir culture entrapped in casein and in whey protein as starter cultures for the production of Feta-type cheese. Microbiological analysis showed that counts of enterobacteria, coliforms, and staphylococci were significantly reduced due to kefir culture. In addition, the effect of kefir culture on the formation of volatile compounds, such as esters, organic acids, alcohols, carbonyl compounds, and lactones, was also investigated using the SPME GC/MS technique. Cheese samples produced with kefir culture entrapped in milk proteins presented improved profile of aroma-related compounds. Principal component analysis of the results indicated that the volatile composition of the different cheese types was dependent on the nature of the starter culture. Finally, the sensory evaluation showed that the products produced with kefir culture had a soft, fine taste, and were of improved quality.

  3. Analysis of polymorphisms in milk proteins from cloned and sexually reproduced goats.

    PubMed

    Xing, H; Shao, B; Gu, Y Y; Yuan, Y G; Zhang, T; Zang, J; Cheng, Y

    2015-12-08

    This study evaluates the relationship between the genotype and milk protein components in goats. Milk samples were collected from cloned goats and normal white goats during different postpartum (or abortion) phases. Two cloned goats, originated from the same somatic line of goat mammary gland epithelial cells, and three sexually reproduced normal white goats with no genetic relationships were used as the control. The goats were phylogenetically analyzed by polymerase chain reaction-restriction fragment length polymorphism. The milk protein components were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The results indicated that despite the genetic fingerprints being identical, the milk protein composition differed between the two cloned goats. The casein content of cloned goat C-50 was significantly higher than that of cloned goat C-4. Conversely, although the genetic fingerprints of the normal white goats N-1, N-2, and N-3 were not identical, the milk protein profiles did not differ significantly in their milk samples (obtained on postpartum day 15, 20, 25, 30, and 150). These results indicated an association between milk protein phenotypes and genetic polymorphisms, epigenetic regulation, and/or non-chromosomal factors. This study extends the knowledge of goat milk protein polymorphisms, and provides new strategies for the breeding of high milk-yielding goats.

  4. Protein chemical synthesis in drug discovery.

    PubMed

    Liu, Fa; Mayer, John P

    2015-01-01

    The discovery of novel therapeutics to combat human disease has traditionally been among the most important goals of research chemists. After a century of innovation, state-of-the-art chemical protein synthesis is now capable of efficiently assembling proteins of up to several hundred residues in length from individual amino acids. By virtue of its unique ability to incorporate non-native structural elements, chemical protein synthesis has been seminal in the recent development of several novel drug discovery technologies. In this chapter, we review the key advances in peptide and protein chemistry which have enabled our current synthetic capabilities. We also discuss the synthesis of D-proteins and their applications in mirror image phage-display and racemic protein crystallography, the synthesis of enzymes for structure-based drug discovery, and the direct synthesis of homogenous protein pharmaceuticals.

  5. Nuclear Factor of κB1 Is a Key Regulator for the Transcriptional Activation of Milk Synthesis in Bovine Mammary Epithelial Cells.

    PubMed

    Huang, Xin; Zang, Yanli; Zhang, Minghui; Yuan, Xiaohan; Li, Meng; Gao, Xuejun

    2017-02-03

    The nuclear factor of κB (NFκB) family has been well known for its significant role in regulating the expression of numerous genes that control many biological processes. However, it is unclear whether NFκB could regulate milk synthesis. In this study, we identified NFκB1 as a critical regulator for milk synthesis in bovine mammary epithelial cells (BMECs). Gene function study revealed that NFκB1 modulates the expression of mammalian target of rapamycin (mTOR), sterol response element-binding protein (SREBP)-1c, and β4Gal-T2 for milk synthesis. Furthermore, chromatin immunoprecipitation assays showed that both methionine (Met) and estrogen (E) triggered NFκB1 to bind to gene promoters of mTOR, SREBP-1c, and β4Gal-T2 in BMECs. In addition, we confirmed that Met and E triggered NFκB1 expression and phosphorylation via phosphatidylinositol-3-kinase (PI3K) but not mTOR signaling pathway. Taken together, our study reveals that NFκB1 acts as a PI3K but not mTOR-dependent critical mediator for the transcriptional activation of signaling molecules regulating milk synthesis in BMECs.

  6. Chronological protein synthesis in regenerating rat liver.

    PubMed

    He, Jinjun; Hao, Shuai; Zhang, Hao; Guo, Fuzheng; Huang, Lingyun; Xiao, Xueyuan; He, Dacheng

    2015-07-01

    Liver regeneration has been studied for decades; however, its regulation remains unclear. In this study, we report a dynamic tracing of protein synthesis in rat regenerating liver with a new proteomic technique, (35) S in vivo labeling analysis for dynamic proteomics (SiLAD). Conventional proteomic techniques typically measure protein alteration in accumulated amounts. The SiLAD technique specifically detects protein synthesis velocity instead of accumulated amounts of protein through (35) S pulse labeling of newly synthesized proteins, providing a direct way for analyzing protein synthesis variations. Consequently, protein synthesis within short as 30 min was visualized and protein regulations in the first 8 h of regenerating liver were dynamically traced. Further, the 3.5-5 h post partial hepatectomy (PHx) was shown to be an important regulatory turning point by acute regulation of many proteins in the initiation of liver regeneration. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Effect of summer season on milk protein fractions in Holstein cows.

    PubMed

    Bernabucci, U; Basiricò, L; Morera, P; Dipasquale, D; Vitali, A; Piccioli Cappelli, F; Calamari, L

    2015-03-01

    Milk characteristics are affected by heat stress, but very little information is available on changes of milk protein fractions and their relationship with cheesemaking properties of milk. The main objective of the study was to evaluate the effect of hot season on milk protein fractions and cheesemaking properties of milk for Grana Padano cheese production. The study was carried out in a dairy farm with a cheese factory for transforming the milk to Grana Padano cheese. The study was carried out from June 2012 to May 2013. Temperature and relative humidity of the inside barn were recorded daily during the study period using 8 electronic data loggers programmed to record every 30 min. Constant managerial conditions were maintained during the experimental periods. During the experimental period, feed and diet characteristics, milk yield, and milk characteristics were recorded in summer (from June 29 to July 27, 2012), winter (from January 25 to March 8, 2013), and spring (from May 17 to May 31, 2013). Milk yield was recorded and individual milk samples were taken from 25 cows selected in each season during the p.m. milking. Content of fat, proteins, caseins (CN), lactose and somatic cell count (SCC), titratable acidity, and milk rennet coagulation properties were determined on fresh samples. Milk protein fraction concentrations were determined by the sodium dodecyl sulfate-PAGE. Data were tested for nonnormality by the Shapiro-Wilk test. In case of nonnormality, parameters were normalized by log or exponential transformation. The data were analyzed with repeated measures ANOVA using a mixed model procedure. For all the main milk components (fat, protein, total solids, and solids-not-fat), the lowest values were observed in the summer and the greatest values were observed in the winter. Casein fractions, with the exception of γ-CN, showed the lowest values in the summer and the greatest values in the winter. The content of IgG and serum albumin was greater in summer

  8. Effects of enzymatic dephosphorylation on infant in vitro gastrointestinal digestibility of milk protein concentrate.

    PubMed

    Liu, Dasong; Wang, Yuanyuan; Yu, Yun; Hu, Jinhua; Lu, Naiyan; Regenstein, Joe M; Wang, Miao; Zhou, Peng

    2016-04-15

    This study investigated the effects of dephosphorylation extent on infant in vitro gastric clotting property and gastrointestinal digestibility of milk protein concentrate. Dephosphorylation was affected by phosphatase type and incubation pH. A series of milk protein concentrate with 0-69% dephosphorylation were obtained by incubation with calf intestinal alkaline phosphatase at pH 6.5 for 0-420 min. Both β- and αs1-caseins in the modified milk protein concentrate showed multiply dephosphorylated isoforms with different numbers of phosphate groups depending on the extent of dephosphorylation. With increased dephosphorylation of milk protein concentrate, the gastric clotting extent decreased and the gastrointestinal digestibility increased under infant in vitro conditions. These results suggested the potential of developing a dephosphorylated milk protein concentrate, with improved gastric clotting property and gastrointestinal digestibility, to simulate the multiply phosphorylated patterns of human casein and hence to further the humanization of infant formula on a molecular level.

  9. Good tolerance to goat's milk in patients with recurrent aphthous ulcers with increased immunoreactivity to cow's milk proteins.

    PubMed

    Besu, Irina; Jankovic, Ljiljana; Konic-Ristic, Aleksandra; Damjanovic, Ana; Besu, Valeri; Juranic, Zorica

    2013-08-01

    Recurrent aphthous ulcers (RAU) represent a very common, but poorly understood mucosal disorder. The connection between immunity to cow's milk proteins (CMP) and oral diseases was noted earlier. The goal of this study was to determine the prevalence of the increased levels of serum antibodies to goat's milk proteins (GMP), by enzyme-linked immunosorbent assay (ELISA) test, in subjects who have RAU and proven increased immunity to CMP. Fifty subjects with RAU (36 with proven increased immunity to CMP and 14 without this increased immunity) were included in this research. Levels of serum IgA, IgG, and IgE antibodies to the same quantity of the examined antigens were determined by ELISA. The statistical analysis of data was performed by Wilcoxon rank-sum test and Mann-Whitney test. The levels of serum antifresh cow's milk IgA, IgG, and IgE antibodies were significantly higher than the levels of serum antifresh goat's milk, in subjects with RAU with proven increased immunoreactivity to CMP (P = 0.0003; P < 0.0001; P < 0.0001). These results indicate that patients with RAU with increased immunity to CMP could consider the use of goat's milk as the alternative protein source. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  10. Milk protein profiles in response to Streptococcus agalactiae subclinical mastitis in dairy cows.

    PubMed

    Pongthaisong, Pongphol; Katawatin, Suporn; Thamrongyoswittayakul, Chaiyapas; Roytrakul, Sittiruk

    2016-01-01

    The objective of this study was to investigate the milk protein profiles of normal milk and those of milk during the course of subclinical mastitis, caused by natural Streptococcus agalactiae infection. Two-dimensional gel electrophoresis and liquid chromatography mass spectrometry were used to assess protein profiles and to identify the proteins. The results showed that S. agalactiae subclinical mastitis altered the protein profiles of milk. Following Mascot database matching, 11 and 12 protein types were identified in the milk collected from healthy and S. agalactiae subclinical mastitic udders, respectively. The distinct presence of the antibacterial protein cathelicidin-1 was detected in infected milk samples, which in turn was highly correlated to the severity of subclinical mastitis as represented by the milk somatic cell count (r = 0.616), but not the bacterial count. The protein profile of milk reveals changes in the host response to S. agalactiae intramammary infection; cathelicidin-1 could therefore serve as a biomarker for the detection of subclinical mastitis in dairy cows.

  11. Comprehensive proteomic analysis of the human milk proteome: contribution of protein fractionation.

    PubMed

    Mangé, A; Bellet, V; Tuaillon, E; Van de Perre, P; Solassol, J

    2008-12-15

    In-depth analysis of the milk proteome by mass spectrometry is challenged by the presence of few high-abundance proteins that interfere with the detection of lower-abundance proteins. Here, we evaluated the proteomic analysis of milk samples following a strong anion exchange fractionation procedure using denaturating conditions ensuring the disruption of protein-protein interactions. Crude whey or skim milk and their different resulting fractions were analyzed by protein chip array mass spectrometry. Using protein chip array mass spectrometry, several high-abundance proteins were localized in distinct fractions increasing the total number of unique peptides and proteins detected. This total number increased by about 20-30% by combining different chromatographic surface arrays used for capture. Reproducible results were obtained in human skim milk and whey; however this approach was not successful with milk fat globule membrane and required refinement. Hence, milk profiling by anion exchange fractionation combined to protein chip array mass spectrometry represents a promising tool to detect unknown low-abundance milk proteins that may ultimately prove useful as biomarkers of diseases transmitted by breastfeeding.

  12. Rapid enrichment of bioactive milk proteins and iterative, consolidated protein identification by multidimensional protein identification technology.

    PubMed

    Panchaud, Alexandre; Kussmann, Martin; Affolter, Michael

    2005-10-01

    Direct injection of complex protein mixtures, e.g. those derived from crude biological fluids, is often incompatible with conventional LC supports, because of column clogging and rapid deterioration of chromatographic performance. In this paper, we report the use of restricted access media to rapidly enrich and fractionate human breast milk. This resin, combining size exclusion and anion exchange functionalities, yielded a fraction enriched in soluble CD14 and showing specific sCD14-dependant activity. This fraction was split into five aliquots, which were individually characterized using multidimensional protein identification technology. Reproducibility of the results was addressed by analysing and comparing five datasets using different protein identification tools available within the Sequest software. Furthermore, a comparison of three major releases of the Ensembl human protein database was performed to examine the effect of database updates on our results. We report here the benefit of repeated analysis of aliquots of the same fraction: first to increase the confidence in peptide identification by repeated confirmation in several aliquots; and second to assess experimental reproducibility. We demonstrate furthermore the effect of database modifications on the results and the importance of constantly re-analysing data with new releases to keep them consistent and up to date with the latest protein identities and predictions available.

  13. Protein Synthesis--An Interactive Game.

    ERIC Educational Resources Information Center

    Clements, Lee Ann J.; Jackson, Karen E.

    1998-01-01

    Describes an interactive game designed to help students see and understand the dynamic relationship between DNA, RNA, and proteins. Appropriate for either a class or laboratory setting, following a lecture session about protein synthesis. (DDR)

  14. Protein Synthesis--An Interactive Game.

    ERIC Educational Resources Information Center

    Clements, Lee Ann J.; Jackson, Karen E.

    1998-01-01

    Describes an interactive game designed to help students see and understand the dynamic relationship between DNA, RNA, and proteins. Appropriate for either a class or laboratory setting, following a lecture session about protein synthesis. (DDR)

  15. The distribution of environmental contaminants and pharmaceuticals among skim milk, milk fat, curd, whey, and milk protein fractions through milk processing

    USDA-ARS?s Scientific Manuscript database

    Twenty-seven environmental contaminants and pharmaceuticals encompassing a wide range of physicochemical properties were utilized to determine the effects of milk processing on xenobiotic distribution among milk fractions. Target compounds included radiolabeled antibiotics [ciprofloxacin (CIPR), cl...

  16. Quest for the chemical synthesis of proteins.

    PubMed

    Engelhard, Martin

    2016-05-01

    The chemical synthesis of proteins has been the wish of chemists since the early 19th century. There were decisive methodological steps necessary to accomplish this aim. Cornerstones were the introduction of the Z-protecting group of Bergmann and Zervas, the development of Solid-phase Peptide Synthesis of Merrifield, and the establishment of Native Chemical Ligation by Kent. Chemical synthesis of proteins has now become generally applicable technique for the synthesis of proteins with tailor made properties which can be applied not only in vitro but also in vivo .Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  17. Breast milk jaundice: in vitro inhibition of rat liver bilirubin-uridine diphosphate glucuronyltransferase activity and Z protein-bromosulfophthalein binding by human breast milk.

    PubMed

    Foliot, A; Ploussard, J P; Housset, E; Christoforov

    1976-06-01

    Twenty-four samples of breast milk from nine mothers of infants suffering from breast milk jaundice were studied. Eight samples of milk from mothers of nonjaundiced infants, along with five formula milks enriched with polyunsaturated fatty acids, served as controls. Milks from mothers with jaundiced infants had no inhibitory effect when assayed immediately after thawing. However, after these milk samples were stores at 4 degrees, they strongly inhibited bilirubin conjugation (80.3% inhibition of uridine diphosphate glucuronyltransferase (UDPGT) activity) and bromosulfophthalein (BSP) binding to cytoplasmic Z protein (dye binding inhibited 82.1%). There was no effect on BSP binding to Y protein (see Table 1). Heating the milk to 56 degrees modified the results in the following manner; when the milk was heated immediately after thawing, no inhibitory effect was seen, even after storage for 96 hr. On the other hand, when the milk was first stored at 96 hr and then heated, it had the same inhibitory effects as the milks which were stored without heating. The present study shows that pathologic breast milk will inhibit BSP-Z protein binding only when stored under conditions that also cause the appearance of the capacity to inhibit bilirubin conjugation in vitro, as well as causing the liberation of nonesterified fatty acids. Thus, the appearance of this inhibitory capacity in vitro seems linked to the lipolytic activity particular to pathologic milks.

  18. Milk protein composition and stability changes affected by iron in water sources.

    PubMed

    Wang, Aili; Duncan, Susan E; Knowlton, Katharine F; Ray, William K; Dietrich, Andrea M

    2016-06-01

    Water makes up more than 80% of the total weight of milk. However, the influence of water chemistry on the milk proteome has not been extensively studied. The objective was to evaluate interaction of water-sourced iron (low, medium, and high levels) on milk proteome and implications on milk oxidative state and mineral content. Protein composition, oxidative stability, and mineral composition of milk were investigated under conditions of iron ingestion through bovine drinking water (infused) as well as direct iron addition to commercial milk in 2 studies. Four ruminally cannulated cows each received aqueous infusions (based on water consumption of 100L) of 0, 2, 5, and 12.5mg/L Fe(2+) as ferrous lactate, resulting in doses of 0, 200, 500 or 1,250mg of Fe/d, in a 4×4Latin square design for a 14-d period. For comparison, ferrous sulfate solution was directly added into commercial retail milk at the same concentrations: control (0mg of Fe/L), low (2mg of Fe/L), medium (5mg of Fe/L), and high (12.5mg of Fe/L). Two-dimensional electrophoresis coupled with matrix-assisted laser desorption/ionization-tandem time-of-flight (MALDI-TOF/TOF) high-resolution tandem mass spectrometry analysis was applied to characterize milk protein composition. Oxidative stability of milk was evaluated by the thiobarbituric acid reactive substances (TBARS) assay for malondialdehyde, and mineral content was measured by inductively coupled plasma mass spectrometry. For milk from both abomasal infusion of ferrous lactate and direct addition of ferrous sulfate, an iron concentration as low as 2mg of Fe/L was able to cause oxidative stress in dairy cattle and infused milk, respectively. Abomasal infusion affected both caseins and whey proteins in the milk, whereas direct addition mainly influenced caseins. Although abomasal iron infusion did not significantly affect oxidation state and mineral balance (except iron), it induced oxidized off-flavor and partial degradation of whey proteins. Direct

  19. Effects of glucose availability on expression of the key genes involved in synthesis of milk fat, lactose and glucose metabolism in bovine mammary epithelial cells.

    PubMed

    Liu, Hongyun; Zhao, Ke; Liu, Jianxin

    2013-01-01

    As the main precursor for lactose synthesis, large amounts of glucose are required by lactating dairy cows. Milk yield greatly depends on mammary lactose synthesis due to its osmoregulatory property for mammary uptake of water. Thus, glucose availability to the mammary gland could be a potential regulator of milk production. In the present study, the effect of glucose availability on expression of the key genes involved in synthesis of milk fat, lactose and glucose metabolism in vitro was investigated. Bovine mammary epithelial cells (BMEC) were treated for 12 h with various concentrations of glucose (2.5, 5, 10 or 20 mmol/L). The higher concentrations of glucose (10-20 mmol/L) did not affect the mRNA expression of acetyl-CoA carboxylase, diacyl glycerol acyl transferase, glycerol-3 phosphate acyl transferase and α-lactalbumin, whereas fatty acid synthase, sterol regulatory element binding protein-1 and beta-1, 4-galactosyl transferase mRNA expression increased at 10 mmol/L and then decreased at 20 mmol/L. The content of lactose synthase increased with increasing concentration of glucose, with addition of highest value at 20 mmol/L of glucose. Moreover, the increased glucose concentration stimulated the activities of pyruvate kinase and glucose-6-phosphate dehydrogenase, and elevated the energy status of the BMEC. Therefore, it was deduced that after increasing glucose availability, the extra absorbed glucose was partitioned to entering the synthesis of milk fat and lactose by the regulation of the mRNA expression of key genes, promoting glucose metabolism by glycolysis and pentose phosphate pathway as well as energy status. These results indicated that the sufficient availability of glucose in BMEC may promote glucose metabolism, and affect the synthesis of milk composition.

  20. Health-promoting properties of bioactive peptides derived from milk proteins in infant food: a review.

    PubMed

    Raikos, Vassilios; Dassios, Theodore

    2014-01-01

    Milk proteins have attracted extensive interest in terms of their bioavailability following ingestion. Enzymatic digestion of dairy products generates numerous peptides with various biological activities. Both human milk and infant formulas based on cow's milk are potential sources of bioactive peptides. This review aims to present current knowledge on the formation and fate of bioactive peptides from milk feeds intended for infants. Emphasis is placed on the source of the bioactive peptides with the nutritional impact of human milk and cow milk-based formulas on infant health being critically discussed from that perspective. Furthermore, the effect of processing and in vitro or in vivo digestion on the release and availability of peptides with bioactive sequences is evaluated. Considerable differences with respect to bioavailability and metabolic effects between the biologically active fragments generated following ingestion of human milk and infant formulas are documented. Peptides from milk protein of bovine origin could be a valuable supplement to human milk as multiple health-promoting properties are attributed to peptide fractions identified in standard cow milk-based infant formulas.

  1. Cooling causes changes in the distribution of lipoprotein lipase and milk fat globule membrane proteins between the skim milk and cream phase.

    PubMed

    Dickow, J A; Larsen, L B; Hammershøj, M; Wiking, L

    2011-02-01

    Lipoprotein lipase (LPL) activity and free fatty acid levels were studied in freshly milked, uncooled milk from individual Danish Holstein or Jersey cows, or after storage for up to 24h at either a cooling temperature (4°C) or at the milking temperature (31°C). Upon cooling for up to 24h, LPL activity increased in the cream phase, whereas the activity in the skim milk was steady, as observed for Jersey cows, or increased, as seen for the Holsteins. Storage at 31°C decreased the LPL activity in both the cream phase and the skim milk phase. The increase in free fatty acid levels was found to depend on LPL activity, incubation temperature, substrate availability, and incubation time. Furthermore, the migration of milk proteins between the skim milk phase and the cream phase upon cooling of milk from Jersey cows or from Danish Holstein cows was studied using proteomic methods involving 2-dimensional gel electrophoresis and mass spectrometry. Proteins associated with the milk fat globules were isolated from all milk fractions and analyzed. Major changes in the distributions of proteins between the skim milk phase and the cream phase were observed after cooling at 4°C for 4h, where a total of 29 proteins between the 2 breeds was found to change their association with the milk fat globule membrane (MFGM) significantly. Among these, the MFGM proteins adipophilin, fatty acid-binding protein, and lactadherin, as well as the non-MFGM proteins β-casein, lactoferrin, and heat shock protein-71, were identified. Adipophilin, lactadherin, and lactoferrin were quantitatively more associated with the MFGM upon cold storage at 4°C, whereas β-casein, fatty acid-binding protein, and heat shock protein-71 were found to be less associated with the MFGM upon cold storage.

  2. Energetic efficiency of milk synthesis in dual-purpose cows grazing tropical pastures.

    PubMed

    Aguilar-Pérez, Carlos Fernando; Ku-Vera, Juan Carlos; Magaña-Monforte, Juan Gabriel

    2011-04-01

    The aim of this study was to assess the energetic efficiency of milk synthesis by grazing dual-purpose cows with or without a starch-based supplement in tropical South Mexico. Forty-six Holstein × Zebu cows were used in a 2 × 2 × 2 factorial design. Factors analysed were diet (supplemented, unsupplemented), age (young: 1-2 calvings, mature: >3 calvings) and day of lactation (21 and 84 days post-calving). The supplement represented about 30% of estimated dry matter (DM) intake. Grass intake was measured using the n-alkane technique at 21 and 84 days post-calving when calculations of efficiency were performed. Efficiency for milk synthesis was reported as feed conversion efficiency (FCE, kilograms of milk per kilogram of DM intake), gross energetic efficiency (GEE, milk energy output/metabolisable energy (ME) intake) and efficiency of ME use for lactation (k(l), adjusted to zero energy balance). There were no interactions between factors. FCE and GEE were not different between diets, but supplemented cows had a lower (p < 0.01) k(l) value (0.62) than unsupplemented cows (0.67), suggesting a diverted partition of nutrients towards body tissue. Mature cows were more efficient (p < 0.001) than young cows in terms of FCE (1.13 vs 0.87) and GEE (0.34 vs 0.26), but equal in terms of k(l) (0.65). FCE (1.10 vs 0.90) and GEE (0.34 vs 0.27) were both higher on day 21 compared with day 84 post-calving, with a trend for a higher k(l) in early lactation. Dual-purpose cows used tropical grasses efficiently for milk synthesis, and higher milk yield observed in supplemented cows was due to a higher intake of nutrients rather than a higher energetic efficiency.

  3. Changes in the surface protein of the fat globules during homogenization and heat treatment of concentrated milk.

    PubMed

    Ye, Aiqian; Anema, Skelte G; Singh, Harjinder

    2008-08-01

    The changes in milk fat globules and fat globule surface proteins of both low-preheated and high-preheated concentrated milks, which were homogenized at low or high pressure, were examined. The average fat globule size decreased with increasing homogenization pressure. The total surface protein (mg m-2) of concentrated milk increased after homogenization, the extent of the increase being dependent on the temperature and the pressure of homogenization, as well as on the preheat treatment. The concentrates obtained from high-preheated milks had higher surface protein concentration than the concentrates obtained from low-preheated milks after homogenization. Concentrated milks heat treated at 79 degrees C either before or after homogenization had greater amounts of fat globule surface protein than concentrated milks heat treated at 50 or 65 degrees C. This was attributed to the association of whey protein with the native MFGM (milk fat globule membrane) proteins and the adsorbed skim milk proteins. Also, at the same homogenization temperature and pressure, the amount of whey protein on the fat globule surface of the concentrated milk that was heated after homogenization was greater than that of the concentrated milk that was heated before homogenization. The amounts of the major native MFGM proteins did not change during homogenization, indicating that the skim milk proteins did not displace the native MFGM proteins but adsorbed on to the newly formed surface.

  4. Changes in the physical properties, solubility, and heat stability of milk protein concentrates prepared from partially acidified milk.

    PubMed

    Eshpari, H; Tong, P S; Corredig, M

    2014-12-01

    A limiting factor in using milk protein concentrates (MPC) as a high-quality protein source for different food applications is their poor reconstitutability. Solubilization of colloidal calcium phosphate (CCP) from casein micelles during membrane filtration (e.g., through acidification) may affect the structural organization of these protein particles and consequently the rehydration and functional properties of the resulting MPC powder. The main objective of this study was to investigate the effects of acidification of milk by glucono-δ-lactone (GDL) before ultrafiltration (UF) on the composition, physical properties, solubility, and thermal stability (after reconstitution) of MPC powders. The MPC samples were manufactured in duplicate, either by UF (65% protein, MPC65) or by UF followed by diafiltration (80% protein, MPC80), using pasteurized skim milk, at either the native milk pH (~pH 6.6) or at pH 6.0 after addition of GDL, followed by spray drying. Samples of different treatments were reconstituted at 5% (wt/wt) protein to compare their solubility and thermal stability. Powders were tested in duplicate for basic composition, calcium content, reconstitutability, particle size, particle density, and microstructure. Acidification of milk did not have any significant effect on the proximate composition, particle size, particle density, or surface morphology of the MPC powders; however, the total calcium content of MPC80 decreased significantly with acidification (from 1.84 ± 0.03 to 1.59 ± 0.03 g/100 g of powder). Calcium-depleted MPC80 powders were also more soluble than the control powders. Diafiltered dispersions were significantly less heat stable (at 120°C) than UF samples when dissolved at 5% solids. The present work contributes to a better understanding of the differences in MPC commonly observed during processing.

  5. Effect of dietary protein level and rumen-protected amino acid supplementation on amino acid utilization for milk protein in lactating dairy cows.

    PubMed

    Lee, C; Giallongo, F; Hristov, A N; Lapierre, H; Cassidy, T W; Heyler, K S; Varga, G A; Parys, C

    2015-03-01

    This study investigated the effect of metabolizable protein (MP) supply and rumen-protected (RP) Lys and Met supplementation on productivity, nutrient digestibility, urinary N losses, apparent total-tract digestibility of dietary AA, and the efficiency of AA utilization for milk protein synthesis in dairy cows. The experiment was conducted with 8 ruminally cannulated Holstein cows in a replicated 4×4 Latin square design trial with 21-d periods. Treatments were (1) MP-adequate diet (AMP; MP balance of -24 g/d); (2) MP-deficient diet (DMP; MP balance of -281 g/d); (3) DMP supplemented with 100 g of RPLys/cow per day (estimated digestible Lys supply=24 g/d; DMPL; MP balance of -305g/d); and (4) DMPL supplemented with 24 g of RPMet/cow per day (estimated digestible Met supply=15 g/d; DMPLM; MP balance of -256g/d). Diet had no effect on total-tract nutrient digestibility, milk production, and milk composition, but the DMP diets decreased urinary N excretion and the ammonia emitting potential of manure. Plasma Met concentration was increased by DMPLM compared with AMP. Supplementation with RPLys had no effect on plasma Lys. Concentration of most AA in milk protein was increased or tended to be increased by DMPLM compared with DMPL. Except for the AA supplemented as RPAA (i.e., Met and Lys), apparent total-tract digestibility of all dietary AA was generally greater for the DMP diets and ranged from 33% (Arg, AMP diet) to 67% (Thr, DMPL diet). Apparent recovery of dietary AA in milk protein followed the same trends, being greater for the DMP diets than AMP and generally lower for Lys and Met with the RPAA-supplemented diets versus AMP and DMP. The RPAA were apparently not used for milk protein synthesis in the conditions of this experiment. The AA recoveries in milk protein varied from around 17% (Ala) to 70% (Pro). Milk protein recoveries of essential AA (EAA) were around 54% for the DMP diet and 49% for AMP. The estimated efficiency of utilization of digestible EAA for

  6. Crop milk protein is synthesised following activation of the IRS1/Akt/TOR signalling pathway in the domestic pigeon (Columba livia).

    PubMed

    Hu, X-C; Gao, C-Q; Wang, X-H; Yan, H-C; Chen, Z-S; Wang, X-Q

    2016-12-01

    The experiment was conducted to study whether insulin receptor substance 1 (IRS1) / Protein kinase B (Akt)/target of the rapamycin (TOR) signalling pathway activation stimulates crop milk protein synthesis in the domestic pigeon (Columba livia). Crop milk was collected from ten 1-d-old squabs and analysed for nutrient content. During the non-breeding period and the first day of lactation, blood samples were collected from 5 pairs of breeding pigeons and the levels of prolactin and insulin were determined. Crop samples were collected from 5 pairs of breeders at d 14 and 16 of the incubation period and d 1, 3 and 7 of the lactation period. Crop samples were evaluated for changes in crop weight and thickness and changes in the expression patterns of IRS1/Akt/TOR signalling pathway-related proteins. The results demonstrated that prolactin induces a gradual increase in the relative weight and thickness of the crop, with crops reaching a maximum size at the third day of lactation. Pigeon crop milk contains 64.1% crude protein and 29.7% crude fat based on dry weight. Serum prolactin and insulin levels in the lactation period were significantly higher than those in the non-breeding period. Compared with non-breeding pigeons, the expression of the phosphorylated IRS1 phosphorylated Akt, phosphorylated TOR, phosphorylated ribosomal protein S6 kinase, phosphorylated S6, phosphorylated eukaryotic initiation factor 4E binding protein 1 and eukaryotic initiation factor 4E were significantly up-regulated in the crop of pigeons in the lactation period. In conclusion, prolactin might induce changes in crop tissue and form the physiological structure for crop milk synthesis. Furthermore, the synthesis of crop milk protein is regulated by activation of the IRS1/Akt/TOR signalling pathway.

  7. Detection and characterisation of Complement protein activity in bovine milk by bactericidal sequestration assay.

    PubMed

    Maye, Susan; Stanton, Catherine; Fitzgerald, Gerald F; Kelly, Philip M

    2015-08-01

    While the Complement protein system in human milk is well characterised, there is little information on its presence and activity in bovine milk. Complement forms part of the innate immune system, hence the importance of its contribution during milk ingestion to the overall defences of the neonate. A bactericidal sequestration assay, featuring a Complement sensitive strain, Escherichia coli 0111, originally used to characterise Complement activity in human milk was successfully applied to freshly drawn bovine milk samples, thus, providing an opportunity to compare Complement activities in both human and bovine milks. Although not identical in response, the levels of Complement activity in bovine milk were found to be closely comparable with that of human milk. Differential counts of Esch. coli 0111 after 2 h incubation were 6.20 and 6.06 log CFU/ml, for raw bovine and human milks, respectively - the lower value representing a stronger Complement response. Exposing bovine milk to a range of thermal treatments e.g. 42, 45, 65, 72, 85 or 95 °C for 10 min, progressively inhibited Complement activity by increasing temperature, thus confirming the heat labile nature of this immune protein system. Low level Complement activity was found, however, in 65 and 72 °C heat treated samples and in retailed pasteurised milk which highlights the outer limit to which high temperature, short time (HTST) industrial thermal processes should be applied if retention of activity is a priority. Concentration of Complement in the fat phase was evident following cream separation, and this was also reflected in the further loss of activity recorded in low fat variants of retailed pasteurised milk. Laboratory-based churning of the cream during simulated buttermaking generated an aqueous (buttermilk) phase with higher levels of Complement activity than the fat phase, thus pointing to a likely association with the milk fat globule membrane (MFGM) layer.

  8. T-2 mycotoxin inhibits mitochondrial protein synthesis

    SciTech Connect

    Pace, J.G.; Watts, M.R.; Canterbury, W.J.

    1988-01-01

    The authors investigated the effect of T-2 toxin on rat liver mitochondrial protein synthesis. Isolated rat liver mitochondria were supplemented with an S-100 supernatant from rat liver and an external ATP-generating system. An in-vitro assay employing cycloheximide, and inhibitor of cytoplasmic protein synthesis, and chloramphenicol, and inhibitor of mitochondrial protein synthesis, to distinguish mitochondrial protein synthesis from the cytoplasmic process. Amino acid incorporation into mitochondria was dependent on the concentration of mitochondria and was inhibited by chloramphenicol. The rate of uptake of tritium leucine into mitochondrial protein was unaffected by the addition of T-2 toxin and was not a rate-limiting step in incorporation. However, 0.02 micrograms/ml of T-2 toxin decreased the rate of protein synthesis inhibition correlated with the amount of T-2 toxin taken up by the mitochondria. While T-2 toxin is known to inhibit eukaryotic protein synthesis, this is the first time T-2 was shown to inhibit mitochondrial protein synthesis.

  9. Leucine stimulation of skeletal muscle protein synthesis

    SciTech Connect

    Layman, D.K.; Grogan, C.K.

    1986-03-01

    Previous work in this laboratory has demonstrated a stimulatory effect of leucine on skeletal muscle protein synthesis measured in vitro during catabolic conditions. Studies in other laboratories have consistently found this effect in diaphragm muscle, however, studies examining effects on nitrogen balance or with in vivo protein synthesis in skeletal muscle are equivocal. This experiment was designed to determine the potential of leucine to stimulate skeletal muscle protein synthesis in vivo. Male Sprague-Dawley rats weighing 200 g were fasted for 12 hrs, anesthetized, a jugular cannula inserted, and protein synthesis measured using a primed continuous infusion of /sup 14/C-tyrosine. A plateau in specific activity was reached after 30 to 60 min and maintained for 3 hrs. The leucine dose consisted of a 240 umole priming dose followed by a continuous infusion of 160 umoles/hr. Leucine infusion stimulated protein synthesis in the soleus muscle (28%) and in the red (28%) and white portions (12%) of the gastrocnemius muscle compared with controls infused with only tyrosine. The increased rates of protein synthesis were due to increased incorporation of tyrosine into protein and to decreased specific activity of the free tyrosine pool. These data indicate that infusion of leucine has the potential to stimulate in vivo protein synthesis in skeletal muscles.

  10. Modulation of protein synthesis by polyamines.

    PubMed

    Igarashi, Kazuei; Kashiwagi, Keiko

    2015-03-01

    Polyamines are ubiquitous small basic molecules that play important roles in cell growth and viability. Since polyamines mainly exist as a polyamine-RNA complex, we looked for proteins whose synthesis is preferentially stimulated by polyamines at the level of translation, and thus far identified 17 proteins in Escherichia coli and 6 proteins in eukaryotes. The mechanisms of polyamine stimulation of synthesis of these proteins were investigated. In addition, the role of eIF5A, containing hypusine formed from spermidine, on protein synthesis is described. These results clearly indicate that polyamines and eIF5A contribute to cell growth and viability through modulation of protein synthesis. © 2015 International Union of Biochemistry and Molecular Biology.

  11. Immediate and residual effects of heat stress and restricted intake on milk protein and casein composition and energy metabolism.

    PubMed

    Cowley, F C; Barber, D G; Houlihan, A V; Poppi, D P

    2015-04-01

    The effects of heat stress on dairy production can be separated into 2 distinct causes: those effects that are mediated by the reduced voluntary feed intake associated with heat stress, and the direct physiological and metabolic effects of heat stress. To distinguish between these, and identify their effect on milk protein and casein concentration, mid-lactation Holstein-Friesian cows (n = 24) were housed in temperature-controlled chambers and either subjected to heat stress [HS; temperature-humidity index (THI) ~78] or kept in a THI<70 environment and pair-fed with heat-stressed cows (TN-R) for 7 d. A control group of cows was kept in a THI<70 environment with ad libitum feeding (TN-AL). A subsequent recovery period (7 d), with THI<70 and ad libitum feeding followed. Intake accounted for only part of the effects of heat stress. Heat stress reduced the milk protein concentration, casein number, and casein concentration and increased the urea concentration in milk beyond the effects of restriction of intake. Under HS, the proportion in total casein of αS1-casein increased and the proportion of αS2-casein decreased. Because no effect of HS on milk fat or lactose concentration was found, these effects appeared to be the result of specific downregulation of mammary protein synthesis, and not a general reduction in mammary activity. No residual effects were found of HS or TN-R on milk production or composition after THI<70 and ad libitum intake were restored. Heat-stressed cows had elevated blood concentrations of urea and Ca, compared with TN-R and TN-AL. Cows in TN-R had higher serum nonesterified fatty acid concentrations than cows in HS. It was proposed that HS and TN-R cows may mobilize different tissues as endogenous sources of energy.

  12. Milk bioactive peptide database: A comprehensive database of milk protein-derived bioactive peptides and novel visualization.

    PubMed

    Nielsen, Søren Drud; Beverly, Robert L; Qu, Yunyao; Dallas, David C

    2017-10-01

    During processing and digestion, milk proteins are disassembled into peptides with an array of biological functions, including antimicrobial, angiotensin-converting enzyme inhibition, antioxidant, opioid, and immunomodulation. These functions are summarized in numerous reviews, yet information on which peptides have which functions remains scattered across hundreds of research articles. We systematically searched the literature for all instances of bioactive peptides derived from milk proteins from any mammalian source. The data were compiled into a comprehensive database, which can be used to search for specific functions, peptides, or proteins (http://mbpdb.nws.oregonstate.edu). To review this large dataset, the bioactive peptides reported in the literature were visually mapped on the parent protein sequences, providing information on sites with highest abundance of bioactive peptides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. [Effect of proteins from bovine milk serum on the multiplication of human cancerous cells].

    PubMed

    Bourtourault, M; Buléon, R; Sampérez, S; Jouan, P

    1991-01-01

    The addition of bovine milk whey to the culture medium of human cancerous cells (MCF-7 and PC-3) results in a significant reduction of cells growth. Milk whey acts more efficiently on MCF-7 than on PC-3 growth. The inhibition could be due to a protein. Its identification is now on progress.

  14. Bioavailability of milk protein-derived bioactive peptides: a glycaemic management perspective.

    PubMed

    Horner, Katy; Drummond, Elaine; Brennan, Lorraine

    2016-06-01

    Milk protein-derived peptides have been reported to have potential benefits for reducing the risk of type 2 diabetes. However, what the active components are and whether intact peptides exert this bioactivity has received little investigation in human subjects. Furthermore, potentially useful bioactive peptides can be limited by low bioavailability. Various peptides have been identified in the gastrointestinal tract and bloodstream after milk-protein ingestion, providing valuable insights into their potential bioavailability. However, these studies are currently limited and the structure and sequence of milk peptides exerting bioactivity for glycaemic management has received little investigation in human subjects. The present article reviews the bioavailability of milk protein-derived peptides in human studies to date, and examines the evidence on milk proteins and glycaemic management, including potential mechanisms of action. Areas in need of advancement are identified. Only by establishing the bioavailability of milk protein-derived peptides, the active components and the mechanistic pathways involved can the benefits of milk proteins for the prevention or management of type 2 diabetes be fully realised in future.

