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Sample records for milk protein synthesis

  1. MATERNAL PROTEIN HOMEOSTASIS AND MILK PROTEIN SYNTHESIS DURING FEEDING AND FASTING IN HUMANS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about amino acid (aa) and protein metabolism in lactating women. We hypothesized: 1) aa sources other than the plasma acid pool provide substrate for milk protein synthesis in humans; and 2) if albumin was one such source, then albumin fractional synthesis rate (FSR) is higher in th...

  2. 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

  3. 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

    2016-01-01

    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. Insulin regulates milk protein synthesis at multiple levels in the bovine mammary gland.

    PubMed

    Menzies, Karensa K; Lefèvre, Christophe; Macmillan, Keith L; Nicholas, Kevin R

    2009-05-01

    The role of insulin in milk protein synthesis is unresolved in the bovine mammary gland. This study examined the potential role of insulin in the presence of two lactogenic hormones, hydrocortisone and prolactin, in milk protein synthesis. Insulin was shown to stimulate milk protein gene expression, casein synthesis and (14)C-lysine uptake in mammary explants from late pregnant cows. A global assessment of changes in gene expression in mammary explants in response to insulin was undertaken using Affymetrix microarray. The resulting data provided insight into the molecular mechanisms stimulated by insulin and showed that the hormone stimulated the expression of 28 genes directly involved in protein synthesis. These genes included the milk protein transcription factor, ELF5, translation factors, the folate metabolism genes, FOLR1 and MTHFR, as well as several genes encoding enzymes involved in catabolism of essential amino acids and biosynthesis of non-essential amino acids. These data show that insulin is not only essential for milk protein gene expression, but stimulates milk protein synthesis at multiple levels within bovine mammary epithelial cells. PMID:19107532

  5. 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

  6. Effects of phenylalanine and threonine oligopeptides on milk protein synthesis in cultured bovine mammary epithelial cells.

    PubMed

    Zhou, M M; Wu, Y M; Liu, H Y; Liu, J X

    2015-04-01

    This study was conducted to investigate the effects of phenylalanine (Phe) and threonine (Thr) oligopeptides on αs1 casein gene expression and milk protein synthesis in bovine mammary epithelial cells. Primary mammary epithelial cells were obtained from Holstein dairy cows and incubated in Dulbecco's modified Eagle's medium-F12 medium (DMEM/F12) containing lactogenic hormones (prolactin and glucocorticoids). Free Phe (117 μg/ml) was substituted partly with peptide-bound Phe (phenylalanylphenylalanine, phenylalanyl threonine, threonyl-phenylalanyl-phenylalanine) in the experimental media. After incubation with experimental medium, cells were collected for gene expression analysis and medium was collected for milk protein or amino acid determination. The results showed that peptide-bound Phe at 10% (11.7 μg/ml) significantly enhanced αs1 casein gene expression and milk protein synthesis as compared with equivalent amount of free Phe. When 10% Phe was replaced by phenylalanylphenylalanine, the disappearance of most essential amino acids increased significantly, and gene expression of peptide transporter 2 and some amino acid transporters was significantly enhanced. These results indicate that the Phe and Thr oligopeptides are important for milk protein synthesis, and peptide-bound amino acids could be utilised more efficiently in milk protein synthesis than the equivalent amount of free amino acids. PMID:25199802

  7. Synthesis of milk specific fatty acids and proteins by dispersed goat mammary-gland epithelial cells.

    PubMed Central

    Hansen, H O; Tornehave, D; Knudsen, J

    1986-01-01

    The method now described for preparation of dispersed lactating goat mammary-gland cells gives a high yield of morphologically and functionally normal mammary cells. The cells synthesize specific goat milk fatty acids in the right proportions, and they respond to hormones by increased protein synthesis. The cells can be frozen and thawed without losing the above properties, which makes them an excellent tool for metabolic and hormonal studies. Images Fig. 1. Fig. 2. PMID:3800930

  8. The Homeodomain Protein Ladybird Late Regulates Synthesis of Milk Proteins during Pregnancy in the Tsetse Fly (Glossina morsitans)

    PubMed Central

    Attardo, Geoffrey M.; Benoit, Joshua B.; Michalkova, Veronika; Patrick, Kevin R.; Krause, Tyler B.; Aksoy, Serap

    2014-01-01

    Regulation of tissue and development specific gene expression patterns underlies the functional specialization of organs in multi-cellular organisms. In the viviparous tsetse fly (Glossina), the female accessory gland is specialized to generate nutrients in the form of a milk-like secretion to support growth of intrauterine larva. Multiple milk protein genes are expressed specifically in the female accessory gland and are tightly linked with larval development. Disruption of milk protein synthesis deprives developing larvae of nutrients and results in extended larval development and/or in abortion. The ability to cause such a disruption could be utilized as a tsetse control strategy. Here we identify and delineate the regulatory sequence of a major milk protein gene (milk gland protein 1:mgp1) by utilizing a combination of molecular techniques in tsetse, Drosophila transgenics, transcriptomics and in silico sequence analyses. The function of this promoter is conserved between tsetse and Drosophila. In transgenic Drosophila the mgp1 promoter directs reporter gene expression in a tissue and stage specific manner orthologous to that of Glossina. Analysis of the minimal required regulatory region of mgp1, and the regulatory regions of other Glossina milk proteins identified putative homeodomain protein binding sites as the sole common feature. Annotation and expression analysis of Glossina homeodomain proteins identified ladybird late (lbl) as being accessory gland/fat body specific and differentially expressed between lactating/non-lactating flies. Knockdown of lbl in tsetse resulted in a significant reduction in transcript abundance of multiple milk protein genes and in a significant loss of fecundity. The role of Lbl in adult reproductive physiology is previously unknown. These results suggest that Lbl is part of a conserved reproductive regulatory system that could have implications beyond tsetse to other vector insects such as mosquitoes. This system is critical

  9. 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.

  10. Alpha-ketoglutarate enhances milk protein synthesis by porcine mammary epithelial cells.

    PubMed

    Jiang, Qian; He, Liuqin; Hou, Yongqing; Chen, Jiashun; Duan, Yehui; Deng, Dun; Wu, Guoyao; Yin, Yulong; Yao, Kang

    2016-09-01

    Alpha-ketoglutarate (AKG), a key intermediate in the Krebs cycle, has been reported to promote protein synthesis through activating mechanistic targeting of rapamycin (mTOR) in enterocytes. The study tested the hypothesis that AKG may enhance growth and milk protein synthesis in porcine mammary epithelial cells (PMECs). PMECs were cultured for 96 h in Dulbecco's modified Eagle's-F12 Ham medium (DMEM-F12) containing prolactin (2 µg/ml) and AKG (0 or 1.5 mM). At the end of 96-h culture, the abundance of apoptosis-related proteins (caspase-3, caspase-9), milk-specific proteins (α-lactalbumin and β-casein), mTOR signaling proteins (mTOR, p-mTOR, PERK, p-PERK, eIF2a, P70S6K and p-P70S6K), and endoplasmic reticulum stress (ERS)-associated proteins (BiP and CHOP) in PMEC were determined. Addition of AKG dose-dependently enhanced cell viability in the absence or presence of prolactin, with optimal concentrations of AKG being at 1.0 and 1.5 mM, respectively. In the presence of prolactin, addition of 1.5 mM AKG: (1) decreased (P < 0.05) the abundance of caspase-3 and caspase-9 by 21 and 39 %; (2) enhanced (P < 0.05) the phosphorylation of p-mTOR and p-P70S6K by 39 and 89 %, respectively; (3) increased (P < 0.05) the production of β-casein and α-lactalbumin by 16 and 20 %, respectively; (4) attenuated (P < 0.05) the expression of CHOP by 34 % but promoted (P < 0.05) the expression of BiP by 46 %; (5) increased (P < 0.05) the secretion of lactose by 15 %, when compared to the 0 mM AKG group. Rapamycin (50 nM; an inhibitor of mTOR) attenuated (P < 0.05) the stimulatory effect of AKG on mTOR signaling and syntheses of milk protein and lactose, while relieving (P < 0.05) an inhibitory effect of AKG on expression of proteins related to ERS. Collectively, our results indicate that AKG enhances milk protein production by modulating mTOR and ERS signaling pathways in PMECs. PMID:27188418

  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. PMID:22226014

  12. 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. PMID:26254527

  13. Short communication: Altered expression of specificity protein 1 impairs milk fat synthesis in goat mammary epithelial cells.

    PubMed

    Zhu, J J; Luo, J; Xu, H F; Wang, H; Loor, J J

    2016-06-01

    Specificity protein 1 (encoded by SP1) is a novel transcription factor important for the regulation of lipid metabolism and the normal function of various hormones in model organisms. Its potential role, if any, on ruminant milk fat is unknown. Despite the lower expression of the lipolysis-related gene ATGL (by 44 and 37% respectively), both the adenoviral overexpression and the silencing of SP1 [via short interfering (si)RNA] markedly reduced cellular triacylglycerol (TAG) content (by 28 and 25%, respectively), at least in part by decreasing the expression of DGAT1 (-36% in adenovirus treatment) and DGAT2 (-81 and -87%, respectively) that are involved in TAG synthesis. Consistent with the markedly lower expression of genes related to lipid droplet formation and secretion (TIP47 by 19 and 32%, and ADFP by 25 and 25%, respectively), cellular lipid droplet content was also decreased sharply, by 9 and 8.5%, respectively, after adenoviral overexpression of SP1 or its silencing via siRNA. Overall, the results underscored a potentially important role of SP1 in maintaining milk-fat droplet synthesis in goat mammary epithelial cells. PMID:26995134

  14. 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. PMID:23158513

  15. Arginine Supplementation Recovered the IFN-γ-Mediated Decrease in Milk Protein and Fat Synthesis by Inhibiting the GCN2/eIF2α Pathway, Which Induces Autophagy in Primary Bovine Mammary Epithelial Cells

    PubMed Central

    Xia, Xiaojing; Che, Yanyi; Gao, Yuanyuan; Zhao, Shuang; Ao, Changjin; Yang, Hongjian; Liu, Juxiong; Liu, Guowen; Han, Wenyu; Wang, Yuping; Lei, Liancheng

    2016-01-01

    During the lactation cycle of the bovine mammary gland, autophagy is induced in bovine mammary epithelial cells (BMECs) as a cellular homeostasis and survival mechanism. Interferon gamma (IFN-γ) is an important antiproliferative and apoptogenic factor that has been shown to induce autophagy in multiple cell lines in vitro. However, it remains unclear whether IFN-γ can induce autophagy and whether autophagy affects milk synthesis in BMECs. To understand whether IFN-γ affects milk synthesis, we isolated and purified primary BMECs and investigated the effect of IFN-γ on milk synthesis in primary BMECs in vitro. The results showed that IFN-γ significantly inhibits milk synthesis and that autophagy was clearly induced in primary BMECs in vitro within 24 h. Interestingly, autophagy was observed following IFN-γ treatment, and the inhibition of autophagy can improve milk protein and milk fat synthesis. Conversely, upregulation of autophagy decreased milk synthesis. Furthermore, mechanistic analysis confirmed that IFN-γ mediated autophagy by depleting arginine and inhibiting the general control nonderepressible-2 kinase (GCN2)/eukaryotic initiation factor 2α (eIF2α) signaling pathway in BMECs. Then, it was found that arginine supplementation could attenuate IFN-γ-induced autophagy and recover milk synthesis to some extent. These findings may not only provide a novel measure for preventing the IFN-γ-induced decrease in milk quality but also a useful therapeutic approach for IFN-γ-associated breast diseases in other animals and humans. PMID:27025389

  16. Arginine Supplementation Recovered the IFN-γ-Mediated Decrease in Milk Protein and Fat Synthesis by Inhibiting the GCN2/eIF2α Pathway, Which Induces Autophagy in Primary Bovine Mammary Epithelial Cells.

    PubMed

    Xia, Xiaojing; Che, Yanyi; Gao, Yuanyuan; Zhao, Shuang; Ao, Changjin; Yang, Hongjian; Liu, Juxiong; Liu, Guowen; Han, Wenyu; Wang, Yuping; Lei, Liancheng

    2016-05-31

    During the lactation cycle of the bovine mammary gland, autophagy is induced in bovine mammary epithelial cells (BMECs) as a cellular homeostasis and survival mechanism. Interferon gamma (IFN-γ) is an important antiproliferative and apoptogenic factor that has been shown to induce autophagy in multiple cell lines in vitro. However, it remains unclear whether IFN-γ can induce autophagy and whether autophagy affects milk synthesis in BMECs. To understand whether IFN-γ affects milk synthesis, we isolated and purified primary BMECs and investigated the effect of IFN-γ on milk synthesis in primary BMECs in vitro. The results showed that IFN-γ significantly inhibits milk synthesis and that autophagy was clearly induced in primary BMECs in vitro within 24 h. Interestingly, autophagy was observed following IFN-γ treatment, and the inhibition of autophagy can improve milk protein and milk fat synthesis. Conversely, upregulation of autophagy decreased milk synthesis. Furthermore, mechanistic analysis confirmed that IFN-γ mediated autophagy by depleting arginine and inhibiting the general control nonderepressible-2 kinase (GCN2)/eukaryotic initiation factor 2α (eIF2α) signaling pathway in BMECs. Then, it was found that arginine supplementation could attenuate IFN-γ-induced autophagy and recover milk synthesis to some extent. These findings may not only provide a novel measure for preventing the IFN-γ-induced decrease in milk quality but also a useful therapeutic approach for IFN-γ-associated breast diseases in other animals and humans. PMID:27025389

  17. 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.

  18. 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.

  19. 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. PMID:26467738

  20. Leucine and histidine independently regulate milk protein synthesis in bovine mammary epithelial cells via mTOR signaling pathway*

    PubMed Central

    Gao, Hai-na; Hu, Han; Zheng, Nan; Wang, Jia-qi

    2015-01-01

    The aim of this study is to investigate the effects of leucine (Leu) and histidine (His) on the expression of both the mammalian target of rapamycin (mTOR) signaling pathway-related proteins and caseins in immortalized bovine mammary epithelial cells (CMEC-H), using a single supplement through Western blotting. The Earle’s balanced salt solution (EBSS) was set as the control group and other treatment groups, based on the EBSS, were added with different concentrations of Leu or His, respectively. The results showed that, compared with the control group, the expression of caseins and the phosphorylation of mTOR (Ser2481), Raptor (Ser792), eIF4E (Ser209), and eEF2 (Thr56) increased with the Leu concentrations ranging from 0.45 to 10.80 mmol/L (P<0.01). The P-4EBP1 (Thr37) at 10.80 mmol/L Leu, and P-RPS6 (Ser235/236) at 5.40 to 10.80 mmol/L Leu all decreased. Similarly, the His supplementation from 0.15 to 9.60 mmol/L increased the expression of αs2-casein, β-casein, κ-casein, P-mTOR (Ser2481), P-Raptor (Ser792), P-S6K1 (Thr389), P-4EBP1 (Thr37), P-eIF4E (Ser209), and P-eEF2 (Thr56) (P<0.01) in CMEC-H, whereas the αs1-casein expression was only reduced at 9.60 mmol/L His, G protein β subunit-like protein (GβL) at 0.15 and 9.60 mmol/L His, and P-RPS6 at 4.80 to 9.60 mmol/L His. Our linear regression model assay suggested that the αs1-casein expression was positively correlated with P-mTOR (P<0.01), P-S6K1 (P<0.01), and P-eEF2 (P<0.01) for the addition of Leu, while the expressions of β-casein (P<0.01) and κ-casein (P<0.01) were positively correlated with P-eEF2 for the addition of His. In conclusion, the milk protein synthesis was up-regulated through activation of the mTOR pathway with the addition of Leu and His in CMEC-H. PMID:26055918

  1. WISP3 (CCN6) Regulates Milk Protein Synthesis and Cell Growth Through mTOR Signaling in Dairy Cow Mammary Epithelial Cells.