  15. Proteomic characterization of human milk fat globule membrane proteins during a 12 month lactation period.

    PubMed

    Liao, Yalin; Alvarado, Rudy; Phinney, Brett; Lönnerdal, Bo

    2011-08-05

    The milk fat globule membrane (MFGM) contains proteins which have been implicated in a variety of health benefits. Milk fat globule membrane proteins were isolated from human milk during a 12 month lactation period and subjected to in-solution digestion and liquid chromatography tandem mass spectrometry analysis. Data were pooled, and our results showed that 191 proteins were identified. Relative quantification of the identified MFGM proteins during the course of lactation was performed by label free spectral counting and differentiation expression analysis, which showed some proteins decreasing during the course of lactation whereas some increased or remained at a relatively constant level. The human MFGM proteins are distributed between intracellular, extracellular, and membrane-associated proteins, and they are mainly involved in cell communication and signal transduction, immune function, metabolism and energy production. This study provides more insights into the dynamic composition of human MFGM proteins, which in turn will enhance our understanding of the physiological significance of MFGM proteins.

  16. Balanced intraintestinal nutrition: digestion, absorption and biological value of selected preparations of milk proteins.

    PubMed

    Ziemlański, S; Cieślakowa, D; Kunachowicz, H; Pałaszewska, M

    1978-01-01

    The absorption of an enzymatic hydrolysate of whey proteins, hydrolysates of milk proteins and casein, 7% hydrolysate of bovine blood produced by Polfa under the trade name "Aminokwasy", and a standard mixture of amino acids from isolated small intestine loop of dogs and rats was compared. The composition of amino acids of the initial proteins and hydrolysates obtained from these proteins was determined. The biological value of selected proteins and hydrolysates was assessed determining the mean weight gain, nitrogen content of the body, urinary excretion of urea and creatinine, blood urea level and NPU. No significant differences were found in the absorption of nitrogen from the hydrolysate of milk and whey proteins. The nutritional value of whey protein hydrolysate was, however, slightly higher than that of an analogous hydrolysate of milk proteins. It seems that of all tested proteins whey hydrolysate (free of lactose) is the most suitable source for obtaining preparations for no-residue intraintestinal feeding.

  17. Bioactive peptides derived from milk proteins and their health beneficial potentials: an update.

    PubMed

    Nagpal, Ravinder; Behare, Pradip; Rana, Rajiv; Kumar, Ashwani; Kumar, Manoj; Arora, Sanu; Morotta, Fransesco; Jain, Shalini; Yadav, Hariom

    2011-01-01

    It has been well recognized that dietary proteins provide a rich source of biologically active peptides. Today, milk proteins are considered the most important source of bioactive peptides and an increasing number of bioactive peptides have been identified in milk protein hydrolysates and fermented dairy products. Bioactive peptides derived from milk proteins offer a promising approach for the promotion of health by means of a tailored diet and provide interesting opportunities to the dairy industry for expansion of its field of operation. The potential health benefits of milk protein-derived peptides have been a subject of growing commercial interest in the context of health-promoting functional foods. Hence, these peptides are being incorporated in the form of ingredients in functional and novel foods, dietary supplements and even pharmaceuticals with the purpose of delivering specific health benefits.

  18. Bioactive Proteins in Human Milk: Health, Nutrition, and Implications for Infant Formulas.

    PubMed

    Lönnerdal, Bo

    2016-06-01

    Breast milk confers many benefits to the newborn and developing infant. There is substantial support for better long-term outcomes, such as less obesity, diabetes, and cardiovascular disease, in breastfed compared with formula-fed infants. More short-term outcomes, such as incidence and duration of illness, nutrient status, and cognitive development during the first year of life also demonstrate benefits of breastfeeding. Several proteins in breast milk, including lactoferrin, α-lactalbumin, milk fat globule membrane proteins, and osteopontin, have been shown to have bioactivities that range from involvement in the protection against infection to the acquisition of nutrients from breast milk. In some cases, bovine counterparts of these proteins exert similar bioactivities. It is possible by dairy technology to add protein fractions highly enriched in these proteins to infant formula.

  19. Consuming Transgenic Goats' Milk Containing the Antimicrobial Protein Lysozyme Helps Resolve Diarrhea in Young Pigs

    PubMed Central

    Cooper, Caitlin A.; Garas Klobas, Lydia C.; Maga, Elizabeth A.; Murray, James D.

    2013-01-01

    Childhood diarrhea is a significant problem in many developing countries and E. coli is a main causative agent of diarrhea in young children. Lysozyme is an antimicrobial protein highly expressed in human milk, but not ruminant milk, and is thought to help protect breastfeeding children against diarrheal diseases. We hypothesized that consumption of milk from transgenic goats which produce human lysozyme (hLZ-milk) in their milk would accelerate recovery from bacterial-induced diarrhea. Young pigs were used as a model for children and infected with enterotoxigenic E. coli. Once clinical signs of diarrhea developed, pigs were fed hLZ-milk or non-transgenic control goat milk three times a day for two days. Clinical observations and complete blood counts (CBC) were performed. Animals were euthanized and samples collected to assess differences in histology, cytokine expression and bacterial translocation into the mesenteric lymph node. Pigs consuming hLZ-milk recovered from clinical signs of infection faster than pigs consuming control milk, with significantly improved fecal consistency (p = 0.0190) and activity level (p = 0.0350). The CBC analysis showed circulating monocytes (p = 0.0413), neutrophils (p = 0.0219), and lymphocytes (p = 0.0222) returned faster to pre-infection proportions in hLZ-milk fed pigs, while control-fed pigs had significantly higher hematocrit (p = 0.027), indicating continuing dehydration. In the ileum, pigs fed hLZ-milk had significantly lower expression of pro-inflammatory cytokine IL-8 (p = 0.0271), longer intestinal villi (p<0.0001), deeper crypts (p = 0.0053), and a thinner lamina propria (p = 0.0004). These data demonstrate that consumption of hLZ-milk helped pigs recover from infection faster, making hLZ-milk an effective treatment of E. coli-induced diarrhea. PMID:23516474

  20. Milk protein for improved metabolic health: a review of the evidence

    PubMed Central

    2013-01-01

    Epidemiological evidence shows that consumption of dairy products is associated with decreased prevalence of metabolic related disorders, whilst evidence from experimental studies points towards dairy protein as a dietary component which may aid prevention of type 2 diabetes (T2DM). Poor metabolic health is a common characteristic of overweight, obesity and aging, and is the forerunner of T2DM and cardiovascular disease (CVD), and an ever increasing global health issue. Progressive loss of metabolic control is evident from a blunting of carbohydrate, fat and protein metabolism, which is commonly manifested through decreased insulin sensitivity, inadequate glucose and lipid control, accompanied by a pro-inflammatory environment and hypertension. Adverse physiological changes such as excess visceral adipose tissue deposition and expansion, lipid overspill and infiltration into liver, muscle and other organs, and sarcopaenia or degenerative loss of skeletal muscle mass and function all underpin this adverse profile. ‘Sarcobesity’ and sarcopaenic diabetes are rapidly growing health issues. As well as through direct mechanisms, dairy protein may indirectly improve metabolic health by aiding loss of body weight and fat mass through enhanced satiety, whilst promoting skeletal muscle growth and function through anabolic effects of dairy protein-derived branch chain amino acids (BCAAs). BCAAs enhance muscle protein synthesis, lean body mass and skeletal muscle metabolic function. The composition and processing of dairy protein has an impact on digestion, absorption, BCAA kinetics and function, hence the optimisation of dairy protein composition through selection and combination of specific protein components in milk may provide a way to maximize benefits for metabolic health. PMID:23822206

  1. Effect of long-term bovine somatotropin (sometribove) treatment on nitrogen (protein) distribution in Jersey milk.

    PubMed

    Kindstedt, P S; Pell, A N; Rippe, J K; Tsang, D S; Hartnell, G F

    1991-01-01

    Twenty-six Jersey cows were assigned randomly to one of two treatments. Twelve cows received biweekly subcutaneous injection of 500 mg of sometribove, USAN (recombinant methionyl bovine somatotropin), beginning 60 +/- 3 d postpartum and continuing throughout one lactation. Fourteen control animals received injections of placebo carrier. Milk samples were taken biweekly on weeks alternate to injection when differences in milk components were expected to be greatest compared with controls. The milk samples were analyzed for total nitrogen, noncasein nitrogen, and non-protein nitrogen. The average SCC for control and treatment groups was 44,000 +/- 47,000 and 56,000 +/- 65,000. Milk from sometribove-treated cows was significantly lower in total protein (3.92, 4.12%), true protein (3.74, 3.95%), and casein (3.11, 3.34%) than that from control cows on d 8 of the 14 d injection cycle. Casein as a percentage of true protein was lower (83.38, 84.52%), and non-protein nitrogen as a percentage of total nitrogen was higher (4.61, 4.26%) in milk from treated cows. The theoretical yield of Cheddar cheese was ca. .07% less for milk from treated cows than from control cows due to ca. 1% less casein as a percentage of true protein in the former. The differences in nitrogen distribution represent the response during the middle of the injection cycle when milk output was the highest and milk protein the lowest rather than the average response for the injection cycle. The results of the study indicate minimal impact on the cheese manufacturer because in practice milk is commingled from many dairies.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. A microfiltration process to maximize removal of serum proteins from skim milk before cheese making.

    PubMed

    Nelson, B K; Barbano, D M

    2005-05-01

    Microfiltration (MF) is a membrane process that can separate casein micelles from milk serum proteins (SP), mainly beta-lactoglobulin and alpha-lactalbumin. Our objective was to develop a multistage MF process to remove a high percentage of SP from skim milk while producing a low concentration factor retentate from microfiltration (RMF) with concentrations of soluble minerals, nonprotein nitrogen (NPN), and lactose similar to the original skim milk. The RMF could be blended with cream to standardize milk for traditional Cheddar cheese making. Permeate from ultrafiltration (PUF) obtained from the ultrafiltration (UF) of permeate from MF (PMF) of skim milk was successfully used as a diafiltrant to remove SP from skim milk before cheese making, while maintaining the concentration of lactose, NPN, and nonmicellar calcium. About 95% of the SP originally in skim milk was removed by combining one 3 x MF stage and two 3 x PUF diafiltration stages. The final 3 x RMF can be diluted with PUF to the desired concentration of casein for traditional cheese making. The PMF from the skim milk was concentrated in a UF system to yield an SP concentrate with protein content similar to a whey protein concentrate, but without residuals from cheese making (i.e., rennet, culture, color, and lactic acid) that can produce undesirable functional and sensory characteristics in whey products. Additional processing steps to this 3-stage MF process for SP removal are discussed to produce an MF skim retentate for a continuous cottage cheese manufacturing process.

  3. Evaluation of milk basic protein supplementation on bone density and bone metabolism in Chinese young women.

    PubMed

    Zou, Zhi-Yong; Lin, Xiao-Ming; Xu, Xian-Rong; Xu, Rui; Ma, Le; Li, Ying; Wang, Ming-Fang

    2009-08-01

    Milk is a good source of bioavailable calcium compared with other foods. Recent in vitro and in vivo studies have shown that milk whey protein, especially its basic protein fraction (milk basic protein, MBP), contains several components capable of promoting bone formation and inhibiting bone resorption. The objective of this study was to examine the effects of MBP on bone mineral density (BMD) and bone metabolism of healthy young women. Eighty-four healthy young women were randomly assigned to three groups: control group, whole milk group or MBP group treated with milk containing 40 mg MBP for 8 months. The bone mineral density of total body, the lumbar vertebrae L2-L4 and the left forearm of each subject were measured by dual-energy X-ray absorptiometry (DEXA) at 0 and 8 months of treatment. Serum indexes of bone metabolism were measured at 0, 3, 6 and 8 months. Eighty-one subjects who completed the study in accordance with the protocol were included in the analysis. Total BMD in all groups significantly increased compared with baseline values. However, no significant difference on the mean rate of gain of total BMD was observed among the MBP group (2.19%), the whole milk group (2.63%) and the control group (1.61%). Serum cross-linked N-teleopeptides of type-I collagen (NTx) in MBP group at 8 months and in whole milk group at 6 months were significantly decreased from baseline. There were no significant differences between whole milk group and MBP group; however, after combining the milk groups, NTx had significantly decreased from baseline. No significant increase was observed in serum bone-specific alkaline phosphatase (BAP) in both whole milk group and MBP group. No significant effect of MBP on bone mineral density and bone metabolism was observed, but milk supplementation was effective in suppressing bone resorption.

  4. Microstructural Changes in High-Protein Nutrition Bars Formulated with Extruded or Toasted Milk Protein Concentrate.

    PubMed

    Banach, J C; Clark, S; Lamsal, B P

    2016-02-01

    Milk protein concentrates with more than 80% protein (that is, MPC80) are underutilized as the primary protein source in high-protein nutrition bars as they impart crumbliness and cause hardening during storage. High-protein nutrition bar texture changes are often associated with internal protein aggregations and macronutrient phase separation. These changes were investigated in model high-protein nutrition bars formulated with MPC80 and physically modified MPC80s. High-protein nutrition bars formulated with extruded MPC80s hardened slower than those formulated with toasted or unmodified MPC80. Extruded MPC80 had reduced free sulfhydryl group exposure, whereas measurable increases were seen in the toasted MPC80. High-protein nutrition bar textural performance may be related to the number of exposed free sulfhydryl groups in MPC80. Protein aggregations resulting from ingredient modification and high-protein nutrition bar storage were studied with sodium dodecyl sulfate polyacrylamide gel electrophoresis. Disulfide-based protein aggregations and changes in free sulfhydryl concentration were not consistently relatable to high-protein nutrition bar texture change. However, the high-protein nutrition bars formulated with extruded MPC80 were less prone to phase separations, as depicted by confocal laser scanning microscopy, and underwent less texture change during storage than those formulated with toasted or unmodified MPC80.

  5. Multiparous cows categorized by milk protein concentration and energy-corrected milk yield during early lactation--metabolism, productivity and effect of a short-term feed restriction.

    PubMed

    Sigl, T; Gellrich, K; Meyer, H H D; Kaske, M; Wiedemann, S

    2013-04-01

    The objective of this experiment was to study milk productivity, metabolic adaptation and effect of a short-term feed restriction (FR) on key performance indicators during early lactation in cows classified according to energy-corrected milk (ECM) yield and milk protein concentration. Twenty-three multiparous Holstein-Friesian cows were categorized in four groups according to respective averaged values on Days 23-25 postpartum: high ECM yield and high protein concentration; low ECM yield and low protein concentration; high ECM yield and low protein concentration and low ECM yield and high protein concentration. Dry matter intake was reduced to 68.3% for three subsequent days. Our results showed that short-time FR in early lactation succeeded in enhancing energy deficit of cows in all groups. Milk fat, milk protein and lactose concentrations as well as milk fat yield were not influenced by FR. Several hepatic genes encoding for enzymes involved in catabolism of amino acids, β-oxidation, gluconeogenesis and ketogenesis as well as mRNA encoding for insulin receptor showed increased transcript abundances after FR, primarily in cows with high milk yield and low milk protein concentration.

  6. Synthesis of post-translationally modified proteins.

    PubMed

    van Kasteren, Sander

    2012-10-01

    Post-translational modifications of proteins can have dramatic effect on the function of proteins. Significant research effort has gone into understanding the effect of particular modifications on protein parameters. In the present paper, I review some of the recently developed tools for the synthesis of proteins modified with single post-translational modifications at specific sites in the protein, such as amber codon suppression technologies, tag and modify, and native chemical ligation.

  7. Experimental and Modelling Study of the Denaturation of Milk Protein by Heat Treatment

    PubMed Central

    Qian, Fang; Sun, Jiayue; Cao, Di; Tuo, Yanfeng; Jiang, Shujuan; Mu, Guangqing

    2017-01-01

    Heat treatment of milk aims to inhibit the growth of microbes, extend the shelf-life of products and improve the quality of the products. Heat treatment also leads to denaturation of whey protein and the formation of whey protein-casein polymer, which has negative effects on milk product. Hence the milk heat treatment conditions should be controlled in milk processing. In this study, the denaturation degree of whey protein and the combination degree of whey protein and casein when undergoing heat treatment were also determined by using the Native-PAGE and SDS-PAGE analysis. The results showed that the denaturation degree of whey protein and the combination degree of whey protein with casein extended with the increase of the heat-treated temperature and time. The effects of the heat-treated temperature and heat-treated time on the denaturation degree of whey protein and on the combination degree of whey protein and casein were well described using the quadratic regression equation. The analysis strategy used in this study reveals an intuitive and effective measure of the denaturation degree of whey protein, and the changes of milk protein under different heat treatment conditions efficiently and accurately in the dairy industry. It can be of great significance for dairy product proteins following processing treatments applied for dairy product manufacturing. PMID:28316470

  8. Experimental and Modelling Study of the Denaturation of Milk Protein by Heat Treatment.

    PubMed

    Qian, Fang; Sun, Jiayue; Cao, Di; Tuo, Yanfeng; Jiang, Shujuan; Mu, Guangqing

    2017-01-01

    Heat treatment of milk aims to inhibit the growth of microbes, extend the shelf-life of products and improve the quality of the products. Heat treatment also leads to denaturation of whey protein and the formation of whey protein-casein polymer, which has negative effects on milk product. Hence the milk heat treatment conditions should be controlled in milk processing. In this study, the denaturation degree of whey protein and the combination degree of whey protein and casein when undergoing heat treatment were also determined by using the Native-PAGE and SDS-PAGE analysis. The results showed that the denaturation degree of whey protein and the combination degree of whey protein with casein extended with the increase of the heat-treated temperature and time. The effects of the heat-treated temperature and heat-treated time on the denaturation degree of whey protein and on the combination degree of whey protein and casein were well described using the quadratic regression equation. The analysis strategy used in this study reveals an intuitive and effective measure of the denaturation degree of whey protein, and the changes of milk protein under different heat treatment conditions efficiently and accurately in the dairy industry. It can be of great significance for dairy product proteins following processing treatments applied for dairy product manufacturing.

  9. Effects of the processing methods of corn grain and soybean meal on milk protein expression profiles in dairy cows.

    PubMed

    Li, S S; Shen, J S; Ren, D X; Liu, J X

    2015-02-01

    A proteomic approach was used to investigate the effects of the processing method of corn grain and soybean meal on the milk protein expression profile in lactating dairy cows. A total of 12 multiparous Holstein dairy cows were used in a 4×4 Latin square design with a 2×2 factorial arrangement. The primary factors examined were corn (finely ground (FGC) v. steam-flaked (SFC)) and soybean meal (solvent-extracted (SSBM) v. heat-treated (HSBM)), which were used to formulate four diets with the same basal ingredient: 27% FGC and 9% SSBM; 27% SFC and 9% SSBM; 27% FGC and 9% HSBM; and 27% SFC and 9% HSBM. Each period lasted for 21 days. Milk samples were collected on days 18, 19 and 20 of each period. Changes in the milk proteins were assessed by two-dimensional (2D) electrophoresis and ImageMaster 2D Platinum 6.0 software. A total of 13 spots displayed variations in protein spot abundance according to the statistical analysis. These spots were identified by a matrix-assisted laser desorption/ionization-time of flight/time of flight MS. According to the gels, the relative abundance of α(s2)-casein (CN) fragments was higher in the cows fed the SFC-HSBM than that for SFC-SSBM, whereas β-CN, α-lactalbumin and zinc-alpha-2-glycoprotein fragments were down-regulated in HSBM-fed cows. The relative decrease of β-CN expression was validated by western blot and agreed with the MS data. These results suggested that the method used to process soybean meal modified the synthesis and secretion of milk proteins in lactating dairy cows' mammary glands.

  10. Chemical protein synthesis (CPS) meeting 2013.

    PubMed

    Metanis, Norman

    2013-07-22

    Building bonds in Vienna: The Chemical Protein Synthesis meeting recently took place at the University of Vienna, Austria. This report describes the event and highlights the science presented over the four days.

  11. NIRS and MIRS technique for the determination of protein and fat content in milk powder

    NASA Astrophysics Data System (ADS)

    Wu, Di; Feng, Shuijuan; He, Chao; He, Yong

    2008-03-01

    It is very important to detect the protein and fat content in milk powder fast and non-destructively. Near-infrared (NIR) and mid-infrared(MIR) spectroscopy techniques have been compared and evaluated for the determination of the protein and fat content in milk powder with the use of Least-squares support vector machines (LS-SVM). LS-SVM models have been developed by using both NIR and MIR spectra. Both methods have shown good correlations between infrared transmission values and two nutrition contents. MIRS provided better prediction performance over NIRS. It is concluded that infrared spectroscopy technique can quantify of the protein and fat content in milk powder fast and nondestructively. The process is simple and easy to operate than chemistry methods. The results can be beneficial for designing a simple and non-destructive instrument with MIRS or NIRS spectral sensor for the determination of the protein fat content in milk powder.

  12. Expression of Active Fluorophore Proteins in the Milk of Transgenic Pigs Bypassing the Secretory Pathway

    PubMed Central

    Mukherjee, Ayan; Garrels, Wiebke; Talluri, Thirumala R.; Tiedemann, Daniela; Bősze, Zsuzsanna; Ivics, Zoltán; Kues, Wilfried A.

    2016-01-01

    We describe the expression of recombinant fluorescent proteins in the milk of two lines of transgenic pigs generated by Sleeping Beauty transposon-mediated genetic engineering. The Sleeping Beauty transposon consisted of an ubiquitously active CAGGS promoter driving a fluorophore cDNA, encoding either Venus or mCherry. Importantly, the fluorophore cDNAs did not encode for a signal peptide for the secretory pathway, and in previous studies of the transgenic animals a cytoplasmic localization of the fluorophore proteins was found. Unexpectedly, milk samples from lactating sows contained high levels of bioactive Venus or mCherry fluorophores. A detailed analysis suggested that exfoliated cells of the mammary epithelium carried the recombinant proteins passively into the milk. This is the first description of reporter fluorophore expression in the milk of livestock, and the findings may contribute to the development of an alternative concept for the production of bioactive recombinant proteins in the udder. PMID:27086548

  13. Prediction of individual milk proteins including free amino acids in bovine milk using mid-infrared spectroscopy and their correlations with milk processing characteristics.

    PubMed

    McDermott, A; Visentin, G; De Marchi, M; Berry, D P; Fenelon, M A; O'Connor, P M; Kenny, O A; McParland, S

    2016-04-01

    The aim of this study was to evaluate the effectiveness of mid-infrared spectroscopy in predicting milk protein and free amino acid (FAA) composition in bovine milk. Milk samples were collected from 7 Irish research herds and represented cows from a range of breeds, parities, and stages of lactation. Mid-infrared spectral data in the range of 900 to 5,000 cm(-1) were available for 730 milk samples; gold standard methods were used to quantify individual protein fractions and FAA of these samples with a view to predicting these gold standard protein fractions and FAA levels with available mid-infrared spectroscopy data. Separate prediction equations were developed for each trait using partial least squares regression; accuracy of prediction was assessed using both cross validation on a calibration data set (n=400 to 591 samples) and external validation on an independent data set (n=143 to 294 samples). The accuracy of prediction in external validation was the same irrespective of whether undertaken on the entire external validation data set or just within the Holstein-Friesian breed. The strongest coefficient of correlation obtained for protein fractions in external validation was 0.74, 0.69, and 0.67 for total casein, total β-lactoglobulin, and β-casein, respectively. Total proteins (i.e., total casein, total whey, and total lactoglobulin) were predicted with greater accuracy then their respective component traits; prediction accuracy using the infrared spectrum was superior to prediction using just milk protein concentration. Weak to moderate prediction accuracies were observed for FAA. The greatest coefficient of correlation in both cross validation and external validation was for Gly (0.75), indicating a moderate accuracy of prediction. Overall, the FAA prediction models overpredicted the gold standard values. Near-unity correlations existed between total casein and β-casein irrespective of whether the traits were based on the gold standard (0.92) or mid

  14. Effect of gestation length on the levels of five innate defence proteins in human milk.

    PubMed

    Broadhurst, Marita; Beddis, Keryn; Black, Janet; Henderson, Harold; Nair, Arun; Wheeler, Thomas

    2015-01-01

    Human milk contains a range of host defence proteins that appear to contribute to health and wellbeing, but their variability in abundance among individuals has not been very well characterised. Milk from mothers of premature infants has altered composition, but the effect of gestation length on the host-defence properties of milk is not known. A study was therefore undertaken to determine the variability and effect of gestation length on the abundance of five host-defence proteins in milk; lactoferrin, secretory IgA, IgG, secretory component, and complement C3. Milk was obtained from 30 mothers at their second and fifth week of lactation. These were from three groups of ten mothers having had very premature (V; 28-32 weeks gestation), premature (P; 33-36 weeks) or full term deliveries (T; 37-41 weeks). The concentration of each of the five proteins was measured in each milk sample by either ELISA or quantitative western blotting. The concentration of IgG, and complement C3 ranged 22- and 17-fold respectively between mothers, while lactoferrin, secretory IgA, and secretory component ranged 7-, 9-, and 4-fold, respectively. The V group had significantly lower concentrations of four of the five proteins, the exception being IgG. Levels of these four proteins also decreased between weeks 2 and 5 of lactation in the P and T groups. Significant correlation was found between the concentrations of the host defence proteins within individual mothers, indicating some degree of co-ordinate regulation. Mothers vary widely in the levels of host defence proteins in milk. Very short gestation length results in decreased abundance of host-defence proteins in milk. This may have functional implications for very premature infants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Minor milk constituents are affected by protein concentration and forage digestibility in the feed ration.

    PubMed

    Larsen, Torben; Alstrup, Lene; Weisbjerg, Martin Riis

    2016-02-01

    The present study was conducted in order to investigate if selected minor milk components would be indicative for the nutritional situation of the cow. Forty-eight dairy cows were offered a high digestible ration vs. a lower digestible ration combined with 2 protein levels in a 4 × 4 Latin square design. Milk glucose, glucose-6-phosphate, cholesterol, triacylglycerides (TAG), uric acid and β-hydroxybutyrate (BHBA) were measured and correlated mutually and towards other milking parameters (yield, h since last milking, days in milk (DIM), urea, etc). The variation range of the suggested variables were broad, a fact that may support their utilisation as predictive parameters. The content of milk metabolites was significantly affected by the change in rations as milk glucose, glucose-6-phosphate, uric acid, and the ratio cholesterol: triacylglycerides increased with higher energy intake while BHBA and TAG decreased. The content of some of the milk metabolites changed during 24 h day/night periods: BHBA, cholesterol, uric acid and TAG increased whereas free glucose decreased in the night period. Certain associations between milk metabolites and calculated energy parameters like ECM, body condition score (BCS), and body weight gain were found, however, these associations were to some extent explained by an interaction with DIM, just as changes in milk metabolites during a 24 h period seems to interfere. It is concluded that the practical use of the suggested milk variables should be based on more than one metabolite and that stage of lactation and possibly time of the day where the milk is collected should be incorporated in predictive models.

  16. Comparative proteomics of milk fat globule membrane proteins from transgenic cloned cattle.

    PubMed

    Sui, Shunchao; Zhao, Jie; Wang, Jianwu; Zhang, Ran; Guo, Chengdong; Yu, Tian; Li, Ning

    2014-01-01

    The use of transgenic livestock is providing new methods for obtaining pharmaceutically useful proteins. However, the protein expression profiles of the transgenic animals, including expression of milk fat globule membrane (MFGM) proteins, have not been well characterized. In this study, we compared the MFGM protein expression profile of the colostrum and mature milk from three lines of transgenic cloned (TC) cattle, i.e., expressing recombinant human α-lactalbumin (TC-LA), lactoferrin (TC-LF) or lysozyme (TC-LZ) in the mammary gland, with those from cloned non-transgenic (C) and conventionally bred normal animals (N). We identified 1, 225 proteins in milk MFGM, 166 of which were specifically expressed only in the TC-LA group, 265 only in the TC-LF group, and 184 only in the TC-LZ group. There were 43 proteins expressed only in the transgenic cloned animals, but the concentrations of these proteins were below the detection limit of silver staining. Functional analysis also showed that the 43 proteins had no obvious influence on the bovine mammary gland. Quantitative comparison revealed that MFGM proteins were up- or down-regulated more than twofold in the TC and C groups compared to N group: 126 in colostrum and 77 in mature milk of the TC-LA group; 157 in colostrum and 222 in mature milk of the TC-LF group; 49 in colostrum and 98 in mature milk of the TC-LZ group; 98 in colostrum and 132 in mature milk in the C group. These up- and down-regulated proteins in the transgenic animals were not associated with a particular biological function or pathway, which appears that expression of certain exogenous proteins has no general deleterious effects on the cattle mammary gland.

  17. Comparative Proteomics of Milk Fat Globule Membrane Proteins from Transgenic Cloned Cattle

    PubMed Central

    Wang, Jianwu; Zhang, Ran; Guo, Chengdong; Yu, Tian; Li, Ning

    2014-01-01

    The use of transgenic livestock is providing new methods for obtaining pharmaceutically useful proteins. However, the protein expression profiles of the transgenic animals, including expression of milk fat globule membrane (MFGM) proteins, have not been well characterized. In this study, we compared the MFGM protein expression profile of the colostrum and mature milk from three lines of transgenic cloned (TC) cattle, i.e., expressing recombinant human α-lactalbumin (TC-LA), lactoferrin (TC-LF) or lysozyme (TC-LZ) in the mammary gland, with those from cloned non-transgenic (C) and conventionally bred normal animals (N). We identified 1, 225 proteins in milk MFGM, 166 of which were specifically expressed only in the TC-LA group, 265 only in the TC-LF group, and 184 only in the TC-LZ group. There were 43 proteins expressed only in the transgenic cloned animals, but the concentrations of these proteins were below the detection limit of silver staining. Functional analysis also showed that the 43 proteins had no obvious influence on the bovine mammary gland. Quantitative comparison revealed that MFGM proteins were up- or down-regulated more than twofold in the TC and C groups compared to N group: 126 in colostrum and 77 in mature milk of the TC-LA group; 157 in colostrum and 222 in mature milk of the TC-LF group; 49 in colostrum and 98 in mature milk of the TC-LZ group; 98 in colostrum and 132 in mature milk in the C group. These up- and down-regulated proteins in the transgenic animals were not associated with a particular biological function or pathway, which appears that expression of certain exogenous proteins has no general deleterious effects on the cattle mammary gland. PMID:25133402

  18. Manganese binding proteins in human and cow's milk

    SciTech Connect

    Loennerdal, B.; Keen, C.L.; Hurley, L.S.

    1985-03-01

    Manganese nutrition in the neonatal period is poorly understood, due in part to a lack of information on the amount of manganese in infant foods and its bioavailability. Since the molecular localization of an element in foods is one determinant of its subsequent bioavailability, a study was made of the binding of manganese in human and cow's milk. An extrinsic label of /sup 54/Mn was shown to equilibrate isotopically with native manganese in milks and formulas. Milk samples were separated into fat, casein and whey by ultracentrifugation. In human milk, the major part (71%) of manganese was found in whey, 11% in casein and 18% in the lipid fraction. In contrast, in cow's milk, 32% of total manganese was in whey, 67% in casein and 1% in lipid. Within the human whey fraction, most of the manganese was bound to lactoferrin, while in cow's whey, manganese was mostly complexed to ligands with molecular weights less than 200. The distribution of manganese in formulas was closer to that of human milk than of cow's milk. The bioavailability of manganese associated with lactoferrin, casein and low molecular weight complexes needs to be assessed.

  19. Quantitation of human milk proteins and their glycoforms using multiple reaction monitoring (MRM).

    PubMed

    Huang, Jincui; Kailemia, Muchena J; Goonatilleke, Elisha; Parker, Evan A; Hong, Qiuting; Sabia, Rocchina; Smilowitz, Jennifer T; German, J Bruce; Lebrilla, Carlito B

    2017-01-01

    Human milk plays a substantial role in the child growth, development and determines their nutritional and health status. Despite the importance of the proteins and glycoproteins in human milk, very little quantitative information especially on their site-specific glycosylation is known. As more functions of milk proteins and other components continue to emerge, their fine-detailed quantitative information is becoming a key factor in milk research efforts. The present work utilizes a sensitive label-free MRM method to quantify seven milk proteins (α-lactalbumin, lactoferrin, secretory immunoglobulin A, immunoglobulin G, immunoglobulin M, α1-antitrypsin, and lysozyme) using their unique peptides while at the same time, quantifying their site-specific N-glycosylation relative to the protein abundance. The method is highly reproducible, has low limit of quantitation, and accounts for differences in glycosylation due to variations in protein amounts. The method described here expands our knowledge about human milk proteins and provides vital details that could be used in monitoring the health of the infant and even the mother. Graphical Abstract The glycopeptides EICs generated from QQQ.

  20. Molecular characterization of two novel milk proteins in the tsetse fly (Glossina morsitans morsitans)

    PubMed Central

    Yang, Guangxiao; Attardo, Geoffrey M.; Lohs, Claudia; Aksoy, Serap

    2009-01-01

    Tsetse reproduction is unique among insects due to the small numbers of offspring the flies produce and because the female fly carries and nourishes her offspring for their entire immature development. Larval nourishment is supplied by the female as a “milk” substance synthesized by a specialized accessory gland. The milk consists of ~50% fat and ~50% protein. Two milk proteins were identified as the Major Milk gland Protein (GmmMGP) and Transferrin (GmmTsf). Here we describe the identification of two novel gene transcripts (gmmmgp2 and gmmmgp3) produced by the milk gland tissue. These putative secretory products bear no homology to known proteins in the NCBI nr database. Transcripts for these genes can only be detected in the milk gland and their temporal expression correlates with larval development. Functional analysis of these products by RNA interference (RNAi) knockdown analysis shows that GmmMGP2 is critical to reproductive function. The protein appears to affect ovulation, suggesting that it may play a regulatory role in the tsetse reproductive cycle. GmmMGP3 knockdown lacks a phenotype, suggesting its function as a milk protein is possibly redundant. PMID:20136662

  1. Anti-inflammatory mechanisms of bioactive milk proteins in the intestine of newborns.

    PubMed

    Chatterton, Dereck E W; Nguyen, Duc Ninh; Bering, Stine Brandt; Sangild, Per Torp

    2013-08-01

    The human newborn infant is susceptible to gut inflammatory disorders. In particular, growth-restricted infants or infants born prematurely may develop a severe form of intestinal inflammation known as necrotizing enterocolitis (NEC), which has a high mortality. Milk provides a multitude of proteins with anti-inflammatory properties and in this review we gather together some recent significant advances regarding the isolation and proteomic identification of these minor constituents of both human and bovine milk. We introduce the process of inflammation, with a focus on the immature gut, and describe how a multitude of milk proteins act against the inflammatory process according to both in vitro and in vivo studies. We highlight the effects of milk proteins such as caseins, and of whey proteins such as alpha-lactalbumin, beta-lactoglobulin, lactoferrin, osteopontin, immunoglobulins, trefoil factors, lactoperoxidase, superoxide dismutase, platelet-activating factor acetylhydrolase, alkaline phosphatase, and growth factors (TGF-β, IGF-I and IGF-II, EGF, HB-EGF). The effects of milk fat globule proteins, such as TLR-2, TLR-4, sCD14 and MFG-E8/lactadherin, are also discussed. Finally, we indicate how milk proteins could be useful for the prophylaxis and therapy of intestinal inflammation in infants and children. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. The effect of addition of selected milk protein preparations on the growth of Lactobacillus acidophilus and physicochemical properties of fermented milk.

    PubMed

    Gustaw, Waldemar; Kozioł, Justyna; Radzki, Wojciech; Skrzypczak, Katarzyna; Michalak-Majewska, Monika; Sołowiej, Bartosz; Sławińska, Aneta; Jabłońska-Ryś, Ewa

    2016-01-01

    The intake of fermented milk products, especially yoghurts, has been systematically increasing for a few decades. The purpose of this work was to obtain milk products fermented with a mix of bacterial cultures (yoghurt bacteria and Lactobacillus acidophillus LA-5) and enriched with selected milk protein preparations. Secondly, the aim of the work was to determine physiochemical and rheological properties of the obtained products. The following additives were applied in the experiment: whey protein concentrate (WPC 65), whey protein isolate (WPI), demineralised whey powder (SPD), caseinoglycomacropeptide (CGMP), α-lactalbumin (α-la), sodium caseinate (KNa) and calcium caseinate (KCa). Milk was fermented using probiotic strain Lactobacillus acidophillus LA-5 and a typical yoghurt culture. The products were analysed in terms of the survivability of bacterial cells during refrigerated storage, rheological properties and syneresis. Fermented milk products were obtained using blends of bacterial strains: ST-B01:Lb-12 (1:1), ST-B01:Lb-12:LA-5 (1:1:2). Milk beverages fermented with typical yoghurt bacteria and LA-5 strain showed intensive syneresis. The addition of LA-5 strain caused formation of harder acid gels, comparing to typical yoghurts. Milk products which were prepared from skimmed milk possessed higher values of hardness and consistency coefficient. The increase of concentrations of milk preparations (except of WPI) did not cause significant differences in the hardness of acidic gels obtained by fermentation of mixed culture with a probiotic strain. The applied preparations improved physiochemical properties of the milk beverages which were prepared with a probiotic strain. The increase of protein milk preparations concentration resulted in a gradual decrease of the secreted whey. Among the products that were made of full milk powder and were subjected to three weeks of refrigerated storage the highest survivability of Lb. acidophilus LA-5 was noticed in the

  3. Bioactive Functions of Milk Proteins: a Comparative Genomics Approach.

    PubMed

    Sharp, Julie A; Modepalli, Vengama; Enjapoori, Ashwanth Kumar; Bisana, Swathi; Abud, Helen E; Lefevre, Christophe; Nicholas, Kevin R

    2014-12-01

    The composition of milk includes factors required to provide appropriate nutrition for the growth of the neonate. However, it is now clear that milk has many functions and comprises bioactive molecules that play a central role in regulating developmental processes in the young while providing a protective function for both the suckled young and the mammary gland during the lactation cycle. Identifying these bioactives and their physiological function in eutherians can be difficult and requires extensive screening of milk components that may function to improve well-being and options for prevention and treatment of disease. New animal models with unique reproductive strategies are now becoming increasingly relevant to search for these factors.

  4. Human milk galectin-3 binding protein and breast-feeding-associated HIV transmission.

    PubMed

    Chan, Christina S; Kim, Hae-Young; Autran, Chloe; Kim, Jae H; Sinkala, Moses; Kankasa, Chipepo; Mwiya, Mwiya; Thea, Donald M; Aldrovandi, Grace M; Kuhn, Louise; Bode, Lars

    2013-12-01

    Analysis of milk from 247 HIV-infected Zambian mothers showed that galectin-3 binding protein concentrations were significantly higher among HIV-infected mothers who transmitted HIV through breast-feeding (6.51 ± 2.12 μg/mL) than among nontransmitters but were also correlated with higher milk and plasma HIV RNA copies/mL and lower CD4+ cell counts. The association between galectin-3 binding protein and postnatal transmission was attenuated after adjustment for milk and plasma HIV load and CD4+ cell counts. This suggests that although milk galectin-3 binding protein is a marker of advanced maternal disease, it does not independently modify transmission risk.

  5. The effect of milk protein on the bioavailability of cocoa polyphenols.

    PubMed

    Keogh, J B; McInerney, J; Clifton, P M

    2007-04-01

    In order to determine whether milk proteins interact with cocoa polyphenols to modulate the uptake and concentration of polyphenols in plasma, 24 middle-aged men and women consumed 2 g of chocolate polyphenols, plus sugar and cocoa butter in 200 mL water, on 2 occasions. On 1 occasion, the chocolate mix contained 2.45 g of milk proteins. Blood samples were taken fasting and at regular intervals for 8 h. Catechin and epicatechins levels were measured in these samples and no differences were seen in average concentrations between the 2 treatments. Milk protein caused a slight increase in concentration at the early time points and a decrease at the later time points. In conclusion, milk powder did not influence the average concentration of polyphenols. While it slightly accelerated absorption, this is of no physiological significance.

  6. Compared with casein or total milk protein, digestion of milk soluble proteins is too rapid to sustain the anabolic postprandial amino acid requirement.

    PubMed

    Lacroix, Magali; Bos, Cécile; Léonil, Joëlle; Airinei, Gheorge; Luengo, Catherine; Daré, Sophie; Benamouzig, Robert; Fouillet, Hélène; Fauquant, Jacques; Tomé, Daniel; Gaudichon, Claire

    2006-11-01

    The in vivo quality of milk protein fractions has seldom been studied in humans. Our objective was to compare the postprandial utilization of dietary nitrogen from 3 [(15)N]-labeled milk products: micellar caseins (MC), milk soluble protein isolate (MSPI), and total milk protein (TMP). The macronutrient intakes of 23 healthy volunteers were standardized for 1 wk, after which time the subjects ingested a meal containing MC (n = 8), MSPI (n = 7), or TMP (n = 8). [(15)N] was measured for an 8-h period in plasma amino acids, proteins, and urea and in urinary urea. The transfer of dietary nitrogen to urea occurred earlier after MSPI ingestion than after MC and TMP ingestion, and concentrations remained high for 8 h, concomitantly with higher but transient hyperaminoacidemia and a higher incorporation of dietary nitrogen into plasma amino acids. In contrast, deamination, postprandial hyperaminoacidemia, and the incorporation of dietary nitrogen into plasma amino acids were lower in the MC and TMP groups. Finally, total postprandial deamination values were 18.5 +/- 2.9%, 21.1 +/- 2.8%, and 28.2 +/- 2.9% of ingested nitrogen in the TMP, MC, and MSPI groups, respectively. Our results confirm the major role of kinetics in dietary nitrogen postprandial utilization and highlight the paradox of MSPI, which, despite its high Protein Digestibility Corrected Amino Acid Score, ensures a rate of amino acid delivery that is too rapid to sustain the anabolic requirement during the postprandial period. Milk proteins had the best nutritional quality, which suggested a synergistic effect between soluble proteins and caseins.