    PubMed

    Jiang, Nan; Wang, Yu; Yu, Zhiqiang; Hu, Lijun; Liu, Chaonan; Gao, Xueli; Zheng, Shimin

    2015-08-01

    The mTOR/S6K1 signaling pathway is the primary regulator of milk protein synthesis. While mTOR is known to be regulated at the translational level by amino acids, the mechanism by which mTOR accepts the amino acid signal is not yet clear. In this study, we describe the discovery of WISP3 as a potentially novel signaling factor that connects mTOR and amino acids. Treatment of dairy cow mammary epithelial cells with amino acids (lysine or methionine) increased both cell growth and the expression of β-casein (CSN2), WISP3, mTOR, and phospho-mTOR (p-mTOR). Notably, overexpressing WISP3 in these cells also increased both cell growth and the expression of CSN2, mTOR, and p-mTOR and decreased the expression of glycogen synthase kinase 3β (GSK3β), while repressing WISP3 had the opposite effect. The increase of the expression of CSN2, mTOR, and p-mTOR mediated by amino acid could be inhibited by repressing WISP3. The increase of the expression of CSN2, mTOR, and p-mTOR mediated by WISP3 overexpression could be inhibited by overexpressing GSK3β, and vice versa. Taken together, these results reveal that through its amino acid-mediated regulation of the mTOR pathway, WISP3 is an important regulatory factor involved in the amino acid-mediated regulation of milk protein synthesis and cell growth. PMID:26061139

  2. Protein Evolution of Human Milk.

    PubMed

    Thakkar, Sagar K; Giuffrida, Francesca; Bertschy, Emmanuelle; De Castro, Antonio; Destaillats, Frédéric; Lee, Le Ye

    2016-01-01

    Given the documented short- and long-term advantages of breastfeeding, human milk (HM) as a sole source of nutrition for the first few months of newborn life is considered a normative standard. Each macroconstituent of HM plays a crucial role in the growth and development of the baby. Lipids are largely responsible for providing more than 50% of the energy as well as providing essential fatty acids and minor lipids that are integral to all cell membranes. Carbohydrates can be broadly divided into lactose and oligosaccharides, which are a readily digestible source of glucose and indigestible nonnutritive components, respectively. Proteins in HM provide essential amino acids indispensable for the growth of infants. What is more interesting is that protein concentration profoundly changes from colostrum to mature milk. In this report, we share data from an observatory, single-center, longitudinal trial assessing the constituents of HM collected 30, 60 and 120 days postpartum from 50 mothers (singleton deliveries: 25 male and 25 female infants). The protein content decreased with evolving stages of lactation from an average of 1.45 to 1.38 g/100 ml. The data did not show any gender differences as it was reported for lipid content at 120 days postpartum by our group. Additionally, we also share consolidated literature data on protein evolution of HM during the first year of lactation. PMID:27336906

  3. 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

  4. [Dietetic treatment of cow's milk protein allergy].

    PubMed

    Dupont, C; Chouraqui, J-P; de Boissieu, D; Bocquet, A; Bresson, J-L; Briend, A; Darmaun, D; Frelut, M-L; Ghisolfi, J; Girardet, J-P; Goulet, O; Hankard, R; Rieu, D; Rigo, J; Vidailhet, M; Turck, D

    2011-01-01

    New data on food allergy has recently changed the management of children with cow's milk protein allergy (CMPA). The diagnosis of CMPA first requires the elimination of cow's milk proteins and then an oral provocation test following a standard diagnostic procedure for food allergy, without which the elimination diet is unjustified and sometimes harmful. Once the diagnosis is made, the elimination diet is strict, at least until the age of 9-12 months. If the child is not breastfed or the mother cannot or no longer wishes to breastfeed, the first choice is a formula based on extensive hydrolyzate of cow's milk (eHF), provided that its effectiveness has been demonstrated. When eHF fails, a formula based on amino acids is warranted. eHF based on rice protein hydrolysates is an alternative to cow's milk eHF. Infant formulas based on soy protein can be used after the age of 6 months, after verification of good clinical tolerance to soy. Most commonly, CMPA disappears within 2 or 3 years of life. However, the age of recovery varies depending on the child and the type of CMPA, and whether or not it is IgE-mediated, the first being more sustainable. When the child grows, a hospital oral provocation test evaluates the development of tolerance and, if possible, authorizes continuing the reintroduction of milk proteins at home. Some children with CMPA will tolerate only a limited daily amount of cow's milk proteins. The current therapeutic options are designed to accelerate the acquisition of tolerance, which seems facilitated by regular exposure to cow's milk proteins. PMID:21115329

  5. Flavor and stability of milk proteins.

    PubMed

    Smith, T J; Campbell, R E; Jo, Y; Drake, M A

    2016-06-01

    A greater understanding of the nature and source of dried milk protein ingredient flavor(s) is required to characterize flavor stability and identify the sources of flavors. The objective of this study was to characterize the flavor and flavor chemistry of milk protein concentrates (MPC 70, 80, 85), isolates (MPI), acid and rennet caseins, and micellar casein concentrate (MCC) and to determine the effect of storage on flavor and functionality of milk protein concentrates using instrumental and sensory techniques. Spray-dried milk protein ingredients (MPC, MPI, caseins, MCC) were collected in duplicate from 5 commercial suppliers or manufactured at North Carolina State University. Powders were rehydrated and evaluated in duplicate by descriptive sensory analysis. Volatile compounds were extracted by solid phase microextraction followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry. Compounds were identified by comparison of retention indices, odor properties, and mass spectra against reference standards. A subset of samples was selected for further analysis using direct solvent extraction with solvent-assisted flavor extraction, and aroma extract dilution analysis. External standard curves were created to quantify select volatile compounds. Pilot plant manufactured MPC were stored at 3, 25, and 40°C (44% relative humidity). Solubility, furosine, sensory properties, and volatile compound analyses were performed at 0, 1, 3, 6, and 12 mo. Milk proteins and caseins were diverse in flavor and exhibited sweet aromatic and cooked/milky flavors as well as cardboard, brothy, tortilla, soapy, and fatty flavors. Key aroma active compounds in milk proteins and caseins were 2-aminoacetophenone, nonanal, 1-octen-3-one, dimethyl trisulfide, 2-acetyl-1-pyrroline, heptanal, methional, 1-hexen-3-one, hexanal, dimethyl disulfide, butanoic acid, and acetic acid. Stored milk proteins developed animal and burnt sugar flavors over time. Solubility of

  6. 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

  7. 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. PMID:26134630

  8. 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. PMID:26634581

  9. 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

  10. 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

  11. [Immune stimulative potency of milk proteins].

    PubMed

    Ambroziak, Adam; Cichosz, Grazyna

    2014-02-01

    Milk proteins are characterized by the highest immune stimulative potency from among all the proteins present in human diet. Whey proteins and numerous growth factors that regulate insulin secretion, differentiation of intestine epithelium cells, and also tissue restoration, are priceless in stimulation the immune system. Lactoferrin shows the most comprehensive pro-health properties: antioxidative, anticancer, immune stimulative and even chemopreventive. Also peptides and amino acids formed from casein and whey proteins possess immune stimulative activity. The most valuable proteins, i.e. lactoferrin, immune globulins, lactoperoxidase and lisozyme, together with bioactive peptides, are resistant to pepsin and trypsin activity. This is why they maintain their exceptional biological activity within human organism. Properly high consumption of milk proteins conditions correct function of immune system, especially at children and elderly persons. PMID:24720113

  12. Measures of de novo synthesis of milk components from propionate in lactating goats

    SciTech Connect

    Emmanuel, B.; Kennelly, J.J.

    1985-02-01

    Possible direct contributions of propionate to de novo synthesis of milk components by the mammary gland of lactating goats fed a concentrate-roughage diet have been studied in vivo by primed constant infusion of (1-carbon-14)propionate into the right mammary artery. Specific radioactivities of milk galactose, fatty acids, and protein were higher in the infused than in the uninfused half of the mammary gland, suggesting de novo synthesis of these compounds in the udder. Specific radioactivities of milk glucose in both udder halves were identical, ruling out any possibility of mammary gland-derived glucose from propionate of blood plasma under the experimental conditions. Of milk galactose, .8% was derived from propionate of blood plasma, and of milk glucose, 98% was derived from glucose of blood plasma. After intraruminal infusion of unlabeled propionic acid at 11 g/h, concentration of propionate in blood plasma was doubled, its contribution to milk galactose was increased to 1.5%, and proportions of milk odd-numbered fatty acids were increased. Propionate was incorporated largely into milk odd-numbered fatty acids. The authors conclude that small amounts of propionate can be incorporated into principal components of milk in the mammary gland of lactating goats.

  13. Treatment of Cow's Milk Protein Allergy

    PubMed Central

    De Greef, Elisabeth; Devreker, Thierry

    2014-01-01

    The diagnosis and treatment of cow's milk protein allergy (CMPA) is still a challenge. A systematic literature search was performed using Embase, Medline, The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials for the diagnosis and treatment of cow's milk allergy (CMA). Since none of the symptoms of CMPA is specific and since there is no sensitive diagnostic test (except a challenge test), the diagnosis of CMPA remains difficult. A "symptom-based score" is useful in children with symptoms involving different organ systems. The recommended dietary treatment is an extensive cow milk based hydrolysate. Amino acid based formula is recommended in the most severe cases. However, soy infant formula and hydrolysates from other protein sources (rice) are gaining popularity, as they taste better and are cheaper than the extensive cow's milk based hydrolysates. Recent meta-analyses confirmed the safety of soy and estimate that not more than 10-15% of CMPA-infants become allergic to soy. An accurate diagnosis of CMA is still difficult. The revival of soy and the development of rice hydrolysates challenge the extensive cow's milk based extensive hydrolysates as first option and amino acid formula. PMID:24749081

  14. 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.

  15. Transcriptional enhancer from milk protein genes

    SciTech Connect

    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.

  16. 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.

  17. 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. PMID:27034058

  18. 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.

  19. DIETARY PROTEIN AND LACTOSE INCREASE TRANSLATION INITIATION FACTOR ACTIVATION AND TISSUE PROTEIN SYNTHESIS IN NEONATAL PIGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protein synthesis and eukaryotic initiation factor (eIF) activation are increased in muscle and liver of pigs parenterally infused with amino acids and insulin. To examine the effects of enteral protein and carbohydrate on protein synthesis, pigs (n = 42, 1.7 kg body wt) were fed isocaloric milk die...

  20. Water sorption by proteins: milk and whey proteins.

    PubMed

    Kinsella, J E; Fox, P F

    1986-01-01

    The content and physical state of water in foods influence their physical, chemical, quality, safety, and functional behavior. Information concerning the sorption behavior of dairy proteins, in the water activity (Aw) range 0 to 0.9, is collated in this paper. The sorption behavior of proteins in general, the kinetics of absorption, factors affecting water binding, the phenomenon of desorption hysteresis, and the chemical and physical nature of water/protein interactions are reviewed in general terms. This is followed by a discussion of thermodynamic aspects of sorption phenomena and the adequacy of the various equations for describing sorption isotherms of proteins. After a discussion of the methods available for measuring sorption by milk proteins, the sorption behavior of various milk protein preparations, i.e., nonfat dry milk, whey proteins, caseins, and milk powders is summarized. Finally, the water activity of cheese and its relationship to solute mobility and solvent water are discussed. Some of the unique features of protein behavior, i.e., conformational changes, swelling, and solubilization are cited as possible sources of disparities between various reports. PMID:3527564

  1. 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. PMID:27272960

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

    PubMed Central

    Osman Swar, Mohammed

    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.

  3. Peptides from milk proteins and their properties.

    PubMed

    Kilara, Arun; Panyam, Dinakar

    2003-01-01

    This review has attempted to study the literature pertaining to peptides derived from milk proteins. Hydrolysis of milk proteins to generate peptides has been practiced for a long time and it was recognized early on in this process that the taste of hydrolyzates might hinder use of these products in food formulations. Modification of protein is necessary to form a more acceptable or utilizable product, to form a product that is less susceptible to deteriorative reactions and to form a product that is of higher nutritionall quality. Modifications may be achieved by a number of chemical and enzymatic means. This review has considered only enzymatic modification of dairy proteins. Modified proteins contain peptides and some of these peptides have been purified and their functionalities have been compared with unmodified proteins. This paper has examined the literature pertaining to improvement in functionality of enzyme-modified proteins. Improvements in solubility, emulsification, foaming and gelation were examined. There is limited information available on the sequence of the peptides necessary to improve the functional characteristics of proteins. Knowing the sequences of desirable functional peptides can lead to genetic alteration of proteins to improve functionality. Addition of synthetic peptides to intact proteins may be another way in which the functionality of proteins can be augmented. Some of the peptides in milk proteins are capable of affecting biological functions of an organism. These effects can be antimicrobial and probiotic, i.e., prevent the growth and proliferation of undesirable and pathogenic organisms, or they may promote the growth of desirable bacteria in the digestive tract of humans and animals. Peptides derived from milk protein have been shown to exert digestive and metabolic effects as well. They may also influence the immune system. These biological effects may play an important role in the development of medical foods that treat or

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Protein degradation in bovine milk caused by Streptococcus agalactiae.

    PubMed

    Åkerstedt, Maria; Wredle, Ewa; Lam, Vo; Johansson, Monika

    2012-08-01

    Streptococcus (Str.) agalactiae is a contagious mastitis bacterium, often associated with cases of subclinical mastitis. Different mastitis bacteria have been evaluated previously from a diagnostic point of view, but there is a lack of knowledge concerning their effect on milk composition. Protein composition is important in achieving optimal yield and texture when milk is processed to fermented products, such as cheese and yoghurt, and is thus of great economic value. The aim of this in vitro study was to evaluate protein degradation mainly caused by exogenous proteases originating from naturally occurring Str. agalactiae. The samples were incubated at 37°C to imitate degradation caused by the bacteria in the udder. Protein degradation caused by different strains of Str. agalactiae was also investigated. Protein degradation was observed to occur when Str. agalactiae was added to milk, but there were variations between strains of the bacteria. Caseins, the most economically important proteins in milk, were degraded up to 75% in milk inoculated with Str. agalactiae in relation to sterile ultra-high temperature (UHT) milk, used as control milk. The major whey proteins, α-lactalbumin and β-lactoglobulin, were degraded up to 21% in relation to the sterile control milk. These results suggest that different mastitis bacteria but also different strains of mastitis bacteria should be evaluated from a milk quality perspective to gain knowledge about their ability to degrade the economically important proteins in milk. PMID:22850579

  6. Derivation of factors to estimate daily fat, protein, and somatic cell score from one milking of cows milked twice daily

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to derive factors to predict daily fat (F) and protein (P) yield or somatic cell score (SCS) when milk is sampled once for cows milked twice per d. Milk samples were collected for each milking on test-day by Dairy Herd Improvement personnel from herds recording milking times and m...

  7. Comparative aspects of milk fat synthesis.

    PubMed

    Dils, R R

    1986-03-01

    This general review attempts to capture the interest of nonspecialists, especially those whose main interest is the dairy cow, in the extraordinary diversity of milk fats synthesized and secreted by different mammalian species. The review compares differences in the gross proportions of fats in the milk of various species and discusses different strategies for providing the suckling young with sufficient energy as fat. Despite the constancy of the gross chemical composition of the milk fat globule and its membrane produced by mammals, there are striking differences among species in the fatty acid composition of milk triacylglycerols (triglycerides). The origins of the short-, medium-, and long-chain fatty acids of milk triacylglycerols are reviewed with emphasis on differences between ruminants and nonruminants. Because there appears to be less difference among mammals in the mechanisms of fatty acid desaturation, chain elongation, and esterification by the mammary gland, these topics are only briefly reviewed. PMID:3711414

  8. 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. PMID:26874417

  9. Milk protein responses in dairy cows to changes in postruminal supplies of arginine, isoleucine, and valine.

    PubMed

    Haque, M N; Rulquin, H; Lemosquet, S

    2013-01-01

    An ideal profile of essential AA (EAA) can improve the efficiency of metabolizable protein (or PDIE, the equivalent in the INRA feeding system) utilization in dairy cows. Compared with other EAA, existing recommendations for the requirements of Arg, Ile, and Val are few and inconsistent. Four multiparous Holstein dairy cows at 22±6 wk of lactation received 4 treatments (duodenal infusions of 445±22.4 g/d of an EAA mixture complementing a low-protein diet in a 4×4 Latin square design with a period length of 1 wk). The control treatment provided a balanced supply (in % of PDIE) of 5.1% Arg, 5.2% Ile, and 5.9% Val, whereas in the 3 subsequent treatments of -Arg, -Ile, and -Val, the concentrations of these 3 EAA were reduced to 3.5, 4.1, and 4.5%, respectively. All treatments were made isonitrogenous and were balanced to provide 7 other EAA (Lys, Met, His, Leu, Phe, Thr, and Trp), according to the recommendations described in the literature. Combined, the diet and the infusions provided 14.3±0.1% crude protein on a dry matter basis, and 66.0±1.2 g of PDIE/Mcal of net energy for lactation. Neither dry matter intake (19.2 kg/d) nor milk yield (30.4±0.4 kg/d) was affected by treatments. The -Arg and -Ile treatments did not modify milk protein synthesis or the efficiency of N utilization. However, the -Val treatment decreased milk protein content by 4.9% and milk crude protein content by 4.3%, and tended to decrease the efficiency of N use for milk protein yield by 3.7% (compared with the control). These effects of Val were related to a decrease in the plasma concentration of Val as well as a trend toward decreasing plasma concentrations of Met, His, and the sum of all EAA and nonessential AA in the -Val treatment, which indicates a different utilization of all AA in response to the Val deficit. The deletion of Ile, compared with the deletion of Val, tended to decrease the milk protein-to-fat ratio by 3.8%. In conclusion, the supply of Arg at 3.5% of PDIE was not

  10. The effect of short-term hyperammonaemia on milk synthesis in dairy cows.

    PubMed

    Purdie, Norm G; Trout, Donald R; Cieslar, Scott R L; Madsen, Torben G; Poppi, Dennis P; Cant, John P

    2009-02-01

    To test the hypothesis that ammonia detoxification in ruminants consumes amino acids to the detriment of milk protein production, we infused four lactating dairy cows with ammonium acetate or sodium acetate in switchback experiments. Plasma ammonia concentrations increased to 411 microm within 1 h of the start of infusion of ammonium acetate at 567 mmol/h. The rate constant for ammonia clearance from plasma was 0 x 054/min and the half-life was 12 x 9 min. Infusion at 567 mmol/h for 1 h followed by 1 h without infusion, repeated four times between am- and pm-milking, caused a decrease in feed intake. Compared with sodium acetate, continuous infusion of ammonium acetate at 360 mmol/h throughout an entire 10-h milking interval increased plasma ammonia concentrations to 193 microm and caused a 20% decrease in milk, protein and lactose production with no effect on percentage composition of milk or the yield of milk fat. Arterial concentrations of glucose and non-esterified fatty acids tended to increase; there was no effect on arterial acetate, beta-hydroxybutyrate or triacylglcerol, and branched-chain amino acids, Lys and Thr decreased. Mammary plasma flow, estimated by assuming 100% uptake/output of Phe+Tyr, was significantly correlated with milk yield. Mammary uptakes of acetate tended to be reduced by hyperammonaemia, but uptakes of other energy metabolites and amino acids were not affected. Thus, while an increase in amino acid consumption during hyperammonaemia was apparent from the drop in circulating concentrations of Leu, Ile, Val, Lys and Thr, there was no evidence to support the hypothesis that milk yield is affected by the lower concentrations. An ammonia-induced depression in feed intake may have caused the decrease in milk synthesis. PMID:18922195

  11. Binding of drugs in milk: the role of casein in milk protein binding.

    PubMed

    Stebler, T; Guentert, T W

    1990-06-01

    Unbound fractions of 14C-labeled diazepam and tenoxicam in skimmed milk of various species (man, horse, goat, cow, sheep, dog, rabbit) with different milk compositions were determined. Furthermore, the protein binding of five 14C-labeled benzodiazepines differing in their lipophilicity (bromazepam, clonazepam, diazepam, flumazenil, and flunitrazepam) were measured in human milk and in artificially prepared solutions of individual milk proteins (lactoferrin, 2.4 g/liter; alpha-lactalbumin, 2.1 g/liter; albumin, 0.4 g/liter; and casein--2.1, 3.4, and 13.3 g/liter). The extent of binding was determined by equilibrium dialysis of protein solution against 1/15 M phosphate buffer, made isocryoscopic with lactose. The results showed that the casein fraction is a major binding component in milk for all tested drugs. The extent of binding of diazepam and tenoxicam in the milk of various species was independent of the whey protein concentration. In human milk the fraction of bromazepam, clonazepam, diazepam, and flunitrazepam bound to casein was higher than that bound to any other of the milk proteins tested. Albumin contributed little to the overall binding of these benzodiazepines, and lactoferrin and alpha-lactalbumin did not account for significant binding. The benzodiazepine antagonist flumazenil showed the lowest overall binding in milk and in casein solution. As the casein concentration is highest in colostral milk and drops during the course of lactation, it is expected that M/P ratios of drugs strongly bound to casein are higher during the first days postpartum than in later phases of lactation. PMID:2367331

  12. 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. PMID:27444727

  13. 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

  14. 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

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

    PubMed

    Maningat, Patricia D; Sen, Partha; Rijnkels, Monique; Hadsell, Darryl L; Bray, Molly S; Haymond, Morey W

    2011-04-27

    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

  16. Milk protein IgG and IgA: The association with milk-induced gastrointestinal symptoms in adults

    PubMed Central

    Anthoni, Sari; Savilahti, Erkki; Rautelin, Hilpi; Kolho, Kaija-Leena

    2009-01-01

    AIM: To study the association between serum levels of milk protein IgG and IgA antibodies and milk-related gastrointestinal symptoms in adults. METHODS: Milk protein IgG and IgA antibodies were determined in serum samples of 400 subjects from five outpatient clinics in Southern Finland. Subjects were randomly selected from a total of 1900 adults undergoing laboratory investigations in primary care. All 400 participants had completed a questionnaire on abdominal symptoms and dairy consumption while waiting for the laboratory visit. The questionnaire covered the nature and frequency of gastrointestinal problems, the provoking food items, family history and allergies. Twelve serum samples were disqualified due to insufficient amount of sera. The levels of specific milk protein IgG and IgA were measured by using the ELISA technique. The association of the milk protein-specific antibody level was studied in relation to the milk-related gastrointestinal symptoms and dairy consumption. RESULTS: Subjects drinking milk (n = 265) had higher levels of milk protein IgG in their sera than non-milk drinkers (n = 123, P < 0.001). Subjects with gastrointestinal problems related to milk drinking (n = 119) consumed less milk but had higher milk protein IgG levels than those with no milk-related gastrointestinal symptoms (n = 198, P = 0.02). Among the symptomatic subjects, those reporting dyspeptic symptoms had lower milk protein IgG levels than non-dyspeptics (P < 0.05). However, dyspepsia was not associated with milk drinking (P = 0.5). The association of high milk protein IgG levels with constipation was close to the level of statistical significance. Diarrhea had no association with milk protein IgG level (P = 0.5). With regard to minor symptoms, flatulence and bloating (P = 0.8), were not associated with milk protein IgG level. Milk protein IgA levels did not show any association with milk drinking or abdominal symptoms. The levels of milk protein IgA and IgG declined as the age

  17. Protein composition affects variation in coagulation properties of buffalo milk.

    PubMed

    Bonfatti, V; Gervaso, M; Rostellato, R; Coletta, A; Carnier, P

    2013-07-01

    The aim of this study was to investigate the effects exerted by the content of casein and whey protein fractions on variation of pH, rennet-coagulation time (RCT), curd-firming time (K20), and curd firmness of Mediterranean buffalo individual milk. Measures of milk protein composition and assessment of genotypes at CSN1S1 and CSN3 were obtained by reversed-phase HPLC analysis of 621 individual milk samples. Increased content of αS1-casein (CN) was associated with delayed coagulation onset and increased K20, whereas average pH, RCT, and K20 decreased when β-CN content increased. Milk with low κ-CN content exhibited low pH and RCT relative to milk with high content of κ-CN. Increased content of glycosylated κ-CN was associated with unfavorable effects on RCT. Effects of milk protein composition on curd firmness were less important than those on pH, RCT, and K20. Likely, this occurred as a consequence of the very short RCT of buffalo milk, which guaranteed a complete strengthening of the curd even in the restricted 31 min time of analysis of coagulation properties and for samples initially showing soft curds. Effects of CSN1S1-CSN3 genotypes on coagulation properties were not to be entirely ascribed to existing variation in milk protein composition associated with polymorphisms at CSN1S1 and CSN3 genes. Although the role of detailed milk protein composition in variation of cheese yield needs to be further investigated, findings of this study suggest that modification of the relative content of specific CN fractions can relevantly influence the behavior of buffalo milk during processing. PMID:23684020

  18. Innovative uses of milk protein concentrates in product development.

    PubMed

    Agarwal, Shantanu; Beausire, Robert L W; Patel, Sonia; Patel, Hasmukh

    2015-03-01

    Milk protein concentrates (MPCs) are complete dairy proteins (containing both caseins and whey proteins) that are available in protein concentrations ranging from 42% to 85%. As the protein content of MPCs increases, the lactose levels decrease. MPCs are produced by ultrafiltration or by blending different dairy ingredients. Although ultrafiltration is the preferred method for producing MPCs, they also can be produced by precipitating the proteins out of milk or by dry-blending the milk proteins with other milk components. MPCs are used for their nutritional and functional properties. For example, MPC is high in protein content and averages approximately 365 kcal/100 g. Higher-protein MPCs provide protein enhancement and a clean dairy flavor without adding significant amounts of lactose to food and beverage formulations. MPCs also contribute valuable minerals, such as calcium, magnesium, and phosphorus, to formulations, which may reduce the need for additional sources of these minerals. MPCs are multifunctional ingredients and provide benefits, such as water binding, gelling, foaming, emulsification, and heat stability. This article will review the development of MPCs and milk protein isolates including their composition, production, development, functional benefits, and ongoing research. The nutritional and functional attributes of MPCs are discussed in some detail in relation to their application as ingredients in major food categories. PMID:25757895

  19. Methionine sulfoxide profiling of milk proteins to assess the influence of lipids on protein oxidation in milk.

    PubMed

    Wüst, Johannes; Pischetsrieder, Monika

    2016-06-15

    Thermal treatment of milk and milk products leads to protein oxidation, mainly the formation of methionine sulfoxide. Reactive oxygen species, responsible for the oxidation, can be generated by Maillard reaction, autoxidation of sugars, or lipid peroxidation. The present study investigated the influence of milk fat on methionine oxidation in milk. For this purpose, quantitative methionine sulfoxide profiling of all ten methionine residues of β-lactoglobulin, α-lactalbumin, and αs1-casein was carried out by ultrahigh-performance liquid chromatography-electrospray ionization tandem mass spectrometry with scheduled multiple reaction monitoring (UHPLC-ESI-MS/MS-sMRM). Analysis of defatted and regular raw milk samples after heating for up to 8 min at 120 °C and analysis of ultrahigh-temperature milk samples with 0.1%, 1.5%, and 3.5% fat revealed that methionine oxidation of the five residues of the whey proteins and of residues M 123, M 135, and M 196 of αs1-casein was not affected or even suppressed in the presence of milk fat. Only the oxidation of residues M 54 and M 60 of αs1-casein was promoted by lipids. In evaporated milk samples, formation of methionine sulfoxide was hardly influenced by the fat content of the samples. Thus, it can be concluded that lipid oxidation products are not the major cause of methionine oxidation in milk. PMID:26927981

  20. Chronic food protein-induced enterocolitis syndrome caused by cow's milk proteins passed through breast milk.

    PubMed

    Miceli Sopo, Stefano; Monaco, Serena; Greco, Monica; Scala, Guglielmo

    2014-01-01

    We describe 2 cases of food protein-induced enterocolitis syndrome (FPIES) caused by cow's milk (CM) passed through breast milk. The onset in both cases was characterized by chronic symptoms (regurgitation, colic, diarrhea, failure to thrive); in one patient, two acute episodes due to the direct consumption of CM formula by the infant were also reported. The diagnosis of FPIES through breast milk can be easily overlooked, especially in milder cases. We also discuss some important issues concerning the general management of the disease. In conclusion, (1) the diagnosis of chronic FPIES should be taken into account even in exclusively breast-fed infants who present suggestive symptoms such as persistent regurgitation, small amounts of vomiting, lethargy, failure to thrive, dehydration, diarrhea (sometimes bloody) and abdominal distention. A 2-week maternal elimination diet should be considered even in apparently mild cases. (2) CM seems to be the most frequently reported culprit food. (3) In those cases in which acute FPIES is elicited by the direct consumption of the culprit food in breast-fed infants, maternal diet may be unrestricted. PMID:25034379

  1. 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. PMID:26467442

  2. Increased milk protein synthesis in response to exogenous growth hormone is associated with changes in mechanistic (mammalian) target of rapamycin (mTOR)C1-dependent and independent cell signaling.

    PubMed

    Sciascia, Q; Pacheco, D; McCoard, S A

    2013-04-01

    The objective of this study was to determine if increased milk protein synthesis observed in lactating dairy cows treated with growth hormone (GH) was associated with mechanistic (or mammalian) target of rapamycin complex 1 (mTORC1) regulation of downstream factors controlling nucleocytoplasmic export and translation of mRNA. To address this objective, biochemical indices of mammary growth and secretory activity and the abundance and phosphorylation status of mTORC1 pathway factors were measured in mammary tissues harvested from nonpregnant lactating dairy cows 6 d after treatment with a slow-release formulation of GH or saline (n=4/group). Treatment with GH increased mammary parenchymal weight and total protein content and tended to increase ribosome number and cell size, whereas protein synthetic efficiency, capacity, and cell number were unchanged. Cellular abundance of the mTORC1 components mTOR and (phosphorylated) mTOR(Ser2448) increased, as did complex eukaryotic initiation factor 4E:eukaryotic initiation factor 4E binding protein 1 (eIF4E:4EBP1), whereas no change was observed for mTORC1-downstream targets 4EBP1, 4EBP1(Ser65), p70/p85(S6K) and p70(S6K)Thre389/p85(S6K)Thre412. Changes in activation were not observed for any of the targets measured. These results indicate that GH treatment influences signaling to mTORC1 but not downstream targets involved in the nucleocytoplasmic export and translation of mRNA. Increased eIF4E:4EBP1 complex formation indicates involvement of the mitogen-activated protein kinase (MAPK) pathway. Abundance of MAPK pathway components eIF4E, eIF4E(Ser209), eIF4E:eIF4G complex, MAP kinase-interacting serine/threonine-protein kinase 1 (MKNK1), MKNK1(Thr197202), and ribosomal protein S6 kinase, 90kDa, polypeptide 1 (RPS6KA1) increased significantly in response to GH, whereas relative activation of the proteins was unchanged. Expression of IGFBP3 and IGFBP5 increased, that of IGF1R decreased, and that of IGF1 remained unchanged in

  3. Early post parturient changes in milk acute phase proteins.

    PubMed

    Thomas, Funmilola C; Waterston, Mary; Hastie, Peter; Haining, Hayley; Eckersall, P David

    2016-08-01

    The periparturient period is one of the most critical periods in the productive life of a dairy cow, and is the period when dairy cows are most susceptible to developing new intramammary infections (IMI) leading to mastitis. Acute phase proteins (APP) such as haptoglobin (Hp), mammary associated serum amyloid A3 (M-SAA3) and C-reactive protein (CRP) have been detected in milk during mastitis but their presence in colostrum and milk in the immediate postpartum period has had limited investigation. The hypothesis was tested that APP are a constituent of colostrum and milk during this period. Enzyme linked immunosorbent assays (ELISAs) were used to determine each APP's concentration in colostrum and milk collected daily from the first to tenth day following calving in 22 Holstein-Friesian dairy cows. Haptoglobin was assessed in individual quarters and composite milk samples while M-SAA3 and CRP concentration were determined in composite milk samples. Change in Hp in relation to the high abundance proteins during the transition from colostrum to milk were evaluated by 1 and 2 dimension electrophoresis and western blot. In 80% of the cows all APPs were detected in colostrum on the first day following parturition at moderately high levels but gradually decreased to minimal values in the milk by the 6th day after calving. The remaining cows (20%) showed different patterns in the daily milk APP concentrations and when an elevated level is detected could reflect the presence of IMI. Demonstration that APP are present in colostrum and milk following parturition but fall to low levels within 4 days means that elevated APP after this time could be biomarkers of post parturient mastitis allowing early intervention to reduce disease on dairy farms. PMID:27600971

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

    PubMed

    Jung, Tae-Hwan; Yun, Sung-Seob; Lee, Won-Jae; Kim, Jin-Wook; Ha, Ho-Kyung; Yoo, Michelle; Hwang, Hyo-Jeong; Jeon, Woo-Min; Han, Kyoung-Sik

    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. 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

  6. 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. PMID:18001429

  7. Assessment of the effect of methionine supplementation and inclusion of hydrolyzed wheat protein in milk protein-based milk replacers on the performance of intensively fed Holstein calves.