  7. Effect of thermal processing of cow and buffalo milk on the allergenic response to caseins and whey proteins in mice.

    PubMed

    Shandilya, Umesh Kumar; Kapila, Rajeev; Haq, Raies M; Kapila, Suman; Kansal, V K

    2013-07-01

    Heat treatment is the most common method for reducing pathogen load, but it remains controversial in reducing the incidence of hyperimmune reactions. The aim of this study was to compare the allergenicity of caseins (CSN) and whey proteins (WP) of thermally processed cow and buffalo milk in a mouse model. Swiss albino mice were sensitised by intraperitoneal injections (administered in three doses at weekly intervals) of CSN or WP from cow or buffalo milk for the evaluation of humoral response and splenocyte stimulation index. After 3 weeks of intraperitoneal stimulation of mice with milk proteins, the sterilised milk protein group displayed significantly lowered (P ≤ 0.05) serum IgG and IgE levels, while considerably increased cow milk protein-specific responses (IgE) were shown by proteins of pasteurised milk compared with those of raw milk. The stimulation index of splenocytes induced by CSN or WP of boiled and sterilised milk was also lower (P ≤ 0.05) than that of raw milk of both cow and buffalo. The experiment showed that boiling and sterilisation of cow and buffalo milk clearly affect the allergenicity by decreasing the humoral and cell-mediated responses in mice. All results indicated that CSN and WP of sterilised milk are less allergenic than those of raw milk in mice. © 2013 Society of Chemical Industry.

  8. Case report: hematemesis could be an unusual presentation of cow's milk protein allergy in children in Egypt.

    PubMed

    Zaher, Manal Mohamed; Ahmed, Eman Mohamed; Morsy, Amal Abd El Alim

    2014-01-01

    Cow's milk protein allergy (CMPA) is common in infants with variable clinical presentation including varied gastrointestinal manifestation. Cow's milk protein allergy chiefly, involving occurs in children below the age of 3 years, successful therapy depends on completely eliminating cow's milk proteins (CMP) from the child's diet. Ideally, with the replacement of hypo or an allergenic food. Symptoms suggestive of CMPA may be encountered in approximately 5 to 15% of infants emphasizing the importance of controlled elimination/milk challenge procedures. We report on an Egyptian male infant, who developed frequent attacks of hematemesis when begin to eat foods other than breast milk including cow's milk and its dairy products at the age of three months. Possible cow's milk protein allergy was suspected. Further diagnostic work-up was done including: Hb, hematocrit, MCV: iron, ferritin, CRP, occult blood in stools, antibodies to H-pylori and upper GIT endoscopy and biopsy from snip of duodenal mucosa. Measurement of serum cow milk protein specific IgE by radio allegro sorbent test (RAST) technique (immune CAP specific IgE method) and results revealed cow's milk protein allergy. It is concluded that cow's milk protein allergy should be considered in cases of hematemesis presented in early infancy in infants who fed cow's milk early and that hematemesis should be added to the list of clinical presentation of CMPA.

  9. Characterization of milk proteins-lutein complexes and the impact on lutein chemical stability.

    PubMed

    Yi, Jiang; Fan, Yuting; Yokoyama, Wallace; Zhang, Yuzhu; Zhao, Liqing

    2016-06-01

    In this study, the interaction of WPI (whey protein isolate) and SC (sodium caseinate) with hydrophobic lutein was investigated through UV-vis spectroscopy and circular dichroism (CD) as well as fluorescence. The effects on lutein's chemical stability were also examined. The decrease of turbidity of lutein suggested that lutein's aqueous solubility was improved after binding with milk proteins. CD analysis indicated lutein had little impact on the secondary structures of both proteins. Different preparation methods have significant impacts on the binding constant. Fluorescence results indicated that WPI and SC interact with lutein by hydrophobic contacts. Milk proteins have protective effects on lutein against oxidation and decomposition, and SC showed better capability in protecting lutein from oxidation than WPI during 16 days storage. The lutein's chemical stability was increased with increasing of proteins concentration. The results indicated that milk proteins may act as effective carriers for lipophilic nutraceuticals.

  10. External cavity-quantum cascade laser (EC-QCL) spectroscopy for protein analysis in bovine milk.

    PubMed

    Kuligowski, Julia; Schwaighofer, Andreas; Alcaráz, Mirta Raquel; Quintás, Guillermo; Mayer, Helmut; Vento, Máximo; Lendl, Bernhard

    2017-04-22

    The analytical determination of bovine milk proteins is important in food and non-food industrial applications and yet, rather labour-intensive wet-chemical, low-throughput methods have been employed since decades. This work proposes the use of external cavity-quantum cascade laser (EC-QCL) spectroscopy for the simultaneous quantification of the most abundant bovine milk proteins and the total protein content based on the chemical information contained in mid-infrared (IR) spectral features of the amide I band. Mid-IR spectra of protein standard mixtures were used for building partial least squares (PLS) regression models. Protein concentrations in commercial bovine milk samples were calculated after chemometric compensation of the matrix contribution employing science-based calibration (SBC) without sample pre-processing. The use of EC-QCL spectroscopy together with advanced multivariate data analysis allowed the determination of casein, α-lactalbumin, β-lactoglobulin and total protein content within several minutes.

  11. A milk diet partly containing soy protein does not change growth but regulates jejunal proteins in young goats.

    PubMed

    Kuhla, S; Rudolph, P E; Albrecht, D; Schoenhusen, U; Zitnan, R; Tomek, W; Huber, K; Voigt, J; Metges, C C

    2007-09-01

    Soy protein is known to alter intestinal function and structure. We determined in young goats whether a diet partly containing soy protein differently affects intestinal morphology and the jejunal and hepatic proteome as compared with a milk diet. Fourteen male 2-wk-old White German dairy goat kids were fed comparable diets based on whole cow's milk in which 35% of the crude protein was casein (milk protein group; MP) or soy protein supplemented by indispensable AA (SPAA) for 34 d (n = 7/group). Body weight gain and food efficiency were not different. Jejunal and hepatic tissue was collected to determine intestinal morphology by microscopy and protein repertoire by 2-dimensional gel electrophoresis and mass spectrometry. Jejunal crypt depth was reduced and villus height to crypt depth ratio was higher in SPAA than in milk protein. Out of 131 proteins identified, 32 proteins were found to be differently expressed in both groups. In SPAA, down-regulated jejunal proteins were involved in processes related to cytoskeleton generation, protein, lipid, and energy metabolism. Downregulated hepatic proteins were related to glycolysis and Krebs cycle. Thirteen proteins were upregulated in SPAA. Among these, 2 hepatic proteins were related to carbohydrate breakdown. The other 11 jejunal proteins were involved in cytoskeleton assembly, proteolysis, and carbohydrate breakdown. In addition, glutathione-S-transferase was found to be upregulated in the medial jejunum. In conclusion, a SPAA diet as compared with a milk diet was related to changes in jejunal morphology and jejunal proteins relevant for protein turnover, energy metabolism, and cytoskeleton assembly with no apparent impact on animal BW gain.

  12. Development of immunoglobulin G and immunoglobulin E antibodies to cow's milk proteins and ovalbumin after a temporary neonatal exposure to hydrolyzed and whole cow's milk proteins.

    PubMed

    Juvonen, P; Månsson, M; Kjellman, N I; Björkstén, B; Jakobsson, I

    1999-08-01

    The ingestion of food antigens usually results in the induction of oral tolerance, but the clinical and immunologic consequences of brief exposure to cow's milk proteins during the neonatal period are not well-documented. The aim of this work was to study immunoglobulin (Ig)E and IgG responses to cow's milk proteins and ovalbumin after exposure during the first three days of life in infants who were otherwise exclusively breast-fed. A group of 129 infants was randomly assigned at birth to one of three feeding regimens: human milk (HM), cow's milk formula (CMF), or a casein hydrolysate formula (CHF), during the first three days of life. They were then all exclusively breast-fed for a varying period of time and followed for two years. Serum IgG and IgE antibodies to cow's milk proteins and ovalbumin (OVA) were analyzed in blood samples obtained at birth, at 4 days and at 2, 4, 8, 12 and 24 months of age. The levels of IgG antibodies to beta-lactoglobulin (IgG-BLG) and bovine serum albumin (IgG-BSA) were higher in the CMF and the HM groups than in the CHF group for up to two years. This was particularly obvious for IgG-BLG in infants who started weaning before two months. The levels of IgG antibodies to casein (IgG-CAS) were higher in the CMF group, as compared with the CHF group at 8 and 12 months. The levels of IgG antibodies to OVA were similar in all three feeding groups. The levels of IgE antibodies to CAS or OVA were similar in the three feeding groups. Exposure to cow's milk during the first three days of life stimulated IgG antibody production to cow's milk proteins and this was still obvious at 2 years of age, while feeding with a casein hydrolysate during the first three days of life was associated with low levels of IgG antibodies to cow's milk proteins.

  13. Conjugated linoleic acid-induced milk fat depression in lactating ewes is accompanied by reduced expression of mammary genes involved in lipid synthesis.

    PubMed

    Hussein, M; Harvatine, K H; Weerasinghe, W M P B; Sinclair, L A; Bauman, D E

    2013-06-01

    Conjugated linoleic acids (CLA) are produced during rumen biohydrogenation and exert a range of biological effects. The trans-10,cis-12 CLA isomer is a potent inhibitor of milk fat synthesis in lactating dairy cows and some aspects of the mechanism have been established. Conjugated linoleic acid-induced milk fat depression has also been observed in small ruminants and our objective was to examine the molecular mechanism in lactating ewes. Multiparous lactating ewes were fed a basal ration (0.55:0.45 concentrate-to-forage ratio; dry matter basis) and randomly allocated to 2 dietary CLA levels (n=8 ewes/treatment). Treatments were zero CLA (control) or 15 g/d of lipid-encapsulated CLA supplement containing cis-9,trans-11 and trans-10,cis-12 CLA isomers in equal proportions. Treatments were fed for 10 wk and the CLA supplement provided 1.5 g of trans-10,cis-12/d. No treatment effects were observed on milk yield or milk composition for protein or lactose at wk 10 of the study. In contrast, CLA treatment significantly decreased both milk fat percentage and milk fat yield (g/d) by about 23%. The de novo synthesized fatty acids (FA; C16) was increased (10%) for the CLA treatment. In agreement with the reduced de novo FA synthesis, mRNA abundance of acetyl-coenzyme A carboxylase α, FA synthase, stearoyl-CoA desaturase 1, and glycerol-3-phosphate acyltransferase 6 decreased by 25 to 40% in the CLA-treated group. Conjugated linoleic acid treatment did not significantly reduce the mRNA abundance of enzymes involved in NADPH production, but the mRNA abundance for sterol regulatory element-binding factor 1 and insulin-induced gene 1, genes involved in regulation of transcription of lipogenic enzymes, was decreased by almost 30 and 55%, respectively, with CLA treatment. Furthermore, mRNA abundance of lipoprotein lipase decreased by almost 40% due to CLA treatment

  14. Selenoprotein P Is the Major Selenium Transport Protein in Mouse Milk

    PubMed Central

    Hill, Kristina E.; Motley, Amy K.; Winfrey, Virginia P.; Burk, Raymond F.

    2014-01-01

    Selenium is transferred from the mouse dam to its neonate via milk. Milk contains selenium in selenoprotein form as selenoprotein P (Sepp1) and glutathione peroxidase-3 (Gpx3) as well as in non-specific protein form as selenomethionine. Selenium is also present in milk in uncharacterized small-molecule form. We eliminated selenomethionine from the mice in these experiments by feeding a diet that contained sodium selenite as the source of selenium. Selenium-replete dams with deletion of Sepp1 or Gpx3 were studied to assess the effects of these genes on selenium transfer to the neonate. Sepp1 knockout caused a drop in milk selenium to 27% of the value in wild-type milk and a drop in selenium acquisition by the neonates to 35%. In addition to decreasing milk selenium by eliminating Sepp1, deletion of Sepp1 causes a decline in whole-body selenium, which likely also contributes to the decreased transfer of selenium to the neonate. Deletion of Gpx3 did not decrease milk selenium content or neonate selenium acquisition by measurable amounts. Thus, when the dam is fed selenium-adequate diet (0.25 mg selenium/kg diet), milk Sepp1 transfers a large amount of selenium to neonates but the transfer of selenium by Gpx3 is below detection by our methods. PMID:25068390

  15. Composition, yield, and functionality of reduced-fat Oaxaca cheese: effects of using skim milk or a dry milk protein concentrate.

    PubMed

    Caro, I; Soto, S; Franco, M J; Meza-Nieto, M; Alfaro-Rodríguez, R H; Mateo, J

    2011-02-01

    The effect of adding either skim milk or a commercial dry milk protein concentrate (MPC) to whole milk on the composition, yield, and functional properties of Mexican Oaxaca cheese were investigated. Five batches of Oaxaca cheeses were produced. One batch (the control) was produced from whole milk containing 3.5% fat and 9% nonfat solids (SNF). Two batches were produced from milk standardized with skim milk to 2.7 and 1.8% fat, maintaining the SNF content at 9%. In the other 2 batches, an MPC (40% protein content) was used to standardize the milk to a SNF content of 10 and 11%, maintaining the milk fat content at 3.5%. The use of either skim milk or MPC caused a significant decrease in the fat percentage in cheese. The use of skim milk or MPC showed a nonsignificant tendency to lower total solids and fat recoveries in cheese. Actual, dry matter, and moisture-adjusted cheese yields significantly decreased with skim milk addition, but increased with MPC addition. However, normalized yields adjusted to milk fat and protein reference levels did not show significant differences between treatments. Considering skim milk-added and control cheeses, actual yield increased with cheese milk fat content at a rate of 1.34 kg/kg of fat (R=0.88). In addition, cheese milk fat and SNF:fat ratio proved to be strong individual predictors of cheese moisture-adjusted yield (r(2) ≈ 0.90). Taking into account the results obtained from control and MPC-added cheeses, a 2.0-kg cheese yield increase rate per kg of milk MPC protein was observed (R=0.89), with TS and SNF being the strongest predictors for moisture adjusted yield (r(2) ≈ 0.77). Reduced-fat Oaxaca cheese functionality differed from that of controls. In unmelted reduced-fat cheeses, hardness and springiness increased. In melted reduced-fat cheeses, meltability and free oil increased, but stretchability decreased. These changes were related to differences in cheese composition, mainly fat in dry matter and calcium in SNF.

  16. Functions of milk protein gene 5' flanking regions on human growth hormone gene.

    PubMed

    Ninomiya, T; Hirabayashi, M; Sagara, J; Yuki, A

    1994-03-01

    Fragments containing 5' flanking regions of four bovine milk protein genes--alpha lactalbumin (b alpha LA), alpha S1 casein (b alpha S1CN), beta casein (b beta CN), kappa casein (b kappa CN)--and mouse whey acidic protein (mWAP) gene were prepared by PCR and ligated to human growth hormone (hGH) gene. These recombinant DNAs were microinjected into rat embryos to produce transgenic rats, and the functions of the 5' regions to direct secretion of hGH in the milk were tested. Although milk was obtained only in 5 of 19 mWAP/hGH rat lines, more than two-thirds of the rats carrying the other four DNAs produced milk. More than 80% of the lactated rats carrying b alpha LA/, b beta CN/, and mWAP/hGH, and 33% of the lactated b alpha S1CN/hGH rats secreted detectable amounts of hGH (> 0.05 microgram/ml) in the milk. In some rats, the hGH concentrations in the milk were comparable to or more than that of the corresponding milk protein in bovine milk. The ranges of hGH concentrations in the milk of b alpha LA/, b beta CN/, b alpha S1CN/, and mWAP/hGH rats were 1.13-4,360 micrograms/ml, 0.11-10,900 micrograms/ml, 86.8-6,480 micrograms/ml, and 6.87-151 micrograms/ml, respectively. HGH was also detected in the sera of these rats, and some abnormalities of growth and reproduction were observed. All but one virgin mWAP/hGH rat secreted up to 0.0722 microgram/ml of hGH in the serum, and more than half of them showed abnormal fat accumulations at their abdomen.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. An adjuvant-free mouse model to evaluate the allergenicity of milk whey protein.

    PubMed

    Gonipeta, B; Parvataneni, S; Tempelman, R J; Gangur, V

    2009-10-01

    Milk allergy is the most common type of food allergy in humans with the potential for fatality. An adjuvant-free mouse model would be highly desirable as a preclinical research tool to develop novel hypoallergenic or nonallergenic milk products. Here we describe an adjuvant-free mouse model of milk allergy that uses transdermal sensitization followed by oral challenge with milk protein. Groups of BALB/c mice were exposed to milk whey protein via a transdermal route, without adjuvant. Systemic IgG1 and IgE antibody responses to transdermal exposure as well as systemic anaphylaxis and hypothermia response to oral protein challenge were studied. Transdermal exposure resulted in a time- and dose-dependent induction of significant IgE and IgG1 antibody responses. Furthermore, oral challenge of sensitized mice resulted in significant clinical symptoms of systemic anaphylaxis within 1 h and significant hypothermia at 30 min postchallenge. To study the underlying mechanism, we examined allergen-driven spleen cell T-helper 2 cytokine (IL-4) responses. There was a robust dose- and time-dependent activation of memory IL-4 responses in allergic mice but not in healthy control mice. These data demonstrate for the first time a novel transdermal sensitization followed by oral challenge mouse model of milk allergy that does not use adjuvant. It is expected that this model may be used not only to study mechanisms of milk allergy, but also to evaluate novel milk products for allergenic potential and aid in the production of hypo- or nonallergenic milk products.

  18. Investigating the genetic polymorphism of sheep milk proteins: a useful tool for dairy production.

    PubMed

    Selvaggi, Maria; Laudadio, Vito; Dario, Cataldo; Tufarelli, Vincenzo

    2014-12-01

    Sheep is the second most important dairy species after cow worldwide, and especially in the Mediterranean and Middle East regions. In some countries, the difficult environmental conditions require a peculiar adaptation and, in these contexts, sheep are able to provide higher quality protein than cattle. In the least-developed countries, the amount of dairy sheep and ovine milk production is progressively increasing. In order to improve dairy productions, in particular those with local connotations, it is necessary to obtain in-depth information regarding milk quality and rheological properties. The genetic polymorphisms of milk proteins are often associated with quantitative and qualitative parameters in milk and are potential candidate markers that should be included in breeding strategies similar to those already available for cattle. Due to the current and growing interest in this topic and considering the large amount of new information, the aim of this study was to review the literature on sheep milk protein polymorphisms with a particular emphasis on recent findings in order to give scientists useful support. Moreover, the effects of different protein variants on milk yield and composition are discussed.

  19. A pilot study on the protein composition of induced nonpuerperal human milk.

    PubMed

    Perrin, Maryanne Tigchelaar; Wilson, Erica; Chetwynd, Ellen; Fogleman, April

    2015-02-01

    Our understanding of the components of human puerperal milk is extensive and increasing, yet the literature on nonpuerperal human milk has been limited to studies that measure the success of induced lactation. This study aimed to describe the composition of total protein and key bioactive proteins when lactation is induced in nonpuerperal women. Two women who induced lactation in the absence of pregnancy provided weekly milk samples over a 2-month period for analysis of total protein, secretory immunoglobulin A (sIgA), lysozyme, and lactoferrin. Composition was compared to the mature milk of 3 puerperal control subjects who were 11 months postpartum. Median total protein for subject A was 2.30 g/dL (interquartile range [IQR] = 0.46) and showed a significant downward trend over time (P < .0001), whereas the median total protein for subject B was 2.21 g/dL (IQR = 0.18) and showed a nonsignificant decline (P = .232). Total protein in both nonpuerperal subjects was elevated compared to control subjects. Secretory IgA activity declined for both nonpuerperal subjects over time, whereas lysozyme concentrations increased over time. Both sIgA and lysozyme approached the levels seen in the puerperal controls. Lactoferrin levels remained stable for both nonpuerperal subjects and were elevated compared to puerperal milk samples. This pilot study suggests that nonpuerperal milk has similar or higher levels of total protein, sIgA, lactoferrin, and lysozyme compared to puerperal, mature milk at 11 months postpartum, which warrants more attention as adoptive mothers increasingly choose to induce lactation. © The Author(s) 2014.

  20. Protein synthesis in geostimulated root caps

    NASA Technical Reports Server (NTRS)

    Feldman, L. J.

    1982-01-01

    A study is presented of the processes occurring in the root cap of corn which are requisite for the formation of root cap inhibitor and which can be triggered or modulated by both light and gravity. The results of this study indicate the importance of protein synthesis for light-induced gravitropic bending in roots. Root caps in which protein synthesis is prevented are unable to induce downward bending. This suggests that light acts by stimulating proteins which are necessary for the translation of the gravitropic stimulus into a growth response (downward bending). The turnover of protein with time was also examined in order to determine whether light acts by stimulating the synthesis of unique proteins required for downward growth. It is found that auxin in combination with light allows for the translation of the gravitropic stimulus into a growth response at least in part through the modification of protein synthesis. It is concluded that unique proteins are stimulated by light and are involved in promoting the downward growth in roots which are responding to gravity.

  1. Protein synthesis in geostimulated root caps

    NASA Technical Reports Server (NTRS)

    Feldman, L. J.

    1982-01-01

    A study is presented of the processes occurring in the root cap of corn which are requisite for the formation of root cap inhibitor and which can be triggered or modulated by both light and gravity. The results of this study indicate the importance of protein synthesis for light-induced gravitropic bending in roots. Root caps in which protein synthesis is prevented are unable to induce downward bending. This suggests that light acts by stimulating proteins which are necessary for the translation of the gravitropic stimulus into a growth response (downward bending). The turnover of protein with time was also examined in order to determine whether light acts by stimulating the synthesis of unique proteins required for downward growth. It is found that auxin in combination with light allows for the translation of the gravitropic stimulus into a growth response at least in part through the modification of protein synthesis. It is concluded that unique proteins are stimulated by light and are involved in promoting the downward growth in roots which are responding to gravity.

  2. Proteomic characterization of specific minor proteins in the human milk casein fraction.

    PubMed

    Liao, Yalin; Alvarado, Rudy; Phinney, Brett; Lönnerdal, Bo

    2011-12-02

    Human milk contains many bioactive proteins that are likely to support the early development of the newborn. The aim of this study was to identify whether there are specific minor proteins associated with the human milk casein micelle prepared by the acid precipitation method. Protein identification was performed by liquid chromatography tandem mass spectrometry analysis. Eighty-two proteins were identified in the casein micelle, 18 of which are not present in their whey compartment. Thirty-two of these proteins specifically associated with the casein micelle have not previously been identified in human milk or colostrum. Proteins involved in immune function comprised the major part (28%) of total proteins, and another significant part is involved in metabolism/energy production (22%). Most of the proteins were of extracellular or cytoplasmic origin (accounting for 50 and 29%, respectively). This study indicates that various soluble proteins should be considered as part of the casein compartment, prepared by the acid precipitation method. The data provide new insight not only into the proteomic profile of the human milk casein micelle and its physiological significance, but also into the proper proportion of casein and casein-associated proteins to use in infant formula.

  3. Comparison of composition and sensory properties of 80% whey protein and milk serum protein concentrates.

    PubMed

    Evans, J; Zulewska, J; Newbold, M; Drake, M A; Barbano, D M

    2010-05-01

    Milk serum protein concentrates (SPC) are proteins found in cheese whey that are removed directly from milk. Because SPC are not exposed to the cheese-making process, enzymatic or chemical reactions that can lead to off-flavors are reduced. The objectives of this study were to identify and compare the composition, flavor, and volatile components of 80% protein SPC and whey protein concentrates (WPC). Each pair of 80% SPC and WPC was manufactured from the same lot of milk and this was replicated 3 times. At each replication, spray-dried product from each protein source was collected. Commercial 80% WPC were also collected from several manufacturers for sensory and volatile analyses. A trained sensory panel documented the sensory profiles of the rehydrated powders. Volatile components were extracted by solid-phase microextraction and solvent extraction followed by solvent-assisted flavor evaporation with gas chromatography-mass spectrometry and gas chromatography-olfactometry. Consumer acceptance testing of acidified 6% protein beverages made with 80% SPC and WPC produced in the pilot plant and with WPC from commercial sources was conducted. The SPC was lower in fat and had a higher pH than the WPC produced in the pilot plant or commercial WPC. Few sensory differences were found between the rehydrated SPC and WPC manufactured in this study, but their flavor profiles were distinct from the flavor of rehydrated commercial WPC. The pilot-plant WPC had higher concentrations of lipid oxidation products compared with SPC, which may be related to the higher fat content of WPC. There was a large difference in appearance between 80% SPC and WPC: solutions of SPC were clear and those of WPC were opaque. Concentrations of lipid oxidation products in commercial WPC were generally higher than those in pilot-plant SPC or WPC. Sensory profiles of the peach-flavored protein beverage included cereal, free fatty acid, and soapy flavors and bitter taste in beverages made from pilot

  4. The effect of spray-drying parameters on the flavor of nonfat dry milk and milk protein concentrate 70.

    PubMed

    Park, Curtis W; Stout, Mark A; Drake, MaryAnne

    2016-12-01

    Unit operations during production influence the sensory properties of nonfat dry milk (NFDM) and milk protein concentrate (MPC). Off-flavors in dried dairy ingredients decrease consumer acceptance of ingredient applications. Previous work has shown that spray-drying parameters affect physical and sensory properties of whole milk powder and whey protein concentrate. The objective of this study was to determine the effect of inlet temperature and feed solids concentration on the flavor of NFDM and MPC 70% (MPC70). Condensed skim milk (50% solids) and condensed liquid MPC70 (32% solids) were produced using pilot-scale dairy processing equipment. The condensed products were then spray dried at either 160, 210, or 260°C inlet temperature and 30, 40, or 50% total solids for NFDM and 12, 22, or 32% for MPC70 in a randomized order. The entire experiment was replicated 3 times. Flavor of the NFDM and MPC70 was evaluated by sensory and instrumental volatile compound analyses. Surface free fat, particle size, and furosine were also analyzed. Both main effects (30, 40, and 50% solids and 160, 210, and 260°C inlet temperature) and interactions between solids concentration and inlet temperature were investigated. Interactions were not significant. In general, results were consistent for NFDM and MPC70. Increasing inlet temperature and feed solids concentration increased sweet aromatic flavor and decreased cardboard flavor and associated lipid oxidation products. Increases in furosine with increased inlet temperature and solids concentration indicated increased Maillard reactions during drying. Particle size increased and surface free fat decreased with increasing inlet temperature and solids concentration. These results demonstrate that increasing inlet temperatures and solids concentration during spray drying decrease off-flavor intensities in NFDM and MPC70 even though the heat treatment is greater compared with low temperature and low solids.

  5. A High-Concentrate Diet Induced Milk Fat Decline via Glucagon-Mediated Activation of AMP-Activated Protein Kinase in Dairy Cows

    PubMed Central

    Li, Lin; Cao, Yang; Xie, Zhenglu; Zhang, Yuanshu

    2017-01-01

    Dairy cows are often fed a high-concentrate (HC) diet to meet lactation demands; however, long-term concentrate feeding is unhealthy and decreases milk fat. Therefore, we investigated the effects of liver lipid metabolism on milk fat synthesis. Ten lactating Holstein cows were assigned randomly into HC and LC (low-concentrate) diet groups. After 20 weeks of feeding, milk fat declined, and lipopolysaccharide levels in the jugular, portal, and hepatic veins increased in the HC group. Liver consumption and release of nonesterified fatty acid (NEFA) into the bloodstream also decreased. AMP-activated protein kinase alpha (AMPKα) was up-regulated significantly in the livers of the HC-fed cows. The HC diet also up-regulated the expression of the transcription factor peroxisome proliferator-activated receptor α (PPARα) and its downstream targets involved in fatty acid oxidation, including carnitine palmitoyltransferase-1,2 (CPT-1, CPT-2), liver-fatty acid-binding protein (L-FABP), and acyl-CoA oxidase (ACO). The HC diet increased blood glucagon (GC) levels, and liver glucagon receptor (GCGR) expression was elevated. Cumulatively, a long-term HC diet decreased plasma concentrations of NEFA via the GC/GCGR-AMPK-PPARα signalling pathway and reduced their synthesis in the liver. The decreased NEFA concentration in the blood during HC feeding may explain the decline in the milk fat of lactating cows. PMID:28287130

  6. Distribution of animal drugs among curd, whey, and milk protein fractions in spiked skim milk and whey

    USDA-ARS?s Scientific Manuscript database

    It is important to understand the partitioning of drugs in processed milk and milk products, when drugs are present in raw milk, in order to estimate the potential consumer exposure. Radioisotopically labelled erythromycin, ivermectin, ketoprofen, oxytetracycline, penicillin G, sulfadimethoxine, and...

  7. Diet, cow's milk protein antibodies and the risk of IDDM in Finnish children. Childhood Diabetes in Finland Study Group.

    PubMed

    Virtanen, S M; Saukkonen, T; Savilahti, E; Ylönen, K; Räsänen, L; Aro, A; Knip, M; Tuomilehto, J; Akerblom, H K

    1994-04-01

    Associations of infant feeding patterns and milk consumption with cow's milk protein antibody titres were studied in 697 newly-diagnosed diabetic children, 415 sibling-control children and 86 birth-date- and sex-matched population-based control children in the nationwide "Childhood Diabetes in Finland" study. IgA and IgG antibody titres to the proteins of cow's milk formula, BLG and BSA, and IgM antibody titres to cow's milk formula proteins were measured by ELISA. Several inverse correlations were observed between the duration of breast-feeding or age at introduction of dairy products and antibody titres, and positive correlations were observed between milk consumption and antibody titres in all three populations studied. Multivariate analyses which included the infant feeding variables, milk consumption and current age simultaneously showed that the earlier the introduction of dairy products and the greater the consumption of milk was, the higher several antibody titres were. High IgA antibody titres to cow's milk formula were associated with a greater risk of IDDM both among diabetic-population-control and diabetic-sibling-control pairs when adjusted for other cow's milk antibody titres, dietary variables and in diabetic-sibling-control pairs also for ICA. The results suggest that young age at introduction of dairy products and high milk consumption during childhood increase the levels of cow's milk antibodies and that high IgA antibodies to cow's milk formula are independently associated with increased risk of IDDM.

  8. Monotreme lactation protein is highly expressed in monotreme milk and provides antimicrobial protection.

    PubMed

    Enjapoori, Ashwantha Kumar; Grant, Tom R; Nicol, Stewart C; Lefèvre, Christophe M; Nicholas, Kevin R; Sharp, Julie A

    2014-09-22

    Monotremes (platypus and echidna) are the descendants of the oldest ancestor of all extant mammals distinguished from other mammals by mode of reproduction. Monotremes lay eggs following a short gestation period and after an even briefer incubation period, altricial hatchlings are nourished over a long lactation period with milk secreted by nipple-less mammary patches located on the female's abdomen. Milk is the sole source of nutrition and immune protection for the developing young until weaning. Using transcriptome and mass spectrometry analysis of milk cells and milk proteins, respectively, a novel Monotreme Lactation Protein (MLP) was identified as a major secreted protein in milk. We show that platypus and short-beaked echidna MLP genes show significant homology and are unique to monotremes. The MLP transcript was shown to be expressed in a variety of tissues; however, highest expression was observed in milk cells and was expressed constitutively from early to late lactation. Analysis of recombinant MLP showed that it is an N-linked glycosylated protein and biophysical studies predicted that MLP is an amphipathic, α-helical protein, a typical feature of antimicrobial proteins. Functional analysis revealed MLP antibacterial activity against both opportunistic pathogenic Staphylococcus aureus and commensal Enterococcus faecalis bacteria but showed no effect on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Salmonella enterica. Our data suggest that MLP is an evolutionarily ancient component of milk-mediated innate immunity absent in other mammals. We propose that MLP evolved specifically in the monotreme lineage supporting the evolution of lactation in these species to provide bacterial protection, at a time when mammals lacked nipples. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  9. Monotreme Lactation Protein Is Highly Expressed in Monotreme Milk and Provides Antimicrobial Protection

    PubMed Central

    Enjapoori, Ashwantha Kumar; Grant, Tom R.; Nicol, Stewart C.; Lefèvre, Christophe M.; Nicholas, Kevin R.; Sharp, Julie A.

    2014-01-01

    Monotremes (platypus and echidna) are the descendants of the oldest ancestor of all extant mammals distinguished from other mammals by mode of reproduction. Monotremes lay eggs following a short gestation period and after an even briefer incubation period, altricial hatchlings are nourished over a long lactation period with milk secreted by nipple-less mammary patches located on the female’s abdomen. Milk is the sole source of nutrition and immune protection for the developing young until weaning. Using transcriptome and mass spectrometry analysis of milk cells and milk proteins, respectively, a novel Monotreme Lactation Protein (MLP) was identified as a major secreted protein in milk. We show that platypus and short-beaked echidna MLP genes show significant homology and are unique to monotremes. The MLP transcript was shown to be expressed in a variety of tissues; however, highest expression was observed in milk cells and was expressed constitutively from early to late lactation. Analysis of recombinant MLP showed that it is an N-linked glycosylated protein and biophysical studies predicted that MLP is an amphipathic, α-helical protein, a typical feature of antimicrobial proteins. Functional analysis revealed MLP antibacterial activity against both opportunistic pathogenic Staphylococcus aureus and commensal Enterococcus faecalis bacteria but showed no effect on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Salmonella enterica. Our data suggest that MLP is an evolutionarily ancient component of milk-mediated innate immunity absent in other mammals. We propose that MLP evolved specifically in the monotreme lineage supporting the evolution of lactation in these species to provide bacterial protection, at a time when mammals lacked nipples. PMID:25245409

  10. Biologically active breast milk proteins in association with very preterm delivery and stage of lactation.

    PubMed

    Mehta, R; Petrova, A

    2011-01-01

    The aim of this study was to identify the independent effect of very preterm gestation on breast milk content of biologically active proteins (secretory immunoglobulin A (sIgA), lysozyme, lactoferrin, osteoprotegerin (OPG), leptin, adiponectin and β-endorphin (b-EP)) during the first month of lactation. We collected samples of transitional (6 to 8 and 13 to 15 days) and mature (20 to 22 and 27 to 29 days) milk from mothers after term (38 to 41 weeks) or very preterm (24 to 31 weeks) delivery. The levels of sIgA, lysozyme, lactoferrin, OPG, leptin, adiponectin and b-EP in the breast milk were quantified using enzyme-linked immunosorbent assay or enzyme immunoassay kits. Statistical analysis included descriptive statistics and regression analysis. Sixty breast milk samples were collected from 15 mothers after very preterm (preterm breast milk, PBM) and 20 samples from 5 mothers after term (term breast milk, TBM) deliveries. Decrease in lysozyme, lactoferrin, OPG, leptin, adiponectin and b-EP but no change in sIgA was recorded during the first month of lactation in both TBM and PBM. The IgA, lysozyme and adiponectin were higher in PBM than in TBM, whereas concentrations of lactoferrin, OPG and leptin were higher in TBM than in PBM (P<0.05 to 0.0001). A similar pattern was seen in the lysozyme, leptin and adiponectin concentration in mature milk. Increased b-EP levels in breast milk were associated with the vaginal mode of delivery but not gestational age. Although a similar pattern of change was observed in the breast milk bioactive proteins during the first month of lactation after term and very preterm gestation, PBM is a better source of factors with antibacterial/anti-inflammatory activities but is constantly deficient in leptin, which is involved in neuroendocrine regulation.

  11. Milk Proteins, Peptides, and Oligosaccharides: Effects against the 21st Century Disorders

    PubMed Central

    Hsieh, Chia-Chien; Hernández-Ledesma, Blanca; Fernández-Tomé, Samuel; Weinborn, Valerie; Barile, Daniela; de Moura Bell, Juliana María Leite Nobrega

    2015-01-01

    Milk is the most complete food for mammals, as it supplies all the energy and nutrients needed for the proper growth and development of the neonate. Milk is a source of many bioactive components, which not only help meeting the nutritional requirements of the consumers, but also play a relevant role in preventing various disorders. Milk-derived proteins and peptides have the potential to act as coadjuvants in conventional therapies, addressing cardiovascular diseases, metabolic disorders, intestinal health, and chemopreventive properties. In addition to being a source of proteins and peptides, milk contains complex oligosaccharides that possess important functions related to the newborn's development and health. Some of the health benefits attributed to milk oligosaccharides include prebiotic probifidogenic effects, antiadherence of pathogenic bacteria, and immunomodulation. This review focuses on recent findings demonstrating the biological activities of milk peptides, proteins, and oligosaccharides towards the prevention of diseases of the 21st century. Processing challenges hindering large-scale production and commercialization of those bioactive compounds have been also addressed. PMID:25789308

  12. Epidermal growth factor-like proteins in breast fluid and human milk.

    PubMed

    Connolly, J M; Rose, D P

    1988-01-01

    Epidermal growth factor (EGF), and the transforming growth factor-alpha (TGF-alpha) family of proteins, which also bind to the EGF receptor, have been associated with human breast cancer. The total EGF-like proteins were determined by a radioreceptor assay, and TGF-alpha by radioimmunoassay, in human milk and breast fluid samples. The breast fluids were collected by nipple aspiration from healthy premenopausal women. Both the 24 milks and 18 breast fluids assayed contained EGF-like proteins, at concentrations ranging from 32-600 ng/ml (median, 140 ng/ml), and 62-654 ng/ml (median, 205 ng/ml) respectively. Immunoreactive TGF-alpha proteins were detected at higher levels in 21 breast fluids (range, 0-50.0; median 5.1 ng/ml) than in 24 milk samples (range, 0-8.4; median, 0.8 ng/ml).

  13. Bioactive peptides derived from human milk proteins--mechanisms of action.

    PubMed

    Wada, Yasuaki; Lönnerdal, Bo

    2014-05-01

    Human milk contains a multitude of bioactive proteins with very diverse functions, which are beneficial for the rapidly growing neonate. The large variety of bioactivities is accomplished by the combination of bioactive proteins per se and gastrointestinal release of bioactive peptides derived from them. The bioactivities exerted by these peptides include enhancement of mineral absorption, immunomodulation, opioid, antihypertensive and antimicrobial activities. Notably, several of the activities are not attributed to the parental proteins, but exclusively to released bioactive peptides. This article reviews studies on bioactive peptides derived from major human milk proteins, such as caseins, α-lactalbumin and lactoferrin, during gastrointestinal digestion. Studies of bovine milk counterparts are also cited as a comparison. Copyright © 2014. Published by Elsevier Inc.

  14. Protein Synthesis Initiation Factors: Phosphorylation and Regulation

    SciTech Connect

    Karen S. Browning

    2009-06-15

    The initiation of the synthesis of proteins is a fundamental process shared by all living organisms. Each organism has both shared and unique mechanisms for regulation of this vital process. Higher plants provide for a major amount of fixation of carbon from the environment and turn this carbon into food and fuel sources for our use. However, we have very little understanding of how plants regulate the synthesis of the proteins necessary for these metabolic processes. The research carried out during the grant period sought to address some of these unknowns in the regulation of protein synthesis initiation. Our first goal was to determine if phosphorylation plays a significant role in plant initiation of protein synthesis. The role of phosphorylation, although well documented in mammalian protein synthesis regulation, is not well studied in plants. We showed that several of the factors necessary for the initiation of protein synthesis were targets of plant casein kinase and showed differential phosphorylation by the plant specific isoforms of this kinase. In addition, we identified and confirmed the phosphorylation sites in five of the plant initiation factors. Further, we showed that phosphorylation of one of these factors, eIF5, affected the ability of the factor to participate in the initiation process. Our second goal was to develop a method to make initiation factor 3 (eIF3) using recombinant methods. To date, we successfully cloned and expressed 13/13 subunits of wheat eIF3 in E. coli using de novo gene construction methods. The final step in this process is to place the subunits into three different plasmid operons for co-expression. Successful completion of expression of eIF3 will be an invaluable tool to the plant translation community.

  15. Mitochondrial nucleoid interacting proteins support mitochondrial protein synthesis.

    PubMed

    He, J; Cooper, H M; Reyes, A; Di Re, M; Sembongi, H; Litwin, T R; Gao, J; Neuman, K C; Fearnley, I M; Spinazzola, A; Walker, J E; Holt, I J

    2012-07-01

    Mitochondrial ribosomes and translation factors co-purify with mitochondrial nucleoids of human cells, based on affinity protein purification of tagged mitochondrial DNA binding proteins. Among the most frequently identified proteins were ATAD3 and prohibitin, which have been identified previously as nucleoid components, using a variety of methods. Both proteins are demonstrated to be required for mitochondrial protein synthesis in human cultured cells, and the major binding partner of ATAD3 is the mitochondrial ribosome. Altered ATAD3 expression also perturbs mtDNA maintenance and replication. These findings suggest an intimate association between nucleoids and the machinery of protein synthesis in mitochondria. ATAD3 and prohibitin are tightly associated with the mitochondrial membranes and so we propose that they support nucleic acid complexes at the inner membrane of the mitochondrion.

  16. Mitochondrial nucleoid interacting proteins support mitochondrial protein synthesis

    PubMed Central

    He, J.; Cooper, H. M.; Reyes, A.; Di Re, M.; Sembongi, H.; Litwin, T. R.; Gao, J.; Neuman, K. C.; Fearnley, I. M.; Spinazzola, A.; Walker, J. E.; Holt, I. J.

    2012-01-01

    Mitochondrial ribosomes and translation factors co-purify with mitochondrial nucleoids of human cells, based on affinity protein purification of tagged mitochondrial DNA binding proteins. Among the most frequently identified proteins were ATAD3 and prohibitin, which have been identified previously as nucleoid components, using a variety of methods. Both proteins are demonstrated to be required for mitochondrial protein synthesis in human cultured cells, and the major binding partner of ATAD3 is the mitochondrial ribosome. Altered ATAD3 expression also perturbs mtDNA maintenance and replication. These findings suggest an intimate association between nucleoids and the machinery of protein synthesis in mitochondria. ATAD3 and prohibitin are tightly associated with the mitochondrial membranes and so we propose that they support nucleic acid complexes at the inner membrane of the mitochondrion. PMID:22453275

  17. Isolation and identification of a high molecular weight protein in sow milk.

    PubMed

    Qin, Y; Qi, N; Tang, Y; He, J; Li, X; Gu, F; Zou, S

    2015-05-01

    A high molecular weight protein (HMWP) was isolated and purified from sow milk, and some of its biochemical characteristics and biological functions were identified. The origin of HMWP was also investigated. The molecular weight of HMWP was determined to be about 115 000 and 114 800 by SDS-PAGE and gel filtration, respectively. The sequence of 10 amino acids in N-terminal of HMWP was Ala-Leu-Val-Gln-Ser-Cys-Leu-Asn-Leu-Val. The sequence was blasted against GenBank. No protein showed significant similarity with this sequence suggesting the HMWP may be novel. The result of liquid chromatography mass spectrometry (LC-MS) also proved HMWP could be a novel protein. By amino acid assay, HMWP was rich in glutamate (including glutamine), cysteine, glycine, aspartic acid (including asparagines) and proline. The content of hydrophobic amino acids (Ala, Val, Leu, Ile, Met, Phe and Pro) was lower at 18.59% of the total amino acids suggesting HMWP has high solubility in water. Western blots of lectins were used to identify the kinds of carbohydrate residues attached to HMWP qualitatively. The result showed that HMWP was a kind of glycoprotein containing N-acetylneuraminic acid (NeuNAc), mannose (Man) and/or N-acetylglucosamine (GlcNAc). By isoelectric focusing, HMWP pI was found to be 5.1. Compared with milk fat globule membrane protein (MFGMP) isolated from the sow milk in SDS-PAGE, MFGMP did not contain HMWP. HMWP was assumed to be a secretory milk protein. HMWP was not found in bovine, goat, rabbit or human milk in SDS-PAGE gel suggesting HMWP may be unique to sow milk. By Western blot, HMWP could be detected in sow milk, not in sow serum, which suggests it is synthesized and secreted by the mammary gland. HMWP concentrations in sows milk were the lowest in the first day of lactation, rose significantly during lactation 1 to 7 days. The HMWP content of sows milk remained relatively constant ((1.95±0.13) g/l) during lactation 7 to 20 days. HMWP significantly inhibited

  18. [Effectiveness of the use of iodized milk protein to improve girls' sufficiency with iodine].

    PubMed

    Bol'shakova, L S; Lisitsin, A B; Chernukha, I M; Zubtsov, Iu N; Litvinova, E V

    2014-01-01

    The work presents the results of the research capabilities of the use of iodized milk protein as a component of food supplement and enriched food product for the correction of iodine sufficiency in girls. Milk iodinated protein was produced by the enzyme-effective iodization of amino acid residues of cow's milk whey proteins. The study involved 30 girls, whose average age was 19.9 +/- 1.4 years. Participants of observation were divided into three groups, for 10 people each. The first group received daily serving of meat cutlets (50g), enriched with dairy iodinated protein. Iodine content in the finished minced was 100 mcg. The second group received iodinated milk protein in the form of food supplement with iodine content of 100 mcg. The third group was a control one. The duration of observations was 30 days. To assess the effectiveness of measures the concentration of iodine in urine, blood levels of thyroid-stimulating hormone and free thyroxine have been determined, changes in cognitive processes (memory and attention) with the use of psychological tests have been evaluated. Studies have shown the effectiveness of using of iodized milk protein for the correction of iodine deficiency in girls. The use of iodized protein, as part of the enriched product and in the form of food supplement increased urinary iodine level and had a positive influence on the state of the hypophysial-thyroid system. In addition, the use of iodized milk protein helped to improve the cognitive functions of the students, which can be considered as an additional positive effect of correction of iodine deficiency.

  19. Free Maillard Reaction Products in Milk Reflect Nutritional Intake of Glycated Proteins and Can Be Used to Distinguish "Organic" and "Conventionally" Produced Milk.

    PubMed

    Schwarzenbolz, Uwe; Hofmann, Thomas; Sparmann, Nina; Henle, Thomas

    2016-06-22

    Using LC-MS/MS and isotopically labeled standard substances, quantitation of free Maillard reaction products (MRPs), namely, N(ε)-(carboxymethyl)lysine (CML), 5-(hydroxymethyl)-1H-pyrrole-2-carbaldehyde (pyrraline, PYR), N(δ)-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H), and N(ε)-fructosyllysine (FL), in bovine milk was achieved. Considerable variations in the amounts of the individual MRPs were found, most likely as a consequence of the nutritional uptake of glycated proteins. When comparing commercial milk samples labeled as originating from "organic" or "conventional" farming, respectively, significant differences in the content of free PYR (organic milk, 20-300 pmol/mL; conventional milk, 400-1000 pmol/mL) were observed. An analysis of feed samples indicated that rapeseed and sugar beet are the main sources for MRPs in conventional farming. Furthermore, milk of different dairy animals (cow, buffalo, donkey, goat, ewe, mare, camel) as well as for the first time human milk was analyzed for free MRPs. The distribution of their concentrations, with FL and PYR as the most abundant in human milk and with a high individual variability, also points to a nutritional influence. As the components of concentrated feed do not belong to the natural food sources of ruminants and equidae, free MRPs in milk might serve as indicators for an adequate animal feeding in near-natural farming and can be suitable parameters to distinguish between an "organic" and "conventional" production method of milk.

  20. Proteomic analysis of differentially expressed proteins in bovine milk during experimentally induced Escherichia coli mastitis

    USDA-ARS?s Scientific Manuscript database

    The objectives of the current study were to profile changes in protein composition using 2-dimensional gel electrophoresis (2D-GE) on whey samples from a group of 8 cows prior to and 18 hours after infection with Escherichia coli, and to identify differentially expressed milk proteins by peptide seq...

  1. Effect of high hydrostatic pressure processing on in vitro digestion of milk proteins and fats

    USDA-ARS?s Scientific Manuscript database

    The use of high hydrostatic pressure processing (HPP) is increasing in popularity in the food industry. Its ability to modify milk proteins and fats suggests that it may be useful in creating foods that suppress appetite; however, its effect on the digestibility of proteins and fats is unclear. The...

  2. Multidrug transporter ABCG2/breast cancer resistance protein secretes riboflavin (vitamin B2) into milk.

    PubMed

    van Herwaarden, Antonius E; Wagenaar, Els; Merino, Gracia; Jonker, Johan W; Rosing, Hilde; Beijnen, Jos H; Schinkel, Alfred H

    2007-02-01

    The multidrug transporter breast cancer resistance protein (BCRP/ABCG2) is strongly induced in the mammary gland during pregnancy and lactation. We here demonstrate that BCRP is responsible for pumping riboflavin (vitamin B(2)) into milk, thus supplying the young with this important nutrient. In Bcrp1(-/-) mice, milk secretion of riboflavin was reduced >60-fold compared to that in wild-type mice. Yet, under laboratory conditions, Bcrp1(-/-) pups showed no riboflavin deficiency due to concomitant milk secretion of its cofactor flavin adenine dinucleotide, which was not affected. Thus, two independent secretion mechanisms supply vitamin B(2) equivalents to milk. BCRP is the first active riboflavin efflux transporter identified in mammals and the first transporter shown to concentrate a vitamin into milk. BCRP activity elsewhere in the body protects against xenotoxins by reducing their absorption and mediating their excretion. Indeed, Bcrp1 activity increased excretion of riboflavin into the intestine and decreased its systemic availability in adult mice. Surprisingly, the paradoxical dual utilization of BCRP as a xenotoxin and a riboflavin pump is evolutionarily conserved among mammals as diverse as mice and humans. This study establishes the principle that an ABC transporter can transport a vitamin into milk and raises the possibility that other vitamins and nutrients are likewise secreted into milk by ABC transporters.

  3. Soluble Milk Protein Supplementation with Moderate Physical Activity Improves Locomotion Function in Aging Rats

    PubMed Central

    Lafoux, Aude; Baudry, Charlotte; Bonhomme, Cécile; Le Ruyet, Pascale; Huchet, Corinne

    2016-01-01

    Aging is associated with a loss of muscle mass and functional capacity. Present study was designed to compare the impact of specific dairy proteins on muscular function with or without a low-intensity physical activity program on a treadmill in an aged rat model. We investigated the effects of nutritional supplementation, five days a week over a 2-month period with a slow digestible protein, casein or fast digestible proteins, whey or soluble milk protein, on strength and locomotor parameters in sedentary or active aged Wistar RjHan rats (17–19 months of age). An extensive gait analysis was performed before and after protein supplementation. After two months of protein administration and activity program, muscle force was evaluated using a grip test, spontaneous activity using an open-field and muscular mass by specific muscle sampling. When aged rats were supplemented with proteins without exercise, only minor effects of different diets on muscle mass and locomotion were observed: higher muscle mass in the casein group and improvement of stride frequencies with soluble milk protein. By contrast, supplementation with soluble milk protein just after physical activity was more effective at improving overall skeletal muscle function in old rats compared to casein. For active old rats supplemented with soluble milk protein, an increase in locomotor activity in the open field and an enhancement of static and dynamic gait parameters compared to active groups supplemented with casein or whey were observed without any differences in muscle mass and forelimb strength. These results suggest that consumption of soluble milk protein as a bolus immediately after a low intensity physical activity may be a suitable nutritional intervention to prevent decline in locomotion in aged rats and strengthen the interest to analyze the longitudinal aspect of locomotion in aged rodents. PMID:27973615

  4. Lactobacillus gasseri requires peptides, not proteins or free amino acids, for growth in milk.

    PubMed

    Arakawa, K; Matsunaga, K; Takihiro, S; Moritoki, A; Ryuto, S; Kawai, Y; Masuda, T; Miyamoto, T

    2015-03-01

    Lactobacillus gasseri is a widespread commensal lactic acid bacterium inhabiting human mucosal niches and has many beneficial effects as a probiotic. However, L. gasseri is difficult to grow in milk, which hurts usability for the food industry. It had been previously reported that supplementation with yeast extract or proteose peptone, including peptides, enables L. gasseri to grow well in milk. In this study, our objective was to confirm peptide requirement of L. gasseri and evaluate efficacy of peptide release by enzymatic proteolysis on growth of L. gassei in milk. Three strains of L. gasseri did not grow well in modified DeMan, Rogosa, Sharpe broth without any nitrogen sources (MRS-N), but addition of a casein-derived peptide mixture, tryptone, promoted growth. In contrast, little effect was observed after adding casein or a casein-derived amino acid mixture, casamino acids. These results indicate that L. gasseri requires peptides, not proteins or free amino acids, among milk-derived nitrogen sources for growth. Lactobacillus gasseri JCM 1131T hardly had growth capacity in 6 kinds of milk-based media: bovine milk, human milk, skim milk, cheese whey, modified MRS-N (MRSL-N) supplemented with acid whey, and MRSL-N supplemented with casein. Moreover, treatment with digestive proteases, particularly pepsin, to release peptides made it grow well in each milk-based medium. The pepsin treatment was the most effective for growth of strain JCM 1131T in skim milk among the tested food-grade proteases such as trypsin, α-chymotrypsin, calf rennet, ficin, bromelain, and papain. As well as strain JCM 1131T, pepsinolysis of milk improved growth of other L. gasseri strains and some strains of enteric lactobacilli such as Lactobacillus crispatus, Lactobacillus gallinarum, Lactobacillus johnsonii, and Lactobacillus reuteri. These results suggest that some relatives of L. gasseri also use peptides as desirable nitrogen sources, and that milk may be a good supplier of nutritious

  5. Effect of homogenization and pasteurization on the structure and stability of whey protein in milk.

    PubMed

    Qi, Phoebe X; Ren, Daxi; Xiao, Yingping; Tomasula, Peggy M

    2015-05-01

    The effect of homogenization alone or in combination with high-temperature, short-time (HTST) pasteurization or UHT processing on the whey fraction of milk was investigated using highly sensitive spectroscopic techniques. In pilot plant trials, 1-L quantities of whole milk were homogenized in a 2-stage homogenizer at 35°C (6.9 MPa/10.3 MPa) and, along with skim milk, were subjected to HTST pasteurization (72°C for 15 s) or UHT processing (135°C for 2 s). Other whole milk samples were processed using homogenization followed by either HTST pasteurization or UHT processing. The processed skim and whole milk samples were centrifuged further to remove fat and then acidified to pH 4.6 to isolate the corresponding whey fractions, and centrifuged again. The whey fractions were then purified using dialysis and investigated using the circular dichroism, Fourier transform infrared, and Trp intrinsic fluorescence spectroscopic techniques. Results demonstrated that homogenization combined with UHT processing of milk caused not only changes in protein composition but also significant secondary structural loss, particularly in the amounts of apparent antiparallel β-sheet and α-helix, as well as diminished tertiary structural contact. In both cases of homogenization alone and followed by HTST treatments, neither caused appreciable chemical changes, nor remarkable secondary structural reduction. But disruption was evident in the tertiary structural environment of the whey proteins due to homogenization of whole milk as shown by both the near-UV circular dichroism and Trp intrinsic fluorescence. In-depth structural stability analyses revealed that even though processing of milk imposed little impairment on the secondary structural stability, the tertiary structural stability of whey protein was altered significantly. The following order was derived based on these studies: raw whole>HTST, homogenized, homogenized and pasteurized>skimmed and pasteurized, and skimmed UHT

  6. Food allergy and the potential allergenicity-antigenicity of microparticulated egg and cow's milk proteins.

    PubMed

    Sampson, H A; Cooke, S K

    1990-08-01

    Approximately 3-4 million Americans experience food allergic reactions at some time in their lives. In the pediatric population, eggs and milk are most frequently implicated in food allergic reactions. The most well-understood adverse reactions to foods are secondary to the development of IgE antibodies to specific food antigens. Once an individual becomes sensitized (i.e., makes specific IgE antibodies), ingestion of the food may lead to a variety of cutaneous, respiratory, and/or gastrointestinal symptoms, and anaphylactic shock. The use of SDS-PAGE and immunoblot analyses with sera from documented food allergic patients provide a very sensitive indicator of the antigenic/allergic composition of various foods. As demonstrated in a study of infant formulas of hydrolyzed cow's milk protein, the absence of demonstrable bands on SDS-PAGE gels and immunoblots correlates with an inability to provoke an allergic response. In addition, it was demonstrated that SDS-PAGE with silver staining could detect protein fractions at a concentration of 50-100 ng/ml, a concentration below which allergic individuals are unlikely to react. These studies confirmed that patients clinically allergic to egg and/or cow's milk possess IgE and IgG antibodies to protein fractions in egg and cow's milk, as well as the microparticulated egg/cow's milk proteins, Simplesse and Beta IL. Compared to egg and cow's milk, there is no evidence that the Simplesse or Beta IL test materials possess any "novel" protein fractions or antigens. In addition, there is no evidence that these microparticulated proteins result in increased immunologic activity, as determined by the intensity of protein band staining.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Protein synthesis during encystment of Azotobacter vinelandii

    SciTech Connect

    Su, C.J.; da Cunha, A.; Wernette, C.M.; Reusch, R.N.; Sadoff, H.L.

    1987-10-01

    Proteins synthesized during the encystment of Azotobacter vinelandii were radiolabeled with (/sup 35/S) methionine and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Pulse labeling was used to demonstrate that early encystment-specific proteins were beginning to be synthesized by 2 h and reach peak levels about 12 h after initiation of encystment. One such protein was identified as a ..beta..-ketoacyl acyl-carrier protein synthase. The concentration of early proteins began to decrease at 16 h, when intermediate proteins specific to the differentiation process began to be synthesized. The cessation of synthesis of intermediate proteins began at 20 h postinitiation, and the labeling pattern of proteins then remained constant throughout the remaining 4 days of encystment.

  8. Nutrient-independent and nutrient-dependent factors stimulate protein synthesis in colostrum-fed newborn pigs.

    PubMed

    Burrin, D G; Davis, T A; Ebner, S; Schoknecht, P A; Fiorotto, M L; Reeds, P J; McAvoy, S

    1995-05-01

    We hypothesized that nonnutrient components, including growth factors, present in colostrum contribute to the stimulation of protein synthesis in colostrum-fed neonatal pigs. We studied neonatal pigs fed mature milk, colostrum, or a formula containing a macronutrient composition comparable to that of colostrum for 24 h. We measured the circulating concentrations of insulin, insulin-like growth factor I, glucose, and amino acids at intervals throughout the 24-h period, after which we measured in vivo protein synthesis using a flooding dose of [3H]phenylalanine. The rates of protein synthesis in several tissues measured after 24 h of feeding were greater than those we reported previously after 6 h of feeding. The acute (within 6 h) stimulation of protein synthesis in visceral and skeletal muscle tissues of neonatal pigs fed milk, colostrum, or formula was primarily influenced by nutrient intake and associated with rapid secretion of insulin. Indirect evidence suggests that intestinal absorption of ingested colostral insulin was minimal. However, the sustained increase in tissue protein synthesis between 6 and 24 h coincided with an increase in circulating insulin-like growth factor I. We found a novel, specific stimulation of skeletal muscle and jejunal protein synthesis in colostrum-fed pigs that can be attributed to some nonnutrient component of colostrum.

  9. Studies of composition and major protein level in milk and colostrum of mares.

    PubMed

    Pecka, Ewa; Dobrzański, Zbigniew; Zachwieja, Andrzej; Szulc, Tadeusz; Czyż, Katarzyna

    2012-02-01

    The aim of the study was to determine the changes in composition and physicochemical features (pH, density, thermostability and acidity) of mare colostrum and milk, and of protein fraction contribution (serum albumin, β-casein, γ-casein, α-lactalbumin, G class immunoglobulins) depending on lactation stage. The research material was colostrum and milk samples from 12 Arabian mares. Colostrum samples were collected within 2 h after parturition and milk samples were collected twice, in the 3rd and 6th weeks of lactation. The level of basic milk components decreased significantly (only lactose content increased) as compared to colostrum. Total bacteria count and somatic cell count decreased significantly with an increase in resistance and urea level. The changes observed were connected to differentiated contribution of particular protein fractions and their relative proportions. Lower levels of γ-casein (P ≤ 0.05), β-casein, serum albumin as well as α-lactalbumin were observed in colostrum as compared to those in milk. Any relationship between lactation stage and β-casein content was observed. Serum albumin and α-lactalbumin content increased in subsequent milkings. The level of G class immunoglobulins decreased significantly and its highest level was noted in colostrum. Any significant differences between the 3rd and 6th lactation weeks were obtained. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

  10. Effect of Milk Proteins on Adhesion of Bacteria to Stainless Steel Surfaces

    PubMed Central

    Barnes, L.-M.; Lo, M. F.; Adams, M. R.; Chamberlain, A. H. L.

    1999-01-01

    Stainless steel coupons were treated with skim milk and subsequently challenged with individual bacterial suspensions of Staphylococcus aureus, Pseudomonas fragi, Escherichia coli, Listeria monocytogenes, and Serratia marcescens. The numbers of attached bacteria were determined by direct epifluorescence microscopy and compared with the attachment levels on clean stainless steel with two different surface finishes. Skim milk was found to reduce adhesion of S. aureus, L. monocytogenes, and S. marcescens. P. fragi and E. coli attached in very small numbers to the clear surfaces, making the effect of any adsorbed protein layer difficult to assess. Individual milk proteins α-casein, β-casein, κ-casein, and α-lactalbumin were also found to reduce the adhesion of S. aureus and L. monocytogenes. The adhesion of bacteria to samples treated with milk dilutions up to 0.001% was investigated. X-ray photoelectron spectroscopy was used to determine the proportion of nitrogen in the adsorbed films. Attached bacterial numbers were inversely related to the relative atomic percentage of nitrogen on the surface. A comparison of two types of stainless steel surface, a 2B and a no. 8 mirror finish, indicated that the difference in these levels of surface roughness did not greatly affect bacterial attachment, and reduction in adhesion to a milk-treated surface was still observed. Cross-linking of adsorbed proteins partially reversed the inhibition of bacterial attachment, indicating that protein chain mobility and steric exclusion may be important in this phenomenon. PMID:10508087

  11. Effect of milk proteins on adhesion of bacteria to stainless steel surfaces.

    PubMed

    Barnes, L M; Lo, M F; Adams, M R; Chamberlain, A H

    1999-10-01

    Stainless steel coupons were treated with skim milk and subsequently challenged with individual bacterial suspensions of Staphylococcus aureus, Pseudomonas fragi, Escherichia coli, Listeria monocytogenes, and Serratia marcescens. The numbers of attached bacteria were determined by direct epifluorescence microscopy and compared with the attachment levels on clean stainless steel with two different surface finishes. Skim milk was found to reduce adhesion of S. aureus, L. monocytogenes, and S. marcescens. P. fragi and E. coli attached in very small numbers to the clear surfaces, making the effect of any adsorbed protein layer difficult to assess. Individual milk proteins alpha-casein, beta-casein, kappa-casein, and alpha-lactalbumin were also found to reduce the adhesion of S. aureus and L. monocytogenes. The adhesion of bacteria to samples treated with milk dilutions up to 0.001% was investigated. X-ray photoelectron spectroscopy was used to determine the proportion of nitrogen in the adsorbed films. Attached bacterial numbers were inversely related to the relative atomic percentage of nitrogen on the surface. A comparison of two types of stainless steel surface, a 2B and a no. 8 mirror finish, indicated that the difference in these levels of surface roughness did not greatly affect bacterial attachment, and reduction in adhesion to a milk-treated surface was still observed. Cross-linking of adsorbed proteins partially reversed the inhibition of bacterial attachment, indicating that protein chain mobility and steric exclusion may be important in this phenomenon.

  12. Human Milk Analyser shows that the lactation period affects protein levels in preterm breastmilk.

    PubMed

    Kreissl, Alexandra; Zwiauer, Valentina; Repa, Andreas; Binder, Christoph; Thanhaeuser, Margarita; Jilma, Bernd; Berger, Angelika; Haiden, Nadja

    2016-06-01

    This study measured the composition of preterm human breastmilk, particularly the protein content, with the MIRIS Human Milk Analyser, compared our results with published values and determined the relationship between protein content and lactation period. We analysed 83 samples of 24-hour pooled human milk from 76 mothers who delivered preterm infants weighing under 1500 g at less than 32 weeks of gestational age. The milk's protein, fat and energy were measured by the MIRIS Human Milk Analyser and compared to reference values. The relationship between protein content and lactation period was quantified. On average, the samples contained 1.1 ± 0.37 g (0.2-2.2 g) of protein, 3.2 ± 0.85 g (range 1.1-6.1 g) of fat, 6.6 ± 0.34 g of lactose (5.5-8.0 g) and 60 ± 11 kcal (39-94 kcal) of energy per 100 mL. The wide variations in macronutrient content were not influenced by the gestational age of the infant and the lactation day results from 70 of the mothers correlated inversely with the protein content (p < 0.0001; r = -0.42). The MIRIS proved useful, but some adjustments are needed. Variations in macronutrients were high in the breastmilk of women who delivered preterm babies and the protein content decreased with lactation. With adjustments, the MIRIS might provide a helpful tool for individualised fortification. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  13. A peptidomic analysis of human milk digestion in the infant stomach reveals protein-specific degradation patterns.

    PubMed

    Dallas, David C; Guerrero, Andrés; Khaldi, Nora; Borghese, Robyn; Bhandari, Aashish; Underwood, Mark A; Lebrilla, Carlito B; German, J Bruce; Barile, Daniela

    2014-06-01

    In vitro digestion of isolated milk proteins results in milk peptides with a variety of actions. However, it remains unclear to what degree protein degradation occurs in vivo in the infant stomach and whether peptides previously annotated for bioactivity are released. This study combined nanospray LC separation with time-of-flight mass spectrometry, comprehensive structural libraries, and informatics to analyze milk from 3 human mothers and the gastric aspirates from their 4- to 12-d-old postpartum infants. Milk from the mothers contained almost 200 distinct peptides, demonstrating enzymatic degradation of milk proteins beginning either during lactation or between milk collection and feeding. In the gastric samples, 649 milk peptides were identified, demonstrating that digestion continues in the infant stomach. Most peptides in both the intact milk and gastric samples were derived from β-casein. The numbers of peptides from β-casein, lactoferrin, α-lactalbumin, lactadherin, κ-casein, serum albumin, bile salt-associated lipase, and xanthine dehydrogenase/oxidase were significantly higher in the gastric samples than in the milk samples (P < 0.05). A total of 603 peptides differed significantly in abundance between milk and gastric samples (P < 0.05). Most of the identified peptides have previously identified biologic activity. Gastric proteolysis occurs in the term infant in the first 2 wk of life, releasing biologically active milk peptides with immunomodulatory and antibacterial properties of clinical relevance to the proximal intestinal tract. Data are available via ProteomeXchange (identifier PXD000688).

  14. Production of two vaccinating recombinant rotavirus proteins in the milk of transgenic rabbits.

    PubMed

    Soler, Eric; Le Saux, Agnès; Guinut, Frédéric; Passet, Bruno; Cohen, Ruxandra; Merle, Christine; Charpilienne, Annie; Fourgeux, Cynthia; Sorel, Véronique; Piriou, Antoine; Schwartz-Cornil, Isabelle; Cohen, Jean; Houdebine, Louis-Marie

    2005-12-01

    Rotaviruses are the main cause of infantile viral gastroenteritis worldwide leading to approximately 500,000 deaths each year mostly in the developing world. For unknown reasons, live attenuated viruses used in classical vaccine strategies were shown to be responsible for intussusception (a bowel obstruction). New strategies allowing production of safe recombinant non-replicating rotavirus candidate vaccine are thus clearly needed. In this study we utilized transgenic rabbit milk as a source of rotavirus antigens. Individual transgenic rabbit lines were able to produce several hundreds of micrograms per ml of secreted recombinant VP2 and VP6 proteins in their milk. Viral proteins expressed in our model were immunogenic and were shown to induce a significant reduction in viral antigen shedding after challenge with virulent rotavirus in the adult mouse model. To our knowledge, this is the first report of transgenic mammal bioreactors allowing the rapid co-production of two recombinant viral proteins in milk to be used as a vaccine.

  15. Origins of the protein synthesis cycle

    NASA Technical Reports Server (NTRS)

    Fox, S. W.

    1981-01-01

    Largely derived from experiments in molecular evolution, a theory of protein synthesis cycles has been constructed. The sequence begins with ordered thermal proteins resulting from the self-sequencing of mixed amino acids. Ordered thermal proteins then aggregate to cell-like structures. When they contained proteinoids sufficiently rich in lysine, the structures were able to synthesize offspring peptides. Since lysine-rich proteinoid (LRP) also catalyzes the polymerization of nucleoside triphosphate to polynucleotides, the same microspheres containing LRP could have synthesized both original cellular proteins and cellular nucleic acids. The LRP within protocells would have provided proximity advantageous for the origin and evolution of the genetic code.

  16. Origins of the protein synthesis cycle

    NASA Technical Reports Server (NTRS)

    Fox, S. W.

    1981-01-01

    Largely derived from experiments in molecular evolution, a theory of protein synthesis cycles has been constructed. The sequence begins with ordered thermal proteins resulting from the self-sequencing of mixed amino acids. Ordered thermal proteins then aggregate to cell-like structures. When they contained proteinoids sufficiently rich in lysine, the structures were able to synthesize offspring peptides. Since lysine-rich proteinoid (LRP) also catalyzes the polymerization of nucleoside triphosphate to polynucleotides, the same microspheres containing LRP could have synthesized both original cellular proteins and cellular nucleic acids. The LRP within protocells would have provided proximity advantageous for the origin and evolution of the genetic code.

  17. Effect of κ-casein B relative content in bulk milk κ-casein on Montasio, Asiago, and Caciotta cheese yield using milk of similar protein composition.

    PubMed

    Bonfatti, V; Cecchinato, A; Di Martino, G; De Marchi, M; Gallo, L; Carnier, P

    2011-02-01

    The aim of this study was to investigate the effect exerted by the relative content of κ-casein (κ-CN) B in bulk milk κ-CN on coagulation properties and cheese yield of 3 Italian cheese varieties (Montasio, Asiago, and Caciotta). Twenty-four cheese-making experiments were carried out in 2 industrial and 1 small-scale dairy plant. Detailed protein composition of bulk milk of 380 herds providing milk to these dairies was analyzed by reversed-phase HPLC. To obtain 2 experimental milks differing in the relative content of κ-CN B in κ-CN, herds were selected on the basis of bulk milk protein composition and relative content of κ-CN genetic variants. Milk was collected and processed separately for the 2 groups of selected herds. A difference of 20% in the relative content of κ-CN B in κ-CN was obtained for the 2 experimental milks for Montasio and a difference of 15% for Asiago and Caciotta. The 2 experimental milks were of similar protein and CN content, casein number, pH, CN composition, and β-CN genetic composition. For each cheese-making trial, amounts of milk, ranging from 2,000 to 6,000kg, were manufactured. Each vat contained milk collected at least from 4 dairy herds. Cheese yield after brining and at the end of the aging was recorded. Milk with a greater proportion of κ-CN B in κ-CN (HIGHB) exhibited similar coagulation properties and greater cheese yield compared with milk with a lower proportion of κ-CN B in κ-CN (LOWB). The increased cheese yield observed for HIGHB when manufacturing Montasio cheese was ascribed to a greater fat content compared with LOWB. The probability of HIGHB giving a cheese yield 5% greater than that of LOWB ranged from 51 to 67% for Montasio cheese, but was less than 21% for Asiago and Caciotta cheeses. Variation in relative content of κ-CN B in κ-CN content did not relevantly affect industrial cheese yield when milks of similar CN composition were processed. An indirect effect due to the increased κ-CN content of κ

  18. The Measurement of Protein in Powdered Milk Products and Infant Formulas: A Review and Recent Developments.

    PubMed

    Elgar, Dave; Evers, Jaap M; Holroyd, Stephen E; Johnson, Richard; Rowan, Angela

    2016-01-01

    Proteins are a key nutritional component of both powdered milk and infant formula types of product, and reliable methods for their determination are important for manufacturing and international trade. In this review, we distinguish between methods used for determining protein quality for nutrition purposes and those used for determining chemically defined protein. The former methods cover the ability of a dietary protein source to meet human nutritional requirements for the indispensable amino acids. The latter are chemical methods for the determination of total protein and can be divided into three broad types: total nitrogen determination, direct protein determination, and indirect protein determination. Current techniques and recent developments in each are reviewed.

  19. Dietary cow's milk protein does not alter the frequency of diabetes in the BB rat.

    PubMed

    Malkani, S; Nompleggi, D; Hansen, J W; Greiner, D L; Mordes, J P; Rossini, A A

    1997-07-01

    One theory of the pathogenesis of IDDM proposes that exposure to cow's milk proteins triggers the disease in genetically susceptible individuals. We tested this hypothesis in the BB/Wor rat model of human IDDM. Diabetes-prone (DP) BB/Wor rats spontaneously develop IDDM. Coisogenic diabetes-resistant (DR) BB/Wor rats do not develop diabetes spontaneously, but IDDM can readily be induced by treatment with polyinosinic:polycytidylic acid and depletion of RT6+ T-cells. Pregnant BB/Wor rats were fed one of four experimental diets or a standard Purina commercial rat chow (5010) that was certified to be free of cow's milk protein. Offspring were maintained on the maternal diet after weaning. DP-BB/Wor rats, fed either of two experimental diets based on hydrolyzed casein and free of intact milk protein (Nutramigen or D11236), developed diabetes at only half the rate of animals fed Purina 5010 chow. Neither the addition of bovine serum albumin (BSA) to Nutramigen nor the substitution of total milk protein for the hydrolyzed casein in the D11236 diet increased the frequency of spontaneous diabetes. In contrast, there was no relationship between diet and susceptibility of DR-BB/Wor rats to IDDM induction. However, the methods used to induce IDDM in DR-BB/Wor animals were found to induce antibodies against BSA. We conclude the following: 1) Dietary modification can reduce spontaneous IDDM expression in DP-BB/Wor rats, but the agent of protection is not elimination of cow's milk protein. 2) The addition of BSA or intact milk protein does not abrogate the effectiveness of a protective diet. 3) The genetic susceptibility of the DR-BB/Wor rat to autoimmune diabetes is unaffected by any of the tested diets, but a role of anti-BSA-like autoreactivity in IDDM expression cannot be excluded.

  20. Protein conformational modifications and kinetics of water-protein interactions in milk protein concentrate powder upon aging: effect on solubility.

    PubMed

    Haque, Enamul; Bhandari, Bhesh R; Gidley, Michael J; Deeth, Hilton C; Møller, Sandie M; Whittaker, Andrew K

    2010-07-14

    Protein conformational modifications and water-protein interactions are two major factors believed to induce instability of protein and eventually affect the solubility of milk protein concentrate (MPC) powder. To test these hypotheses, MPC was stored at different water activities (a(w) 0.0-0.85) and temperatures (25 and 45 degrees C) for up to 12 weeks. Samples were examined periodically to determine solubility, change in protein conformation by Fourier transform infrared (FTIR) spectroscopy and principal component analysis (PCA), and water status (interaction of water with the protein molecule/surface) by measuring the transverse relaxation time (T(2)) with proton nuclear magnetic resonance ((1)H NMR). The solubility of MPC decreased significantly with aging, and this process was enhanced by increasing water activity (a(w)) and storage temperature. Minor changes in protein secondary structure were observed with FTIR, which indicated some degree of unfolding of protein molecules. PCA of the FTIR data was able to discriminate samples according to moisture content and storage period. Partial least-squares (PLS) analysis showed some correlation between FTIR spectral feature and solubility. The NMR T(2) results indicated the presence of three distinct populations of water molecules, and the proton signal intensity and T(2) values of proton fractions varied with storage conditions (humidity, temperature) and aging. Results suggest that protein/protein interactions may be initiated by unfolding of protein molecules that eventually affects solubility.

  1. Proteomic Profiling Comparing the Effects of Different Heat Treatments on Camel (Camelus dromedarius) Milk Whey Proteins

    PubMed Central

    Benabdelkamel, Hicham; Masood, Afshan; Alanazi, Ibrahim O.; Alzahrani, Dunia A.; Alrabiah, Deema K.; AlYahya, Sami A.; Alfadda, Assim A.

    2017-01-01

    Camel milk is consumed in the Middle East because of its high nutritional value. Traditional heating methods and the duration of heating affect the protein content and nutritional quality of the milk. We examined the denaturation of whey proteins in camel milk by assessing the effects of temperature on the whey protein profile at room temperature (RT), moderate heating at 63 °C, and at 98 °C, for 1 h. The qualitative and quantitative variations in the whey proteins before and after heat treatments were determined using quantitative 2D-difference in gel electrophoresis (DIGE)-mass spectrometry. Qualitative gel image analysis revealed a similar spot distribution between samples at RT and those heated at 63 °C, while the spot distribution between RT and samples heated at 98 °C differed. One hundred sixteen protein spots were determined to be significantly different (p < 0.05 and a fold change of ≥1.2) between the non-heated and heated milk samples. Eighty protein spots were decreased in common in both the heat-treated samples and an additional 25 spots were further decreased in the 98 °C sample. The proteins with decreased abundance included serum albumin, lactadherin, fibrinogen β and γ chain, lactotransferrin, active receptor type-2A, arginase-1, glutathione peroxidase-1 and, thiopurine S, etc. Eight protein spots were increased in common to both the samples when compared to RT and included α-lactalbumin, a glycosylation-dependent cell adhesion molecule. Whey proteins present in camel milk were less affected by heating at 63 °C than at 98 °C. This experimental study showed that denaturation increased significantly as the temperature increased from 63 to 98 °C. PMID:28350354

  2. Proteomic Profiling Comparing the Effects of Different Heat Treatments on Camel (Camelus dromedarius) Milk Whey Proteins.

    PubMed

    Benabdelkamel, Hicham; Masood, Afshan; Alanazi, Ibrahim O; Alzahrani, Dunia A; Alrabiah, Deema K; AlYahya, Sami A; Alfadda, Assim A

    2017-03-28

    Camel milk is consumed in the Middle East because of its high nutritional value. Traditional heating methods and the duration of heating affect the protein content and nutritional quality of the milk. We examined the denaturation of whey proteins in camel milk by assessing the effects of temperature on the whey protein profile at room temperature (RT), moderate heating at 63 °C, and at 98 °C, for 1 h. The qualitative and quantitative variations in the whey proteins before and after heat treatments were determined using quantitative 2D-difference in gel electrophoresis (DIGE)-mass spectrometry. Qualitative gel image analysis revealed a similar spot distribution between samples at RT and those heated at 63 °C, while the spot distribution between RT and samples heated at 98 °C differed. One hundred sixteen protein spots were determined to be significantly different (p < 0.05 and a fold change of ≥1.2) between the non-heated and heated milk samples. Eighty protein spots were decreased in common in both the heat-treated samples and an additional 25 spots were further decreased in the 98 °C sample. The proteins with decreased abundance included serum albumin, lactadherin, fibrinogen β and γ chain, lactotransferrin, active receptor type-2A, arginase-1, glutathione peroxidase-1 and, thiopurine S, etc. Eight protein spots were increased in common to both the samples when compared to RT and included α-lactalbumin, a glycosylation-dependent cell adhesion molecule. Whey proteins present in camel milk were less affected by heating at 63 °C than at 98 °C. This experimental study showed that denaturation increased significantly as the temperature increased from 63 to 98 °C.

  3. The Effect of UV-C Pasteurization on Bacteriostatic Properties and Immunological Proteins of Donor Human Milk

    PubMed Central

    Christen, Lukas; Lai, Ching Tat; Hartmann, Ben; Hartmann, Peter E.; Geddes, Donna T.

    2013-01-01

    Background Human milk possesses bacteriostatic properties, largely due to the presence of immunological proteins. Heat treatments such as Holder pasteurization reduce the concentration of immunological proteins in human milk and consequently increase the bacterial growth rate. This study investigated the bacterial growth rate and the immunological protein concentration of ultraviolet (UV-C) irradiated, Holder pasteurized and untreated human milk. Methods Samples (n=10) of untreated, Holder pasteurized and UV-C irradiated human milk were inoculated with E. coli and S. aureus and the growth rate over 2 hours incubation time at 37°C was observed. Additionally, the concentration of sIgA, lactoferrin and lysozyme of untreated and treated human milk was analyzed. Results The bacterial growth rate of untreated and UV-C irradiated human milk was not significantly different. The bacterial growth rate of Holder pasteurized human milk was double compared to untreated human milk (p<0.001). The retention of sIgA, lactoferrin and lysozyme after UV-C irradiation was 89%, 87%, and 75% respectively, which were higher than Holder treated with 49%, 9%, and 41% respectively. Conclusion UV-C irradiation of human milk preserves significantly higher levels of immunological proteins than Holder pasteurization, resulting in bacteriostatic properties similar to those of untreated human milk. PMID:24376898

  4. Genome-wide association mapping for milk fat composition and fine mapping of a QTL for de novo synthesis of milk fatty acids on bovine chromosome 13.