    PubMed

    Castro, J J; Hwang, G H; Saito, A; Vermeire, D A; Drackley, J K

    2016-08-01

    The objectives of this study were to compare 2 milk replacers containing only milk proteins with or without supplemental Met, and to compare a milk replacer containing hydrolyzed wheat protein at 4.5% of dry matter (DM) and supplemental Lys and Met against the 2 all-milk-protein formulas, by assessing their effect on the growth performance, efficiency, and plasma urea nitrogen of pre-weaning Holstein calves. Thus, 57 Holstein calves were allotted to the following 3 treatments: (1) a skim milk plus whey protein concentrate-based milk replacer (SMWP) containing about 2.6% Lys and 0.6% Met on a DM basis; (2) SMWP + M based on skim milk and whey proteins, containing about 2.6% Lys, and supplemental Met to reach 0.9% on a DM basis; and (3) a skim milk plus whey protein concentrate plus 4.5% of the DM as hydrolyzed wheat protein based milk replacer (HWP + LM) where the wheat protein replaced 50% of the whey protein concentrate, and also contained supplemental Lys and Met to match the profile of SMWP + M (i.e., Lys 2.6 and Met 0.9% on DM basis). No difference in any of the responses was observed by supplementing the milk protein based formula with Met or when hydrolyzed wheat protein was added to the formula. Results indicate that (1) a milk replacer based on skim milk protein and whey protein with a Lys concentration of ~2.6% does not benefit from Met supplementation, and (2) milk replacer containing 4.5% of the DM as hydrolyzed wheat protein and supplemented with Lys and Met can support the same growth performance as milk protein-based formulas. PMID:27179863

  8. Rapid fingerprinting of milk thermal processing history by intact protein mass spectrometry with nondenaturing chromatography.

    PubMed

    Johnson, Phil; Philo, Mark; Watson, Andrew; Mills, E N Clare

    2011-12-14

    Thermal processing of foods results in proteins undergoing conformational changes, aggregation, and chemical modification notably with sugars via the Maillard reaction. This can impact their functional, nutritional, and allergenic properties. Native size-exclusion chromatography with online electrospray mass spectrometry (SEC-ESI-MS) was used to characterize processing-induced changes in milk proteins in a range of milk products. Milk products could be readily grouped into either pasteurized liquid milks, heavily processed milks, or milk powders by SEC behavior, particularly by aggregation of whey proteins by thermal processing. Maillard modification of all major milk proteins by lactose was observed by MS and was primarily present in milk powders. The method developed is a rapid tool for fingerprinting the processing history of milk and has potential as a quality control method for food ingredient manufacture. The method described here can profile milk protein oligomeric state, aggregation, and Maillard modification in a single shot, rapid analysis. PMID:22007861

  9. OMICS-rooted studies of milk proteins, oligosaccharides and lipids.

    PubMed

    Casado, Begoña; Affolter, Michael; Kussmann, Martin

    2009-12-01

    Milk has co-evolved with mammals and mankind to nourish their offspring and is a biological fluid of unique complexity and richness. It contains all necessary nutrients for the growth and development of the newborn. Structure and function of biomolecules in milk such as the macronutrients (glyco-) proteins, lipids, and oligosaccharides are central topics in nutritional research. Omics disciplines such as proteomics, glycomics, glycoproteomics, and lipidomics enable comprehensive analysis of these biomolecule components in food science and industry. Mass spectrometry has largely expanded our knowledge on these milk bioactives as it enables identification, quantification and characterization of milk proteins, carbohydrates, and lipids. In this article, we describe the biological importance of milk macronutrients and review the application of proteomics, glycomics, glycoproteomics, and lipidomics to the analysis of milk. Proteomics is a central platform among the Omics tools that have more recently been adapted and applied to nutrition and health research in order to deliver biomarkers for health and comfort as well as to discover beneficial food bioactives. PMID:19793547

  10. Growth and metabolic responses in low-birth-weight infants fed human milk fortified with human milk protein or with a bovine milk protein preparation.

    PubMed

    Moro, G E; Minoli, I; Fulconis, F; Clementi, M; Räihä, N C

    1991-08-01

    Unfortified human milk does not normally provide enough protein to secure maximal growth in low-body-weight (LBW) infants. Due to the practical difficulties in obtaining human milk protein (HMP), a bovine milk protein preparation (BMP) was designed by computer calculation to contain as close as possible the amino acid composition of the nutritionally available human milk proteins. Twenty-one AGA, LBW infants (BW of 1,180 to 1,600 g, GA of 27 to 33 weeks) were randomly assigned to be fed HM enriched either with HMP (9 infants) or BMP (12 infants). When full volume intake (170 ml/kg/day) was reached, the protein intakes were 3.6 +/- 0.5 and 3.3 +/- 0.3 g/kg/day, respectively, in the two diet groups. During the study period of 24 days, the infants achieved intrauterine or better weight gains: 32.9 +/- 3.3 g/day (17.7 +/- 1.9 g/kg/day) in the HMP group and 34.7 +/- 7.3 g/day (18.3 +/- 3.5 g/kg/day) in the BMP group. Serum urea nitrogen, acid-base status, and albumin values were normal and similar in both groups of infants. Plasma concentrations of total essential and total amino acids at the end of the study were 3,999 and 1,539 mumol/L and 3,899 and 1,422 mumol/L in the HMP and the BMP groups, respectively. The concentrations of all individual plasma amino acids were similar in both feeding groups. These results show that feeding human milk fortified with a modified bovine milk protein preparation produces satisfactory growth and a plasma amino acid profile similar to that found in LBW infants fed exclusively human milk protein at similar intakes. PMID:1941407

  11. 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. PMID:24534502

  12. Severe cow's milk protein allergy in a Chinese neonate.

    PubMed

    Siu, L Y; Tse, K; Lui, Y S

    2001-12-01

    Cow's milk protein allergy is a growing problem in developed countries. We report the case of a Chinese infant, born at term, who presented on day 28 with severe growth failure, chronic diarrhoea, and metabolic acidosis. Investigations supported a diagnosis of cow's milk protein allergy. This was confirmed by withdrawing and reintroducing the relevant infant formula under controlled clinical conditions. Both acidosis and diarrhoea were seen to resolve, and 'catch-up' growth was evident after introduction of an elemental infant formula. Early recognition of this problem leads to a rapid 'cure', as seen in this case. However, later presentation with other atopic conditions has been reported. PMID:11773683

  13. Thermal properties of milk fat, xanthine oxidase, caseins and whey proteins in pulsed electric field-treated bovine whole milk.

    PubMed

    Sharma, Pankaj; Oey, Indrawati; Everett, David W

    2016-09-15

    Thermodynamics of milk components (milk fat, xanthine oxidase, caseins and whey proteins) in pulsed electric field (PEF)-treated milk were compared with thermally treated milk (63 °C for 30 min and 73 °C for 15s). PEF treatments were applied at 20 or 26 kV cm(-1) for 34 μs with or without pre-heating of milk (55 °C for 24s), using bipolar square wave pulses in a continuous mode of operation. PEF treatments did not affect the final temperatures of fat melting (Tmelting) or xanthine oxidase denaturation (Tdenaturation), whereas thermal treatments increased both the Tmelting of milk fat and the Tdenaturation for xanthine oxidase by 2-3 °C. Xanthine oxidase denaturation was ∼13% less after PEF treatments compared with the thermal treatments. The enthalpy change (ΔH of denaturation) of whey proteins decreased in the treated-milk, and denaturation increased with the treatment intensity. New endothermic peaks in the calorimetric thermograms of treated milk revealed the formation of complexes due to interactions between MFGM (milk fat globule membrane) proteins and skim milk proteins. Evidence for the adsorption of complexes onto the MFGM surface was obtained from the increase in surface hydrophobicity of proteins, revealing the presence of unfolded hydrophobic regions. PMID:27080877

  14. In vitro digestibility and immunoreactivity of bovine milk proteins.

    PubMed

    Do, Andrew B; Williams, Kristina; Toomer, Ondulla T

    2016-01-01

    Current models of digestibility solely utilize pepsin stability to assess the safety of allergenic food proteins. However, in vivo complete protein digestion requires acid denaturation and pepsin, trypsin, and/or chymotrypsin cleavage. This study aimed to identify the immunoreactivity and allergenicity of stable bovine milk proteins, using an improved digestibility model to simulate physiological gastric and intestinal conditions in vitro. Gel electrophoresis and immunoblot analysis were used to determine protein stability and immunoreactivity, respectively. Immunoreactivity of bovine milk proteins, β-lactoglobulin (β-LG) and casein (CN) was greatly diminished with gastric simulation (0-60 min), but some proteins were stable and immunoreactive with simulated intestinal digestive conditions (0-60 min). This study demonstrates the need for improved digestibility models for more accurate assessment of the behavior of food allergens in vivo. PMID:26213013

  15. 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.

  16. 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. PMID:24484379

  17. Water Stress and Protein Synthesis

    PubMed Central

    Dhindsa, R. S.; Cleland, R. E.

    1975-01-01

    Water stress causes a reduction in hydrostatic pressure and can cause an increase in abscisic acid in plant tissues. To assess the possible role of abscisic acid and hydrostatic pressure in water stress effects, we have compared the effects of water stress, abscisic acid, and an imposed hydrostatic pressure on the rate and pattern of protein synthesis in Avena coleoptiles. Water stress reduces the rate and changes the pattern of protein synthesis as judged by a double labeling ratio technique, Abscisic acid reduces the rate but does not alter the pattern of protein synthesis. Gibberellic acid reverses the abscisic acid-induced but not the stress-induced inhibition of protein synthesis. The effect of hydrostatic pressure depends on the gas used. With a 19: 1 N2-air mixture, the rate of protein synthesis is increased in stressed but not in turgid tissues. An imposed hydrostatic pressure alters the pattern of synthesis in stressed tissues, but does not restore the pattern to that found in turgid tissues. Because of the differences in response, we conclude that water stress does not affect protein synthesis via abscisic acid or reduced hydrostatic pressure. PMID:16659167

  18. Growth of an extracellular proteinase-deficient strain of Pseudomonas fluorescens on milk and milk proteins.

    PubMed

    Torrie, J P; Cholette, H; Froehlich, D A; McKellar, R C

    1983-08-01

    An extracellular proteinase-and lipase-deficient mutant of a psychrotroph, Pseudomonas fluorescens strain 32A, has been isolated and the absence of the proteinase enzyme confirmed by growth on differential media, enzyme assay and polyacrylamide gel electrophoresis. Competition between the parent and the mutant was observed when equal numbers of the 2 strains were inoculated together into raw skim-milk at 6 degrees C. Bitterness was detected at 6 degrees C in pasteurized skim-milk inoculated with the parent cells concurrent with the detection of proteolytic activity. In the case of the mutant, slight bitterness which did not increase with increasing cell numbers was detected in the absence of proteolysis. Mutant cells failed to grow on Na caseinate as the sole source of carbon. It was concluded that the extracellular proteinase, while not essential for growth in milk, does provide a selective advantage to the producer organism. This enzyme is, however, essential for growth on milk proteins and contributes to the development of bitterness in pasteurized milk. PMID:6413562

  19. 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

    2013-04-01

    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. PMID:23464874

  20. Comparison of Milk Fat Globule Membrane (MFGM) Proteins of Chianina and Holstein Cattle Breed Milk Samples Through Proteomics Methods

    PubMed Central

    Murgiano, Leonardo; Timperio, Anna Maria; Zolla, Lello; Bongiorni, Silvia; Valentini, Alessio; Pariset, Lorraine

    2009-01-01

    Identification of proteins involved in milk production is important to understand the biology of lactation. Many studies have advanced the understanding of mammary function and milk secretion, but the critical molecular mechanisms implicated in milk fat secretion is still incomplete. Milk Fat Globules are secreted from the apical surface of the mammary cells, surrounded by a thin membrane bilayer, the Milk Fat Globule Membrane (MFGM), formed by proteins which have been suggested to be cholesterolemia-lowering factors, inhibitors of cancer cell growth, vitamin binders, bactericidal, suppressors of multiple sclerosis. Using a proteomic approach, we compared MFGM from milk samples of individuals belonging to two different cattle breeds, Chianina and Holstein, representative of selection for milk and meat traits, respectively. We were able to isolate some of the major MFGM proteins in the examined samples and to identify differences between the protein fractions of the two breeds. We detected differences in the amount of proteins linked to mammary gland development and lipid droplets formation, as well as host defence mechanisms. We have shown that proteomics is a suitable, unbiased method for the study of milk fractions proteins and a powerful tool in nutritional genomics. PMID:22253986

  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. PMID:25835028

  2. 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

  3. 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

  4. 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

  5. The effect of long term under- and over-feeding on the expression of six major milk protein genes in the mammary tissue of sheep.

    PubMed

    Tsiplakou, Eleni; Flemetakis, Emmanouil; Kouri, Evangelia-Diamanto; Karalias, George; Sotirakoglou, Kyriaki; Zervas, George

    2015-08-01

    Milk protein synthesis in the mammary gland involves expression of six major milk protein genes whose nutritional regulation remains poorly defined. In this study, the effect of long term under- and over-feeding on the expression of αs1-casein: CSN1S1, αs2-casein: CSN1S2, β-casein: CSN2, κ-casein: CSN3, α-lactalbumin: LALBA and β-lactoglobulin: BLG gene in sheep mammary tissue (MT) was examined. Twenty-four lactating dairy sheep, at 90-98 d in milk, were divided into three groups and fed the same ration, for 60 d, in quantities which met 70% (underfeeding), 100% (control) and 130% (overfeeding) of their energy and crude protein requirements. The results showed a significant reduction on mRNA of CSN1S1, CSN1S2, CSN2 and BLG gene in the MT of underfed sheep compared with the overfed ones and a significant reduction in CSN3 and LALBA gene expression compared with the respective control animals. Significant positive correlations were observed between the mRNA levels of milk proteins' genes with the milk protein yield and milk yield respectively. In conclusion, the feeding level and consequently the nutrients availability, affected the milk protein yield and milk volume by altering the CSN1S1, CSN1S2, CSN2, CSN3, LALBA and BLG gene expression involved in their metabolic pathways. PMID:26130072

  6. 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.