    PubMed

    Olsen, Hanne Gro; Knutsen, Tim Martin; Kohler, Achim; Svendsen, Morten; Gidskehaug, Lars; Grove, Harald; Nome, Torfinn; Sodeland, Marte; Sundsaasen, Kristil Kindem; Kent, Matthew Peter; Martens, Harald; Lien, Sigbjørn

    2017-02-13

    Bovine milk is widely regarded as a nutritious food source for humans, although the effects of individual fatty acids on human health is a subject of debate. Based on the assumption that genomic selection offers potential to improve milk fat composition, there is strong interest to understand more about the genetic factors that influence the biosynthesis of bovine milk and the molecular mechanisms that regulate milk fat synthesis and secretion. For this reason, the work reported here aimed at identifying genetic variants that affect milk fatty acid composition in Norwegian Red cattle. Milk fatty acid composition was predicted from the nation-wide recording scheme using Fourier transform infrared spectroscopy data and applied to estimate heritabilities for 36 individual and combined fatty acid traits. The recordings were used to generate daughter yield deviations that were first applied in a genome-wide association (GWAS) study with 17,343 markers to identify quantitative trait loci (QTL) affecting fatty acid composition, and next on high-density and sequence-level datasets to fine-map the most significant QTL on BTA13 (BTA for Bos taurus chromosome). The initial GWAS revealed 200 significant associations, with the strongest signals on BTA1, 13 and 15. The BTA13 QTL highlighted a strong functional candidate gene for de novo synthesis of short- and medium-chained saturated fatty acids; acyl-CoA synthetase short-chain family member 2. However, subsequent fine-mapping using single nucleotide polymorphisms (SNPs) from a high-density chip and variants detected by resequencing showed that the effect was more likely caused by a second nearby gene; nuclear receptor coactivator 6 (NCOA6). These findings were confirmed with results from haplotype studies. NCOA6 is a nuclear receptor that interacts with transcription factors such as PPARγ, which is a major regulator of bovine milk fat synthesis. An initial GWAS revealed a highly significant QTL for de novo-synthesized fatty

  5. Protein feeding pattern, casein feeding, or milk-soluble protein feeding did not change the evolution of body composition during a short-term weight loss program.

    PubMed

    Adechian, Solange; Balage, Michèle; Remond, Didier; Migné, Carole; Quignard-Boulangé, Annie; Marset-Baglieri, Agnès; Rousset, Sylvie; Boirie, Yves; Gaudichon, Claire; Dardevet, Dominique; Mosoni, Laurent

    2012-10-15

    Studies have shown that timing of protein intake, leucine content, and speed of digestion significantly affect postprandial protein utilization. Our aim was to determine if one can spare lean body mass during energy restriction by varying the quality and the timing of protein intake. Obese volunteers followed a 6-wk restricted energy diet. Four groups were compared: casein pulse, casein spread, milk-soluble protein (MSP, = whey) pulse, and MSP spread (n = 10-11 per group). In casein groups, caseins were the only protein source; it was MSP in MSP groups. Proteins were distributed in four meals per day in the proportion 8:80:4:8% in the pulse groups; it was 25:25:25:25% in the spread groups. We measured weight, body composition, nitrogen balance, 3-methylhistidine excretion, perception of hunger, plasma parameters, adipose tissue metabolism, and whole body protein metabolism. Volunteers lost 7.5 ± 0.4 kg of weight, 5.1 ± 0.2 kg of fat, and 2.2 ± 0.2 kg of lean mass, with no difference between groups. In adipose tissue, cell size and mRNA expression of various genes were reduced with no difference between groups. Hunger perception was also never different between groups. In the last week, due to a higher inhibition of protein degradation and despite a lower stimulation of protein synthesis, postprandial balance between whole body protein synthesis and degradation was better with caseins than with MSP. It seems likely that the positive effect of caseins on protein balance occurred only at the end of the experiment.

  6. Proteomic profiling of camel and cow milk proteins under heat treatment.

    PubMed

    Felfoul, Imène; Jardin, Julien; Gaucheron, Frédéric; Attia, Hamadi; Ayadi, M A

    2017-02-01

    Cow and camel milk proteins before and after heat treatment at 80°C for 60min were identified using LC/MS and LC-MS/MS following monodimensional electrophoresis. The database used for the identification of camel and cow proteins was set from http://www.uniprot.org/. The obtained results showed that, after heating, camel milk at 80°C for 60min, camel α-lactalbumin (α-la) and peptidoglycan recognition protein (PGRP) were not detected while camel serum albumin (CSA) was significantly diminished. When heating cow milk at 80°C for 60min, α-lactalbumin (α-la) and β-lactoglobulin (β-lg) were not significantly detected. Moreover, 19 protein bands from SDS-PAGE were analyzed and a total of 45 different proteins were identified by LC-MS/MS. Casein fractions were kept intact under a heat treatment of 80°C during 60min of both camel and cow milks. Camel and bovine whey proteins were affected by a heat treatment of 80°C for 60min. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Effects of a supra-sustained gelatin-milk protein diet compared with (supra-)sustained milk protein diets on body-weight loss.

    PubMed

    Hochstenbach-Waelen, Ananda; Soenen, Stijn; Westerterp, Klaas R; Westerterp-Plantenga, Margriet S

    2011-05-01

    Diets higher in protein content result in increased satiety and energy expenditure. In the short term, gelatin showed stronger hunger suppression and less subsequent energy intake compared with other proteins. The present study investigated whether a supra-sustained gelatin-milk protein (GMP) diet promotes weight loss compared with a sustained milk protein (SMP) diet and a supra-sustained milk protein (SSMP) diet during an 8-week diet period. A total of seventy-two healthy subjects (31·2 (sd 4·8) kg/m2; 43 (sd 10) years) followed one of the three diets in a subject-specific amount: SMP, SSMP or GMP diet. During weeks 1-4, energy intake was 100 % of individual energy requirement: 10, 40 and 50 % of energy (En %) as protein, fat and carbohydrate, respectively (SMP diet), and 20, 30 and 50 En % as protein, fat and carbohydrate, respectively (SSMP diet or GMP diet). During weeks 5-8, energy intake was 33 % of individual energy requirement: 30, 35 and 35 En % as protein, fat and carbohydrate, respectively (SMP diet), and 60, 5 and 35 En % as protein, fat and carbohydrate, respectively (SSMP diet or GMP diet). Thus, absolute protein intake was kept constant throughout per subject. Significant decreases in BMI (P < 0·0001) were similar between the GMP ( - 1·7 (sd 0·5) kg/m2) and the SMP ( - 2·1 (sd 0·8) kg/m2) and SSMP ( - 1·6 (sd 0·5) kg/m2) diets. Decreases in fat-free mass (FFM), fat mass (FM) and FM %, and increases in FFM % were similar between the GMP and both control diets. Changes in RQ differed (P < 0·05) between the GMP ( - 0·01 (sd 0·06)) and SSMP ( - 0·04 (sd 0·04)) diets. Changes in HDL concentrations differed (P < 0·05) between the GMP ( - 0·21 (sd 0·18) mmol/l) and the SMP and SSMP diets ( - 0·08 (sd 0·18) mmol/l and - 0·09 (sd 0·26) mmol/l, respectively). In conclusion, a gelatin-milk protein diet does not induce more beneficial effects during an 8-week weight-loss period compared with a SMP or

  8. IDENTIFICATION OF PROTEIN FRACTIONS OF MILK COWS CASEIN COMPLEX.

    PubMed

    Iukalo, A V

    2015-01-01

    To date, dozens of biologically active peptides formed during proteolysis of casein fractions have been discovered. The use of these peptides is closely related to the necessity of their rapid identification. The aim of this work was the development of an electrophoresis system for rapid identification of individual fractions in serial studies and the separation of the milk casein complex. Considering the abnormal nature of the interaction of caseins with the sodium dodecyl sulfate and similar values of their molecular masses, the anode electrophoresis system in a homogeneous polyacrylamide gel was taken as a basis. Caseins, in this system, are separated according to their charge and located on the electrophoregram in accordance with the modern classification. Urea was used as a disaggregating agent in gel. It was shown that the use of Studier type apparatus for electrophoresis with changeable dimensions of electrophoretic chamber significantly reduces (to 45 min) the time for identification of casein fractions. This method may be useful for rapid identification of casein fractions, as well as for rapid analysis of natural milk and milk products.

  9. Effect of fat and protein content of milk from individual cows on the specificity rates of antibiotic residue screening tests.

    PubMed

    Andrew, S M

    2000-12-01

    The effect of high concentrations of milk protein and milk fat on the specificity rates of several antibiotic residue screening tests was evaluated in this study. Milk was sampled from 60 Jersey and 30 Holstein cows at one milking and analyzed for beta-lactam residues using four antibiotic residue screening tests. Cows selected were not treated with an antibiotic for at least 30 d prior to sample collection, and milk was visibly normal. Before milk collection, quarter foremilk was aseptically sampled for mastitis pathogen analysis. Milk subsamples were analyzed for fat and protein contents, and somatic cell counts (SCC). Ten Jersey and four Holstein cows were infected with one or more mastitis pathogens. Concentrations of milk fat (4.78 vs. 3.39%) and protein (3.81 vs. 3.00%) were greater for Jersey cows compared with Holstein cows. Milk SCC averaged 148,000/ml and did not differ by breed. The specificity rates were greater than 0.9 for three of the four screening tests. Across breeds, there was an increased probability of a false-positive outcome for the Penzyme test (Coulter Food Science, Milwaukee, WI)), with increased milk protein content and decreased SCC. Increased milk fat content was associated with an increased probability of false-positive outcomes for the CITE Snap test (IDEXX Laboratories, Inc., Westbrook, ME). High concentrations of milk protein and milk fat can adversely affect antibiotic residue test performance, but the degree of the effect is dependent upon the analytical method of the screening test.

  10. Using Confocal Laser Scanning Microscopy to Probe the Milk Fat Globule Membrane and Associated Proteins

    PubMed Central

    Gallier, Sophie; Gragson, Derek; JiméNez-Flores, Rafael; Everett, David

    2010-01-01

    The bovine milk fat globule membrane (MFGM) is an important, biologically relevant membrane due to its functional and health properties. Its composition has been thoroughly studied but its structure, especially the lateral organization of its components, still remains unclear. We have used confocal laser scanning microscopy (CLSM) to investigate the surface structure of the MFGM in globules with different degree of processing using two types of fluorescently-labeled phospholipid probes and a protein dye. Using this technique, we have observed heterogeneities in the distribution of MFGM lipids and proteins relating to the processing and size of the globules. The effect of pre-treating the milk (centrifugation, pasteurization-homogenization and churning) was studied by double-staining the surface of the milk fat globules, followed by observation using CLSM, and by determining the phospholipid profile of raw milk, raw cream, processed milk and buttermilk powder. Our findings agree with other techniques by showing that the composition of the MFGM changes with processing through the loss of phospholipids and the adsorption of caseins and whey proteins onto the surface. PMID:20218614

  11. Effect of two pasteurization methods on the protein content of human milk.

    PubMed

    Baro, Cristina; Giribaldi, Marzia; Arslanoglu, Sertac; Giuffrida, Maria Gabriella; Dellavalle, Giuseppina; Conti, Amedeo; Tonetto, Paola; Biasini, Augusto; Coscia, Alessandra; Fabris, Claudio; Moro, Guido Eugenio; Cavallarin, Laura; Bertino, Enrico

    2011-06-01

    The Holder method is the recommended pasteurization method for human milk banks, as it ensures the microbiological safety of human milk (HM). The loss of some biologically active milk components, due to the heat treatment, is a main limit to the diffusion of donor HM. High-temperature short-time (HTST) pasteurization may be an alternative to maintain the nutritional and immunological quality of HM. The aim of the present study was to compare the impact of Holder and HTST pasteurization on the HM protein profile. The protein patterns of HTST-treated milk and raw milk were similar. The Holder method modified bile salt-stimulated lipase, lactoferrin and components of the immune system. The HTST method preserved the integrity of bile salt-stimulated lipase, lactoferrin and, to some extent, of IgAs. Holder pasteurization decreased the amount of bile salt-stimulated lipase and inactivated the remaining molecules, while the HTST method did not alter its activity. Pasteurization increased the bioavailable lysine quantity. HTST pasteurization seems to better retain the protein profile and some of the key active components of donor HM.

  12. Potential clinical applications of multi-functional milk proteins and peptides in cancer management.

    PubMed

    Chen, H Y F; Mollstedt, O; Tsai, Men-Hwei; Kreider, R B

    2014-01-01

    The progression of cancer involves multiple changes that alter intracellular signaling to promote cell proliferation. Subsequent remodeling of the tumor microenvironment enhances metastasis by manipulating the immune system. Research in the past decade has shown that milk proteins and peptides are often multi-functional, exerting activities such as anti-microbial, immunomodulatory, cancer cell apoptosis, anti-metastasis, and antioxidant effects. Several milk-derived biologics, such as HAMLET (human α-lactalbumin made lethal to tumor cells) and the human recombinant form of lactoferrin, already demonstrated promising results in clinical trials. Lactoferricin peptide analogs are in early clinical development as antimicrobial agents and cancer immunotherapies. In addition, milk proteins and peptides are well tolerated and many exhibit oral bioavailability; thus they may complement standard therapies to boost overall success in cancer treatments. Lactoferrin, colostrum, and specific milk-derived peptide fractions are currently being developed as clinical nutrition for cancer prevention and chemotherapy protection. This review highlights the potential applications of milk proteins and peptides as pharmaceutical drug candidates and clinical nutrition in the overall management of cancer.

  13. Manufacture of modified milk protein concentrate utilizing injection of carbon dioxide.

    PubMed

    Marella, Chenchaiah; Salunke, P; Biswas, A C; Kommineni, A; Metzger, L E

    2015-06-01

    Dried milk protein concentrate is produced from skim milk using a combination of processes such as ultrafiltration (UF), evaporation or nanofiltration, and spray drying. It is well established that dried milk protein concentrate (MPC) that contains 80% (MPC80) and greater protein content (relative to dry matter) can lose solubility during storage as a result of protein-protein interactions and formation of insoluble complexes. Previous studies have shown that partial replacement of calcium with sodium improves MPC80 functionality and prevents the loss in solubility during storage. Those studies have used pH adjustment with the addition of acids, addition of monovalent salts, or ion exchange treatment of UF retentate. The objective of this study was to use carbon dioxide to produce MPC80 with improved functionality. In this study, reduced-calcium MPC80 (RCMPC) was produced from skim milk that was subjected to injection of 2,200 ppm of CO2 before UF, along with additional CO2 injection at a flow rate of 1.5 to 2 L/min during UF. A control MPC80 (CtrlMPC) was also produced from the same lot of skim milk without injection of CO2. The above processes were replicated 3 times, using different lots of skim milk for each replication. All the UF retentates were spray dried using a pilot-scale dryer. Skim milk and UF retentates were tested for ζ-potential (net negative charge), particle size, and viscosity. All the MPC were stored at room (22±1°C) and elevated (40°C) temperatures for 6 mo. Solubility was measured by dissolving the dried MPC in water at 22°C and at 10°C (cold solubility). Injection of CO2 and the resultant solubilization of calcium phosphate had a significant effect on UF performance, resulting in 10 and 20% loss in initial and average flux, respectively. Processing of skim milk with injection of CO2 also resulted in higher irreversible fouling resistances. Compared with control, the reduced-calcium MPC had 28 and 34% less ash and calcium, respectively

  14. EFFECT OF ABOMASAL INFUSION OF FORMATE ON MILK PROTEIN OF COWS FED A METHIONINE-DEFICIENT DIET

    USDA-ARS?s Scientific Manuscript database

    Carbon from formate is transferred to the methyl group of Met in milk protein via the folate cycle. We hypothesized that post-ruminal formate infusion to dairy cows would partially compensate for dietary Met deficiency and enhance milk protein production. Six midlactation cows were used in a balance...

  15. Filter-aided sample preparation with dimethyl labeling to identify and quantify milk fat globule membrane proteins.

    PubMed

    Lu, Jing; Boeren, S; de Vries, S C; van Valenberg, H J F; Vervoort, J; Hettinga, K

    2011-12-10

    Bovine milk is a major nutrient source in many countries and it is produced at an industrial scale. Milk is a complex mixture of proteins, fats, carbohydrates, vitamins and minerals. The composition of the bovine milk samples can vary depending on the genetic makeup of the bovine species as well as environmental factors. It is therefore important to study the qualitative and quantitative differences of bovine milk samples. Proteins in milk can be present in casein micelles, in the serum (the water soluble fraction) or in fat globules. These fat globules have a double membrane layer with proteins being bound to or being incapsulated in the membrane layer. The identification and molecular composition of the milk proteins have gained increased interest in recent years. Proteomic techniques make it now possible to identify up to many thousands of proteins in one sample, however quantification of proteins is as yet not straightforward. We analyzed the proteins of the milk fat globule membrane using dimethyl labeling methods combined with a filter-aided sample preparation protocol. Using these methods, it is now possible to quantitatively study the detailed protein composition of many milk samples in a short period of time. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Mapping quantitative trait loci for milk production and genetic polymorphisms of milk proteins in dairy sheep

    PubMed Central

    2005-01-01

    In this paper, we present recent advances in the molecular dissection of complex traits in dairy sheep and discuss their possible impact on breeding schemes. In the first step, we review the literature data on genetic polymorphisms and the effects of sheep αs1-casein and β-lactoglobulin loci. It is concluded that the results are rather inconsistent and cannot be used in dairy sheep selection. In a second step, we describe the strategy implemented in France, Italy and Spain taking advantage of the genetic maps for QTL detection. These studies were part of a European project, called "genesheepsafety", which investigated both milk production and functional traits. Preliminary QTL results are presented for production traits. PMID:15601591

  17. Short communication: Effects of lysolecithin on milk fat synthesis and milk fatty acid profile of cows fed diets differing in fiber and unsaturated fatty acid concentration.

    PubMed

    Rico, D E; Ying, Y; Harvatine, K J

    2017-09-13

    Thirteen multiparous Holstein cows were used in a crossover design that tested the effect of lysolecithin in diets differing in neutral detergent fiber (NDF) and unsaturated fatty acid (FA) concentrations. Experimental periods were 20 d in length and included two 10-d phases. A standard fiber and lower fat diet was fed the first 10 d (30.5% NDF, no added oil, lower-risk phase) and a lower NDF and higher oil diet was fed during the second 10 d (29.0% NDF and 2% oil from whole soybeans and soybean oil, high-risk phase). Treatments were control and 10 g/d of lysolecithin (LYSO) extended in a ground corn carrier. Milk was sampled on d 0, 5, and 10 of each phase for determination of fat and protein concentration and FA profile. We found no effect of treatment or treatment by time interaction for dry matter intake, milk yield, or milk protein concentration. A treatment by time interaction was observed for milk fat concentration and yield. Milk fat concentration was higher in LYSO on d 5 of the lower-risk phase, but decreased progressively in both treatments during the high-risk phase. Milk fat yield was not different among treatments during the lower-risk phase, but was lower in LYSO on d 15 and tended to be lower on d 20 during the high-risk phase. Concentrations of milk de novo FA decreased and preformed FA increased during the high-risk phase, but we found no effect of treatment or treatment by time interactions. We noted an effect of time, but no treatment or treatment by time interactions for milk trans FA isomers. Briefly, trans-11 C18:1 and cis-9,trans-11 conjugated linoleic acid progressively decreased as trans-10 C18:1 and trans-10,cis-12 conjugated linoleic acid progressively increased during the high-risk phase. The LYSO increased milk fat concentration when feeding a higher fiber and lower unsaturated FA diet, but decreased milk fat yield when feeding a lower fiber and higher unsaturated FA diet, although biohydrogenation pathways and capacity did not appear

  18. SPECIFIC PROTEIN SYNTHESIS IN CELLULAR DIFFERENTIATION

    PubMed Central

    Paul, M.; Goldsmith, M. R.; Hunsley, J. R.; Kafatos, F. C.

    1972-01-01

    Silkmoth follicles, arranged in a precise developmental sequence within the ovariole, yield pure and uniform populations of follicular epithelial cells highly differentiated for synthesis of the proteinaceous eggshell (chorion). These cells can be maintained and labeled efficiently in organ culture; their in vitro (and cell free) protein synthetic activity reflects their activity in vivo. During differentiation the cells undergo dramatic changes in protein synthesis. For 2 days the cells are devoted almost exclusively to production of distinctive chorion proteins of low molecular weight and of unusual amino acid composition. Each protein has its own characteristic developmental kinetics of synthesis. Each is synthesized as a separate polypeptide, apparently on monocistronic messenger RNA (mRNA), and thus reflects the expression of a distinct gene. The rapid changes in this tissue do not result from corresponding changes in translational efficiency. Thus, the peptide chain elongation rate is comparable for chorion and for proteins synthesized at earlier developmental stages (1.3–1.9 amino acids/sec); moreover, the spacing of ribosomes on chorion mRNA (30–37 codons per ribosome) is similar to that encountered in other eukaryotic systems. PMID:4656706

  19. Application of mass spectrometry for the detection of glycation and oxidation products in milk proteins.

    PubMed

    Meltretter, Jasmin; Pischetsrieder, Monika

    2008-04-01

    Protein mass spectometry techniques, such as electrospray ionization mass spectrometry or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), are effective methods to screen for protein modifications derived from the Maillard reaction. The analysis of the intact proteins reveals the major modification, most commonly the Amadori product, whereas partial enzymatic hydrolysis prior to mass spectrometry additionally allows the detection of minor adducts. Therefore, a mass spectrometric method was developed for the analysis of whey protein modifications occurring during heat treatment. The two main whey proteins, alpha-lactalbumin and beta-lactoglobulin, were incubated with lactose in a milk model and modifications were recorded using MALDI-TOF-MS. The analysis of the intact proteins revealed protein species with 0-4 lactulosyl residues. Partial enzymatic hydrolysis with endoproteinase AspN prior to mass spectrometric analysis enabled the detection of further modifications and their localization in the amino acid sequence. Detected modifications were lactulosyllysine, N epsilon-(carboxymethyl)lysine, lysine aldehyde, methionine sulfoxide, cyclization of N-terminal glutamic acid to a pyrrolidone, and oxidation of cysteine or tryptophan. Protein modifications in heated milk and commercially available dairy products can be analyzed after the separation of the milk proteins using one-dimensional SDS-PAGE.

  20. Cell Surface Properties of Lactococcus lactis Reveal Milk Protein Binding Specifically Evolved in Dairy Isolates.

    PubMed

    Tarazanova, Mariya; Huppertz, Thom; Beerthuyzen, Marke; van Schalkwijk, Saskia; Janssen, Patrick; Wels, Michiel; Kok, Jan; Bachmann, Herwig

    2017-01-01

    Surface properties of bacteria are determined by the molecular composition of the cell wall and they are important for interactions of cells with their environment. Well-known examples of bacterial interactions with surfaces are biofilm formation and the fermentation of solid materials like food and feed. Lactococcus lactis is broadly used for the fermentation of cheese and buttermilk and it is primarily isolated from either plant material or the dairy environment. In this study, we characterized surface hydrophobicity, charge, emulsification properties, and the attachment to milk proteins of 55 L. lactis strains in stationary and exponential growth phases. The attachment to milk protein was assessed through a newly developed flow cytometry-based protocol. Besides finding a high degree of biodiversity, phenotype-genotype matching allowed the identification of candidate genes involved in the modification of the cell surface. Overexpression and gene deletion analysis allowed to verify the predictions for three identified proteins that altered surface hydrophobicity and attachment of milk proteins. The data also showed that lactococci isolated from a dairy environment bind higher amounts of milk proteins when compared to plant isolates. It remains to be determined whether the alteration of surface properties also has potential to alter starter culture functionalities.

  1. Carbohydrate-protein intake and recovery from endurance exercise: is chocolate milk the answer?

    PubMed

    Saunders, Michael John

    2011-07-01

    Postexercise carbohydrate intake has been shown to augment recovery from heavy aerobic exercise. The effects of carbohydrate and protein coingestion (CHO + Pro) have been investigated more recently, including the potential influences of chocolate milk. Some studies report that CHO + Pro beverages (including chocolate milk) enhance subsequent exercise performance versus carbohydrate beverages, although others have reported no positive effects. The putative efficacy of CHO + Pro could be due to influences on glycogen resynthesis, protein turnover, rehydration, attenuations in muscle disruption, or perhaps a combination of these factors. However, there are inconsistencies in the literature regarding the effects of CHO + Pro on these factors, and the mechanisms explaining potential influences of CHO + Pro are not defined clearly. Further research is required to address these limitations, but present evidence suggests that CHO + Pro beverages may positively influence recovery under some exercise conditions, and chocolate milk is likely a good recovery beverage for lactose-tolerant endurance athletes.

  2. Affinity labeling of protein synthesis factors

    SciTech Connect

    Anthony, D.D.; Dever, T.E.; Abramson, R.D.; Lobur, M.; Merrick, W.C.

    1986-05-01

    The authors laboratory is interested in determining those eukaryotic protein synthesis factors which interact with nucleotides and mRNA. To study the binding the authors have used the nucleotides, their analogs, and mRNA analogs as listed below: (1) UV cross-linking with normal (/sup 32/P)XTP; (2) Oxidized GTP; (3) 3'p-azido benzoyl GDP (GTP); (4) 5'p-fluoro sulfonyl benzoyl guanosine; (5) 5'p-fluoro sulfonyl benzoyl adenosine; (6) oxidized mRNA. Currently, they are continuing their efforts to specifically label the proteins, and they are also trying to isolate a single labeled tryptic peptide from the proteins.

  3. Electrolyte-free milk protein solution influences sodium and fluid retention in rats.

    PubMed

    Ishihara, Kengo; Kato, Yoshiho; Usami, Ayako; Yamada, Mari; Yamamura, Asuka; Fushiki, Tohru; Seyama, Yousuke

    2013-01-01

    Milk is an effective post-exercise rehydration drink that maintains the net positive fluid balance. However, it is unclear which components are responsible for this effect. We assessed the effect of milk protein solution (MPS) obtained by dialysis on body fluid retention. Milk, MPS, milk electrolyte solution (MES), sports drink and water were administered to male Wistar rats at a dose of 6 ml/rat after treadmill exercise. Total body fluid retention was assessed by urine volume 4 h after administration of hydrating liquids. The rate of gastric emptying was evaluated by a tracer method using (13)C-labelled acetate. Plasma osmolality, Na and K levels, and urinary Na and K were measured by HPLC and osmometry, respectively. The gastric emptying rate was not delayed by MPS. During 4 h of rehydration, cumulative urine volumes differed significantly between treatment groups (P < 0·05) with 4·9, 2·2 and 3·4 ml from water-, milk- and MPS-fed rats, respectively. Thus, MPS elicited 50 % of the total body fluid retention of milk. Plasma aldosterone levels were significantly higher in MPS- and milk-fed rats compared with water-fed rats. Plasma osmolality was maintained at higher levels in MPS-fed rats than in water- and MES-fed rats (P < 0·05). Cumulative urine Na excretion was also suppressed in the milk- and MPS-fed groups compared with the MES-fed group. Our results demonstrate that MPS obtained by dialysis clearly affects net body water balance without affecting gastric emptying after exercise. This effect was attributed to retention of Na and water, and maintenance of plasma osmolality.

  4. Haematopoietic stem cells require a highly regulated protein synthesis rate.

    PubMed

    Signer, Robert A J; Magee, Jeffrey A; Salic, Adrian; Morrison, Sean J

    2014-05-01

    Many aspects of cellular physiology remain unstudied in somatic stem cells, for example, there are almost no data on protein synthesis in any somatic stem cell. Here we set out to compare protein synthesis in haematopoietic stem cells (HSCs) and restricted haematopoietic progenitors. We found that the amount of protein synthesized per hour in HSCs in vivo was lower than in most other haematopoietic cells, even if we controlled for differences in cell cycle status or forced HSCs to undergo self-renewing divisions. Reduced ribosome function in Rpl24(Bst/+) mice further reduced protein synthesis in HSCs and impaired HSC function. Pten deletion increased protein synthesis in HSCs but also reduced HSC function. Rpl24(Bst/+) cell-autonomously rescued the effects of Pten deletion in HSCs; blocking the increase in protein synthesis, restoring HSC function, and delaying leukaemogenesis. Pten deficiency thus depletes HSCs and promotes leukaemia partly by increasing protein synthesis. Either increased or decreased protein synthesis impairs HSC function.

  5. Effect of protein : energy ratio in milk replacers on growth performance of goat kids.

    PubMed

    Yeom, K-H; Van Trierum, G; Hache, A; Lee, K-W; Beynen, A C

    2002-06-01

    Two separate experiments were carried out to establish the effects of the protein:energy ratio in milk replacers on growth performance, plasma lipid concentrations and fatty acid composition in adipose tissue of male goat kids. In the first experiment there were 211 3-day- old goat kids and in the second experiment there were 121 kids aged 3-7 days. The animals were fed ad libitum for a period of 4 weeks on milk replacers containing either 11.5 or 9.5 g crude protein/MJ metabolizable energy. In essence, protein was exchanged with fat on a weight basis. Milk concentrations were increased from 160 to 190 g/l in experiment 1, from 150 to 180 g/l in experiment 2. There were significant increases in body weight and feed intake when the milk replacer with high protein : energy ratio was fed. Group mean average daily weight gain was 168 and 203 g for the groups with low and high dietary protein:energy ratio in experiment 1; for experiment 2 the values were 139 and 160 g. Average dry matter intake was 18 and 14% higher for the diet with high protein:energy ratio in experiments 1 and 2, respectively. There was no change in either feed conversion (feed:gain ratio) or energy conversion (weight gain:energy intake ratio). There were no consistent diet effects on plasma lipid concentrations. Dietary fatty acid composition was reflected by that of adipose tissue. The milk replacer with high protein:energy ratio produced a small increase in the contents of myristic and palmitic acid in adipose tissue.

  6. Modified water solubility of milk protein concentrate powders through the application of static high pressure treatment.

    PubMed

    Udabage, Punsandani; Puvanenthiran, Amirtha; Yoo, Jin Ah; Versteeg, Cornelis; Augustin, Mary Ann

    2012-02-01

    The effects of high pressure (HP) treatment (100-400 MPa at 10-60 °C) on the solubility of milk protein concentrate (MPC) powders were tested. The solubility, measured at 20 °C, of fresh MPC powders made with no HP treatment was 66%. It decreased by 10% when stored for 6 weeks at ambient temperature (~20 °C) and continued to decrease to less than 50% of its initial solubility after 12 months of storage. Of the combinations of pressure and heat used, a pressure of 200 MPa at 40 °C applied to the concentrate before spray drying was found to be the most beneficial for improved solubility of MPC powders. This combination of pressure/heat improved the initial cold water solubility to 85%. The solubility was maintained at this level after 6 weeks storage at ambient temperature and 85% of the initial solubility was preserved after 12 months. The improved solubility of MPC powders on manufacture and on storage are attributed to an altered surface composition arising from an increased concentration of non-micellar casein in the milk due to HP treatment prior to drying. The improved solubility of high protein powders (95% protein) made from blends of sodium caseinate and whey protein isolate compared with MPC powders (~85% protein) made from ultrafiltered/diafiltered milk confirmed the detrimental role of micellar casein on solubility. The results suggest that increasing the non-micellar casein content by HP treatment of milk or use of blends of sodium caseinate and whey proteins are strategies that may be used to obtain high protein milk powders with enhanced solubility.

  7. Effects of amide-protected and lipid-encapsulated conjugated linoleic acid supplements on milk fat synthesis.

    PubMed

    Perfield, J W; Lock, A L; Pfeiffer, A M; Bauman, D E

    2004-09-01

    The trans-10, cis-12 isomer of conjugated linoleic acid (CLA) is a potent inhibitor of milk fat synthesis; its ability to reduce milk fat output in a controlled manner as a feed supplement, has potential management applications in the dairy industry. The effectiveness of dietary supplements of trans-10, cis-12 CLA is related to the extent to which their metabolism by rumen bacteria is minimized. A number of processes have been used to manufacture "rumen-protected" feed supplements, and their efficacy can be described by the extent of protection from rumen bacteria as well as postruminal bioavailability. The objective of this study was to investigate the effects of 2 rumen-protected CLA supplements on milk fat synthesis. Using the same initial batch of CLA, supplements were manufactured by the formation of fatty acyl amide bonds or by lipid encapsulation. Three rumen fistulated Holstein cows were randomly assigned in a 3 x 3 Latin square experiment. Treatments were 1) no supplement (control), 2) amide-protected CLA supplement, and 3) lipid-encapsulated CLA supplement. Supplements were fed to provide 10 g/d of the trans-10, cis-12 CLA isomer. Over the 7-d treatment period, 21 and 22% reductions in milk fat yield were observed for the amide-protected and lipid-encapsulated supplements, respectively. Transfer of trans-10, cis-12 CLA into milk fat was also similar for the amide-protected (7.1%) and lipid-encapsulated (7.9%) supplements. Overall, the amide-protected and lipid-encapsulated CLA supplements were equally effective at reducing milk fat synthesis and had no effect on milk yield or dry matter intake.

  8. Protein ingestion increases myofibrillar protein synthesis after concurrent exercise.

    PubMed

    Camera, Donny M; West, Daniel W D; Phillips, Stuart M; Rerecich, Tracy; Stellingwerff, Trent; Hawley, John A; Coffey, Vernon G

    2015-01-01

    We determined the effect of protein supplementation on anabolic signaling and rates of myofibrillar and mitochondrial protein synthesis after a single bout of concurrent training. Using a randomized crossover design, eight healthy males were assigned to experimental trials consisting of resistance exercise (8 × 5 leg extension, 80% 1RM) followed by cycling (30 min at approximately 70% V˙O2peak) with either postexercise protein (PRO, 25-g whey protein) or placebo (PLA) ingestion. Muscle biopsies were obtained at rest and at 1 and 4 h after exercise. Akt and mTOR phosphorylation increased 1 h after exercise with PRO (175%-400%, P < 0.01) and was different from PLA (150%-300%, P < 0.001). Muscle RING finger 1 and atrogin-1 messenger RNA (mRNA) were elevated after exercise but were higher with PLA compared with those in PRO at 1 h (50%-315%, P < 0.05), whereas peroxisome proliferator-activated receptor gamma coactivator 1-alpha mRNA increased 4 h after exercise (620%-730%, P < 0.001), with no difference between treatments. Postexercise rates of myofibrillar protein synthesis increased above rest in both trials (75%-145%, P < 0.05) but were higher with PRO (67%, P < 0.05), whereas mitochondrial protein synthesis did not change from baseline. Our results show that a concurrent training session promotes anabolic adaptive responses and increases metabolic/oxidative mRNA expression in the skeletal muscle. PRO ingestion after combined resistance and endurance exercise enhances myofibrillar protein synthesis and attenuates markers of muscle catabolism and thus is likely an important nutritional strategy to enhance adaptation responses with concurrent training.

  9. Transfer of protein antigens into milk after intravenous injection into lactating mice

    SciTech Connect

    Harmatz, P.R.; Hanson, D.G.; Walsh, M.K.; Kleinman, R.E.; Bloch, K.J.; Walker, W.A.

    1986-08-01

    We investigated the transfer of bovine serum /sup 125/I-albumin (/sup 125/I-BSA), bovine /sup 125/I-gamma-globulin (/sup 125/I-BGG), /sup 125/I-ovalbumin (/sup 125/I-OVA), and /sup 125/I-beta-lactoglobulin (/sup 125/I-BLG) from the blood into the milk of lactating mice. Equal amounts (by weight) of the radiolabeled proteins were injected intravenously into mice 1 wk postpartum. Total radioactivity, trichloroacetic acid-precipitable radioactivity, and specifically immunoprecipitable radioactivity were measured in serum, mammary gland homogenate, and milk. Clearance of immunoreactive OVA (iOVA) and iBLG from the circulation was more rapid than iBSA and iBGG. The radioactivity in mammary tissue associated with BSA and BGG was greater than 70% immunoprecipitable throughout the 4-h test interval; /sup 125/I-OVA and /sup 125/I-BLG were less than 12% precipitable 1 and 4 h after injection. In milk obtained at 4 h, there was an approximately 10-fold greater accumulation of iBSA or iBGG than of iOVA or iBLG. These experiments demonstrate that protein antigens differ in their ability to transfer from maternal circulation into milk. The transfer into milk appeared to be in proportion to persistence of the antigens in the maternal circulation.

  10. Severe Food Protein-Induced Enterocolitis Syndrome to Cow's Milk in Infants.

    PubMed

    Yang, Min; Geng, Lanlan; Xu, Zhaohui; Chen, Peiyu; Friesen, Craig A; Gong, Sitang; Li, Ding-You

    2015-12-22

    Cow's milk is the most common cause of food-protein-induced enterocolitis syndrome (FPIES). The aim of this study was to examine the clinical features and treatment outcomes of infants with severe FPIES to cow's milk. We reviewed all infants ≤ 12 months of age who were hospitalized and diagnosed with severe FPIES to cow's milk between 1 January 2011 and 31 August 2014 in a tertiary Children's Medical Center in China. Patients' clinical features, feeding patterns, laboratory tests, and treatment outcomes were reviewed. A total of 12 infants met the inclusion criteria. All infants presented with diarrhea, edema, and hypoalbuminemia. Other main clinical manifestations included regurgitation/vomiting, skin rashes, low-grade fever, bloody and/or mucous stools, abdominal distention, and failure to thrive. They had clinical remission with resolution of diarrhea and significant increase of serum albumin after elimination of cow's milk protein (CMP) from the diet. The majority of infants developed tolerance to the CMP challenge test after 12 months of avoidance. In conclusion, we reported the clinical experience of 12 infants with severe FPIES to cow's milk, which resulted in malnutrition, hypoproteinemia, and failure to thrive. Prompt treatment with CMP-free formula is effective and leads to clinical remission of FPIES in infants.

  11. Antibiotics that target protein synthesis.

    PubMed

    McCoy, Lisa S; Xie, Yun; Tor, Yitzhak

    2011-01-01

    The key role of the bacterial ribosome makes it an important target for antibacterial agents. Indeed, a large number of clinically useful antibiotics target this complex translational ribonucleoprotein machinery. The majority of these compounds, mostly of natural origin, bind to one of the three key ribosomal sites: the decoding (or A-site) on the 30S, the peptidyl transferase center (PTC) on the 50S, and the peptide exit tunnel on the 50S. Antibiotics that bind the A-site, such as the aminoglycosides, interfere with codon recognition and translocation. Peptide bond formation is inhibited when small molecules like oxazolidinones bind at the PTC. Finally, macrolides tend to block the growth of the amino acid chain at the peptide exit tunnel. In this article, the major classes of antibiotics that target the bacterial ribosome are discussed and classified according to their respective target. Notably, most antibiotics solely interact with the RNA components of the bacterial ribosome. The surge seen in the appearance of resistant bacteria has not been met by a parallel development of effective and broad-spectrum new antibiotics, as evident by the introduction of only two novel classes of antibiotics, the oxazolidinones and lipopeptides, in the past decades. Nevertheless, this significant health threat has revitalized the search for new antibacterial agents and novel targets. High resolution structural data of many ribosome-bound antibiotics provide unprecedented insight into their molecular contacts and mode of action and inspire the design and synthesis of new candidate drugs that target this fascinating molecular machine.

  12. Detection of relevant amounts of cow's milk protein in non-pre-packed bakery products sold as cow's milk-free.

    PubMed

    Trendelenburg, V; Enzian, N; Bellach, J; Schnadt, S; Niggemann, B; Beyer, K

    2015-05-01

    Currently, there is no mandatory labelling of allergens for non-pre-packed foods in the EU. Therefore, consumers with food allergy rely on voluntary information provided by the staff. The aim of this study was to characterize allergic reactions to non-pre-packed foods and to investigate whether staff in bakery shops were able to give advice regarding a safe product choice. Questionnaires were sent to 200 parents of children with a food allergy. Staff of 50 bakery shops were interviewed regarding selling non-pre-packed foods to food-allergic customers. Bakery products being recommended as 'cow's milk-free' were bought, and cow's milk protein levels were measured using ELISA. A total of 104 of 200 questionnaires were returned. 25% of the children experienced an allergic reaction due to a non-pre-packed food from bakery shops and 20% from ice cream parlours. Sixty percent of the bakery staff reported serving food-allergic customers at least once a month, 24% once a week. Eighty four percent of the staff felt able to advise food-allergic consumers regarding a safe product choice. Seventy three 'cow's milk-free' products were sold in 44 bakery shops. Cow's milk could be detected in 43% of the bakery products, 21% contained >3 mg cow's milk protein per serving. Staff in bakery shops felt confident about advising customers with food allergy. However, cow's milk was detectable in almost half of bakery products being sold as 'cow's milk-free'. Every fifth product contained quantities of cow's milk exceeding an amount where approximately 10% of cow's milk-allergic children will show clinical relevant symptoms. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Effect of homogenization and heat treatment on the behavior of protein and fat globules during gastric digestion of milk.