  7. Functional Characteristics of Milk Protein Concentrates and Their Modification.

    PubMed

    Uluko, Hankie; Liu, Lu; Lv, Jia-Ping; Zhang, Shu-Wen

    2016-05-18

    A major deterrent to the usage of milk protein concentrate (MPC), a high-protein milk product with increasing demand as a food and sports drink ingredient, has been its poor functional characteristics when compared with other milk protein products such as whey protein concentrate and sodium caseinates. This review discusses the recent research on functional properties of MPC, focusing on factors that may contribute to the poor functional characteristics before, during, and after production. Current research, methods employed, and new understanding on the causes of poor solubility of MPC at mild temperatures (about 20°C) has been presented, including loss of solubility during storage as these areas have received unprecedented attention over the past decade, and also affects other useful functional properties of MPC, such as emulsifying properties, gelation, and foaming. Processing methods, which include heat treatment, high-pressure application, microwave heating, ultrasound application, and enzyme and salts modification, have been used or have potential to modify or improve the functional properties of MPCs. Future research on the effects of these processing methods on the functional properties, including effects of enzyme hydrolysis on bitterness and bioactivity, has also been discussed. PMID:26048645

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

    PubMed

    Artym, Jolanta; Zimecki, Michał

    2013-01-01

    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. PMID:24018446

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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. PMID:23282252

  14. Effect of protein supplementation on milk production and metabolism of dairy cows grazing tropical grass.

    PubMed

    Danes, M A C; Chagas, L J; Pedroso, A M; Santos, F A P

    2013-01-01

    The objectives of this study were to determine if midlactation dairy cows (Bos taurus L.) grazing intensively managed elephantgrass would have their protein requirement met exclusively with the pasture and an energy concentrate, making the use of protein ingredients unnecessary, as well as to determine the dietary crude protein (CP) content that would optimize the efficiency of N utilization (ENU). Thirty-three Holstein and crossbred (Holstein × Jersey) midlactation dairy cows, producing approximately 20 kg/d, were grouped within breed into 11 blocks according to milk yield and days in milk. Within blocks, cows were randomly assigned to 1 of 3 treatments and remained in the study for 11 wk. The control treatment contained only finely ground corn, minerals, and vitamins, and it was formulated to be 8.7% CP. Two higher levels of CP (formulated to be 13.4 and 18.1%) were achieved by replacing corn with solvent-extracted soybean meal (SSBM). Pasture was fertilized with 50 kg of N/ha after each grazing cycle and averaged 18.5% CP (dry matter basis). No differences were observed in milk yield or milk fat, protein, and casein content or casein yield. In addition, pasture intake was not different among treatments. Milk urea N increased linearly as the concentrate CP content increased. Cows fed the 8.7% CP concentrate had higher ENU. In another experiment, 4 ruminally cannulated Holstein dry cows were used in a metabolism trial designed in a 4×4 Latin square. Cows were fed the same treatments described as well as a fourth treatment with 13.4% CP in the concentrate, in which urea replaced SSBM as the main N source. Ruminal volatile fatty acid concentration and microbial synthesis were not affected by levels or sources of N in the concentrate. Ruminal NH(3)N content increased as the concentrate CP content increased. Inclusion of SSBM in the concentrate did not increase production and decreased the ENU of midlactation dairy cows grazing on tropical forage. Supplementation of

  15. The Future of Milk Protein Texturization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Does protein intake alter the precursors for synthesis of lactose and non-essential amino acids by the mammary glands of lactating mice?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aims were to: 1) develop a [U-13C]glucose tracer approach to establish the pathways of and substrates used for milk lactose and casein synthesis in the mouse mammary gland and 2) determine the influence of protein intake on this partition and use for milk synthesis. In Study 1, we determined th...

  17. 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. PMID:26231798

  18. Derivation of factors to estimate daily, fat, protein, and somatic cell score from one milking of cows milked three times daily

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to derive factors to predict daily fat (F) and protein (P) yield and somatic cell score (SCS) when milk is sampled once per d for cows milked three times (3x) per d. Daily milk weights were recorded automatically and samples were collected from 8 herds for each milking on test-day ...

  19. Effect of Asparagus racemosus (shatavari) extract on physicochemical and functional properties of milk and its interaction with milk proteins.

    PubMed

    Veena, N; Arora, Sumit; Singh, R R B; Katara, Antariksh; Rastogi, Subha; Rawat, A K S

    2015-02-01

    The effects of interaction of Asparagus racemosus (shatavari) with milk constituents and physico-chemical and functional characteristics of milk was studied. Addition of freeze dried aqueous shatavari extract at a concentration of 1 g /100 ml of milk showed a decrease in pH, rennet coagulation time and an increase in acidity, viscosity and heat stability at maximum. The extract also imparted brown colour to milk and showed an increase in a* (redness) and b* (yellowness) values but a decrease in L* (lightness) value. Proteins in milk were modified by reaction with shatavari extract. The derivatives formed were characterized in terms of SDS-PAGE. Electrophoretic pattern of sodium caseinate and whey containing 1% shatavari herb extract did not show any difference in band pattern i.e. there was no difference in mobility based on size of the proteins, but the intensity (width) of bands differed. PMID:25694736

  20. 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

  1. 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

  2. Association between milk protein gene variants and protein composition traits in dairy cattle.

    PubMed

    Huang, W; Peñagaricano, F; Ahmad, K R; Lucey, J A; Weigel, K A; Khatib, H

    2012-01-01

    The objective of this study was to identify DNA markers in the 4 casein genes (CSN1S1, CSN1S2, CSN2, and CSN3) and the 2 major whey protein genes (LALBA and LGB) that show associations with milk protein profile measured by reverse-phase HPLC. Fifty-three single nucleotide polymorphisms (SNP) were genotyped for cows in a unique resource population consisting of purebred Holstein and (Holstein × Jersey) × Holstein crossbred animals. Seven traits were analyzed, including concentrations of α(S)-casein (CN), β-CN, κ-CN, α-lactalbumin, β-lactoglobulin, and 2 additional secondary traits, the total concentration of the above 5 milk proteins and the α(S)-CN to β-CN ratio. A substantial fraction of phenotypic variation could be explained by the additive genetic component for the 7 milk protein composition traits studied. Moreover, several SNP were significantly associated with all examined traits at an experiment-wise error rate of 0.05, except for α-lactalbumin. Importantly, the significant SNP explained a large proportion of the phenotypic variation of milk protein composition. Our findings could be used for selecting animals that produce milk with desired composition or desired processing and manufacturing properties. PMID:22192223

  3. 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

  4. Enhancement of RNA Synthesis, Protein Synthesis, and Abscission by Ethylene

    PubMed Central

    Abeles, F. B.; Holm, R. E.

    1966-01-01

    Ethylene stimulated RNA and protein synthesis in bean (Phaseolus vulgaris L. var. Red Kidney) abscission zone explants prior to abscission. The effect of ethylene on RNA synthesis and abscission was blocked by actinomycin D. Carbon dioxide, which inhibits the effect of ethylene on abscission, also inhibited the influence of ethylene on protein synthesis. An aging period appears to be essential before bean explants respond to ethylene. Stimulation of protein synthesis by ethylene occurred only in receptive or senescent explants. Treatment of juvenile explants with ethylene, which has no effect on abscission also has no effect on protein synthesis. Evidence in favor of a hormonal role for ethylene during abscission is discussed. PMID:16656405

  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. Metabolic effects of milk protein intake strongly depend on pre-existing metabolic and exercise status.

    PubMed

    Melnik, Bodo C; Schmitz, Gerd; John, Swen; Carrera-Bastos, Pedro; Lindeberg, Staffan; Cordain, Loren

    2013-01-01

    Milk protein intake has recently been suggested to improve metabolic health. This Perspective provides evidence that metabolic effects of milk protein intake have to be regarded in the context of the individual's pre-existing metabolic and exercise status. Milk proteins provide abundant branched-chain amino acids (BCAAs) and glutamine. Plasma BCAAs and glutamine are increased in obesity and insulin resistance, but decrease after gastric bypass surgery resulting in weight loss and improved insulin sensitivity. Milk protein consumption results in postprandial hyperinsulinemia in obese subjects, increases body weight of overweight adolescents and may thus deteriorate pre-existing metabolic disturbances of obese, insulin resistant individuals. PMID:24225036

  7. Metabolic effects of milk protein intake strongly depend on pre-existing metabolic and exercise status

    PubMed Central

    2013-01-01

    Milk protein intake has recently been suggested to improve metabolic health. This Perspective provides evidence that metabolic effects of milk protein intake have to be regarded in the context of the individual’s pre-existing metabolic and exercise status. Milk proteins provide abundant branched-chain amino acids (BCAAs) and glutamine. Plasma BCAAs and glutamine are increased in obesity and insulin resistance, but decrease after gastric bypass surgery resulting in weight loss and improved insulin sensitivity. Milk protein consumption results in postprandial hyperinsulinemia in obese subjects, increases body weight of overweight adolescents and may thus deteriorate pre-existing metabolic disturbances of obese, insulin resistant individuals. PMID:24225036

  8. 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. PMID:25151883

  9. 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. PMID:27209140

  10. Antioxidant activity of whey protein hydrolysates in milk beverage system.

    PubMed

    Mann, Bimlesh; Kumari, Anuradha; Kumar, Rajesh; Sharma, Rajan; Prajapati, Kishore; Mahboob, Shaik; Athira, S

    2015-06-01

    The aim of the present study was to evaluate the antioxidant activity of flavoured milk enriched with antioxidative whey protein hydrolysates (WPHs) by radical scavenging method. Whey protein concentrate (WPC) was hydrolyzed by using three commercial proteases; flavouzyme, alcalase and corolase PP and these WPHs were analyzed for degree of hydrolysis and antioxidant activity. The antioxidant activities of these WPHs were evaluated using ABTS method. Trolox equivalent antioxidant activity of all the hydrolysates i.e. flavourzyme (0.81 ± 0.04), alcalase (1.16 ± 0.05) and corolase (1.42 ± 0.12) was higher than the WPC (0.19 ± 0.01). Among these, whey protein hydrolysates prepared using corolase showed maximum antioxidant activity. Total 15 β-lactoglobulin, 1 α-lactoalbumin, and 6 β-casein derived peptide fragments were identified in the WPHs by LC-MS/MS. Due to their size and characteristic amino acid composition, all the identified peptides may contribute for the antioxidant activity. The strawberry and chocolate flavoured milk was supplemented with WPC and WPHs and 2 % addition has shown increase in antioxidant activity upto 42 %. The result suggests that WPH could be used as natural biofunctional ingredients in enhancing antioxidant properties of food products. PMID:26028704

  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. 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. PMID:24519815

  13. 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. PMID:27173528

  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. PMID:22365180

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. De novo synthesis of milk triglycerides in humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. 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. PMID:19841193

  18. Postruminal synthesis modifies the odd- and branched-chain fatty acid profile from the duodenum to milk.

    PubMed

    Vlaeminck, B; Gervais, R; Rahman, M M; Gadeyne, F; Gorniak, M; Doreau, M; Fievez, V

    2015-07-01

    Milk odd- and branched-chain fatty acids (OBCFA) have been suggested as potential biomarkers for rumen function. The potential of milk OBCFA as a biomarker depends on whether their profile reflects the profile observed in the duodenum. The objective of this study was to evaluate whether the OBCFA profile in duodenum samples is reflected in plasma and milk. For this, 2 dairy cattle experiments were used. In experiment 1, 4 Holstein cows fitted with rumen and proximal duodenum cannulas were used in a 4×4 Latin square design. The treatments consisted of 2 nitrogen levels (143 vs. 110g of crude protein/kg of dry matter for high and low N, respectively) combined with either 1 of the 2 energy sources (i.e., starch from barley, corn, and wheat or fiber from soybean hulls and dehydrated beet pulp). In experiment 2, 4 Holstein cows fitted with rumen and proximal duodenum cannulas were used in a 3×3 Latin square design, with the treatments consisting of 3 diets: (1) RNB-, a diet with a crude protein content of 122g/kg of dry matter, predicted to provide protein digested in the small intestine according to the requirement of the animals, but with a shortage of rumen degradable protein; (2) RNB- to which 6g/d of niacin was added through inclusion in the mineral and vitamin premix, and (3) RNB- to which urea was added to balance rumen degradable N supply resulting in a CP content of 156g/kg of dry matter. In both experiments, samples of duodenal digesta, plasma, and milk were collected and analyzed for fatty acids. Additionally, lipids in plasma samples were separated in lipid classes and analyzed for fatty acids. The OBCFA profile in milk was enriched in 15:0, iso-17:0, anteiso-17:0, and cis-9-17:1 as compared with duodenal samples, and milk secretions even exceeded duodenal flows, which suggests occurrence of postruminal synthesis, such as de novo synthesis, desaturation, and elongation. The postruminal modification of the OBCFA profile might hamper the application of OBCFA

  19. Identification of short peptide sequences in complex milk protein hydrolysates.

    PubMed

    O'Keeffe, Martina B; FitzGerald, Richard J

    2015-10-01

    Numerous low molecular mass bioactive peptides (BAPs) can be generated during the hydrolysis of bovine milk proteins. Low molecular mass BAP sequences are less likely to be broken down by digestive enzymes and are thus more likely to be active in vivo. However, the identification of short peptides remains a challenge during mass spectrometry (MS) analysis due to issues with the transfer and over-fragmentation of low molecular mass ions. A method is described herein using time-of-flight ESI-MS/MS to effectively fragment and identify short peptides. This includes (a) short synthetic peptides, (b) short peptides within a defined hydrolysate sample, i.e. a prolyl endoproteinase hydrolysate of β-casein and (c) short peptides within a complex hydrolysate, i.e. a Corolase PP digest of sodium caseinate. The methodology may find widespread utilisation in the efficient identification of low molecular mass peptide sequences in food protein hydrolysates. PMID:25872436

  20. 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

    2015-01-01

    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. PMID:26662412

  1. Effect of various protein kinase inhibitors on the induction of milk protein gene expression by prolactin.

    PubMed

    Bayat-Sarmadi, M; Houdebine, L M

    1993-03-01

    Prolactin has many known functions and one of them is to induce the expression of milk protein gene expression in the mammary gland. Specific membrane receptors have been recently characterized but the transduction mechanism involved in the transfer of the prolactin signal to milk protein genes remains unknown. In the present work, it is shown that several protein kinase inhibitors block prolactin action on milk protein genes. Primary rabbit mammary cells were cultured for several days on floating collagen gel in a serum-free medium. Prolactin and the inhibitors of protein kinase were then added to the culture medium. After 1 day, the concentration of alpha s1-casein in the culture medium was measured using a specific radioimmunoassay. The concentration of several mRNAs in cell extracts was also evaluated using Northern blot analysis. alpha s1-Casein secretion and alpha s1-casein mRNA accumulation were induced by prolactin. This induction was blocked by staurosporine, sphingosine, quercetin, genistein and to some extent by o-hydroxyphenyl acetate, but not by H7, polymyxin B, benzylsuccinate and lavendustin A. The concentration of the mRNA coding for transferrin, which is abundantly secreted in rabbit milk independently of prolactin action, was only moderately altered by the inhibitors. The concentration of two house-keeping mRNAs, beta-actin and glyceraldehyde 3-phosphate dehydrogenase, was lowered only by genistein after 1 day but not after 4 h of culture. These data show for the first time that a Ser/Thre kinase, which is not kinase C, and possibly a tyrosine kinase is involved in the transduction of the prolactin message from the receptor to the milk protein genes. PMID:8472863

  2. Purification and characterization of the major whey proteins from the milks of the bottlenose dolphin (Tursiops truncatus), the Florida manatee (Trichechus manatus latirostris), and the beagle (Canis familiaris).