    PubMed

    Ye, Aiqian; Cui, Jian; Dalgleish, Douglas; Singh, Harjinder

    2017-01-01

    The effects of homogenization and heat treatment on the formation and the breakdown of clots during gastric digestion of whole milk were investigated using a human gastric simulator. Homogenization and heat treatment led to formation of coagula with fragmented and crumbled structures compared with the coagulum formed from raw whole milk, but a larger fraction of the protein and more fat globules were incorporated into the coagula induced by action of the milk-clotting enzyme pepsin. The fat globules in the whole milk appeared to be embedded in the clots as they formed. After formation of the clot, the greater numbers of pores in the structures of the clots formed with homogenized milk and heated whole milk led to greater rates of protein hydrolysis by pepsin, which resulted in faster release of fat globules from the clots into the digesta. Coalescence of fat globules occurred both in the digesta and within the protein clots no matter whether they were in homogenized or heated milk samples. The formation of clots with different structures and hence the changes in the rates of protein hydrolysis and the release of milk fat into the digesta in the stomach provide important information for understanding the gastric emptying of milk and the potential to use this knowledge to manipulate the bioavailability of fat and other fat-soluble nutrients in dairy products. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Accounting for energy and protein reserve changes in predicting diet-allowable milk production in cattle.

    PubMed

    Tedeschi, L O; Seo, S; Fox, D G; Ruiz, R

    2006-12-01

    Current ration formulation systems used to formulate diets on farms and to evaluate experimental data estimate metabolizable energy (ME)-allowable and metabolizable protein (MP)-allowable milk production from the intake above animal requirements for maintenance, pregnancy, and growth. The changes in body reserves, measured via the body condition score (BCS), are not accounted for in predicting ME and MP balances. This paper presents 2 empirical models developed to adjust predicted diet-allowable milk production based on changes in BCS. Empirical reserves model 1 was based on the reserves model described by the 2001 National Research Council (NRC) Nutrient Requirements of Dairy Cattle, whereas empirical reserves model 2 was developed based on published data of body weight and composition changes in lactating dairy cows. A database containing 134 individually fed lactating dairy cows from 3 trials was used to evaluate these adjustments in milk prediction based on predicted first-limiting ME or MP by the 2001 Dairy NRC and Cornell Net Carbohydrate and Protein System models. The analysis of first-limiting ME or MP milk production without adjustments for BCS changes indicated that the predictions of both models were consistent (r(2) of the regression between observed and model-predicted values of 0.90 and 0.85), had mean biases different from zero (12.3 and 5.34%), and had moderate but different roots of mean square errors of prediction (5.42 and 4.77 kg/d) for the 2001 NRC model and the Cornell Net Carbohydrate and Protein System model, respectively. The adjustment of first-limiting ME- or MP-allowable milk to BCS changes improved the precision and accuracy of both models. We further investigated 2 methods of adjustment; the first method used only the first and last BCS values, whereas the second method used the mean of weekly BCS values to adjust ME- and MP-allowable milk production. The adjustment to BCS changes based on first and last BCS values was more accurate

  15. Proteolytic activity of Enterococcus faecalis VB63F for reduction of allergenicity of bovine milk proteins.

    PubMed

    Biscola, V; Tulini, F L; Choiset, Y; Rabesona, H; Ivanova, I; Chobert, J-M; Todorov, S D; Haertlé, T; Franco, B D G M

    2016-07-01

    With the aim of screening proteolytic strains of lactic acid bacteria to evaluate their potential for the reduction of allergenicity of the major bovine milk proteins, we isolated a new proteolytic strain of Enterococcus faecalis (Ent. faecalis VB63F) from raw bovine milk. The proteases produced by this strain had strong activity against caseins (αS1-, αS2-, and β-casein), in both skim milk and sodium caseinate. However, only partial hydrolysis of whey proteins was observed. Proteolysis of Na-caseinate and whey proteins, observed after sodium dodecyl sulfate-PAGE, was confirmed by analysis of peptide profiles by reversed-phase HPLC. Inhibition of proteolysis with EDTA indicated that the proteases produced by Ent. faecalis VB63F belonged to the group of metalloproteases. The optimal conditions for their activity were 42°C and pH 6.5. The majority of assessed virulence genes were absent in Ent. faecalis VB63F. The obtained results suggest that Ent. faecalis VB63F could be efficient in reducing the immunoreactivity of bovine milk proteins.

  16. Low levels of aflatoxin B1, ricin and milk enhance recombinant protein production in mammalian cells

    USDA-ARS?s Scientific Manuscript database

    Changing the optimal tissue culture medium by adding low levels of environmental stress such as 1 µM of the fungal toxin aflatoxin B1 (AFB1), 1 ng of the castor bean protein toxin ricin in transduced mammalian cells or 1% reconstituted milk enhances transcription and increases production of the foll...

  17. Do infants with cow's milk protein allergy have inadequate levels of vitamin D?

    PubMed

    Silva, Cristiane M; Silva, Silvia A da; Antunes, Margarida M de C; Silva, Gisélia Alves Pontes da; Sarinho, Emanuel Sávio Cavalcanti; Brandt, Kátia G

    2017-06-17

    To verify whether infants with cow's milk protein allergy have inadequate vitamin D levels. This cross-sectional study included 120 children aged 2 years or younger, one group with cow's milk protein allergy and a control group. The children were recruited at the pediatric gastroenterology, allergology, and pediatric outpatient clinics of a university hospital in the Northeast of Brazil. A questionnaire was administered to the caregiver and blood samples were collected for vitamin D quantification. Vitamin D levels <30ng/mL were considered inadequate. Vitamin D level was expressed as mean and standard deviation, and the frequency of the degrees of sufficiency and other variables, as proportions. Infants with cow's milk protein allergy had lower mean vitamin D levels (30.93 vs.35.29ng/mL; p=0.041) and higher deficiency frequency (20.3% vs.8.2; p=0.049) than the healthy controls. Exclusively or predominantly breastfed infants with cow's milk protein allergy had higher frequency of inadequate vitamin D levels (p=0.002). Regardless of sun exposure time, the groups had similar frequencies of inadequate vitamin D levels (p=0.972). Lower vitamin D levels were found in infants with CMPA, especially those who were exclusively or predominantly breastfed, making these infants a possible risk group for vitamin D deficiency. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  18. Immunocytochemical detection of milk proteins in tracheal aspirates of ventilated infants: a pilot study.

    PubMed

    Miller, Jamey; Colasurdo, Giuseppe N; Khan, Amir M; Jajoo, Charu; Patel, Tarak J; Fan, Leland L; Elidemir, Okan

    2002-11-01

    In this study, we evaluated immunocytochemical staining for milk proteins (alpha-lactalbumin and beta-lactoglobulin) in tracheal aspirates of mechanically ventilated infants, and assessed whether this staining technique supported a clinical diagnosis of aspiration in infants receiving orogastric feedings. All newborns requiring mechanical ventilation in the neonatal intensive care unit of a major tertiary care hospital were potential subjects for this study. Tracheal aspirates were obtained prior to the introduction of enteral feeding and at various time points thereafter in newborns requiring mechanical ventilation. Cells were obtained and processed for immunocytochemical staining of alpha-lactalbumin and beta-lactoglobulin. In total, 88 specimens recovered from 34 infants were adequate for staining. Alveolar macrophages recovered from most of the infants who were never fed (true negative controls) did not display immunoreactivity for milk proteins: 4/34 or 12% of infants' aspirates demonstrated presence of milk proteins before enteral feeding was commenced. Tracheal aspirates obtained from 12 infants after introduction of enteral feedings appeared to support clinical and radiological findings suggestive of aspiration events, with positive immunostaining on several occasions. These observations support our work in a murine model and demonstrate that immunocytochemical staining of tracheal aspirates for milk proteins may enhance the ability to diagnose pulmonary aspiration. Further studies are needed to define the clinical significance of our findings and the effects of single and repeated aspiration events on respiratory status.

  19. Amaltheys: A fluorescence-based analyzer to assess cheese milk denatured whey proteins.

    PubMed

    Lacotte, Pierre; Gomez, Franck; Bardeau, Floriane; Muller, Sabine; Acharid, Abdelhaq; Quervel, Xavier; Trossat, Philippe; Birlouez-Aragon, Inès

    2015-10-01

    The cheese industry faces many challenges to optimize cheese yield and quality. A very precise standardization of the cheese milk is needed, which is achieved by a fine control of the process and milk composition. Thorough analysis of protein composition is important to determine the amount of protein that will be retained in the curd or lost in the whey. The fluorescence-based Amaltheys analyzer (Spectralys Innovation, Romainville, France) was developed to assess pH 4.6-soluble heat-sensitive whey proteins (sWP*) in 5 min. These proteins are those that can be denatured upon heat-treatment and further retained in the curd after coagulation. Monitoring of sWP* in milk and subsequent adaptation of the process is a reliable solution to achieve stable cheese yield and quality. Performance of the method was evaluated by an accredited laboratory on a 0 to 7 g/L range. Accuracy compared with the reference Kjeldahl method is also provided with a standard error of 0.25 g/L. Finally, a 4-mo industrial trial in a cheese plant is described, where Amaltheys was used as a process analytical technology to monitor sWP* content in ingredients and final cheese milk. Calibration models over quality parameters of final cheese were also built from near-infrared and fluorescence spectroscopic data. The Amaltheys analyzer was found to be a rapid, compact, and accurate device to help implementation of standardization procedures in the dairy industry.

  20. Changes over lactation in breast milk serum proteins involved in the maturation of immune and digestive system of the infant.

    PubMed

    Zhang, Lina; de Waard, Marita; Verheijen, Hester; Boeren, Sjef; Hageman, Jos A; van Hooijdonk, Toon; Vervoort, Jacques; van Goudoever, Johannes B; Hettinga, Kasper

    2016-09-16

    To objective of this study was to better understand the biological functions of breast milk proteins in relation to the growth and development of infants over the first six months of life. Breast milk samples from four individual women collected at seven time points in the first six months after delivery were analyzed by filter aided sample preparation and dimethyl labeling combined with liquid chromatography tandem mass spectrometry. A total of 247 and 200 milk serum proteins were identified and quantified, respectively. The milk serum proteome showed a high similarity (80% overlap) on the qualitative level between women and over lactation. The quantitative changes in milk serum proteins were mainly caused by three groups of proteins, enzymes, and transport and immunity proteins. Of these 21 significantly changed proteins, 30% were transport proteins, such as serum albumin and fatty acid binding protein, which are both involved in transporting nutrients to the infant. The decrease of the enzyme bile salt-activated lipase as well as the immunity proteins immunoglobulins and lactoferrin coincide with the gradual maturation of the digestive and immune system of infants. The human milk serum proteome didn't differ qualitatively but it did quantitatively, both between mothers and as lactation advanced. The changes of the breast milk serum proteome over lactation corresponded with the development of the digestive and immune system of infants. Breast milk proteins provide nutrition, but also contribute to healthy development of infants. Despite the previously reported large number of identified breast milk proteins and their changes over lactation, less is known on the changes of these proteins in individual mothers. This study is the first to determine the qualitative and quantitative changes of milk proteome over lactation between individual mothers. The results indicate that the differences in the milk proteome between individual mothers are more related to the

  1. Semi-synthesis of thioamide containing proteins.

    PubMed

    Wang, Yanxin J; Szantai-Kis, D Miklos; Petersson, E James

    2015-05-14

    Our laboratory has shown that the thioamide, a single atom O-to-S substitution, can be a versatile fluorescence quenching probe that is minimally-perturbing when placed at many locations in a protein sequence. In order to make these and other thioamide experiments applicable to full-sized proteins, we have developed methods for incorporating thioamides by generating thiopeptide fragments through solid phase synthesis and ligating them to protein fragments expressed in E. coli. To install donor fluorophores, we have adapted unnatural amino acid mutagenesis methods, including the generation of new tRNA synthetases for the incorporation of small, intrinsically fluorescent amino acids. We have used a combination of these two methods, as well as chemoenzymatic protein modification, to efficiently install sidechain and backbone modifications to generate proteins labeled with fluorophore/thioamide pairs.

  2. Serum protein and casein concentration: effect on pH and freezing point of milk with added CO2.

    PubMed

    Ma, Y; Barbano, D M

    2003-05-01

    The objective of this study was to determine the effect of protein concentration and protein type [i.e., casein (CN) and serum protein (SP)] on pH (0 degree C) and freezing point (FP) of skim milk upon CO2 injection at 0 degree C. CN-free skim milks with increasing SP content (0, 3, and 6%) and skim milks with the same SP content (0.6%) but increasing CN content (2.4, 4.8, and 7.2%) were prepared using a combination of microfiltration and ultrafiltration processes. CO2 was injected into milks at 0 degree C using a continuous flow carbonation unit (230 ml/min). Increasing SP or CN increased milk buffering capacity and protein-bound mineral content. At the same CO2 concentration at 0 degree C, a milk with a higher SP or a higher CN concentration had more resistance to pH change and a greater extent of FP decrease. The buffering capacity provided by an increase of CN was contributed by both the CN itself and the colloidal salts solublized into the serum phase from CN upon carbonation. Skim milks with the same true protein content (3%), one with 2.4% CN plus 0.6% SP and one with 3% SP, were compared. At the same true protein content (3%), increasing the proportion of CN increased milk buffering capacity and protein-bound mineral content. Milk with a higher proportion of CN had more resistance to pH change and a greater extent of FP decrease at the same carbonation level at 0 degree C. Once CO2 was dissolved in the skim portion of a milk, the extent of pH reduction and FP depression depended on protein concentration and protein type (i.e., CN and SP).

  3. Maillard reaction and protein cross-linking in relation to the solubility of milk powders.

    PubMed

    Le, Thao T; Bhandari, Bhesh; Holland, John W; Deeth, Hilton C

    2011-12-14

    Protein changes in relation to solubility, Maillard reaction (MR), and protein cross-linking in whole milk powder (WMP), skim milk powder (SMP), and whey protein concentrate (WPC) stored at different relative humidities (RHs) were investigated by chemical and electrophoretic methods. WMP and SMP reached minimum solubility rapidly, while WPC showed no change in solubility. The loss of solubility corresponded with development of high-molecular-weight protein complexes observed by two-dimensional electrophoresis. The maximal MR rate occurred at 66% RH for WMP and SMP (high lactose/protein ratios) and 84% RH for WPC (low lactose/protein ratios) based on the furosine and hydroxymethylfurfural contents. However, browning was greatest at 84% RH in all powders. The minimum solubility corresponded with the casein and fat contents. The retention of solubility and minimal protein cross-linking of WPC compared to casein-containing powders suggest that the casein content and cross-linking strongly influence the decrease in the solubility of milk powder.

  4. Mechanism and regulation of eukaryotic protein synthesis.

    PubMed Central

    Merrick, W C

    1992-01-01

    This review presents a description of the numerous eukaryotic protein synthesis factors and their apparent sequential utilization in the processes of initiation, elongation, and termination. Additionally, the rare use of reinitiation and internal initiation is discussed, although little is known biochemically about these processes. Subsequently, control of translation is addressed in two different settings. The first is the global control of translation, which is effected by protein phosphorylation. The second is a series of specific mRNAs for which there is a direct and unique regulation of the synthesis of the gene product under study. Other examples of translational control are cited but not discussed, because the general mechanism for the regulation is unknown. Finally, as is often seen in an active area of investigation, there are several observations that cannot be readily accommodated by the general model presented in the first part of the review. Alternate explanations and various lines of experimentation are proposed to resolve these apparent contradictions. PMID:1620067

  5. Elongation factors in protein synthesis.

    PubMed

    Kraal, B; Bosch, L; Mesters, J R; de Graaf, J M; Woudt, L P; Vijgenboom, E; Heinstra, P W; Zeef, L A; Boon, C

    1993-01-01

    Recent discoveries of elongation factor-related proteins have considerably complicated the simple textbook scheme of the peptide chain elongation cycle. During growth and differentiation the cycle may be regulated not only by factor modification but also factor replacement. In addition, rare tRNAs may have their own rare factor proteins. A special case is the acquisition of resistance by bacteria to elongation factor-directed antibiotics. Pertinent data from the literature and our own work with Escherichia coli and Streptomyces are discussed. The GTP-binding domain of EF-Tu has been studied extensively, but little molecular detail is available on the interactions with its other ligands or effectors, or on the way they are affected by the GTPase switch signal. A growing number of EF-Tu mutants obtained by ourselves and others are helping us in testing current ideas. We have found a synergistic effect between EF-Tu and EF-G in their uncoupled GTPase reactions on empty ribosomes. Only the EF-G reaction is perturbed by fluoroaluminates.

  6. Microwave-assisted cross-linking of milk proteins induced by microbial transglutaminase

    PubMed Central

    Chen, Chun-Chi; Hsieh, Jung-Feng

    2016-01-01

    We investigated the combined effects of microbial transglutaminase (MTGase, 7.0 units/mL) and microwave irradiation (MI) on the polymerization of milk proteins at 30 °C for 3 h. The addition of MTGase caused the milk proteins to become polymerized, which resulted in the formation of components with a higher molecular-weight (>130 kDa). SDS-PAGE analysis revealed reductions in the protein content of β-lactoglobulin (β-LG), αS-casein (αS-CN), κ-casein (κ-CN) and β-casein (β-CN) to 50.4 ± 2.9, 33.5 ± 3.0, 4.2 ± 0.5 and 1.2 ± 0.1%, respectively. The use of MTGase in conjunction MI with led to a 3-fold increase in the rate of milk protein polymerization, compared to a sample that contained MTGase but did not undergo MI. Results of two-dimensional gel electrophoresis (2-DE) indicated that κ-CN, β-CN, a fraction of serum albumin (SA), β-LG, α-lactalbumin (α-LA), αs1-casein (αs1-CN), and αs2-casein (αs2-CN) were polymerized in the milk, following incubation with MTGase and MI at 30 °C for 1 h. Based on this result, the combined use of MTGase and MI appears to be a better way to polymerize milk proteins. PMID:27966639

  7. Microwave-assisted cross-linking of milk proteins induced by microbial transglutaminase

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Chi; Hsieh, Jung-Feng

    2016-12-01

    We investigated the combined effects of microbial transglutaminase (MTGase, 7.0 units/mL) and microwave irradiation (MI) on the polymerization of milk proteins at 30 °C for 3 h. The addition of MTGase caused the milk proteins to become polymerized, which resulted in the formation of components with a higher molecular-weight (>130 kDa). SDS-PAGE analysis revealed reductions in the protein content of β-lactoglobulin (β-LG), αS-casein (αS-CN), κ-casein (κ-CN) and β-casein (β-CN) to 50.4 ± 2.9, 33.5 ± 3.0, 4.2 ± 0.5 and 1.2 ± 0.1%, respectively. The use of MTGase in conjunction MI with led to a 3-fold increase in the rate of milk protein polymerization, compared to a sample that contained MTGase but did not undergo MI. Results of two-dimensional gel electrophoresis (2-DE) indicated that κ-CN, β-CN, a fraction of serum albumin (SA), β-LG, α-lactalbumin (α-LA), αs1-casein (αs1-CN), and αs2-casein (αs2-CN) were polymerized in the milk, following incubation with MTGase and MI at 30 °C for 1 h. Based on this result, the combined use of MTGase and MI appears to be a better way to polymerize milk proteins.

  8. Cow's milk and goat's milk.

    PubMed

    Turck, Dominique

    2013-01-01

    Cow's milk is increasingly suggested to play a role in the development of chronic degenerative, non-communicable disorders whereas goat's milk is advocated as having several health benefits. Cow's milk is a rich and cheap source of protein and calcium, and a valuable food for bone health. Despite their high content in saturated fats, consumption of full-fat dairy products does not seem to cause significant changes in cardiovascular disease risk variables. Early introduction of cow's milk is a strong negative determinant of iron status. Unmodified cow's milk does not meet nutritional requirements of infants although it is acceptable to add small volumes of cow's milk to complementary foods. Cow's milk protein allergy has a prevalence ranging from 2 to 7%, and the age of recovery is usually around 2-3 years. The evidence linking cow's milk intake to a later risk of type 1 diabetes or chronic degenerative, non-communicable disorders (obesity, metabolic syndrome, type 2 diabetes, hypertension) is not convincing. Milk probably protects against colorectal cancer, diets high in calcium are a probable cause of prostate cancer, and there is limited evidence suggesting that high consumption of milk and dairy products increases the risk for prostate cancer. There is no evidence to support the use of a cow's milk-free diet as a primary treatment for individuals with autistic spectrum disorders. Unmodified goat's milk is not suitable for infants because of the high protein and minerals content and of a low folate content. Goat's milk has no clear nutritional advantage over cow's milk and is not less allergenic. The European Food Safety Authority recently stated that proteins from goat's milk can be suitable as a protein source for infant and follow-on formula, provided the final product complies with the compositional criteria laid down in Directive 2006/141/EC.

  9. Effects of heating on the secondary structure of proteins in milk powders using mid-infrared spectroscopy.

    PubMed

    Ye, M P; Zhou, R; Shi, Y R; Chen, H C; Du, Y

    2017-01-01

    Milk powder is an important source of protein for adults and children. Protein is very sensitive to heat, which may influence people's usage of nutrients in milk powder. In this study, we describe the temperature-induced secondary structure of protein in milk powders. In this study, whole milk powder containing 24% protein and infant formula containing 11% protein were heated from 25 to 100°C. Attenuated total reflectance (ATR) spectra in the mid-infrared range 400-4,000cm(-1) were used to evaluate the heat effect on the secondary structure of protein in these 2 milk powders. The spectral changes as a function of temperature were maintained by difference spectra, second-derivative spectra and Gauss curve-fitted spectra. The secondary structures of protein in the whole milk powder began to change at 70°C and in the infant formula at 50°C. The β-sheet and β-turn structures in the whole milk powder both decreased in the range of 70 to 85°C, whereas α-helix structures increased. The loss of β-sheet and β-turn may contribute to the formation of α-helix in the whole milk powder. In infant formula powder, the β-sheet structure showed a decrease and then increase, whereas the β-turn structure showed an increase and then decrease in the range of 50 to 75°C, and no change was found for α-helix structures. This implies that heating may induce the transformation from β-sheet to β-turn. Overall, whole milk powder had better temperature stability than infant formula powder, probably because of the lower content of lipid in the former than in the latter. These results help us understand the thermal stability of protein in milk powder. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Structural changes induced by high-pressure processing in micellar casein and milk protein concentrates.

    PubMed

    Cadesky, Lee; Walkling-Ribeiro, Markus; Kriner, Kyle T; Karwe, Mukund V; Moraru, Carmen I

    2017-09-01

    Reconstituted micellar casein concentrates and milk protein concentrates of 2.5 and 10% (wt/vol) protein concentration were subjected to high-pressure processing at pressures from 150 to 450 MPa, for 15 min, at ambient temperature. The structural changes induced in milk proteins by high-pressure processing were investigated using a range of physical, physicochemical, and chemical methods, including dynamic light scattering, rheology, mid-infrared spectroscopy, scanning electron microscopy, proteomics, and soluble mineral analyses. The experimental data clearly indicate pressure-induced changes of casein micelles, as well as denaturation of serum proteins. Calcium-binding αS1- and αS2-casein levels increased in the soluble phase after all pressure treatments. Pressurization up to 350 MPa also increased levels of soluble calcium and phosphorus, in all samples and concentrations, whereas treatment at 450 MPa reduced the levels of soluble Ca and P. Experimental data suggest dissociation of calcium phosphate and subsequent casein micelle destabilization as a result of pressure treatment. Treatment of 10% micellar casein concentrate and 10% milk protein concentrate samples at 450 MPa resulted in weak, physical gels, which featured aggregates of uniformly distributed, casein substructures of 15 to 20 nm in diameter. Serum proteins were significantly denatured by pressures above 250 MPa. These results provide information on pressure-induced changes in high-concentration protein systems, and may inform the development on new milk protein-based foods with novel textures and potentially high nutritional quality, of particular interest being the soft gel structures formed at high pressure levels. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

  11. ADSA Foundation Scholar Award. Formation and physical properties of milk protein gels.

    PubMed

    Lucey, J A

    2002-02-01

    Gelation of milk proteins is the crucial first step in both cheese and yogurt manufacture. Several types of milk gels are discussed, with an emphasis on recent developments in our understanding of how these gels are formed and some of their key physical properties. Areas discussed include the latest dual-binding model for casein micelles; some recent developments in rennet-induced gelation; review of the methods that have been used to monitor milk coagulation; and a discussion of some of the possible causes for the wheying-off defect in yogurts. Casein micelles are the primary building blocks of casein-based gels; however, controversy about its structure continues. The latest model proposed for the formation of casein micelles is the dual-binding model proposed by Horne, 1998, which suggests that casein micelles are formed as a result of two binding mechanisms, namely hydrophobic attraction and colloidal calcium phosphate (CCP) bridging. Most previous models for the casein micelle have treated milk gelation from the viewpoint of simple particle destabilization and aggregation, but they have not been able to explain several unusual rheological properties of milk gels. Although there have been many techniques used to monitor the milk gelation process over the past few decades, only a few appear attractive as possible in-vat coagulation sensors. Another important aspect of milk gels is the defect in yogurts called wheying-off, which is the appearance of whey on the gel surface. The factors responsible for its occurrence are still unclear, but they have been investigated in model acid gel systems.

  12. Synthesis of milligram quantities of proteins using a reconstituted in vitro protein synthesis system.

    PubMed

    Kazuta, Yasuaki; Matsuura, Tomoaki; Ichihashi, Norikazu; Yomo, Tetsuya

    2014-11-01

    In this study, the amount of protein synthesized using an in vitro protein synthesis system composed of only highly purified components (the PURE system) was optimized. By varying the concentrations of each system component, we determined the component concentrations that result in the synthesis of 0.38 mg/mL green fluorescent protein (GFP) in batch mode and 3.8 mg/mL GFP in dialysis mode. In dialysis mode, protein concentrations of 4.3 and 4.4 mg/mL were synthesized for dihydrofolate reductase and β-galactosidase, respectively. Using the optimized system, the synthesized protein represented 30% (w/w) of the total protein, which is comparable to the level of overexpressed protein in Escherichia coli cells. This optimized reconstituted in vitro protein synthesis system may potentially be useful for various applications, including in vitro directed evolution of proteins, artificial cell assembly, and protein structural studies. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Human milk fortifier with high versus standard protein content for promoting growth of preterm infants: A meta-analysis.

    PubMed

    Liu, Tian-Tian; Dang, Dan; Lv, Xiao-Ming; Wang, Teng-Fei; Du, Jin-Feng; Wu, Hui

    2015-06-01

    To compare the growth of preterm infants fed standard protein-fortified human milk with that containing human milk fortifier (HMF) with a higher-than-standard protein content. Published articles reporting randomized controlled trials and prospective observational intervention studies listed on the PubMed®, Embase®, CINAHL and Cochrane Library databases were searched using the keywords 'fortifier', 'human milk', 'breastfeeding', 'breast milk' and 'human milk fortifier'. The mean difference with 95% confidence intervals was used to compare the effect of HMF with a higher-than-standard protein content on infant growth characteristics. Five studies with 352 infants with birth weight ≤ 1750 g and a gestational age ≤ 34 weeks who were fed human milk were included in this meta-analysis. Infants in the experimental groups given human milk with higher-than-standard protein fortifier achieved significantly greater weight and length at the end of the study, and greater weight gain, length gain, and head circumference gain, compared with control groups fed human milk with the standard HMF. HMF with a higher-than-standard protein content can improve preterm infant growth compared with standard HMF. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  14. Cell-free protein synthesis as a promising expression system for recombinant proteins.

    PubMed

    Ge, Xumeng; Xu, Jianfeng

    2012-01-01

    Cell-free protein synthesis (CFPS) has major advantages over traditional cell-based methods in the capability of high-throughput protein synthesis and special protein production. During recent decades, CFPS has become an alternative protein production platform for both fundamental and applied purposes. Using Renilla luciferase as model protein, we describe a typical process of CFPS in wheat germ extract system, including wheat germ extract preparation, expression vector construction, in vitro protein synthesis (transcription/translation), and target protein assay.

  15. Cow's milk protein allergy and other food hypersensitivities in infants.

    PubMed

    Venter, Carina

    2009-01-01

    Food hypersensitivity (FHS) is the umbrella term used to describe both food allergy, which involves the immune system, and food intolerances, which do not. It is therefore important that the diagnosis is made by a specialist health care professional such as a paediatrician or allergist. Some experienced dietitians and health visitors may be able to assist in making a diagnosis. The diagnostic work-up includes a medical history and blood tests/skin tests (where applicable). A food and symptom diary followed by a special test diet to identify the foods causing the infant's symptoms may also be needed. Once a diagnosis is made, dietary advice should be given to eliminate or reduce the intake of the offending foods. For cow's milk hypersensitivity in infants, this will include choosing the most appropriate specialised infant formula.

  16. Study of the protein-bound fraction of calcium, iron, magnesium and zinc in bovine milk

    NASA Astrophysics Data System (ADS)

    Silva, Fernando V.; Lopes, Gisele S.; Nóbrega, Joaquim A.; Souza, Gilberto B.; Nogueira, Ana Rita A.

    2001-10-01

    Two approaches were used to study the interaction of Ca, Fe, Mg and Zn with bovine milk proteins by inductively coupled plasma optical emission spectrometry (ICPOES). Selective separations in bovine milk samples were accomplished employing an acid protein precipitation using 100 g l -1 trichloroacetic acid (TCA), and an enzymatic protein hydrolysis using 50 g l -1 pepsin (PEP) solution, respectively. The results were compared with total mineral contents determined after microwave-assisted acid digestion. The results obtained by enzymatic and acid precipitation evidenced the different interaction forms of Ca, Fe, Mg and Zn in the system formed by milk components. Iron was not solubilized by the TCA treatment, but was recovered completely after the enzymatic treatment. Quantitative recoveries of Ca, Mg and Zn were obtained using both approaches, showing that these analytes were bound to milk compounds affected by either treatment. Calcium, Mg and Zn are mainly associated with colloidal calcium phosphate and Fe is bound to the backbone of the casein polypeptide chain, cleaved by pepsin enzyme. The proposed approaches could be used to assess the complexity of these chemical interactions.

  17. Genetic parameters for milk, fat and protein yields in Murrah buffaloes (Bubalus bubalis Artiodactyla, Bovidae)

    PubMed Central

    2010-01-01

    The objective of the present study was to estimate genetic parameters for test-day milk, fat and protein yields and 305-day-yields in Murrah buffaloes. 4,757 complete lactations of Murrah buffaloes were analyzed. Co-variance components were estimated by the restricted maximum likelihood method. The models included additive direct genetic and permanent environmental effects as random effects, and the fixed effects of contemporary group, milking number and age of the cow at calving as linear and quadratic covariables. Contemporary groups were defined by herd-year-month of test for test-day yields and by herd-year-season of calving for 305-day yields. The heritability estimates obtained by two-trait analysis ranged from 0.15 to 0.24 for milk, 0.16 to 0.23 for protein and 0.13 to 0.22 for fat, yields. Genetic and phenotypic correlations were all positive. The observed population additive genetic variation indicated that selection might be an effective tool in changing population means in milk, fat and protein yields. PMID:21637608

  18. Shift in the isoelectric-point of milk proteins as a consequence of adaptive divergence between the milks of mammalian species

    PubMed Central

    2011-01-01

    Background Milk proteins are required to proceed through a variety of conditions of radically varying pH, which are not identical across mammalian digestive systems. We wished to investigate if the shifts in these requirements have resulted in marked changes in the isoelectric point and charge of milk proteins during evolution. Results We investigated nine major milk proteins in 13 mammals. In comparison with a group of orthologous non-milk proteins, we found that 3 proteins κ-casein, lactadherin, and muc1 have undergone the highest change in isoelectric point during evolution. The pattern of non-synonymous substitutions indicate that selection has played a role in the isoelectric point shift, since residues that show significant evidence of positive selection are much more likely to be charged (p = 0.03 for κ-casein; p < 10-8 for muc1). However, this selection does not appear to be solely due to adaptation to the diversity of mammalian digestive systems, since striking changes are seen among species that resemble each other in terms of their digestion. Conclusion The changes in charge are most likely due to changes of other protein functions, rather than an adaptation to the different mammalian digestive systems. These functions may include differences in bioactive peptide releases in the gut between different mammals, which are known to be a major contributing factor in the functional and nutritional value of mammalian milk. This raises the question of whether bovine milk is optimal in terms of particular protein functions, for human nutrition and possibly disease resistance. This article was reviewed by Fyodor Kondrashov, David Liberles (nominated by David Ardell), and Christophe Lefevre (nominated by Mark Ragan). PMID:21801421

  19. Partition of whey milk proteins in aqueous two-phase systems of polyethylene glycol-phosphate as a starting point to isolate proteins expressed in transgenic milk.

    PubMed

    Capezio, Lorena; Romanini, Diana; Picó, Guillermo A; Nerli, Bibiana

    2005-05-05

    Partitioning behaviour of the bovine whey proteins (bovine serum albumin, alpha lactoalbumin and beta lactoglobulin) and alpha-1 antitrypsin in aqueous two-phase systems prepared with polyethyleneglycol (molecular masses: 1000; 1500 and 3350)-potassium phosphate was analysed. Bovine serum albumin and alpha lactoalbumin concentrated in the polyethyleneglycol rich phase with a partition coefficient of 10.0 and 27.0, respectively, while beta lactoglubulin and alpha-1 antitrypsin showed affinity for the phosphate-rich phase with a partition coefficient of 0.07 and 0.01, respectively. An increase of medium pH induced an increase of the partition coefficient of these proteins while the increase in polyethyleneglycol molecular mass induced the opposite behaviour. The system polyethyleneglycol 1500-pH 6.3 showed the best capacity for recovering the alpha-1 antitrypsin with a yield of 80% and a purification factor between 1.5 and 1.8 from an artificial mixture of the milk whey proteins and alpha-1 antitrypsin. The method appears to be suitable as a starting point to isolate proteins expressed in transgenic milk.

  20. Humoral and cellular responses to cow milk proteins in patients with milk-induced IgE-mediated and non-IgE-mediated disorders.

    PubMed

    Shek, L P C; Bardina, L; Castro, R; Sampson, H A; Beyer, K

    2005-07-01

    Cow milk allergy (CMA) is one of the most common food allergies in childhood. Patients with CMA present with a wide range of immunoglobulin (Ig)E- and non-IgE-mediated clinical syndromes. Limited information is known about the specific humoral and cellular responses to cow milk proteins in these various forms of CMA. The aim of the study was to determine IgE, IgA, IgG1 and IgG4 antibody levels and lymphocyte proliferative responses to the major cow milk allergens in patients with IgE- and non-IgE-mediated CMA. One hundred and forty cow milk allergic patients, 6 months to 22 years of age, were included in the study. One hundred and thirteen patients had IgE-mediated CMA, 11 had milk protein-induced enterocolitis syndrome and 16 had allergic eosinophilic gastroenteritis. Twenty-one patients without food allergy, 8 months to 18 years of age, served as controls. Serum IgE, IgA, IgG1 and IgG4 antibodies to alpha-, beta-, and kappa-casein, alpha-lactalbumin and beta-lactoglobulin were measured using enzyme-linked immunosorbent assays. For a subset of these patients, we performed lymphocyte proliferation assays to the various milk allergens. Patients with IgE-mediated CMA had higher specific IgE concentrations to casein compared with whey proteins (P < 0.001). In this group of patients, there was a positive correlation between IgE levels and levels of the other isotypes for all four milk proteins (P < 0.001). In general, the caseins were the more allergenic and antigenic proteins in all groups of patients. Patients with enterocolitis syndrome produced less milk protein-specific IgG4 (P < 0.05) and had a trend for higher IgA antibody levels when compared to the control group. Lymphocyte proliferative responses in all groups with CMA were significantly higher than controls (P < 0.05), although this response was similar in patients with IgE- and non-IgE-mediated CMA. There is a distinct pattern of humoral antibody response in the different forms of CMA. Patients with Ig

  1. Human Milk Oligosaccharides (HMOS): Structure, Function, and Enzyme-Catalyzed Synthesis.

    PubMed

    Chen, Xi

    2015-01-01

    The important roles played by human milk oligosaccharides (HMOS), the third major component of human milk, in the health of breast-fed infants have been increasingly recognized, as the structures of more than 100 different HMOS have now been elucidated. Despite the recognition of the various functions of HMOS as prebiotics, antiadhesive antimicrobials, and immunomodulators, the roles and the applications of individual HMOS species are less clear. This is mainly due to the limited accessibility to large amounts of individual HMOS in their pure forms. Current advances in the development of enzymatic, chemoenzymatic, whole-cell, and living-cell systems allow for the production of a growing number of HMOS in increasing amounts. This effort will greatly facilitate the elucidation of the important roles of HMOS and allow exploration into the applications of HMOS both as individual compounds and as mixtures of defined structures with desired functions. The structures, functions, and enzyme-catalyzed synthesis of HMOS are briefly surveyed to provide a general picture about the current progress on these aspects. Future efforts should be devoted to elucidating the structures of more complex HMOS, synthesizing more complex HMOS including those with branched structures, and developing HMOS-based or HMOS-inspired prebiotics, additives, and therapeutics.

  2. Milk: the new sports drink? A Review

    PubMed Central

    Roy, Brian D

    2008-01-01

    There has been growing interest in the potential use of bovine milk as an exercise beverage, especially during recovery from resistance training and endurance sports. Based on the limited research, milk appears to be an effective post-resistance exercise beverage that results in favourable acute alterations in protein metabolism. Milk consumption acutely increases muscle protein synthesis, leading to an improved net muscle protein balance. Furthermore, when post-exercise milk consumption is combined with resistance training (12 weeks minimum), greater increases in muscle hypertrophy and lean mass have been observed. Although research with milk is limited, there is some evidence to suggest that milk may be an effective post-exercise beverage for endurance activities. Low-fat milk has been shown to be as effective, if not more effective, than commercially available sports drinks as a rehydration beverage. Milk represents a more nutrient dense beverage choice for individuals who partake in strength and endurance activities, compared to traditional sports drinks. Bovine low-fat fluid milk is a safe and effective post exercise beverage for most individuals, except for those who are lactose intolerant. Further research is warranted to better delineate the possible applications and efficacy of bovine milk in the field of sports nutrition. PMID:18831752

  3. Protein synthesis inhibitor from potato tuber

    SciTech Connect

    Romaen, R. )

    1989-04-01

    A protein fraction capable of inhibit in vitro protein synthesis was found in potato tubers in fresh and wounded tissue. Inhibitor activity from fresh tissue decays with wounding. Inhibition activity was detected absorbed to ribsomal fraction and cytosol of potato tuber tissue by a partially reconstituted in vitro system from potato tuber and wheat germ. Adsorbed ribosomal fraction was more suitable of purification. This fraction was washed from ribosomes with 0.3M KCl, concentrated with ammonium sulfate precipitation and purified through sephadex G100 and sephadex G-75 columns chromatography. After 61 fold purification adsorbed protein fraction can inhibit germination of maize, wheat and sesame seeds, as well as {sup 3}H-leucine incorporation into protein by imbibed maize embryos. Inhibition activity was lost by temperature, alkali and protease-K hydrolysis. Preliminar analysis could not show presence of reductor sugars. Physiological role of this inhibitor in relation to rest and active tissue remains to be studied.

  4. Failure of leucine to stimulate protein synthesis in vivo.

    PubMed Central

    McNurlan, M A; Fern, E B; Garlick, P J

    1982-01-01

    The effect of 100 mumol of leucine on protein synthesis in several tissues was assessed in the intact rat. Leucine had no immediate effect on protein synthesis in gastrocnemius muscle, heart, jejunal serosa, jejunal mucosa or liver in rats which were fed, starved for 2 days or deprived of dietary protein for 9 days. Leucine treatment for 1 h also failed to stimulate protein synthesis in tissues of 2-day-starved animals. PMID:7126170

  5. Prediction of Drug Transfer into Milk Considering Breast Cancer Resistance Protein (BCRP)-Mediated Transport.

    PubMed

    Ito, Naoki; Ito, Kousei; Ikebuchi, Yuki; Toyoda, Yu; Takada, Tappei; Hisaka, Akihiro; Oka, Akira; Suzuki, Hiroshi

    2015-08-01

    Drug transfer into milk is of concern due to the unnecessary exposure of infants to drugs. Proposed prediction methods for such transfer assume only passive drug diffusion across the mammary epithelium. This study reorganized data from the literature to assess the contribution of carrier-mediated transport to drug transfer into milk, and to improve the predictability thereof. Milk-to-plasma drug concentration ratios (M/Ps) in humans were exhaustively collected from the literature and converted into observed unbound concentration ratios (M/Punbound,obs). The ratios were also predicted based on passive diffusion across the mammary epithelium (M/Punbound,pred). An in vitro transport assay was performed for selected drugs in breast cancer resistance protein (BCRP)-expressing cell monolayers. M/Punbound,obs and M/Punbound,pred values were compared for 166 drugs. M/Punbound,obs values were 1.5 times or more higher than M/Punbound,pred values for as many as 13 out of 16 known BCRP substrates, reconfirming BCRP as the predominant transporter contributing to secretory transfer of drugs into milk. Predictability of M/P values for selected BCRP substrates and non-substrates was improved by considering in vitro-evaluated BCRP-mediated transport relative to passive diffusion alone. The current analysis improved the predictability of drug transfer into milk, particularly for BCRP substrates, based on an exhaustive data overhaul followed by focused in vitro transport experimentation.