    PubMed

    Pervaiz, S; Brew, K

    1986-05-01

    The major whey proteins of the milks of the dolphin, manatee, and beagle were purified by gel filtration and ion exchange chromatography and characterized and identified by molecular weight determination, amino acid analysis, N-terminal sequencing, and activity measurements. The major whey protein components from all three species were found to be monomeric beta-lactoglobulins. These proteins were all active in binding retinol. Dolphin milk contained two beta-lactoglobulins (designated 1 and 2) which showed a slight difference in molecular weight and considerably divergent N-terminal sequences, whereas the other milks only contained a single form of beta-lactoglobulin. alpha-Lactalbumins were purified from dolphin and dog milks and were active in promoting lactose synthesis by bovine galactosyltransferase. The dolphin protein had an N-terminal sequence more similar to ruminant alpha-lactalbumins than to those known from other species. Although alpha-lactalbumin activity has been detected in manatee milk at low levels, the corresponding protein was not isolated. In addition, dog milk was found to contain high levels of lysozyme (greater than 1.0 mg/ml), which were identified by activity and sequencing. The functional and evolutionary implications of these results are discussed. PMID:3707136

  3. Rapid separation and quantification of major caseins and whey proteins of bovine milk by capillary electrophoresis.

    PubMed

    Vallejo-Cordoba, B

    1997-01-01

    A rapid capillary zone electrophoresis (CZE) method was established for separating and quantifying major casein and whey proteins in milk. Optimum sample preparation and electrophoretic conditions in a coated capillary maintained at 40 degrees C allowed accurate and reproducible quantification of milk proteins in a single analysis. Sample and run buffer allowed caseins to be maintained in solution by using a combination of urea and a nonionic detergent in phosphate buffer at pH 2.5. Quantitative CZE protein data were derived by calculating percentages and concentrations (mg/mL) of alpha-casein, beta-casein, alpha-lactalbumin, and beta-lactoglobulin. Calibration curves followed linear relationships with highly significant (p < 0.1) correlation coefficients. Relative standard deviations of less than 0.82 (%) for migration times and 2.18 (%) for percent protein indicated that the technique was reproducible. Electrophoretic protein profiles of fresh bovine milk and rehydrated dry milk showed marked quantitative differences in whey protein concentrations. Whey protein represented 12.37 +/- 0.07% beta-lactoglobulin and 3.05 +/- 0.08% alpha-lactalbumin of total protein in typical fresh milk, while only 1.90 +/- 0.16% beta-lactoglobulin and 0.86 +/- 0.04% alpha-lactalbumin of total protein were detected in a commercial rehydrated milk powder. By quantifying these differences, the established technique may allow the detection of substitution of fresh milk with rehydrated milk powder. The accuracy and reproducibility of the technique permitted the quantitation of individual protein concentrations in milk samples, which agreed with ranges reported in the literature. CZE may be well suited for routine use by dairies and regulatory agencies, since it allows the determination of milk proteins in less than 60 min. PMID:9725120

  4. Intestinal threonine utilization for protein and mucin synthesis is decreased in formula-fed preterm pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Threonine is an essential amino acid necessary for synthesis of intestinal (glyco)proteins such as mucin (MUC2) to maintain adequate gut barrier function. In premature infants, reduced barrier function may contribute to the development of necrotizing enterocolitis (NEC). Human milk protects against ...

  5. 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. PMID:26617031

  6. Cows' milk protein-sensitive enteropathy. Combined clinical and histological criteria for diagnosis.

    PubMed Central

    Iyngkaran, N; Robinson, M J; Prathap, K; Sumithran, E; Yadav, M

    1978-01-01

    Cows' milk protein enteropathy is recognised as a significant cause of persistent diarrhoea and malabsorption in young infants, but there are as yet no generally accepted diagnostic criteria. A combined clinical and histological approach to the diagnosis of cows' milk protein-sensitive enteropathy has been used in 15 patients, and the following set of criteria are proposed. (1) Clinical disease (diarrhoea with or without vomiting) while receiving cows' milk protein. (2) Clinical improvement on a diet free of cows' milk protein. (3) Normal or mildly abnormal histology of jejunal mucosa when taken 6-8 weeks after symptoms subside. (4) Histological relapse, with or without clinical relapse, after re-exposure to cows' milk protein. Images Fig. 1 Fig. 2 PMID:564668

  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. 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. PMID:26632331

  9. A proteomic perspective on the changes in milk proteins due to high somatic cell count.

    PubMed

    Zhang, L; Boeren, S; van Hooijdonk, A C M; Vervoort, J M; Hettinga, K A

    2015-08-01

    Although cows with subclinical mastitis have no difference in the appearance of their milk, milk composition and milk quality are altered because of the inflammation. To know the changes in milk quality with different somatic cell count (SCC) levels, 5 pooled bovine milk samples with SCC from 10(5) to 10(6) cells/mL were analyzed qualitatively and quantitatively using both one-dimension sodium dodecyl sulfate PAGE and filter-aided sample preparation coupled with dimethyl labeling, both followed by liquid chromatography tandem mass spectrometry. Minor differences were found on the qualitative level in the proteome from milk with different SCC levels, whereas the concentration of milk proteins showed remarkable changes. Not only immune-related proteins (cathelicidins, IGK protein, CD59 molecule, complement regulatory protein, lactadherin), but also proteins with other biological functions (e.g., lipid metabolism: platelet glycoprotein 4, butyrophilin subfamily 1 member A1, perilipin-2) were significantly different in milk from cows with high SCC level compared with low SCC level. The increased concentration of protease inhibitors in the milk with higher SCC levels may suggest a protective role in the mammary gland against protease activity. Prostaglandin-H2 D-isomerase showed a linear relation with SCC, which was confirmed with an ELISA. However, the correlation coefficient was lower in individual cows compared with bulk milk. These results indicate that prostaglandin-H2 D-isomerase may be used as an indicator to evaluate bulk milk quality and thereby reduce the economic loss in the dairy industry. The results from this study reflect the biological phenomena occurring during subclinical mastitis and in addition provide a potential indicator for the detection of bulk milk with high SCC. PMID:26094216

  10. 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. PMID:818610

  11. The protein and lipid composition of the membrane of milk fat globules depends on their size.

    PubMed

    Lu, Jing; Argov-Argaman, Nurit; Anggrek, Jeni; Boeren, Sjef; van Hooijdonk, Toon; Vervoort, Jacques; Hettinga, Kasper Arthur

    2016-06-01

    In bovine milk, fat globules (MFG) have a heterogeneous size distribution with diameters ranging from 0.1 to 15 µm. Although efforts have been made to explain differences in lipid composition, little is known about the protein composition of MFG membranes (MFGM) in different sizes of MFG. In this study, protein and lipid analyses were combined to study MFG formation and secretion. Two different sized MFG fractions (7.6±0.9 µm and 3.3±1.2 µm) were obtained by centrifugation. The protein composition of MFGM in the large and small MFG fractions was compared using mass-spectrometry-based proteomics techniques. The lipid composition and fatty acid composition of MFG was determined using HPLC-evaporative light-scattering detector and gas chromatography, respectively. Two frequently studied proteins in lipid droplet biogenesis, perilipin-2 and TIP47, were increased in the large and small MFG fractions, respectively. In the large MFG fraction, besides perilipin-2, cytoplasmic vesicle proteins (heat shock proteins, 14-3-3 proteins, and Rabs), microfilaments and intermediate filament-related proteins (actin and vimentin), host defense proteins (cathelicidins), and phosphatidylinositol were higher in concentration. On the other hand, cholesterol synthesis enzymes [lanosterol synthase and sterol-4-α-carboxylate 3-dehydrogenase (decarboxylating)], cholesterol, unsaturated fatty acids, and phosphatidylethanolamine were, besides TIP47, higher in concentration in the small MFG fraction. These results suggest that vesicle proteins, microfilaments and intermediate filaments, cholesterol, and specific phospholipids play an important role in lipid droplet growth, secretion, or both. The observations from this study clearly demonstrated the difference in protein and lipid composition between small and large MFG fractions. Studying the role of these components in more detail in future experiments may lead to a better understanding of fat globule formation and secretion. PMID

  12. Compositional analysis of protein content in milk with near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Bi, Weihong; Yang, Xiaoli; Li, Chao; Liu, Haiying

    2006-02-01

    A fast analytical method was introduced based on near-infrared (NIR) technology in this paper. The protein content was measured in short order using the near-infrared transmission spectroscopy (1000-1700nm) of milk. There were several waves of milk's NIR spectroscopy selected. By correlating the spectrum data of the waves selected and the protein content in milk, a calibration model was established. The protein content could be measured by importing the spectrum data to the calibration model. In this model there were several parameters, which were the spectrum data of the waves selected. Then, the method how to select the waves best was introduced and the characteristic waves of milk were selected by utilizing genetic algorithm. A partial least squares (PLS) regression model between the spectroscopy and the protein content was presented for milk samples, and the predictive repeatability was also researched.

  13. Starch/carrageenan/milk proteins interactions studied using multiple staining and Confocal Laser Scanning Microscopy.

    PubMed

    Matignon, A; Moulin, G; Barey, P; Desprairies, M; Mauduit, S; Sieffermann, J M; Michon, C

    2014-01-01

    This study focused on the effects of the interactions between modified waxy maize starch, kappa carrageenan and skim milk on the microstructure of their mixed systems using Confocal Laser Scanning Microscopy (CLSM). A multiple staining of the components was set up with a view to improving starch covalent staining. In starch/carrageenan pasted mixtures, carrageenan was found to adsorb on and penetrate slightly into the starch granules, whereas no interactions were observed between starch and milk proteins. In ternary mixtures, interactions between starch granules and carrageenan were no longer observed, even when milk proteins were added after starch swelling in the carrageenan solution, thus showing preferential interactions between carrageenan/milk proteins in comparison to carrageenan/starch granules. Modifying the blending order of the components led to microstructure differences depending on several parameters such as starch/carrageenan interactions, carrageenan/milk proteins network structure, level of starch granules disruption and amylopectin contribution to the microstructure. PMID:24274517

  14. The effect of long-term under- and overfeeding on the expression of six major milk proteins' genes in the mammary tissue of goats.

    PubMed

    Tsiplakou, E; Flemetakis, E; Kouri, E-D; Karalias, G; Sotirakoglou, K; Zervas, G

    2016-06-01

    Milk protein synthesis in the mammary gland involves expression of six major milk proteins' genes whose nutritional regulation remains poorly defined. In this study, the effect of long-term under- and overfeeding on the expression of as1-casein: CSN1S1, as2-casein: CSN1S2, β-casein: CSN2, κ-casein: CSN3, α-lactalbumin: LALBA and β-lactoglobulin: BLG gene in goat mammary tissue (MT) was examined. Twenty-four lactating dairy goat, at 90-98 days in milk, were divided into three homogenous subgroups and fed the same ration, for 60 days, in quantities which met 70% (underfeeding), 100% (control) and 130% (overfeeding) of their energy and crude protein requirements. The results showed a significant decrease in mRNA of CSN1S2, CSN2, CSN3 and LALBA genes in the MT of underfed goats compared with the overfed and on the CSN1S1 and BLG gene expressions in the MT of underfed goats compared with the respective control and overfed. CSN2 was the most abundant transcript in goat MT relative to the other milk proteins' genes. Significantly positive correlations were observed between the mRNA levels of caseins' and BLG genes with the milk yield. Moreover, a significant correlation was found between the mRNA levels of CSN1S2 with the milk protein, lactose content and lactose yield and also between the LALBA gene expression with the lactose content and lactose yield respectively. In conclusion, the feeding level and consequently the nutrients availability affected the milk lactose content, protein and lactose yield as well as the milk volume by altering the CSN1S1, CSN1S2, CSN2, CSN3, LALBA and BLG gene expression involved in their metabolic pathways. PMID:26613803

  15. 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

  16. 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)

  17. 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. PMID:25459904

  18. 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

  19. Interlaboratory Study of ELISA Kits for the Detection of Egg and Milk Protein in Processed Foods.

    PubMed

    Kato, Shigeki; Yagi, Takahiro; Kato, Ayako; Yamamoto, Shunsuke; Akimoto, Masanobu; Arihara, Keizo

    2015-01-01

    The labeling of seven specific allergenic ingredients (egg, milk, wheat, buckwheat, peanut, shrimp, and crab) is mandatory in Japan. To ensure proper labeling, two kinds of ELISA kits using polyclonal antibodies have been developed. However, we developed two novel ELISA kits using monoclonal antibodies with improved specificity, the Allergeneye ELISA Egg (AE-Egg) and Allergeneye ELISA Milk (AE-Milk) Kits, to detect egg and milk proteins in processed foods, respectively. Five types of processed food containing 10 mg/kg of egg or milk soluble protein were prepared for an interlaboratory study of the performance of these kits. The kits showed a relatively high reproducibility level of interlaboratory precision (AE-Egg RSDR, 3.7-5.7%; AE-Milk RSDR, 6.8-10.5%) and satisfied the recovery rate stipulated by Japanese guidelines (AE-Egg, 61.6-89.3%; AE-Milk, 52.1-67%) for all processed foods. Our results suggest that the AE-Egg and AE-Milk Kits are precise and reliable tools for detecting egg or milk proteins in processed foods. PMID:26086260

  20. Blood-derived proteins in milk at start of lactation: Indicators of active or passive transfer.

    PubMed

    Wall, Samantha K; Gross, Josef J; Kessler, Evelyne C; Villez, Kris; Bruckmaier, Rupert M

    2015-11-01

    Colostrum has a different composition compared with milk in established lactation. This difference is in part due to the partially open blood-milk barrier, which, when closed, is designed to prevent the interdiffusion of blood and milk components. In the first days of lactation, α-lactalbumin (α-LA), a milk protein, is typically present in blood and several blood-derived proteins are also present in milk, such as IgG1, IgG2, serum albumin (SA), and lactate dehydrogenase (LDH). With the exception of IgG1, which is known to be transferred by active transcellular transport, the other proteins are thought to pass paracellularly through the temporarily open barrier. Along with an exchange of blood and milk components, somatic cell count (SCC) is typically high in colostrum. The decline of these proteins and SCC can be used as indicators to determine transcellular or paracellular transport. Two hypotheses were tested. The first hypothesis was that the decline curve for a protein or SCC would be the same as IgG1, indicating transcellular transport, or the decline curve would be different than IgG1, indicating paracellular transport. The second hypothesis was that the decline curves of SCC and all proteins that are thought to have paracellular transport would be the same. Ten Holstein cows were milked at 4 h after parturition, the next 5 consecutive milkings, and the afternoon milking on d 5, 8, 10, and 14 of lactation for a total of 10 milking time points, and sequential jugular blood samples were also taken. Blood and milk samples were analyzed for the concentrations of LDH, SA, IgG1, IgG2, and α-LA and milk samples were measured for SCC. Protein concentration and SCC curves were generated from all 10 time points and were evaluated using the tau time constant model to determine the rate of decline of the slope of each protein. When examining the first hypothesis, the concentration of IgG1 declined significantly faster in the milk than the proteins IgG2 and LDH, but

  1. 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. PMID:27114253

  2. The Most Common Cow's Milk Allergenic Proteins with Respect to Allergic Symptoms in Iranian Patients.

    PubMed

    Shokouhi Shoormasti, Raheleh; Fazlollahi, Mohammad Reza; Barzegar, Saeedeh; Teymourpour, Pegah; Yazdanyar, Zahra; Lebaschi, Zahra; Nourizadeh, Maryam; Tazesh, Behnaz; Movahedi, Masoud; Kashani, Homa; Pourpak, Zahra; Moin, Mostafa

    2016-04-01

    Cow's milk allergy (CMA) is an immunological response to cow's milk proteins such as casein, α-lactalbumin and β lactoglobulin. The aim of this study was to determine the most common cow's milk allergenic proteins in patients with CMA and identify the most effective proteins in different allergic symptoms. Eighty seven patients (≤18 years) with allergy to cow's milk from 2006 to 2013 entered this study. They had a positive history of allergic reactions to cow's milk and a positive specific IgE test to whole cow's milk. The patients' symptoms were divided into four groups. Serum specific IgEs against four different main proteins of cow's milk were measured using RIDA Allergy Screen. Among 87 patients, 53 (60.5%) were male and the median age was 2.5 years. The frequency of respiratory, skin, gastrointestinal symptoms, and anaphylaxis were 63.3%, 55.7%, 20.3%, and 13.4%, respectively. Specific IgEs to total cow's milk protein (n=75, 89.3%), and the main Cow's Milk Proteins including α-lactalbumin (n=65, 77.4%), casein (n=64, 75.3%), β-lactoglobulin (n=52, 62.7%), and bovine serum albumin (n=35, 44.9%) were detected. Specific IgE tests to β-lactoglobulin were positive in 90% of the patients with anaphylaxis. Moreover, significant relationship was found between specific IgE to β-lactoglobulin and anaphylaxis (p=0.04). Although it is presumed that α-lactalbumin and casein are the most common allergenic proteins of cow's milk, in this study there is a significant relationship between the anaphylaxis and the presence of β-lactoglobulin-specific IgE. Therefore, more precautions are recommended due to possible anaphylactic reactions in patients with a positive test history for β-lactoglobulin specific IgE. PMID:27090370

  3. 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. PMID:26119290

  4. Dataset of milk whey proteins of two indigenous greek goat breeds.

    PubMed

    Anagnostopoulos, Athanasios K; Katsafadou, Angeliki I; Pierros, Vasileios; Kontopodis, Evangelos; Fthenakis, George C; Arsenos, George; Karkabounas, Spyridon Ch; Tzora, Athina; Skoufos, Ioannis; Tsangaris, George Th

    2016-09-01

    Due to its rarity and unique biological traits, as well as its growing financial value, milk of dairy Greek small ruminants is continuously attracting interest from both the scientific community and industry. For the construction of the present dataset, cutting-edge proteomics methodologies were employed, in order to investigate and characterize, for the first time, the milk whey proteome from the two indigenous Greek goat breeds, Capra prisca and Skopelos. In total 822 protein groups were identified in milk whey of the two breeds, The present data are further discussed in the research article "Milk of Greek sheep and goat breeds; characterization by means of proteomics" [1]. PMID:27508219

  5. 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. PMID:27109024

  6. 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. PMID:27234410

  7. Effects of continuous milking during a field trial on productivity, milk protein yield and health in dairy cows.

    PubMed

    Köpf, M; Gellrich, K; Küchenhoff, H; Meyer, H H D; Kliem, H

    2014-07-01

    The objective of this field study with an automatic milking system was to evaluate the effects of omitting the dry period on health and productivity during the subsequent lactation in dairy cows. A total of 98 German Simmental cows of six Southern German farms were assigned randomly to two experimental groups: The first group was dried-off 56 days before calving (D for dried-off, n=49), and the second group was milked continuously during this period until calving (CM for continuous milking, n=49). From the latter a third group emerged, including cows that dried-off themselves spontaneously (DS for dried-off spontaneously, n=14). Blood serum values of glucose, β-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA) and IGF-1 showed most pronounced fluctuations in D cows. Over the entire study period, the concentrations of BHBA and NEFA were markedly lower in the CM and DS groups. Furthermore, IGF-1 concentration was lowest for D cows and also decrease in back fat thickness was more pronounced. Mean concentration of milk protein was markedly higher in CM and DS cows (3.70% and 3.71%) compared with D cows (3.38%). Owing to the lower 305-day milk yield (-15.6%) and the lower total milk yield (-3.1%), the total amount of produced protein in the subsequent lactation was 2.5% (6.8 kg) lower, although the additional protein amount in CM cows from week -8 to calving was 35.7 kg. The greatest benefit resulted from positive effects on fertility and the lower incidence of diseases: CM cows had their first oestrus 1 week earlier compared with D cows, they also conceived earlier and showed a significantly lower risk of developing hypocalcaemia, ketosis and puerperal disorders. The present study showed that the costs of medical treatment and milk losses were twice as high in D cows, compared with CM and DS cows, and thus the reduced costs because of the more stable health outweighed the financial losses of milk yield by +18.49 € per cow and lactation. PMID:26263029

  8. Storage Protein Synthesis in Maize

    PubMed Central

    Larkins, Brian A.; Bracker, Charles E.; Tsai, C. Y.

    1976-01-01

    Undegraded free and membrane-bound polysomes were isolated from developing kernels of Zea mays L. frozen in liquid nitrogen. Freezing in liquid nitrogen was a prerequisite for preserving polysome structure in stored kernels. Membrane-bound polysomes from 22-day post-pollination kernels ground in high pH buffers containing 50 mm Mg2+ contained unique classes of large polysomes. These large polysomes were sensitive to ribonuclease, and electron micrographs verified that they were not formed by aggregation. The membrane-bound polysomes were the principal site of zein synthesis, since the major protein synthesized in vitro was similar to purified zein in its ethanol solubility and mobility on sodium dodecyl sulfate polyacrylamide gels. Images PMID:16659563

  9. 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. PMID:26748454

  10. 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.

  11. 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

  12. 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.

  13. 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

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

    PubMed

    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

  15. 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

  16. Plant proteins in milk replacers for rearing buffalo calves. I. Effect of replacing half of the milk proteins by plant proteins on the preweaning performance of buffalo calves.

    PubMed

    el-Ashry, M A; el-Serafy, A M; Zaki, A A; Soliman, H

    1988-01-01

    In an experiment, 12 female and 8 male buffalo calves aged 3 to 4 weeks with an average of 65.2 kg live body weight were divided into 4 equal groups. Group 1 received dried skim milk plus non-milk fat. In groups 2, 3, and 4, 50% of the milk protein were replaced by American soybean flour, Egyptian soya meal, or corn glutine. Scouring occurred in all groups during the first three weeks. Death losses occurred in group 2 (2 calves) and 4 (1 calf). During the first three experimental weeks the calves consumed on average 828, 868, 847, 696 g dry matter (DM) as liquids. The average daily gain (ADG) was 229, 215, 252, 48 g/d, respectively. The energy consumption reached 4.1, 4.6, 3.8, 16.6 TDN/kg ADG. During the second period, the calves consumed 1.57, 1.45, 1.55, 1.65 kg DM as liquid and solid feedstuff. Up to a live body weight of 90 kg they had a daily increase of 695, 611, 593, 600 g. The energy used amounted to 1.98, 2.08, 2.28, 2.40 TDN/kg ADG. The apparent digestibility of the crude protein was 95, 92, 91, 92% during the first period and 81, 77, 76, 73% during the second period. PMID:3395319

  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. The immunopathogenesis of cow’s milk protein allergy (CMPA)

    PubMed Central

    2012-01-01

    The most frequent symptoms among the manifestations of cow milk protein allergy (CMPA) are gastrointestinal. CMPA pathogenesis involves immunological mechanisms with participation of immunocompetent cells and production of immunoglobulin E (IgE). Nevertheless, recent studies have been focused on the description of other forms of CMPA, not-mediated by IgE reactions, mostly involving the T lymphocite immune system. Thus, in this field it is important to note how different kind of cells are involved in the immunopathogenesis of CMPA, such as antigen-specific T cells, T regulatory cells, cytokines secreted by the different T lymphocite subsets, B lymphocytes, antingen-presenting cells, mast cells, that together orchestrate the complex mechanism leading to the phenotipic expression of CMPA. The progress in the diagnosis of immunologic disorders allowed the recent literature to develop new models for immuno-mediate disorders, involving new cells (such as Treg cells) and thus allowing the acquisition of a new vision of the pathogenesis of atopic diseases. The aim of this review is to describe the immunopathogenetic aspects of CMPA in view of these new discoveries in the immunologic field, considering the immunologic pathway at the basis of both IgE- and not-IgE mediated CMPA. PMID:22824011

  19. The immunopathogenesis of cow's milk protein allergy (CMPA).

    PubMed

    Vitaliti, Giovanna; Giovanna, Vitaliti; Cimino, Carla; Carla, Cimino; Coco, Alfina; Alfina, Coco; Praticò, Andrea Domenico; Domenico, Praticò Andrea; Lionetti, Elena; Elena, Lionetti

    2012-01-01

    The most frequent symptoms among the manifestations of cow milk protein allergy (CMPA) are gastrointestinal. CMPA pathogenesis involves immunological mechanisms with participation of immunocompetent cells and production of immunoglobulin E (IgE). Nevertheless, recent studies have been focused on the description of other forms of CMPA, not-mediated by IgE reactions, mostly involving the T lymphocite immune system. Thus, in this field it is important to note how different kind of cells are involved in the immunopathogenesis of CMPA, such as antigen-specific T cells, T regulatory cells, cytokines secreted by the different T lymphocite subsets, B lymphocytes, antingen-presenting cells, mast cells, that together orchestrate the complex mechanism leading to the phenotipic expression of CMPA.The progress in the diagnosis of immunologic disorders allowed the recent literature to develop new models for immuno-mediate disorders, involving new cells (such as Treg cells) and thus allowing the acquisition of a new vision of the pathogenesis of atopic diseases.The aim of this review is to describe the immunopathogenetic aspects of CMPA in view of these new discoveries in the immunologic field, considering the immunologic pathway at the basis of both IgE- and not-IgE mediated CMPA. PMID:22824011

  20. 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. PMID:23660296

  1. 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

  2. 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. PMID:26869107

  3. Comparison of an extender containing defined milk protein fractions with a skim milk-based extender for storage of equine semen at 5 degrees C.

    PubMed

    Pagl, Roland; Aurich, Jörg E; Müller-Schlösser, Frank; Kankofer, Marta; Aurich, Christine

    2006-09-15

    A problem of semen extenders based on milk or egg yolk is the fact that these biological products consist of a variety of substances. Extenders containing only components with clearly protective effects on spermatozoa would thus be an advantage. In this study, we have compared the effects of an extender containing defined caseinates and whey proteins only (EquiPro, defined milk protein extender) with skim milk extender on equine spermatozoa during cooled storage. The defined milk protein extender was used with and without the antioxidant N-acetyl cysteine (NAC). In a second experiment, semen was diluted with PBS or defined milk protein extender and was either stored directly or 90% of seminal plasma was removed by centrifugation and replaced by defined milk protein extender before storage. In both experiments, eight stallions were available for semen collections. Motility, velocity and membrane integrity of spermatozoa were determined by CASA immediately after semen processing and after 24, 48 and 72 h of storage at 5 degrees C. Total motility after 24 h of storage was lowest in semen diluted with PBS (p<0.05 versus all extenders). At 48 and 72 h, motility of spermatozoa in defined milk protein extender was significantly (p<0.05) higher than in PBS or skim milk extender. Velocity of spermatozoa after storage was highest in defined milk protein extender. Membrane integrity after storage was significantly (p<0.05) lower in semen diluted with PBS than in semen diluted with both extenders. Addition of NAC was without effect on the examined parameters. Centrifugation further increased the percentage of motile and membrane-intact spermatozoa in the defined milk protein extender (p<0.05). Velocity of spermatozoa in this extender was not negatively affected by centrifugation. PMID:16620943

  4. 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. PMID:26830565

  5. Comparison of heat and pressure treatments of skim milk, fortified with whey protein concentrate, for set yogurt preparation: effects on milk proteins and gel structure.

    PubMed

    Needs, E C; Capellas, M; Bland, A P; Manoj, P; MacDougal, D; Paul, G

    2000-08-01

    Heat (85 degrees C for 20 min) and pressure (600 MPa for 15 min) treatments were applied to skim milk fortified by addition of whey protein concentrate. Both treatments caused > 90 % denaturation of beta-lactoglobulin. During heat treatment this denaturation took place in the presence of intact casein micelles; during pressure treatment it occurred while the micelles were in a highly dissociated state. As a result micelle structure and the distribution of beta-lactoglobulin were different in the two milks. Electron microscopy and immunolabelling techniques were used to examine the milks after processing and during their transition to yogurt gels. The disruption of micelles by high pressure caused a significant change in the appearance of the milk which was quantified by measurement of the colour values L*, a* and b*. Heat treatment also affected these characteristics. Casein micelles are dynamic structures, influenced by changes to their environment. This was clearly demonstrated by the transition from the clusters of small irregularly shaped micelle fragments present in cold pressure-treated milk to round, separate and compact micelles formed on warming the milk to 43 degrees C. The effect of this transition was observed as significant changes in the colour indicators. During yogurt gel formation, further changes in micelle structure, occurring in both pressure and heat-treated samples, resulted in a convergence of colour values. However, the microstructure of the gels and their rheological properties were very different. Pressure-treated milk yogurt had a much higher storage modulus but yielded more readily to large deformation than the heated milk yogurt. These changes in micelle structure during processing and yogurt preparation are discussed in terms of a recently published micelle model. PMID:11037230

  6. Production and properties of health-promoting proteins and peptides from bovine colostrum and milk.

    PubMed

    Korhonen, H J

    2013-01-01

    The high nutritive value and diverse functional properties of milk proteins are well known. Beyond these qualities, milk proteins have attracted growing scientific and commercial interest as a source of biologically active molecules. Such proteins are found in abundance in colostrum which is the initial milk secreted by mammalian species during late pregnancy and the first few days after birth of the offspring. The best characterized colostrum-based bioactive proteins include alpha-lactalbumin, beta-lactoglobulin, immunoglobulins, lactoferrin, lactoperoxidase and growth factors. All of them can nowadays be enriched and purified on an industrial scale from bovine colostral whey or cheese whey. These native proteins exhibit a wide range of biological activities that are known to affect the digestive function, metabolic responses to absorbed nutrients, growth and development of organs and disease resistance. Also, some of these proteins may prove beneficial in reduction of the risks of chronic human diseases reflected by the metabolic syndrome. It is speculated that such potentially beneficial effects are partially attributed to bioactive peptides derived from intact proteins. These peptides can be liberated during gastrointestinal digestion or fermentation of milk by starter cultures. The efficacy of a few peptides has been established in animal and human studies and the number of commercial products supplemented with specific milk peptides is envisaged to increase on global markets. Bovine colostrum appears as a highly potential source of biologically active native proteins and peptide fractions for inclusion as health-promoting ingredients in various food applications. PMID:24200017

  7. Dataset of milk whey proteins of three indigenous Greek sheep breeds.

    PubMed

    Anagnostopoulos, Athanasios K; Katsafadou, Angeliki I; Pierros, Vasileios; Kontopodis, Evangelos; Fthenakis, George C; Arsenos, George; Karkabounas, Spyridon Ch; Tzora, Athina; Skoufos, Ioannis; Tsangaris, George Th

    2016-09-01

    The importance and unique biological traits, as well as the growing financial value, of milk from small Greek ruminants is continuously attracting interest from both the scientific community and industry. In this regard the construction of a reference dataset of the milk of the Greek sheep breeds is of great interest. In order to obtain such a dataset we employed cutting-edge proteomics methodologies to investigate and characterize, the proteome of milk from the three indigenous Greek sheep breeds Mpoutsko, Karagouniko and Chios. In total, more than 1300 protein groups were identified in milk whey from these breeds, reporting for the first time the most detailed proteome dataset of this precious biological material. The present results are further discussed in the research paper "Milk of Greek sheep and goat breeds; characterization by means of proteomics" (Anagnostopoulos et al. 2016) [1]. PMID:27508236

  8. A review of nutritional and physiological factors affecting goat milk lipid synthesis and lipolysis.

    PubMed

    Chilliard, Y; Ferlay, A; Rouel, J; Lamberet, G

    2003-05-01

    Although the effect of lactation stage is similar, the responses of milk yield and composition (fat and protein contents) to different types of lipid supplements differ greatly between goats and cows. Milk fat content increases with almost all studied fat supplements in goats but not in cows. However, the response of milk fatty acid (FA) composition is similar, at least for major FA, including conjugated linoleic acid (CLA) in goats and cows supplemented with either protected or unprotected lipid supplements. Goat milk CLA content increases sharply after either vegetable oil supplementation or fresh grass feeding, but does not change markedly when goats receive whole untreated oilseeds. Important interactions are observed between the nature of forages and of oil supplements on trans-10 and trans-11 C18:1 and CLA. Peculiarities of goat milk FA composition and lipolytic system play an important role in the development of either goat flavor (release of branched, medium-chain FA) or rancidity (excessive release of butyric acid). The lipoprotein lipase (LPL) activity, although lower in goat than in cow milk, is more bound to the fat globules and better correlated to spontaneous lipolysis in goat milk. The regulation of spontaneous lipolysis differs widely between goats and cows. Goat milk lipolysis and LPL activity vary considerably and in parallel across goat breeds or genotypes, and are low during early and late lactation, as well as when animals are underfed or receive a diet supplemented with protected or unprotected vegetable oils. This could contribute to decreases in the specific flavor of goat dairy products with diets rich in fat. PMID:12778586

  9. Plant protein in milk replacers for rearing buffalo calves. II. Effect of replacing 75% of the milk proteins by plant proteins on the preweaning performance of buffalo calves.