  6. Determination of free and bound riboflavin in cow's milk using a novel flavin-binding protein.

    PubMed

    Koop, Julia; Monschein, Stefanie; Pauline Macheroux, E; Knaus, Tanja; Macheroux, Peter

    2014-03-01

    A recently described putative protease from the gut bacterium Bacteroides thetaiotaomicron (termed ppBat) exhibits two tryptophan residues in the interface which enable specific binding of the isoalloxazine heterocycle of riboflavin and its two cofactor forms, FMN and FAD. Recombinant ppBat was used to capture riboflavin from bovine milk directly without any prior preparation steps. The flavin-loaded protein was then re-isolated by means of affinity chromatography to identify and quantify the captured flavins. Free riboflavin concentrations were determined to 197 and 151μg/l for milk with 3.5% and 0.5% fat content, respectively. Total riboflavin concentrations were also determined after acid-treatment of milk and were 4-5 times higher than for free riboflavin. Free FMN and FAD were not detectable and only trace amounts of FMN were found in milk following acid treatment. The method appears to be amenable to develop a direct assay for free riboflavin in milk and other foods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Cellular prion protein in mammary gland and milk fractions of domestic ruminants.

    PubMed

    Didier, A; Gebert, R; Dietrich, R; Schweiger, M; Gareis, M; Märtlbauer, E; Amselgruber, W M

    2008-05-09

    The present study shows that PrP(c) is expressed in the mammary gland and milk fractions of domestic ruminants in a species-specific manner. By applying immunohistochemistry, Western blot and ELISA, clear expression differences between bovine, ovine and caprine mammary gland, skimmed milk, acid whey and cream could be demonstrated, the highest relative PrP(c) levels being associated with the cream fraction. In the bovine gland PrP(c) was preferentially detectable at the basolateral surface of mammary gland epithelial cells, whereas in ovine and caprine samples the prion protein was more homogeneously distributed. Moreover, in ovine and caprine bovine mammary gland epithelial cells, apocrine secretory vesicles were strongly stained. Ovine and caprine milk proved to contain PrP(c) in all fractions with an additional truncated form at 12kDa in Western blot. This truncated isoform is the predominate one in caprine acid whey. These results support the hypothesis that the apocrine secretion mode of milk fat globules is a major way of PrP(c) transport into the milk.

  8. Increased Milk Protein Concentration in a Rehydration Drink Enhances Fluid Retention Caused by Water Reabsorption in Rats.

    PubMed

    Ito, Kentaro; Saito, Yuri; Ashida, Kinya; Yamaji, Taketo; Itoh, Hiroyuki; Oda, Munehiro

    2015-01-01

    A fluid-retention effect is required for beverages that are designed to prevent dehydration. That is, fluid absorbed from the intestines should not be excreted quickly; long-term retention is desirable. Here, we focused on the effect of milk protein on fluid retention, and propose a new effective oral rehydration method that can be used daily for preventing dehydration. We first evaluated the effects of different concentrations of milk protein on fluid retention by measuring the urinary volumes of rats fed fluid containing milk protein at concentrations of 1, 5, and 10%. We next compared the fluid-retention effect of milk protein-enriched drink (MPD) with those of distilled water (DW) and a sports drink (SD) by the same method. Third, to investigate the mechanism of fluid retention, we measured plasma insulin changes in rats after ingesting these three drinks. We found that the addition of milk protein at 5 or 10% reduced urinary volume in a dose-dependent manner. Ingestion of the MPD containing 4.6% milk protein resulted in lower urinary volumes than DW and SD. MPD also showed a higher water reabsorption rate in the kidneys and higher concentrations of plasma insulin than DW and SD. These results suggest that increasing milk protein concentration in a beverage enhances fluid retention, which may allow the possibility to develop rehydration beverages that are more effective than SDs. In addition, insulin-modifying renal water reabsorption may contribute to the fluid-retention effect of MPD.

  9. Protein synthesis by ribosomes with tethered subunits.

    PubMed

    Orelle, Cédric; Carlson, Erik D; Szal, Teresa; Florin, Tanja; Jewett, Michael C; Mankin, Alexander S

    2015-08-06

    The ribosome is a ribonucleoprotein machine responsible for protein synthesis. In all kingdoms of life it is composed of two subunits, each built on its own ribosomal RNA (rRNA) scaffold. The independent but coordinated functions of the subunits, including their ability to associate at initiation, rotate during elongation, and dissociate after protein release, are an established model of protein synthesis. Furthermore, the bipartite nature of the ribosome is presumed to be essential for biogenesis, since dedicated assembly factors keep immature ribosomal subunits apart and prevent them from translation initiation. Free exchange of the subunits limits the development of specialized orthogonal genetic systems that could be evolved for novel functions without interfering with native translation. Here we show that ribosomes with tethered and thus inseparable subunits (termed Ribo-T) are capable of successfully carrying out protein synthesis. By engineering a hybrid rRNA composed of both small and large subunit rRNA sequences, we produced a functional ribosome in which the subunits are covalently linked into a single entity by short RNA linkers. Notably, Ribo-T was not only functional in vitro, but was also able to support the growth of Escherichia coli cells even in the absence of wild-type ribosomes. We used Ribo-T to create the first fully orthogonal ribosome-messenger RNA system, and demonstrate its evolvability by selecting otherwise dominantly lethal rRNA mutations in the peptidyl transferase centre that facilitate the translation of a problematic protein sequence. Ribo-T can be used for exploring poorly understood functions of the ribosome, enabling orthogonal genetic systems, and engineering ribosomes with new functions.

  10. Use of different dietary protein sources for lactating goats: milk production and composition as functions of protein degradability and amino acid composition.

    PubMed

    Sanz Sampelayo, M R; Pérez, M L; Gil Extremera, F; Boza, J J; Boza, J

    1999-03-01

    To establish the effect of the nature of four different protein sources [fababeans, 27.8% crude protein (CP); sunflower meal, 41.7% CP; corn gluten feed, 18.8% CP; and cottonseed, 18.3% CP] on milk protein production by goats, the ruminal degradation of these feeds was studied as was the amino acid (AA) composition of the original material and that of the undegradable fractions of the protein sources. Four diets were designed; 20% of their protein was supplied by each of the different sources. Four groups of 5 Granadina goats were used to study the utilization of these diets for milk production. No significant differences were observed in dry matter intake or milk production. The milk produced by goats fed the diet containing sunflower meal had the lowest protein concentration; the highest milk protein concentration was observed for goats fed the diet containing corn gluten feed. From a multivariate analysis, it was deduced that the quickly degradable protein fraction in the rumen and the ruminally undegradable protein fraction were the components of the protein sources most directly related to the milk protein produced. Given the similar AA profiles of the undegradable fractions of the different protein sources, the possible supplementation achieved from these ruminally undegradable fractions must be established by the amount of protein supplied regardless of AA composition.

  11. The effect of high and low levels of supplementation on milk production, nitrogen utilization efficiency, and milk protein fractions in late-lactation dairy cows.

    PubMed

    Reid, M; O'Donovan, M; Murphy, J P; Fleming, C; Kennedy, E; Lewis, E

    2015-08-01

    To fill the feed deficit in the autumn/late lactation period in a seasonal grazing system, supplementation is required. This study aimed to investigate the use of baled grass silage or concentrate as supplementation to grazing dairy cows in late lactation. Eighty-four grass-based spring-calving dairy cows, averaging 212d in milk, were allocated to 1 of 6 treatments [high grass allowance (HG), low grass allowance (LG), grass with a low concentrate allocation (GCL), grass with a low grass silage allocation (GSL), grass with a high concentrate allocation (GCH), and grass with a high grass silage allocation (GSH)] to measure the effects of using baled grass silage or concentrate as supplements to grazed grass. Effects on intake, milk yield, milk composition and N fractions, and N utilization efficiency were measured. Treatments HG and LG received 17 and 14kg of dry matter (DM) grass/cow per d, respectively. Treatments GCL and GSL were offered 14kg of DM grass/cow per d and 3kg of DM of supplementation/cow per d. Treatments GCH and GSH were offered 11kg of DM grass/cow per d and 6kg of DM of supplementation/cow per d. Milk yield was greatest in the GCH treatment and milk solids yield was greatest in both concentrate-supplemented treatments. The HG and LG treatments excreted a greater quantity of N as a proportion of N intake than the supplemented treatments. The HG treatment also excreted the greatest total quantity of N. This indicates an improvement in N utilization efficiency when supplementation is offered compared with grazing only. Offering 6kg of DM of either grass silage or concentrate as supplementation decreased milk true protein concentration compared with offering a grass-only diet. This suggests that increasing the proportion of supplementation relative to grass may negatively affect milk processability, which is associated with milk true protein concentration.

  12. Influences of different thermal processings in milk, bovine meat and frog protein structure.

    PubMed

    Coura Oliveira, Tatiana; Lopes Lima, Samuel; Bressan, Josefina

    2013-01-01

    Several studies have associated the digestibility of proteins to its imunogenic potential. Though, it was objectified to evaluate the impact of the thermal processing with high and low temperatures on the proteins structure of three types of foods, by means of the digestibility in vitro and electroforesis en gel de poliacrilamida. The pasteurize was observed in such a way, firing 95 ºC during 15 minutes, how much freeze dried causes qualitative and quantitative modifications of constituent proteins of the food. The most sensible proteins to the increasing thermal processing order were beef, frog meat, and the last, cow milk.

  13. Native and Heated Hydrolysates of Milk Proteins and Their Capacity to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model.

    PubMed

    Carrillo, Wilman; Guzmán, Xavier; Vilcacundo, Edgar

    2017-09-14

    Casein and whey proteins with and without heat treatment were obtained of whole milk and four commercial milks in Ecuador, and were hydrolyzed. Then, their capacity to inhibit the lipid peroxidation using the TBARS method was evaluated at concentrations of 0.02, 0.04, 0.2, and, 0.4 mg/mL. Native and heated hydrolysates of milk proteins present high inhibitions of lipid peroxidation with a dose dependent effect both in vivo and in vitro tests. Casein and whey proteins obtained from whole milk were the ones with the highest anti-oxidant activity in vitro and in vivo test. Native casein hydrolysate at 0.4 mg/mL present a value of 55.55% of inhibition of lipid peroxidation and heated casein hydrolysate at 0.4 mg/mL presents a value of 58.00% of inhibition of lipid peroxidation. Native whey protein at 0.4 mg/mL present a value of 34.84% of inhibition of lipid peroxidation, and heated whey protein at 0.4 mg/mL presents a value of 40.86% of inhibition of lipid peroxidation. Native and heated casein hydrolysates were more active than native and heated whey protein hydrolysates. Heat treatments have an effect of increasing the in vitro inhibition of lipid peroxidation of hydrolysates of milk protein. Casein and whey hydrolysates were able to inhibiting lipid peroxidation in the zebrafish larvae model. Native casein hydrolysate obtained of whole milk presents 48.35% of inhibition TBARS in vivo, this activity was higher in heated casein hydrolysate obtained of whole milk with a value of 56.28% of inhibition TBARS in vivo. Native whey protein hydrolysate obtained of whole milk presents 35.30% of inhibition TBARS, and heated whey protein hydrolysate obtained of whole milk was higher, with a value of 43.60% of inhibition TBARS in vivo.

  14. Native and Heated Hydrolysates of Milk Proteins and Their Capacity to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model

    PubMed Central

    Carrillo, Wilman; Guzmán, Xavier; Vilcacundo, Edgar

    2017-01-01

    Casein and whey proteins with and without heat treatment were obtained of whole milk and four commercial milks in Ecuador, and were hydrolyzed. Then, their capacity to inhibit the lipid peroxidation using the TBARS method was evaluated at concentrations of 0.02, 0.04, 0.2, and, 0.4 mg/mL. Native and heated hydrolysates of milk proteins present high inhibitions of lipid peroxidation with a dose dependent effect both in vivo and in vitro tests. Casein and whey proteins obtained from whole milk were the ones with the highest anti-oxidant activity in vitro and in vivo test. Native casein hydrolysate at 0.4 mg/mL present a value of 55.55% of inhibition of lipid peroxidation and heated casein hydrolysate at 0.4 mg/mL presents a value of 58.00% of inhibition of lipid peroxidation. Native whey protein at 0.4 mg/mL present a value of 34.84% of inhibition of lipid peroxidation, and heated whey protein at 0.4 mg/mL presents a value of 40.86% of inhibition of lipid peroxidation. Native and heated casein hydrolysates were more active than native and heated whey protein hydrolysates. Heat treatments have an effect of increasing the in vitro inhibition of lipid peroxidation of hydrolysates of milk protein. Casein and whey hydrolysates were able to inhibiting lipid peroxidation in the zebrafish larvae model. Native casein hydrolysate obtained of whole milk presents 48.35% of inhibition TBARS in vivo, this activity was higher in heated casein hydrolysate obtained of whole milk with a value of 56.28% of inhibition TBARS in vivo. Native whey protein hydrolysate obtained of whole milk presents 35.30% of inhibition TBARS, and heated whey protein hydrolysate obtained of whole milk was higher, with a value of 43.60% of inhibition TBARS in vivo. PMID:28906440

  15. Electrophoretic characterization of protein interactions suggesting limited feasibility of accelerated shelf-life testing of ultra-high temperature milk.

    PubMed

    Grewal, Manpreet Kaur; Chandrapala, Jayani; Donkor, Osaana; Apostolopoulos, Vasso; Vasiljevic, Todor

    2017-01-01

    Accelerated shelf-life testing is applied to a variety of products to estimate keeping quality over a short period of time. The industry has not been successful in applying this approach to ultra-high temperature (UHT) milk because of chemical and physical changes in the milk proteins that take place during processing and storage. We investigated these protein changes, applying accelerated shelf-life principles to UHT milk samples with different fat levels and using native- and sodium dodecyl sulfate-PAGE. Samples of UHT skim and whole milk were stored at 20, 30, 40, and 50°C for 28d. Irrespective of fat content, UHT treatment had a similar effect on the electrophoretic patterns of milk proteins. At the start of testing, proteins were bonded mainly through disulfide and noncovalent interactions. However, storage at and above 30°C enhanced protein aggregation via covalent interactions. The extent of aggregation appeared to be influenced by fat content; whole milk contained more fat than skim milk, implying aggregation via melted or oxidized fat, or both. Based on reduction in loss in absolute quantity of individual proteins, covalent crosslinking in whole milk was facilitated mainly by products of lipid oxidation and increased access to caseins for crosslinking reactions. Maillard and dehydroalanine products were the main contributors involved in protein changes in skim milk. Protein crosslinking appeared to follow a different pathway at higher temperatures (≥40°C) than at lower temperatures, making it very difficult to extrapolate these changes to protein interactions at lower temperatures. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Supporting Production of Milk and Milk Components on Low Protein Diets

    USDA-ARS?s Scientific Manuscript database

    There is increasing interest in minimizing crude protein (CP) content of diets fed to dairy cows to reduce production costs and to improve environmental sustainability. Dietary CP not utilized for production is lost largely in the urine, the most polluting form of excretory nitrogen (N). Because mic...

  17. Effect of rumen-protected methionine on feed intake, milk production, true milk protein concentration, and true milk protein yield, and the factors that influence these effects: a meta-analysis.

    PubMed

    Patton, R A

    2010-05-01

    A meta-analysis of published studies was used to investigate the effect of rumen-protected methionine (RPM) added to the diets of lactating dairy cattle on dry matter intake, milk production, true milk protein (TMP) production, and milk fat yield. Differences in responses between 2 commonly used RPM products, Mepron (Evonik Industries, Hanau, Germany) and Smartamine (Adisseo, Antony, France), were investigated as well as dietary and animal factors that could influence responses. Diets were coded with respect to the amino acid (AA) deficiency of the control diet as predicted by the AminoCow model (version 3.5.2, http://www.makemilknotmanure.com/aminocow.php; 0=no AA deficiency, 1=Met deficiency, 2=Met and Lys deficiency, 3=Met and Lys plus at least 1 other AA deficiency) to test the effect of AA deficiencies on RPM response. Thirty-five studies were identified, 17 studies evaluating Mepron, 18 studies evaluating Smartamine, and 1 study evaluating both. This permitted 75 dietary comparisons between control and RPM-added diets. Diets were entered into the AminoCow and the 2001 National Research Council models to compare predictions of Met, Lys, and metabolizable protein (MP) flow. Mean Met and Lys in diets where RPM was fed were estimated to be 2.35 and 6.33% of MP, respectively. Predictions of flows between models were similar. Overall, RPM addition to diets increased production of TMP, both as percentage (0.07%) and yield (27 g/d). Dry matter intake and milk fat percentage were slightly decreased, whereas milk production was slightly increased. Differences between products were detected for all production variables, with Mepron-fed cows producing less TMP percentage but greater milk production, resulting in twice as much TMP yield. Milk protein response to RPM was not related to predicted AA deficiency, calculated Met deficiency, or Met as a percentage of MP. Other dietary factors, including Lys flow (g/d), Lys as percentage of MP, neutral detergent fiber percentage

  18. [Determination of total protein content in soya-bean milk via visual moving reaction boundary titration].

    PubMed

    Guo, Chengye; Wang, Houyu; Zhang, Lei; Fan, Liuyin; Cao, Chengxi

    2013-11-01

    A visual, rapid and accurate moving reaction boundary titration (MRBT) method was used for the determination of the total protein in soya-bean milk. During the process, moving reaction boundary (MRB) was formed by hydroxyl ions in the catholyte and soya-bean milk proteins immobilized in polyacrylamide gel (PAG), and an acid-base indicator was used to denote the boundary motion. The velocity of MRB has a relationship with protein concentration, which was used to obtain a standard curve. By paired t-test, there was no significant difference of the protein content between MRBT and Kjeldahl method at 95% confidence interval. The procedure of MRBT method required about 10 min, and it had linearity in the range of 2.0-14.0 g/L, low limit of detection (0.05 g/L), good precision (RSD of intra-day < 1.90% and inter-day < 4.39%), and high recoveries (97.41%-99.91%). In addition, non-protein nitrogen (NPN) such as melamine added into the soya-bean milk had weak influence on MRBT results.

  19. Functional properties and applications of edible films made of milk proteins.

    PubMed

    Chen, H

    1995-11-01

    Edible films and coatings based on milk proteins have been developed to be used as a protective layer on foods or between food components. The most important functionalities of an edible film or coating include control of mass transfers, mechanical protection, and sensory appeal. Control of mass transfers involves preventing foods from desiccation, regulating microenvironments of gases around foods, and controlling migration of ingredients and additives in the food systems. Adequate mechanical strength of an edible film is necessary to protect the integrity of packaging throughout distribution. The sensory properties of an edible coating or film are a key factor for acceptance of final products. Simple milk protein films are good barriers to gas transfers because of their complex intermolecular bindings. Lipid is frequently incorporated into protein films to improve their properties as barriers to moisture vapor. Protein films are distinctly different in mechanical profiles from those films made of other materials. Approaches traditionally used in material sciences have been adapted and modified for studying the functionality of edible films. Potential uses of innovative processing technologies in film making to alter the film functionality are briefly discussed. A survey of potential applications of edible film based on milk protein is presented.

  20. [Disc electrophoretic characteristics of the serum proteins of "Vitalact"-type "humanized" milk].

    PubMed

    Kalashnikova, L P

    1977-01-01

    Disc-electrophoreograms in the polyacrylamide gel of the cow milk serumal proteins show 11 peaks belonging to immune globulins, the poteose-peptone fraction, the serum-globulin, alpha-lactoalbumin, beta-lactoglobulin and to glucoproteids. Under a high-temperature treatment of humanized milk (105 degrees----10 minutes) a significant denaturation of the serumal proteins, re-distribution and a fall in the amount of proteinic fractions were noted. Beta-lactoglobulins and immune globulins are most sensitive. With disc-eletrophoresis in the polyacrylamide gel of the human milk serumal proteins the densitograms distinctly demonstrate the presence of peaks that correspond to immunoglobulins, proteose-peptones, serum-albumins, alpha-lacto-albumins in the absence of the beta-lactoglobulins fraction. The cited data allow the method of disc-electrophoresis in the polyacrylamide gel to be employed for improving the fractional composition of the serumal proteins in the nutrients intended for nurslings and infants of the first year of life.

  1. Evaluation of microchip material and surface treatment options for IEF of allergenic milk proteins on microchips.

    PubMed

    Poitevin, Martine; Shakalisava, Yuliya; Miserere, Sandrine; Peltre, Gabriel; Viovy, Jean-Louis; Descroix, Stephanie

    2009-12-01

    The use of glass and PDMS microchips has been investigated to perform rapid and efficient separation of allergenic whey proteins by IEF. To decrease EOF and to limit protein adsorption, two coating procedures have been compared. The first one consists in immobilizing hydroxypropyl cellulose (HPC) and the second one poly(dimethylacrylamide-co-allyl glycidyl ether) (PDMA-AGE). EOF limitation has been evaluated using frontal electrophoresis of a fluorescent marker of known effective mobility. EOF velocity was decreased by a factor about 100 and 30, respectively. pH gradient formation has been evaluated for each microchip using fluorescent pI markers. It was demonstrated that as expected a coating was essential to avoid pH gradient drift. Both coatings were efficient on glass microchips, but only PDMA-AGE allowed satisfying focusing of pI markers on PDMS microchips. Fluorescent covalent and noncovalent labelings of milk proteins have been compared by IEF on slab-gels. IEF separation of three major allergenic whey proteins [beta-lactoglobulin A (pI 5.25) and B (pI 5.35) and alpha-lactalbumin (pI 4.2-4.5)] was performed in both microchips. Milk proteins were separated with better resolution and shorter analysis time than by classical CIEF. Finally, better resolutions for milk allergens separation were obtained on glass microchips.

  2. Effects of Holder pasteurization on the protein profile of human milk.

    PubMed

    Peila, Chiara; Coscia, Alessandra; Bertino, Enrico; Cavaletto, Maria; Spertino, Stefano; Icardi, Sara; Tortone, Claudia; Visser, Gerard H A; Gazzolo, Diego

    2016-04-07

    The most widespread method for the treatment of donor milk is the Holder pasteurization (HoP). The available literature data show that HoP may cause degradation of some bioactive components. The aim of this study was to determine the effect of HoP on the protein profile of human milk (HM) using a GeLC-MS method, a proteomic approach and a promising technique able to offer a qualitative HM protein profile. HM samples were collected by standardized methods from 20 mothers carrying both preterm and term newborns. A aliquot of each sample was immediately frozen at -80 °C, whilst another one was Holder pasteurized and then frozen. All samples were then analyzed by GeLC-MS. The protein bands of interest were excised from the gel, digested with trypsin and identified by nano-HPLC-MS/MS analysis. The protein profile before and after HoP showed qualitative differences only in 6 samples out of 20, while in the remaining 14 no detectable differences were found. The differences interested only colostrums and transitional milk samples and regarded the decrease of the electrophoretic bands corresponding to alpha and beta-casein, tenascin, lactoferrin and immunoglobulin. In the majority of samples, HoP did not cause any modification, thereby preserving the biological activity of HM proteins.

  3. Target fortification of breast milk: levels of fat, protein or lactose are not related.

    PubMed

    Fusch, Gerhard; Mitra, Souvik; Rochow, Niels; Fusch, Christoph

    2015-01-01

    Target fortification (TFO) of breast milk has the potential to improve the nutritional outcomes of preterm infants. However, the primary logistic constraint in introducing TFO is analysers that rapidly and accurately analyse macronutrients (fat, protein and lactose). In this prospective observational study, we aim to evaluate whether the levels of fat, protein and carbohydrate could be predicted from one key macronutrient. Macronutrient components were measured in 543 breast milk samples using validated chemical micro-methods. Correlation analysis for fat versus protein, fat versus lactose and lactose versus protein was computed using Pearson's correlation. The concentration of the macronutrients ranged from 0.7 to 10.3 g/100 mL (3.7 ± 1.2, mean ± SD) for fat, 0.7 to 3.2 g/100 mL (1.3 ± 0.3) for protein and 4.0 to 8.8 g/100 mL (5.8 ± 0.7) for lactose, respectively. There was no correlation between the three macronutrients. This lack of correlation underlines the importance of routine and accurate analysis of all three macronutrients in breast milk prior to TFO. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  4. Glucocorticoid effects on hippocampal protein synthesis

    SciTech Connect

    Schlatter, L.K.

    1988-01-01

    Following subcutaneous injection of rats with 5 mg corticosterone, hippocampal slices in vitro show increased ({sup 35}S)-methionine labeling of a cytosolic protein with an apparent molecular weight (M{sub r}) of 35,000 and an isoelectric point (IEP) of 6.6. This labeling is temporally consistent with a transcriptional event, and is steroid- and tissue-specific. The pear serum concentration of steroid occurs one hour or less following the injection. Maximal labeling of this protein is reached whenever serum corticosterone values are approximately 100 ng/ml. When endogenous corticosterone levels are elevated to 100 ng/ml through stressors or exogenous ACTH injections the same maximal increase in synthesis of the 35,000 M{sub r} protein is observed. Adrenalectomy prevents the observed response from occurring following stressor application or ACTH injections. Comparison of the increases observed after administration of the type 2 receptor agonist RU 28362 and aldosterone, which has a higher affinity for the type 1 receptor, shows a 50-fold greater sensitivity of the response to the type 2 receptor agonist. Synthesis of this protein following serum increases of steroid possibly correlates to the theorized function of the type 2 receptor feedback regulation. The similar protein in the liver has an IEP of 6.8 and a slightly higher M{sub r}. A second hippocampal protein with an M{sub r} of 46,000 and an IEP of 6.2 is also increased in labeling. Two additional liver proteins, one of Mr 53,000 (IEP of 6.2) and the other with an M{sub r} of 45,000 (IEP of 8.7-7.8) are increased in the liver following glucocorticoid administration.

  5. Fast and selective determination of total protein in milk powder via titration of moving reaction boundary electrophoresis.

    PubMed

    Guo, Cheng-ye; Wang, Hou-yu; Liu, Xiao-ping; Fan, Liu-yin; Zhang, Lei; Cao, Cheng-xi

    2013-05-01

    In this paper, moving reaction boundary titration (MRBT) was developed for rapid and accurate quantification of total protein in infant milk powder, from the concept of moving reaction boundary (MRB) electrophoresis. In the method, the MRB was formed by the hydroxide ions and the acidic residues of milk proteins immobilized via cross-linked polyacrylamide gel (PAG), an acid-base indicator was used to denote the boundary motion. As a proof of concept, we chose five brands of infant milk powders to study the feasibility of MRBT method. The calibration curve of MRB velocity versus logarithmic total protein content of infant milk powder sample was established based on the visual signal of MRB motion as a function of logarithmic milk protein content. Weak influence of nonprotein nitrogen (NPN) reagents (e.g., melamine and urea) on MRBT method was observed, due to the fact that MRB was formed with hydroxide ions and the acidic residues of captured milk proteins, rather than the alkaline residues or the NPN reagents added. The total protein contents in infant milk powder samples detected via the MRBT method were in good agreement with those achieved by the classic Kjeldahl method. In addition, the developed method had much faster measuring speed compared with the Kjeldahl method.

  6. The evolution of the protein synthesis system. I - A model of a primitive protein synthesis system

    NASA Technical Reports Server (NTRS)

    Mizutani, H.; Ponnamperuma, C.

    1977-01-01

    A model is developed to describe the evolution of the protein synthesis system. The model is comprised of two independent autocatalytic systems, one including one gene (A-gene) and two activated amino acid polymerases (O and A-polymerases), and the other including the addition of another gene (N-gene) and a nucleotide polymerase. Simulation results have suggested that even a small enzymic activity and polymerase specificity could lead the system to the most accurate protein synthesis, as far as permitted by transitions to systems with higher accuracy.

  7. The evolution of the protein synthesis system. I - A model of a primitive protein synthesis system

    NASA Technical Reports Server (NTRS)

    Mizutani, H.; Ponnamperuma, C.

    1977-01-01

    A model is developed to describe the evolution of the protein synthesis system. The model is comprised of two independent autocatalytic systems, one including one gene (A-gene) and two activated amino acid polymerases (O and A-polymerases), and the other including the addition of another gene (N-gene) and a nucleotide polymerase. Simulation results have suggested that even a small enzymic activity and polymerase specificity could lead the system to the most accurate protein synthesis, as far as permitted by transitions to systems with higher accuracy.

  8. Anti-infective proteins in breast milk and asthma-associated phenotypes during early childhood.

    PubMed

    Zhang, Guicheng; Lai, Ching Tat; Hartmann, Peter; Oddy, Wendy H; Kusel, Merci M H; Sly, Peter D; Holt, Patrick G

    2014-10-01

    The impact of breast milk feeding on susceptibility to asthma in childhood is highly controversial, due in part to failure of the majority of studies in the area to adequately account for key confounders exemplified by respiratory infection history, plus the effects of recall bias. As part of a prospective cohort study on the role of respiratory infections in asthma development in high-risk children, we measured the concentration of a panel of anti-infective proteins in maternal milk samples and analyzed associations between these and subsequent atopy-, infection-, and asthma-related outcomes prospectively to age 10 years. We observed significant but transient inverse associations between the concentration of milk proteins and susceptibility to upper respiratory infections in year 1 only, and parallel but positive transient associations with early lower respiratory infections and atopy. No associations were seen with asthma-related outcomes. Breast milk feeding may influence the expression of inflammatory symptoms associated with respiratory infections and atopy in early life, but these effects appear to be inconsistent and transient. The heterogeneous nature of breast-feeding effects suggests it may influence systemic immunoinflammatory function at several different levels. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Utilization of supercritical carbon dioxide to produce milk protein fractions

    USDA-ARS?s Scientific Manuscript database

    The nutritional, functional and bioactive properties of the individual whey proteins are appreciated by health-conscious consumers, yet few methods have been developed to produce these proteins to satisfy demand. The methods that are available are relatively new technologies that have not been prove...

  10. Associations between milk-protein production and reproduction, health, and culling.

    PubMed

    Sargeant, J M; Martin, S W; Lissemore, K D; Leslie, K E; Gibson, J P; Scott, H M; Kelton, D F

    1998-04-16

    Associations between protein production and individual-cow reproductive performance, health, and culling were investigated in a 2-year observational study involving a convenience sample of 75 Ontario, 5 Alberta, and 3 Nova Scotia dairy farms. Protein production was defined by 305-day lactation protein yields and by estimated breeding values for protein yield. After controlling for the level of milk production, herd, parity, breed, and season of calving, there were no significant associations between either measure of protein production and days open or days to first breeding. The only associations between protein production and disease were small positive associations between the estimated breeding value for protein yield and cystic ovaries and mean lactation somatic cell count. The risk of culling, after controlling for the level of milk production, was negatively associated with previous-lactation 305-day protein yield for parity three animals only. The estimated breeding value for protein yield had a small negative association with the overall risk of culling, although the associations were not significant for individual lactations.

  11. Engineering the prion protein using chemical synthesis.

    PubMed

    Ball, H L; King, D S; Cohen, F E; Prusiner, S B; Baldwin, M A

    2001-11-01

    In recent years, the technology of solid-phase peptide synthesis (SPPS) has improved to the extent that chemical synthesis of small proteins may be a viable complementary strategy to recombinant expression. We have prepared several modified and wild-type prion protein (PrP) polypeptides, of up to 112 residues, that demonstrate the flexibility of a chemical approach to protein synthesis. The principal event in prion disease is the conformational change of the normal, alpha-helical cellular protein (PrPc) into a beta-sheet-rich pathogenic isoform (PrP(Sc)). The ability to form PrP(Sc) in transgenic mice is retained by a 106 residue 'mini-prion' (PrP106), with the deletions 23-88 and 141-176. Synthetic PrP106 (sPrP106) and a His-tagged analog (sPrP106HT) have been prepared successfully using a highly optimized Fmoc chemical methodology involving DCC/HOBt activation and an efficient capping procedure with N-(2-chlorobenzyloxycarbonyloxy) succinimide. A single reversed-phase purification step gave homogeneous protein, in excellent yield. With respect to its conformational and aggregational properties and its response to proteinase digestion, sPrP106 was indistinguishable from its recombinant analog (rPrP106). Certain sequences that proved to be more difficult to synthesize using the Fmoc approach, such as bovine (Bo) PrP(90-200), were successfully prepared using a combination of the highly activated coupling reagent HATU and t-Boc chemistry. To mimic the glycosylphosphatidyl inositol (GPI) anchor and target sPrP to cholesterol-rich domains on the cell surface, where the conversion of PrPc is believed to occur, a lipophilic group or biotin, was added to an orthogonally side-chain-protected Lys residue at the C-terminus of sPrP sequences. These groups enabled sPrP to be immobilized on either the cell surface or a streptavidin-coated ELISA plate, respectively, in an orientation analogous to that of membrane-bound, GPI-anchored PrPc. The chemical manipulation of such

  12. Effect of unsaturated fatty acids and triglycerides from soybeans on milk fat synthesis and biohydrogenation intermediates in dairy cattle.

    PubMed

    Boerman, J P; Lock, A L

    2014-11-01

    Increased rumen unsaturated fatty acid (FA) load is a risk factor for milk fat depression. This study evaluated if increasing the amount of unsaturated FA in the diet as triglycerides or free FA affected feed intake, yield of milk and milk components, and feed efficiency. Eighteen Holstein cows (132 ± 75 d in milk) were used in a replicated 3 × 3 Latin square design. Treatments were a control (CON) diet, or 1 of 2 unsaturated FA (UFA) treatments supplemented with either soybean oil (FA present as triglycerides; TAG treatment) or soybean FA distillate (FA present as free FA; FFA treatment). The soybean oil contained a higher concentration of cis-9 C18:1 (26.0 vs. 11.8 g/100g of FA) and lower concentrations of C16:0 (9.6 vs. 15.0 g/100g of FA) and cis-9,cis-12 C18:2 (50.5 vs. 59.1g/100g of FA) than the soybean FA distillate. The soybean oil and soybean FA distillate were included in the diet at 2% dry matter (DM) to replace soyhulls in the CON diet. Treatment periods were 21 d, with the final 4 d used for sample and data collection. The corn silage- and alfalfa silage-based diets contained 23% forage neutral detergent fiber and 17% crude protein. Total dietary FA were 2.6, 4.2, and 4.3% of diet DM for CON, FFA, and TAG treatments, respectively. Total FA intake was increased 57% for UFA treatments and was similar between FFA and TAG. The intakes of individual FA were similar, with the exception of a 24 g/d lower intake of C16:0 and a 64 g/d greater intake of cis-9 C18:1 for the TAG compared with the FFA treatment. Compared with CON, the UFA treatments decreased DM intake (1.0 kg/d) but increased milk yield (2.2 kg/d) and milk lactose concentration and yield. The UFA treatments reduced milk fat concentration, averaging 3.30, 3.18, and 3.11% for CON, FFA, and TAG treatments, respectively. Yield of milk fat, milk protein, and 3.5% fat-corrected milk remained unchanged when comparing CON with the UFA treatments. No differences existed in the yield of milk or milk

  13. Effects of intravenous infusion of amino acids and glucose on the yield and concentration of milk protein in dairy cows.

    PubMed

    Kim, C H; Kim, T G; Choung, J J; Chamberlain, D G

    2001-02-01

    To test the hypothesis that the availability of glucose or its precursors can influence the response of milk protein concentration to the intravenous infusion of amino acids, five cows were used in a 5 x 5 Latin square design with period lengths of 7 d. The five treatments were the basal diet of grass silage ad lib. plus 5 kg/d of a cereal-based supplement containing feather meal (Basal); Basal plus 4 g/d histidine, 8 g/d methionine and 26 g/d lysine (4H); Basal plus 8 g/d histidine, 8 g/d methionine and 26 g/d lysine (SH); and these two amino acid mixtures together with 600 g/d of gluctose (4HG and 8HG respectively). Earlier experiments with this basal diet had shown that histidine was first-limiting for secretion of milk protein, followed by methionine and lysine. The yield of milk protein was increased progressively with the amount of histidine infused. The efficiency of transfer of histidine into milk protein was 0.42 for the 4H and 4HG and 0.35 for the 8H and 8HG treatments, and the concentration of milk protein was increased over Basal by all infusion treatments. However, milk protein concentrations were higher, and lactose concentrations in the milk were lower, in the absence of added glucose. Concentrations of insulin in blood plasma were not affected by treatment. It is concluded that, with the treatments without added glucose, a shortage of glucose prevented an increase in lactose secretion, and hence limited the increase in milk yield, leading to an increased concentration of protein in the milk.

  14. Stability of milk fat globule membrane proteins toward human enzymatic gastrointestinal digestion.

    PubMed

    Le, T T; Van de Wiele, T; Do, T N H; Debyser, G; Struijs, K; Devreese, B; Dewettinck, K; Van Camp, J

    2012-05-01

    The milk fat globule membrane (MFGM) fraction refers to the thin film of polar lipids and membrane proteins that surrounds fat globules in milk. It is its unique biochemical composition that renders MFGM with some beneficial biological activities, such as anti-adhesive effects toward pathogens. However, a prerequisite for the putative bioactivity of MFGM is its stability during gastrointestinal digestion. We, therefore, subjected MFGM material, isolated from raw milk, to an in vitro enzymatic gastrointestinal digestion. Sodium dodecyl sulfate PAGE, in combination with 2 staining methods, Coomassie Blue and periodic acid Schiff staining, was used to evaluate polypeptide patterns of the digest, whereas mass spectrometry was used to confirm the presence of specific MFGM proteins. Generally, it was observed that glycoproteins showed higher resistance to endogenous proteases compared with non-glycosylated proteins. Mucin 1 displayed the highest resistance to digestion and a considerable part of this protein was still detected at its original molecular weight after gastric and small intestine digestion. Cluster of differentiation 36 was also quite resistant to pepsin. A significant part of periodic acid Schiff 6/7 survived the gastric digestion, provided that the lipid moiety was not removed from the MFGM material. Overall, MFGM glycoproteins are generally more resistant to gastrointestinal digestion than serum milk proteins and the presence of lipids, besides glycosylation, may protect MFGM glycoproteins from gastrointestinal digestion. This gastrointestinal stability makes MFGM glycoproteins amenable to further studies in which their putative health-promoting effects can be explored. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Lactosomes: structural and compositional classification of unique nanometer-sized protein lipid particles of human milk

    PubMed Central

    Argov- Argaman, Nurit; Smilowitz, Jennifer T.; Bricarello, Daniel A.; Barboza, Mariana; Lerno, Larry; Froehlich, John W.; Lee, Hyeyoung; Zivkovic, Angela M.; Lemay, Danielle G.; Freeman, Samara; Lebrilla, Carlito B.; Parikh, Atul N.; German, J. Bruce

    2010-01-01

    Milk fat globules (MFG) are accepted primarily as triacylglycerol delivery systems. The identification of nanometer-sized lipid-protein particles termed ‘lactosomes’ that do not contain triacylglycerol raises the question of their possible functions. MFGs were isolated by slow centrifugation and lactosomes were isolated by ultracentrifugation at a density equivalent to plasma HDL (d > 1.063 g/ml) from human milk obtained from six volunteers at different lactation stages. Isolated lactosomes were analyzed and compared with MFGs for their size distribution, lipidome, proteome, and functional activity. Lactosomes from early milk—day 8, were found to be similar in size as those from mature milk >28 days averaging ~25 nm in diameter. In total, 97 non-redundant proteins were identified in the MFG and lactosome fractions, 46 of which were unique to the MFG fraction and 29 of which were unique to the lactosome fraction. The proteins identified in the lactosome and MFG fractions were enriched with proteins identified with immunomodulatory pathways. Unlike MFGs and GM1 laden reconstituted high- density lipoprotein (rHDL) that served as a positive control, lactosomal binding capacity to cholera toxin was weak. Lipidomic analyses found that lactosomes were devoid of triacylglycerol and gangliosides, unlike MFGs, but rich in a variety of phospholipid species. The data found differences in structure, composition and function between lactosomes and MFG suggesting these two particles are derived from different biosynthetic and/or secretory pathways. The results reveal a bioactive lipid-protein, nanometer-length scale particle that is secreted into milk not to supply energy to the infant, but to play unique, protective and regulatory roles. PMID:20925428

  16. Calling Biomarkers in Milk Using a Protein Microarray on Your Smartphone.

    PubMed

    Ludwig, Susann K J; Tokarski, Christian; Lang, Stefan N; van Ginkel, Leendert A; Zhu, Hongying; Ozcan, Aydogan; Nielen, Michel W F

    2015-01-01

    Here we present the concept of a protein microarray-based fluorescence immunoassay for multiple biomarker detection in milk extracts by an ordinary smartphone. A multiplex immunoassay was designed on a microarray chip, having built-in positive and negative quality controls. After the immunoassay procedure, the 48 microspots were labelled with Quantum Dots (QD) depending on the protein biomarker levels in the sample. QD-fluorescence was subsequently detected by the smartphone camera under UV light excitation from LEDs embedded in a simple 3D-printed opto-mechanical smartphone attachment. The somewhat aberrant images obtained under such conditions, were corrected by newly developed Android-based software on the same smartphone, and protein biomarker profiles were calculated. The indirect detection of recombinant bovine somatotropin (rbST) in milk extracts based on altered biomarker profile of anti-rbST antibodies was selected as a real-life challenge. RbST-treated and untreated cows clearly showed reproducible treatment-dependent biomarker profiles in milk, in excellent agreement with results from a flow cytometer reference method. In a pilot experiment, anti-rbST antibody detection was multiplexed with the detection of another rbST-dependent biomarker, insulin-like growth factor 1 (IGF-1). Milk extract IGF-1 levels were found to be increased after rbST treatment and correlated with the results obtained from the reference method. These data clearly demonstrate the potential of the portable protein microarray concept towards simultaneous detection of multiple biomarkers. We envisage broad application of this 'protein microarray on a smartphone'-concept for on-site testing, e.g., in food safety, environment and health monitoring.

  17. Calling Biomarkers in Milk Using a Protein Microarray on Your Smartphone

    PubMed Central

    Ludwig, Susann K. J.; Tokarski, Christian; Lang, Stefan N.; van Ginkel, Leendert A.; Zhu, Hongying; Ozcan, Aydogan; Nielen, Michel W. F.

    2015-01-01

    Here we present the concept of a protein microarray-based fluorescence immunoassay for multiple biomarker detection in milk extracts by an ordinary smartphone. A multiplex immunoassay was designed on a microarray chip, having built-in positive and negative quality controls. After the immunoassay procedure, the 48 microspots were labelled with Quantum Dots (QD) depending on the protein biomarker levels in the sample. QD-fluorescence was subsequently detected by the smartphone camera under UV light excitation from LEDs embedded in a simple 3D-printed opto-mechanical smartphone attachment. The somewhat aberrant images obtained under such conditions, were corrected by newly developed Android-based software on the same smartphone, and protein biomarker profiles were calculated. The indirect detection of recombinant bovine somatotropin (rbST) in milk extracts based on altered biomarker profile of anti-rbST antibodies was selected as a real-life challenge. RbST-treated and untreated cows clearly showed reproducible treatment-dependent biomarker profiles in milk, in excellent agreement with results from a flow cytometer reference method. In a pilot experiment, anti-rbST antibody detection was multiplexed with the detection of another rbST-dependent biomarker, insulin-like growth factor 1 (IGF-1). Milk extract IGF-1 levels were found to be increased after rbST treatment and correlated with the results obtained from the reference method. These data clearly demonstrate the potential of the portable protein microarray concept towards simultaneous detection of multiple biomarkers. We envisage broad application of this ‘protein microarray on a smartphone’-concept for on-site testing, e.g., in food safety, environment and health monitoring. PMID:26308444

  18. Immunochromatography detection of human lactoferrin protein in milk from transgenic cattle.

    PubMed

    Liu, Chuxin; Zhai, Shanli; Zhang, Qingde; Liu, Bang

    2013-01-01

    Transgenic technologies have opened a new era of transgenesis, characterized by manipulating intraspecies or interspecies genes in microorganisms, plants, or animals to change them in desired directions. The advent of genetically modified animals and related products has raised the need for analytical methods, nucleotide- or protein-based, to qualitatively and quantitatively determine the biotechnology ingredients. In this study, we collected milk samples containing human lactoferrin (hLF) protein, to exploit appropriate detection means for exogenous hLF protein. We preliminarily developed two types of competitive immunochromatography strips for quick detection, based on gold-conjugated hLF protein or gold-conjugated polyclonal antibody. As control methods, sodium dodecyl sulfate polyacrylamide gel electrophoresis, dot blot, and Western blot methods were used to check the accuracy of strips, and highly sensitive ELISA with chemiluminescent substrates was developed to determine the concentration of hLF in milk. Comparing the test results of lateral flow strips with qualitative assays, we found our strips gave the same results in a few minutes, showing great advantages with no need of professional technicians or any equipment. Our results demonstrated that all the applied methods were effective to detect hLF, suggesting that they could be used to monitor the production of transgenic milk.

  19. Genetic and phenotypic analysis of daily Israeli Holstein milk, fat, and protein production as determined by a real-time milk analyzer.

    PubMed

    Weller, J I; Ezra, E

    2016-12-01

    The objective was to test the hypothesis that more frequent but less accurately analyzed milk components may give a more representative measure of a cow's total lactation production. Daily records for milk production and fat and protein concentration collected by the AfiLab recording system (Afimilk, Kibbutz Afikim, Israel) from January 2014 to January 2016 from 47 large kibbutz (communal) herds distributed throughout Israel with a total of 37,486 Israeli Holstein cows were compared with the same statistics derived from monthly test day records derived by Bentley and Foss milk analyzers at the central laboratory of the Israel Cattle Breeders Association. The lactation means for all traits were quite similar for the 2 methods in both parities, except for fat production, which was lower for the daily records. This finding corresponded to fat lactation curves, which showed that daily results were lower with low days in milk (DIM) but almost equal to the monthly results after 125 DIM. Relative to monthly records, daily records overestimated protein percentage before 150 DIM and underestimated protein percentage in the second half of the lactation. The standard deviation for first- and second-parity daily records scored by the monthly and daily system were least similar for fat percentage, but even for this trait the difference was no more than 0.1 percentage points. The standard deviations for complete lactation production were slightly lower for the daily results for all traits but protein production. First-parity heritabilities were higher for lactations computed from daily records for all traits except for protein percentage, but differences were not significant. For daily records, coefficients of determination to predict future milk, fat, and protein lactation production from truncated lactations were greatest and root mean squared errors were least if the mean production from the last 2 weeks before the truncation date was used to estimate future production. Daily

  20. Use of test day milk fat and milk protein to detect subclinical ketosis in dairy cattle in Ontario.

    PubMed Central

    Duffield, T F; Kelton, D F; Leslie, K E; Lissemore, K D; Lumsden, J H

    1997-01-01

    Serum beta-hydroxybutyrate (BHB) levels were determined for 1333 dairy cows in various stages of lactation and parity on 93 dairy farms in Ontario. The data were collected in a cross-sectional manner, as part of the 1992 Ontario Dairy Monitoring and Analysis Program. The median serum BHB was 536 mumol/L for all cows, with a range of 0 to 5801 mumol/L. When subclinical ketosis was defined as a serum BHB level of 1200 mumol/L or higher, the prevalence of ketosis for cows in early lactation (< 65 days in milk (DIM)) was 14.1%. Prevalences for mid lactation (65-149 DIM), late lactation (> 149 DIM), and dry cows were 5.3%, 3.2%, and 1.6%, respectively. The mean serum BHB was significantly higher in the early group compared with each of the other 3 groups (P < 0.05). There was a trend of increasing prevalence with increasing parity across all stages of lactation. Only the difference between the parity-1 group and the parity-4 and greater group was statistically significant (P < 0.05). Both test-day fat percent and test-day protein percent were significantly associated with subclinical ketosis. However, test-day fat percent and test-day protein percent, used alone or in combination, were not useful screening tests for identifying cows with subclinical ketosis. PMID:9360791

  1. Transgenic rabbits for the production of biologically-active recombinant proteins in the milk.

    PubMed

    Castro, F O; Limonta, J; Rodriguez, A; Aguirre, A; de la Fuente, J; Aguilar, A; Ramos, B; Hayes, O

    1999-11-01

    The use of live bioreactors for the expression of human genes in the mammary gland of transgenic animals is one of the most cost-effective ways for the production of valuable recombinant therapeutic proteins. Among the transgenic species used so far, rabbits are good candidates for the expression of tens to hundreds of grams of complex proteins in the milk during lactation. The lactating mammary gland of rabbits has proven to be effective in the processing of complex proteins. In this work. the potential use of rabbits as bioreactors is discussed based on our results and the published data.

  2. Mitochondrial Protein Synthesis, Import, and Assembly

    PubMed Central

    Fox, Thomas D.

    2012-01-01

    The mitochondrion is arguably the most complex organelle in the budding yeast cell cytoplasm. It is essential for viability as well as respiratory growth. Its innermost aqueous compartment, the matrix, is bounded by the highly structured inner membrane, which in turn is bounded by the intermembrane space and the outer membrane. Approximately 1000 proteins are present in these organelles, of which eight major constituents are coded and synthesized in the matrix. The import of mitochondrial proteins synthesized in the cytoplasm, and their direction to the correct soluble compartments, correct membranes, and correct membrane surfaces/topologies, involves multiple pathways and macromolecular machines. The targeting of some, but not all, cytoplasmically synthesized mitochondrial proteins begins with translation of messenger RNAs localized to the organelle. Most proteins then pass through the translocase of the outer membrane to the intermembrane space, where divergent pathways sort them to the outer membrane, inner membrane, and matrix or trap them in the intermembrane space. Roughly 25% of mitochondrial proteins participate in maintenance or expression of the organellar genome at the inner surface of the inner membrane, providing 7 membrane proteins whose synthesis nucleates the assembly of three respiratory complexes. PMID:23212899

  3. Protein synthesis in synaptosomes: a proteomics analysis.

    PubMed

    Jiménez, C R; Eyman, M; Lavina, Z Scotto; Gioio, A; Li, K W; van der Schors, R C; Geraerts, W P M; Giuditta, A; Kaplan, B B; van Minnen, J

    2002-05-01

    A proteomics approach was used to identify the translation products of a unique synaptic model system, squid optic lobe synaptosomes. Unlike its vertebrate counterparts, this preparation is largely free of perikaryal cell fragments and consists predominantly of pre-synaptic terminals derived from retinal photoreceptor neurones. We metabolically labelled synaptosomes with [(35)S] methionine and applied two-dimensional gel electrophoresis to resolve newly synthesized proteins at high resolution. Autoradiographs of blotted two-dimensional gels revealed de novo synthesis of about 80 different proteins, 18 of which could be matched to silver-stained gels that were run in parallel. In-gel digestion of the matched spots and mass spectrometric analyses revealed the identities of various cytosolic enzymes, cytoskeletal proteins, molecular chaperones and nuclear-encoded mitochondrial proteins. A number of novel proteins (i.e. not matching with database sequences) were also detected. In situ hybridization was employed to confirm the presence of mRNA and rRNA in synaptosomes. Together, our data show that pre-synaptic endings of squid photoreceptor neurones actively synthesize a wide variety of proteins involved in synaptic functioning, such as transmitter recycling, energy supply and synaptic architecture.

  4. Quantification of milk fat globule membrane proteins using selected reaction monitoring mass spectrometry.

    PubMed

    Fong, Bertram Y; Norris, Carmen S

    2009-07-22

    Although some of the physiological roles of milk fat globule membrane (MFGM) proteins are still unclear, there is increasing evidence that the consumption of bovine MFGM proteins has significant nutritional health benefits for humans; therefore, it may be important to be able to estimate the MFGM proteins in complex ingredients. In this study, the absolute quantification (AQUA) technique, which is typically used for the quantification of proteins in proteomic studies, was applied for the quantification of bovine MFGM proteins in butter milk protein concentrate. Six MFGM proteins (fatty acid binding protein, butyrophilin, PAS 6/7, adipophilin, xanthine oxidase, and mucin 1) were simultaneously quantified using high-resolution selected reaction monitoring mass spectrometry. Samples were rehydrated in 6.7 M urea buffer prior to dilution to 2.2 M before tryspin digestion. Direct rehydration in 2.2 M urea buffer or 2.2 M urea/20% acetonitilrile buffer reduced peptide yield digestion. Isotopically labeled peptides were used as internal standards. The coefficient of variation ranged from 5 to 15%, with a recovery of 84-105%. The limit of detection was in the range of 20-40 pg.

  5. Maternal Obesity Reduces Milk Lipid Production in Lactating Mice by Inhibiting Acetyl-CoA Carboxylase and Impairing Fatty Acid Synthesis

    PubMed Central

    Saben, Jessica L.; Bales, Elise S.; Jackman, Matthew R.; Orlicky, David; MacLean, Paul S.; McManaman, James L.

    2014-01-01

    Maternal metabolic and nutrient trafficking adaptations to lactation differ among lean and obese mice fed a high fat (HF) diet. Obesity is thought to impair milk lipid production, in part, by decreasing trafficking of dietary and de novo synthesized lipids to the mammary gland. Here, we report that de novo lipogenesis regulatory mechanisms are disrupted in mammary glands of lactating HF-fed obese (HF-Ob) mice. HF feeding decreased the total levels of acetyl-CoA carboxylase-1 (ACC), and this effect was exacerbated in obese mice. The relative levels of phosphorylated (inactive) ACC, were elevated in the epithelium, and decreased in the adipose stroma, of mammary tissue from HF-Ob mice compared to those of HF-fed lean (HF-Ln) mice. Mammary gland levels of AMP-activated protein kinase (AMPK), which catalyzes formation of inactive ACC, were also selectively elevated in mammary glands of HF-Ob relative to HF-Ln dams or to low fat fed dams. These responses correlated with evidence of increased lipid retention in mammary adipose, and decreased lipid levels in mammary epithelial cells, of HF-Ob dams. Collectively, our data suggests that maternal obesity impairs milk lipid production, in part, by disrupting the balance of de novo lipid synthesis in the epithelial and adipose stromal compartments of mammary tissue through processes that appear to be related to increased mammary gland AMPK activity, ACC inhibition, and decreased fatty acid synthesis. PMID:24849657

  6. Maternal obesity reduces milk lipid production in lactating mice by inhibiting acetyl-CoA carboxylase and impairing fatty acid synthesis.

    PubMed

    Saben, Jessica L; Bales, Elise S; Jackman, Matthew R; Orlicky, David; MacLean, Paul S; McManaman, James L

    2014-01-01

    Maternal metabolic and nutrient trafficking adaptations to lactation differ among lean and obese mice fed a high fat (HF) diet. Obesity is thought to impair milk lipid production, in part, by decreasing trafficking of dietary and de novo synthesized lipids to the mammary gland. Here, we report that de novo lipogenesis regulatory mechanisms are disrupted in mammary glands of lactating HF-fed obese (HF-Ob) mice. HF feeding decreased the total levels of acetyl-CoA carboxylase-1 (ACC), and this effect was exacerbated in obese mice. The relative levels of phosphorylated (inactive) ACC, were elevated in the epithelium, and decreased in the adipose stroma, of mammary tissue from HF-Ob mice compared to those of HF-fed lean (HF-Ln) mice. Mammary gland levels of AMP-activated protein kinase (AMPK), which catalyzes formation of inactive ACC, were also selectively elevated in mammary glands of HF-Ob relative to HF-Ln dams or to low fat fed dams. These responses correlated with evidence of increased lipid retention in mammary adipose, and decreased lipid levels in mammary epithelial cells, of HF-Ob dams. Collectively, our data suggests that maternal obesity impairs milk lipid production, in part, by disrupting the balance of de novo lipid synthesis in the epithelial and adipose stromal compartments of mammary tissue through processes that appear to be related to increased mammary gland AMPK activity, ACC inhibition, and decreased fatty acid synthesis.

  7. Effects of different industrial heating processes of milk on site-specific protein modifications and their relationship to in vitro and in vivo digestibility.

    PubMed

    Wada, Yasuaki; Lönnerdal, Bo

    2014-05-07

    Heating processes are applied to milk and dairy products to ensure their microbiological safety and shelf lives. However, how differences in "industrial" thermal treatments affect protein digestibility is still equivocal. In this study, raw milk was subjected to pasteurization, three kinds of ultra-high-temperature (UHT) treatment, and in-can sterilization and was investigated by in vitro and in vivo digestion and proteomic methods. In-can sterilized milk, followed by UHT milk samples, showed a rapid decrease in protein bands during the course of digestion. However, protein digestibility determined by a Kjeldahl procedure showed insignificant differences. Proteomic analysis revealed that lactulosyllysine, which reflects a decrease in protein digestibility, in α-lactalbumin, β-lactoglobulin, and caseins was higher in in-can sterilized milk, followed by UHT milk samples. Thus, industrial heating may improve the digestibility of milk proteins by denaturation, but the improvement is likely to be offset by heat-derived modifications involved in decreased protein digestibility.

  8. Increased levels of LPS-binding protein in bovine blood and milk following bacterial lipopolysaccharide challenge.

    PubMed

    Bannerman, Douglas D; Paape, Max J; Hare, William R; Sohn, Eun Jung

    2003-10-01

    Several species of gram-negative bacteria, including Escherichia coli, Klebsiella pneumoniae, and various species of Enterobacter, are common mastitis pathogens. All of these bacteria are characterized by the presence of endotoxin or lipopolysaccharide (LPS) in their outer membrane. The bovine mammary gland is highly sensitive to LPS, and LPS has been implicated, in part, in the pathogenesis of gram-negative mastitis. Recognition of LPS is a key event in the innate immune response to gram-negative infection and is mediated by the accessory molecules CD14 and LPS-binding protein (LBP). The objective of the current study was to determine whether LBP levels increased in the blood and mammary gland following LPS challenge. The left and right quarters of five midlactating Holstein cows were challenged with either saline or LPS (100 microg), respectively, and milk and blood samples collected. Basal levels of plasma and milk LBP were 38 and 6 microg/ml, respectively. Plasma LBP levels increased as early as 8 h post-LPS challenge and reached maximal levels of 138 microg/ ml by 24 h. Analysis of whey samples derived from LPS-treated quarters revealed an increase in milk LBP by 12 h. Similar to plasma, maximal levels of milk LBP (34 microg/ml) were detected 24 h following the initial LPS challenge. Increments in milk LBP levels paralleled a rise in soluble CD14 (sCD14) levels and initial rises in the levels of these proteins were temporally coincident with maximal neutrophil recruitment to the inflamed gland. Because LBP and sCD14 are known to enhance LPS-induced host cell activation and to facilitate detoxification of LPS, these data are consistent with a role for these molecules in mediating mammary gland responses to LPS.

  9. Influence of casein as a percentage of true protein and protein level on color and texture of milks containing 1 and 2% fat.

    PubMed

    Misawa, Noriko; Barbano, David M; Drake, MaryAnne

    2016-07-01

    Combinations of fresh liquid microfiltration retentate of skim milk, ultrafiltered retentate and permeate produced from microfiltration permeate, cream, and dried lactose monohydrate were used to produce a matrix of 20 milks. The milks contained 5 levels of casein as a percentage of true protein of about 5, 25, 50, 75, and 80% and 4 levels of true protein of 3.0, 3.76, 4.34, and 5.0% with constant lactose percentage of 5%. The experiment was replicated twice and repeated for both 1 and 2% fat content. Hunter color measurements, relative viscosity, and fat globule size distribution were measured, and a trained panel documented appearance and texture attributes on all milks. Overall, casein as a percentage of true protein had stronger effects than level of true protein on Hunter L, a, b values, relative viscosity, and fat globule size when using fresh liquid micellar casein concentrates and milk serum protein concentrates produced by a combination of microfiltration and ultrafiltration. As casein as a percentage of true protein increased, the milks became more white (higher L value), less green (lower negative a value), and less yellow (lower b value). Relative viscosity increased and d(0.9) generally decreased with increasing casein as a percentage of true protein. Panelists perceived milks with increasing casein as a percentage of true protein as more white, more opaque, and less yellow. Panelists were able to detect increased throat cling and mouthcoating with increased casein as a percentage of true protein in 2% milks, even when differences in appearance among milks were masked.

  10. Expression of plant sweet protein brazzein in the milk of transgenic mice.

    PubMed

    Yan, Sen; Song, Hong; Pang, Daxin; Zou, Qingjian; Li, Li; Yan, Quanmei; Fan, Nana; Zhao, Xiangjie; Yu, Hao; Li, Zhanjun; Wang, Haijun; Gao, Fei; Ouyang, Hongsheng; Lai, Liangxue

    2013-01-01

    Sugar, the most popular sweetener, is essential in daily food. However, excessive sugar intake has been associated with several lifestyle-related diseases. Finding healthier and more economical alternatives to sugars and artificial sweeteners has received increasing attention to fulfill the growing demand. Brazzein, which comes from the pulp of the edible fruit of the African plant Pentadiplandra brazzeana Baill, is a protein that is 2,000 times sweeter than sucrose by weight. Here we report the production of transgenic mice that carry the optimized brazzein gene driven by the goat Beta-casein promoter, which specifically directs gene expression in the mammary glands. Using western blot analysis and immunohistochemistry, we confirmed that brazzein could be efficiently expressed in mammalian milk, while retaining its sweetness. This study presents the possibility of producing plant protein-sweetened milk from large animals such as cattle and goats.

  11. The diagnosis and management of cow milk protein intolerance in the primary care setting.

    PubMed

    Ewing, Whitney Merrill; Allen, Patricia Jackson

    2005-01-01

    Cow milk protein intolerance (CMPI) affects 3% of infants under the age of 12 months and is often misdiagnosed as GERD or colic, risking dangerous exposure to antigens. Most infants out grow CMPI by 12 months; however, those with IgE-mediated reactions usually continue to be intolerant to cow's milk proteins and also develop other allergens including environmental allergens that cause asthmatic symptoms. Clinical manifestations of CMPI include diarrhea, bloody stools, vomiting, feeding refusal, eczema, atopic dermatitis, urticaria, angioedema, allergic rhinitis, coughing, wheezing, failure to thrive, and anaphylaxis. The research and literature showed that CMPI is easily missed in the primary care setting and needs to be considered as a cause of infant distress and clinical symptoms. This article focuses on correctly diagnosing CMPI and managing it in the primary care setting.

  12. [Incidence of IgE-mediated allergy to cow's milk proteins in the first year of life].

    PubMed

    Sanz Ortega, J; Martorell Aragonés, A; Michavila Gómez, A; Nieto García, A

    2001-06-01

    To study the incidence of IgE-mediated allergy to cow's milk proteins during the first year of life. A multicenter, prospective study of newborns selected from different health centers was performed. The newborn infants were followed-up during the first year of life. Newborns with suspected adverse reaction to cow's milk were sent to the referral hospital for diagnostic study. This study was based on clinical history, skin tests (skin prick test) and on determination of specific IgE in serum (Pharmacia CAP system) against cow's milk and its protein fractions. Diagnosis was confirmed by open challenge. A total of 1,663 newborns were followed-up during the first year of life. Adverse reaction was suspected in 56 infants (3.3%). Allergy to cow's milk proteins was confirmed in 6 infants (0.36 %). Eighty-three percent of (5/6) children with cow's milk allergy had first-degree relatives with atopic disease compared with 19 % of children (329/1657) without cow's milk allergy. Among the entire sample, 26 infants had first-degree relatives with atopic disease and one of these infants (3.8%) developed cow milk allergy. The six children with cow's milk allergy were exclusively breast-fed, and clinical reaction developed within 1 week of the introduction of artificial feeding. The incidence of IgE-mediated allergy to cow's milk was 0.36 %. In infants with two first-degree family members with atopic disease, the probability of developing allergy to cow's milk proteins during the first year of life was 3.8%.

  13. Impact of prolonged leucine supplementation on protein synthesis and lean growth in neonatal pigs.

    PubMed

    Columbus, Daniel A; Steinhoff-Wagner, Julia; Suryawan, Agus; Nguyen, Hanh V; Hernandez-Garcia, Adriana; Fiorotto, Marta L; Davis, Teresa A

    2015-09-15

    Most low-birth weight infants experience extrauterine growth failure due to reduced nutrient intake as a result of feeding intolerance. The objective of this study was to determine whether prolonged enteral leucine supplementation improves lean growth in neonatal pigs fed a restricted protein diet. Neonatal pigs (n = 14-16/diet, 5 days old, 1.8 ± 0.3 kg) were fed by gastric catheter a whey-based milk replacement diet with either a high protein (HP) or restricted protein (RP) content or RP supplemented with leucine to the same level as in the HP diet (RPL). Pigs were fed 40 ml·kg body wt(-1)·meal(-1) every 4 h for 21 days. Feeding the HP diet resulted in greater total body weight and lean body mass compared with RP-fed pigs (P < 0.05). Masses of the longissimus dorsi muscle, heart, and kidneys were greater in the HP- than RP-fed pigs (P < 0.05). Body weight, lean body mass, and masses of the longissimus dorsi, heart, and kidneys in pigs fed the RPL diet were intermediate to RP- and HP-fed pigs. Protein synthesis and mTOR signaling were increased in all muscles with feeding (P < 0.05); leucine supplementation increased mTOR signaling and protein synthesis rate in the longissimus dorsi (P < 0.05). There was no effect of diet on indices of protein degradation signaling in any tissue (P > 0.05). Thus, when protein intake is chronically restricted, the capacity for leucine supplementation to enhance muscle protein accretion in neonatal pigs that are meal-fed milk protein-based diets is limited.

  14. Milk basic protein increases bone mineral density and improves bone metabolism in healthy young women.

    PubMed

    Uenishi, K; Ishida, H; Toba, Y; Aoe, S; Itabashi, A; Takada, Y

    2007-03-01

    Effect of milk basic protein on bone metabolism in healthy young women. Milk has more beneficial effects on bone health than other food sources. Recent in vitro and in vivo studies have shown that milk whey protein, especially its basic protein fraction (milk basic protein, MBP), contains several components capable of promoting bone formation and inhibiting bone resorption. The object of this study was to examine the effect of MBP on the bone mineral density and bone metabolism of healthy young women. Thirty-five healthy young women were randomly assigned to treatment with either placebo or MBP (40 mg per day) for 6 months. The bone mineral density (BMD) of the lumbar vertebrae L2-L4 of each subject was measured by dual-energy X-ray absorptiometry (DXA) at 0 and 6 months of treatment. Serum and urine indexes of bone metabolism were measured at 0, 3 and 6 months. All subjects completed the study in accordance with the protocol. The mean rate of gain of lumbar BMD in the MBP group (1.57%) was significantly higher than in the placebo group (0.13%, P=0.042). When compared with the placebo group, urinary cross-linked N-telopeptides of type-I collagen (NTx) were significantly decreased, and serum osteocalcin was significantly increased in the MBP group at 6 months. These results suggested that MBP supplementation was effective in increasing BMD in young women and that this increase in BMD may be primarily mediated through the promotion of bone formation and inhibition of bone resorption by MBP supplementation.

  15. Molecular and biotechnological advances in milk proteins in relation to human health.

    PubMed

    Kanwar, Jagat R; Kanwar, Rupinder K; Sun, Xueying; Punj, Vasu; Matta, H; Morley, Somasundaram M; Parratt, Andrew; Puri, Munish; Sehgal, Rakesh

    2009-08-01

    Milk and colostrum is a rich source of proteins/peptides which have crucial roles in both neonates and adults. Milk bioactive proteins and peptides are potential health-enhancing nutraceuticals for food. Many bioactive peptides/proteins may be used as nutraceuticals, for example, in the treatment of cancer, asthma, diarrhea, hypertension, thrombosis, dental diseases, as well as mineral malabsorption, and immunodeficiency. The following components of milk are of particular interest in the recent years: 1) Lactoferrin [Lf] has antibacterial, antifungal, antiviral, antiparasite and antitumor activities and accelerates immunomodulatory properties. Lf is a potent inhibitor for several enveloped and naked viruses, such as rotavirus, enterovirus and adenovirus. Lf is resistant to tryptic digestion and breast-fed infants excrete high levels of faecal Lf, so that its effect on viruses replicating in the gastrointestinal tract is of great interest. 2) Casein has been protective in experimental bacteremia by eliciting myelopoiesis. Casein hydrolyzates were also protective in diabetic animals, reduced the tumor growth and diminished colicky symptoms in infants. 3) A Proline rich polypeptide [PRP] revealed variety of immunotropic functions, including promotion of T-cell activation and inhibition of autoimmune disorders such as multiple sclerosis. 4) alpha-Lactalbumin [LA] demonstrates antiviral, antitumor and anti-stress properties. 5) Lactoperoxidase shows antibacterial properties. 6) Lysozyme is effective in treatment of periodentitis and prevention of tooth decay. Taken together, milk-derived proteins and peptides are bio-available and safe for the prevention and treatment of various disorders in humans and may play a complementary [natural agents] rather than a substitutional role to the toxic synthetic pharmacological drugs.

  16. Detection and identification of a soy protein component that cross-reacts with caseins from cow's milk

    PubMed Central

    ROZENFELD, P; DOCENA, G H; AÑÓN, M C; FOSSATI, C A

    2002-01-01

    Soy-based formulas are the most employed cow's milk substitutes in the treatment of cow's milk allergy in our country. Since adverse reactions have been reported in allergic patients as a consequence of exposure to soy proteins, we have investigated the possible cross-reactivity between components from soybean and cow's milk. A cow's milk specific polyclonal antiserum and casein specific monoclonal antibodies were used in immunoblotting and competitive ELISA studies to identify a 30-kD component from soybean that cross-reacts with cow's milk caseins. Its IgE binding capacity was tested by EAST, employing sera from cow's milk allergic patients, not previously exposed to soy proteins. The 30 kD protein was isolated and partially sequenced. It is constituted by two polypeptides (A5 and B3) linked by a disulphide bond. The protein's capacity to bind to the different antibodies relies on the B3 poly-peptide. These results indicate that soy-based formula, which contains the A5-B3 glycinin molecule, could be involved in allergic reactions observed in cow's milk allergic patients exposed to soy-containing foods. PMID:12296853

  17. Synthesis of natural flows at selected sites in and near the Milk River basin, Montana, 1928-89

    USGS Publications Warehouse

    Cary, L.E.; Parrett, Charles

    1995-01-01

    Natural monthly streamflows were synthesized for the years 1928-89 at 2 sites in the St. Mary River Basin and 11 sites in the Milk River Basin in north- central Montana. The sites are represented as nodes in a streamflow accounting model being developed by the Bureau of Reclamation for the Milk River Basin. Recorded flows at most sites have been affected by human activities, including reservoir storage and irrigation diversions. The flows at the model nodes were corrected for the effects of these activities to obtain synthesized flows. The synthesized flows at nodes with seasonal and short-term records were extended using a statistical technique. The methods of synthesis varied, depending on upstream activities and information available. Flows at sites in the St. Mary River Basin and at the Milk River at Eastern Crossing of International Boundary pre- viously had been synthesized. The flows at mainstem sites downstream from the Milk River at Eastern Crossing were synthesized by adding synthesized natural runoff from intervening drainage areas to natural flows for Milk River at Eastern Crossing. Natural runoff from intervening drainage areas was estimated by multiplying recorded flows at selected index gaging stations on tributary streams by the ratio of the intervening drainage area to the combined drainage area of the index stations. The recorded flows for Milk River at Western Crossing of International Boundary and for Peoples Creek near Dodson, Montana, were assumed to be natural flows. The synthesized annual flows at the mouth of the Milk River compared favorably with the recorded flows near the mouth when the effects of upstream irrigation were considered.

  18. Preparation of monoclonal antibodies to xanthine oxidase and other proteins of bovine milk-fat-globule membrane.

    PubMed Central

    Mather, I H; Nace, C S; Johnson, V G; Goldsby, R A

    1980-01-01

    Nine hybridomas secreting monoclonal antibody to proteins of bovine milk-fat-globule membrane were isolated. All nine cell lines continued to secrete monoclonal antibody after serial transfer in culture and after passage as solid tumours in Balb/cJ mice. Four of the cell lines secreted monoclonal antibody specific for xanthine oxidase, one of the major proteins of milk-fat-globule membrane. PMID:6894088

  19. Composite response elements mediate hormonal and developmental regulation of milk protein gene expression.

    PubMed

    Rosen, J M; Zahnow, C; Kazansky, A; Raught, B

    1998-01-01

    Our laboratory has been studying the mechanisms by which hormones regulate the expression of differentiated function in the normal mammary gland and how these regulatory mechanisms have deviated in breast cancer. Two rat milk protein genes, encoding beta-casein and whey acidic protein, have been employed as molecular markers of mammary epithelial cell differentiation. Composite response elements containing multiple binding sites for several transcription factors mediate the hormonal and developmental regulation of milk protein gene expression. In the whey protein gene promoters, these include binding sites for nuclear factor (NF)-I, as well as the glucocorticoid receptor (GR) and signal transducers and activators of transcription (Stat5). In the casein promoters, these include binding sites for Stat5, Yin Yang 1 (YY1), GR and the CCAAT/enhancer binding protein (C/EBP). The C/EBP family of DNA binding proteins may play a pivotal role in maintaining the balance between cell proliferation and terminal differentiation in mammary epithelial cells. During normal mammary gland development, expression of LIP (liver-enriched inhibitory protein, a dominant-negative isoform of C/EBP beta) is hormonally regulated and correlates with cell proliferation during pregnancy. LIP can form heterodimers with other C/EBP family members and suppress their transcriptional activity. In contrast, C/EBP alpha is predominantly expressed during lactation following terminal differentiation. Elevated LIP levels have been detected in mouse, rat and human breast tumours of different aetiologies. This provides a mechanism, therefore, to block terminal differentiation and facilitate continued proliferation.

  20. Permeability of milk protein antigens across the intestinal epithelium in vitro.

    PubMed

    Marcon-Genty, D; Tomé, D; Dumontier, A M; Kheroua, O; Desjeux, J F

    1989-01-01

    Degradations by proteolytic enzymes and intestinal epithelial permeability represent two major drawbacks to the transfer of food protein antigens to blood. These steps were studied in vitro for the milk protein antigens beta-lactoglobulin (beta-Lg), alpha-Lactalbumin (alpha-La) and beta-casein (beta-cas). Pepsin-trypsin hydrolysis and permeability in isolated rabbit ileum in Ussing chamber were suited by ELISA and radiolabelled-protein measurement. Pepsin-trypsin hydrolysis showed an increasing resistance in the order beta-cas less than alpha-La less than beta-Lg. The rate of absorption of the antigenic proteins by isolated rabbit ileum was in the same order, and the rate of absorption of the whole proteins (degraded and antigenic forms) was significantly higher for beta-Lg than for alpha-La and beta-cas. These results suggest a selective intestinal permeability for milk protein antigens. This selectivity is probably important in the mechanism of food protein sensitization via the oral route.

  1. How surface composition of high milk proteins powders is influenced by spray-drying temperature.

    PubMed

    Gaiani, C; Morand, M; Sanchez, C; Tehrany, E Arab; Jacquot, M; Schuck, P; Jeantet, R; Scher, J

    2010-01-01

    High milk proteins powders are common ingredients in many food products. The surface composition of these powders is expected to play an essential role during their storage, handling and/or final application. Therefore, an eventual control of the surface composition by modifying the spray-drying temperature could be very useful in the improvement of powder quality and the development of new applications. For this purpose, the influence of five spray-drying temperatures upon the surface composition of the powders was investigated by X-ray photoelectron spectroscopy. The major milk proteins were studied: native micellar casein and native whey, both more or less enriched in lactose. The results show a surface enrichment in lipids for all the powders and in proteins for many powders. Whatever the drying temperature, lipids and proteins are preferentially located near the surface whereas lactose is found in the core. This surface enrichment is also highly affected by the spray-drying temperature. More lipids, more proteins and less lactose are systematically observed at the surface of powders spray-dried at lower outlet air temperatures. The nature of proteins is also found essential; surface enrichment in lipids being much stronger for whey proteins containing powders than for casein containing powders. Additionally, we found a direct correlation between the lipids surface concentration and the wetting ability for the 25 powders studied.

  2. Colostrum and milk protein rankings and ratios of importance to neonatal calf health using a proteomics approach.

    PubMed

    Nissen, Asger; Andersen, Pia Haubro; Bendixen, Emøke; Ingvartsen, Klaus Lønne; Røntved, Christine Maria

    2017-04-01

    Administration of colostrum to the newborn calf before gut closure is pivotal to its health, because of the transfer of passive immunity. Traditionally, passive immunity has been attributed to the transfer of immunoglobulins although it is increasingly clear that multiple other factors contribute, including innate immune proteins, developmental factors, immunomodulatory factors, and the presence of cellular immunity. The objective of this study was to produce a comprehensive comparison of the bovine colostrum proteome and the milk proteome by applying 2-dimensional liquid chromatography-tandem mass spectrometry. Further, the objectives were to rank proteins mutually and generate protein ratios from the spectral counts of the 2 proteomes and ELISA to gain insight into which proteins could be of most relevance to neonatal calf health. To obtain an in-depth picture of the bovine colostrum and milk proteome, we compared the contents of different fractions from bovine colostrum and milk from our 2 previous studies. A total of 140 colostrum fluid-phase proteins and 103 milk fluid-phase proteins were detected. In the cellular fraction, 324 and 310 proteins were detected in colostrum and milk, respectively. In total, 514 proteins were detected, of which 162 were in the fluid phase. Of these, 50 proteins were exclusively seen in colostrum, 13 were exclusively seen in milk, and 99 were common to colostrum and milk. Ranking of proteins mutually and calculating protein ratios based on spectral counts and ELISA resulted in new information on how proteins were associated with the fluid or cellular fraction of the samples. Interestingly, despite lower counts/concentrations than the classical proteins such as immunoglobulins, β-lactoglobulin, and lactotransferrin, several proteins appeared in higher or similar colostrum:milk spectral count ratios as these. Using this approach indicated, for example, that osteopontin, haptoglobin, milk amyloid A, and gelsolin may be interesting

  3. The role of specific cow's milk proteins in the etiology of recurrent aphthous ulcers.

    PubMed

    Besu, Irina; Jankovic, Ljiljana; Konic-Ristic, Aleksandra; Raskovic, Sanvila; Besu, Valeri; Djuric, Milanko; Cakic, Sasa; Magdu, Ileana Ursu; Juranic, Zorica

    2013-01-01

    Recurrent aphthous ulcerations (RAU), or recurrent aphthous stomatitis, is recognized as one of the most common oral mucosal diseases worldwide. It was noted some connection between immunity to cow's milk proteins (CMP) and oral diseases. The goal of this study was to determine the prevalence of the increased levels of serum antibodies to specific cow's milk proteins (SCMP), constituents of cheese or of whey, by enzyme-linked immunosorbent assay (ELISA) test, in subjects who have RAU. Fifty subjects with RAU and 50 healthy people, as controls (C), were included in this research. Levels of serum IgA, IgG, and IgE antibodies to SCMP were determined by ELISA. The statistical analysis of data was performed by Wilcoxon rank sum test with continuity correction. The levels of serum anti-SCMP IgA, IgG, and IgE antibodies were significantly higher in subjects with RAU in comparison with controls (P < 0.005). These results indicate the strong association between high levels of serum anti-SCMP IgA, IgG, and IgE antibodies, especially to caseins: α-, β-, and κ-casein from cow's milk and clinical manifestations of RAU. Serum immunity to the whey proteins in subjects with RAU was not in so high percentage expressed. © 2012 John Wiley & Sons A/S.

  4. Combined effects of soy isoflavones and milk basic protein on bone mineral density in hind-limb unloaded mice

    PubMed Central

    Matsumoto, Yu; Tousen, Yuko; Nishide, Yoriko; Tadaishi, Miki; Kato, Ken; Ishimi, Yoshiko

    2016-01-01

    We examined whether the combination of isoflavone and milk basic protein both are reported to be effective for bone metabolism, prevents bone loss induced by skeletal hind-limb unloading in mice. Female ddY strain mice, aged 8 weeks, were divided into six groups (n = 6–8 each): (1) normally housed group, (2) loading group, (3) hind-limb unloading group fed a control diet, (4) hind-limb unloading group fed a 0.2% isoflavone conjugates diet, (5) hind-limb unloading group fed a 1.0% milk basic protein diet, and (6) hind-limb unloading group fed a 0.2% isoflavone conjugates and 1.0% milk basic protein diet. After 3 weeks, femoral bone mineral density was markedly reduced in unloading mice. The combination of isoflavone and milk basic protein showed cooperative effects in preventing bone loss and milk basic protein inhibited the increased expression of osteogenic genes in bone marrow cells in unloading mice. These results suggest that the combination of soy isoflavone and milk basic protein may be useful for bone health in subjects with disabling conditions as well as astronauts. PMID:27013781

  5. Milk yield and composition of lactating cows fed steam-flaked sorghum and graded concentrations of ruminally degradable protein.

    PubMed

    Santos, F A; Huber, J T; Theurer, C B; Swingle, R S; Simas, J M; Chen, K H; Yu, P

    1998-01-01

    To determine the effect of various amounts of ruminally undegradable protein in the diets of lactating cows fed steam-flaked sorghum, 24 Holstein cows (90 +/- 50 d in milk) were assigned to three treatments: 0.8% urea, 6% soybean meal, or 5% fish meal. Respective percentages of ruminally undegradable protein in the diets (as a percentage of crude protein) were 30, 35, and 39%. All diets contained 37% alfalfa hay; 3 to 5% cottonseed hulls; 10 to 13% whole cottonseed; 39% steam-flaked sorghum (360 g/L); 5% of a molasses, mineral, and vitamin supplement; and the different protein supplements. Intake of dry matter was higher for cows fed urea than for cows fed soybean meal or fish meal diets. In cows that yielded more than 40 kg/d of milk (4 cows per treatment), the soybean meal and fish meal diets resulted in higher yields of milk and 3.5% fat-corrected milk and a greater efficiency of conversion of feed to milk than did the urea diet. Cows that yielded less than 40 kg/d of milk (4 cows per treatment) at the beginning of treatment tended to yield more milk when fed urea than when fed the protein supplements. Nutrient digestibilities were not greatly affected by source of N, suggesti