    PubMed

    el-Ashry, M A; el-Serafy, A M; Zaki, A A

    1988-01-01

    In an experiment, 9 female and 6 male buffalo calves at the age of 3 to 4 weeks were divided into 3 groups. The animals were given milk replacers in which 75% of the dried skim milk protein had been replaced by American soybean flour (ASP), Egyptian soya meal (ESP), or corn glutine (GP). Scouring occurred in all groups during the first 3 weeks of the experiment, continuing up to the fourth week in groups ESP and GP. In groups ESP and GP one calf each died. During the first 3 weeks of the experiment, the calves consumed on average 747, 631, 787 g dry matter (DM) as liquids. They achieved live weight gains of 314, 83, -286 g/d, with significant differences between the groups. The digestibility of the crude protein was 73, 74, 70%. During the second period--up to 70 or 62.5 kg live body weight--only groups ASP and ESP were investigated. The calves consumed 1.64 or 1.66 kg DM/d as liquid and dry feedstuff. The average daily weight gain was 3.87 or 3.50 TDN/kg ADG. During this period, the crude protein was digested by 76 or 73%. PMID:3202820

  10. Effects of wheat protein in milk replacers on abomasal emptying rate in calves.

    PubMed

    Wittek, T; Ernstberger, M; Muckenhuber, M; Flöck, M

    2016-04-01

    Diarrhoea is a condition with tremendous impact on calf health. Infectious agents play a dominant role; however, non-infective factors may also contribute to pathogenesis of diarrhoea. One factor, the abomasal emptying rate, is mainly influenced by the composition of feed. The aim of the study was to assess the influence of different protein sources in milk replacers on abomasal emptying rate and clinical parameters. The effect of increasing age of the calves on abomasal emptying was also evaluated. The study compared abomasal emptying rates and clinical parameters in calves, which were fed either milk replacer containing only whey protein or one which partially contained wheat protein. Abomasal emptying rate was estimated by ultrasonography. Ten calves were used in the study over 18 days, and each calf was fed 3 periods of 3 days length using different milk replacers in an alternating crossover design. The abomasum was emptied significantly faster when the wheat protein containing milk replacer was fed (half-emptying time wheat protein 49.1 ± 4.1 min, half-emptying time milk protein 59.1 ± 7.4 min); however, clinical parameters and weight gain did not differ between the feeding regimes. Age did not significantly influence abomasal emptying rate. As milk replacers containing wheat proteins increased abomasal emptying rate, they may have a higher potential to initiate diarrhoea, especially if high volumes are fed. Thus, the feeding regimes are likely to be even more important when such milk replacers are used. PMID:26189821

  11. Unusual shift from IgE-mediated milk allergy to food protein-induced enterocolitis syndrome.

    PubMed

    Banzato, C; Piacentini, G L; Comberiati, P; Mazzei, F; Boner, A L; Peroni, D G

    2013-12-01

    Food protein-induced enterocolitis syndrome (FPIES) is a potentially severe non-IgE-mediated food allergy usually caused by cow's milk or soy, and more rarely by solid foods such as rice, oats, barley, chicken, turkey, egg white, green peas and peanuts. In children with FPIES, the presence of specific IgE antibodies to the causative food, either at presentation or during follow-up, defines an "atypical form" of FPIES characterized by a lesser probability of developing tolerance and a potential progression to typical IgE-mediated hypersensitivity. Although it is uncommon, the shift from non-IgE-mediated milk-protein induced enterocolitis syndrome to IgE-mediated milk allergy has recently been described. We report the first case, to our knowledge, of a shift from IgE-mediated cow's milk allergy to pure non-IgE-mediated FPIES, in a 4-month-old male infant. PMID:24619083

  12. Nutritional stimulation of milk protein yield of cows is associated with changes in phosphorylation of mammary eukaryotic initiation factor 2 and ribosomal s6 kinase 1.

    PubMed

    Toerien, Chanelle A; Trout, Donald R; Cant, John P

    2010-02-01

    Production of protein by the lactating mammary gland is stimulated by intake of dietary energy and protein. Mass-action effects of essential amino acids (EAA) cannot explain all of the nutritional response. Protein synthesis in tissues of growing animals is regulated by nutrients through the mammalian target of rapamycin (mTOR) and integrated stress response (ISR) networks. To explore if nutrients signal through the mTOR and ISR networks in the mammary gland in vivo, lactating cows were feed-deprived for 22 h and then infused i.v. for 9 h with EAA+ glucose (Glc), Glc only, l-Met+l-Lys, l-His, or l-Leu. Milk protein yield was increased 33 and 27% by EAA+Glc and Glc infusions, respectively. Infusions of Met+Lys and His generated 35 and 41%, respectively, of the EAA+Glc response. Infusion of EAA+Glc reduced phosphorylation of the ISR target, eukaryotic initiation factor(eIF) 2, in mammary tissue and increased phosphorylation of the mTOR targets, ribosomal S6 kinase 1 (S6K1) and S6. Both responses are stimulatory to protein synthesis. Glucose did not significantly increase mammary S6K1 phosphorylation but reduced eIF2 phosphorylation by 62%, which implicates the ISR network in the stimulation of milk protein yield. In contrast, the EAA infusions increased (P < 0.05) or tended to increase (P < 0.1) mammary mTOR activity and only His, like Glc, decreased eIF2 phosphorylation by 62%. Despite activation of these protein synthesis signals to between 83 and 127% of the EAA+Glc response, EAA infusions produced less than one-half of the milk protein yield response generated by EAA+Glc, indicating that ISR and mTOR networks exert only a portion of the control over protein yield. PMID:20032484

  13. Proteomic profiling of microbial transglutaminase-induced polymerization of milk proteins.

    PubMed

    Hsieh, J F; Pan, P H

    2012-02-01

    Microbial transglutaminase (MTGase)-induced polymerization of individual milk proteins during incubation was investigated using a proteomics-based approach. The addition of MTGase (0.25-2.0 units/mL) caused the milk proteins to polymerize after a 3-h incubation period. Sodium dodecyl sulfate-PAGE analysis showed that the total intensities of the protein bands that corresponded to α(S)-casein, β-casein, and κ-casein decreased from 8,245.6, 6,677.2, and 586.6 arbitrary units to 1,911.7, 0.0, and 66.2 arbitrary units, respectively. Components with higher molecular weights were observed, and the intensity of these proteins increased after 3h of incubation. These results support that inter- or intramolecular crosslinking occurred in the casein proteins of MTGase-treated milk. Two-dimensional electrophoresis analysis indicated that isomers of β-casein, κ-casein, a fraction of serum albumin, α(S1)-casein, α(S2)-casein, β-lactoglobulin, and α-lactalbumin in the milk were polymerized following incubation with MTGase. In addition, MTGase-induced polymerization occurred earlier for β-casein and κ-casein isomers than for other milk proteins. PMID:22281322

  14. 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

  15. 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

    2014-10-01

    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

  16. 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. PMID:26115887

  17. 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

  18. New Milk Protein-Derived Peptides with Potential Antimicrobial Activity: An Approach Based on Bioinformatic Studies

    PubMed Central

    Dziuba, Bartłomiej; Dziuba, Marta

    2014-01-01

    New peptides with potential antimicrobial activity, encrypted in milk protein sequences, were searched for with the use of bioinformatic tools. The major milk proteins were hydrolyzed in silico by 28 enzymes. The obtained peptides were characterized by the following parameters: molecular weight, isoelectric point, composition and number of amino acid residues, net charge at pH 7.0, aliphatic index, instability index, Boman index, and GRAVY index, and compared with those calculated for known 416 antimicrobial peptides including 59 antimicrobial peptides (AMPs) from milk proteins listed in the BIOPEP database. A simple analysis of physico-chemical properties and the values of biological activity indicators were insufficient to select potentially antimicrobial peptides released in silico from milk proteins by proteolytic enzymes. The final selection was made based on the results of multidimensional statistical analysis such as support vector machines (SVM), random forest (RF), artificial neural networks (ANN) and discriminant analysis (DA) available in the Collection of Anti-Microbial Peptides (CAMP database). Eleven new peptides with potential antimicrobial activity were selected from all peptides released during in silico proteolysis of milk proteins. PMID:25141106

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  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. 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. PMID:27213835

  2. 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

  3. 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

  4. 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

  5. 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. PMID:22339698

  6. 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. PMID:26823162

  7. Effect of dietary crude protein concentration on milk production and nitrogen utilization in lactating dairy cows.

    PubMed

    Colmenero, J J Olmos; Broderick, G A

    2006-05-01

    Forty lactating Holstein cows, including 10 with ruminal cannulas, were blocked by days in milk into 8 groups and then randomly assigned to 1 of 8 incomplete 5 x 5 Latin squares to assess the effects of 5 levels of dietary crude protein (CP) on milk production and N use. Diets contained 25% alfalfa silage, 25% corn silage, and 50% concentrate, on a dry matter (DM) basis. Rolled high-moisture shelled corn was replaced with solvent-extracted soybean meal to increase CP from 13.5 to 15.0, 16.5, 17.9, and 19.4% of DM. Each of the 4 experimental periods lasted 28 d, with 14 d for adaptation and 14 d for data collection. Spot sampling of ruminal digesta, blood, urine, and feces was conducted on d 21 of each period. Intake of DM was not affected by diet but milk fat content as well as ruminal acetate, NH3, and branched-chain volatile fatty acids, urinary allantoin, and blood and milk urea all increased linearly with increasing CP. Milk and protein yield showed trends for quadratic responses to dietary CP and were, respectively, 38.3 and 1.18 kg/d at 16.5% CP. As a proportion of N intake, urinary N excretion increased from 23.8 to 36.2%, whereas N secreted in milk decreased from 36.5 to 25.4%, as dietary protein increased from 13.5 to 19.4%. Under the conditions of this study, yield of milk and protein were not increased by feeding more than 16.5% CP. The linear increase in urinary N excretion resulted from a sharp decline in N efficiency as dietary CP content increased. PMID:16606741

  8. Technical note: A portable on-chip assay system for absorbance and plasmonic detection of protein hormone in milk.

    PubMed

    Ozhikandathil, Jayan; Badilescu, Simona; Packirisamy, Muthukumaran

    2015-07-01

    This paper reports a portable device and method to extract and detect protein hormone in milk samples. Recombinant protein hormone spiked into milk samples was extracted by solid-phase extraction, and detection was carried out using the plasmonic property of gold nanoislands deposited on a glass substrate. Trace levels of hormone spiked in milk were analyzed by their optical absorbance property using a microfluidic chip. We built a portable assay system using disposable lab-on-chip devices. The proposed method is able to detect spiked recombinant protein hormone in milk at concentrations as low as 5ng/mL. PMID:25497819

  9. 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.

  10. [Inversion of True Protein Content in Milk Based on Hyperspectral Data].

    PubMed

    Zhang, Qian-qian; Tan, Kun

    2015-12-01

    As an indispensable drink of people's daily life, milk's quality has been also increasingly concerned by consumers. Rapid and accurate detection of milk and its products is the indispensable step for improving the quality of milk and daily products in production. However, traditional methods cannot meet the need. In this paper, rapid quantitative detection of true protein in pure milk was studied by using visible/near-infrared (VIS/NIR) reflectance spectroscopy (350-2500 nm). The spectral data and the protein content data of the pure milk samples were collected by ASD spectrometer and CEM rapid protein analyzer, respectively. Based on the analysis and comparison of different spectrum preprocessing methods and band selection methods, the feature bands were determined. Finally, using the Principle Component Regression (PCR) and Least Squares Support Vector Machine (LS-SVM) model, the regression models between the reflectance spectroscopy and the protein content in milk were presented for pure milk samples and the predictive ability was also analyzed. In this way, the optimal inversion model for true protein content in milk was established. The results were shown as follows: (1) In the process of spectral pretreatment, the combination of multiple scatter correction and second derivative achieved a better result; (2) Compared with the modeling of whole spectral, appropriate variable optimization models had the ability to improve the accuracy of the inversion results and reduce the modeling time; (3) The analysis results between PCR model and LS-SVM model demonstrated that the prediction accuracy of LS-SVM model was better than PCR model. The coefficient of determination (R(P)²) of PCR and LS-SVM were 0.952 2 and 0.958 0 respectively, and the root mean square error of prediction (RMSEP) of PCR and LS-SVM were 0.048 7 and 0.048 2 respectively. The result of this research is expected to provide a novel method for nondestructive and rapid detection of true protein in milk

  11. Chlorolissoclimides: New inhibitors of eukaryotic protein synthesis

    PubMed Central

    Robert, Francis; Gao, Hong Qing; Donia, Marwa; Merrick, William C.; Hamann, Mark T.; Pelletier, Jerry

    2006-01-01

    Lissoclimides are cytotoxic compounds produced by shell-less molluscs through chemical secretions to deter predators. Chlorinated lissoclimides were identified as the active component of a marine extract from Pleurobranchus forskalii found during a high-throughput screening campaign to characterize new protein synthesis inhibitors. It was demonstrated that these compounds inhibit protein synthesis in vitro, in extracts prepared from mammalian and plant cells, as well as in vivo against mammalian cells. Our results suggest that they block translation elongation by inhibiting translocation, leading to an accumulation of ribosomes on mRNA. These data provide a rationale for the cytotoxic nature of this class of small molecule natural products. PMID:16540697

  12. 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. PMID:27596405

  13. 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. PMID:24524762

  14. EFFECT OF ABOMASAL INFUSION OF FORMATE ON MILK PROTEIN OF COWS FED A METHIONINE-DEFICIENT DIET

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. EFFECT OF ANTIBIOTICS AND INHIBITORS ON M PROTEIN SYNTHESIS

    PubMed Central

    Brock, Thomas D.

    1963-01-01

    Brock, Thomas D. (Western Reserve University, Cleveland, Ohio). Effect of antibiotics and inhibitors on M protein synthesis. J. Bacteriol. 85:527–531. 1963.—This work extends the observations of Fox and Krampitz on M protein synthesis in nongrowing cells of streptococci. A survey of a large number of antibiotics and other potential inhibitors was made. Some substances bring about inhibition of fermentation and inhibit M protein synthesis because they deprive the cell of the energy needed for this process. A second group of substances inhibit growth at concentrations tenfold or more lower than they inhibit M protein synthesis. These are the antibiotics which inhibit synthesis of cell wall or other structures in growing cells, but do not affect protein synthesis. A third group of substances inhibit growth and M protein synthesis at the same concentration. These substances probably inhibit growth because they inhibit general protein synthesis, and are therefore specific inhibitors of protein synthesis. In this class are chloramphenicol, erythromycin, and the tetracyclines. Several other antibiotics of previously unknown mode of action are in this class. A fourth group of substances had no effect on M protein synthesis. No substances were found which inhibited M protein synthesis at a lower concentration than that which inhibited growth. M protein synthesis in nongrowing cells may be a useful model system for obtaining a detailed understanding of protein synthesis. PMID:14042928

  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. 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. PMID:18448807

  18. 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

  19. Freeze-drying of "pearl milk tea": A general strategy for controllable synthesis of porous materials.

    PubMed

    Zhou, Yingke; Tian, Xiaohui; Wang, Pengcheng; Hu, Min; Du, Guodong

    2016-01-01

    Porous materials have been widely used in many fields, but the large-scale synthesis of materials with controlled pore sizes, pore volumes, and wall thicknesses remains a considerable challenge. Thus, the controllable synthesis of porous materials is of key general importance. Herein, we demonstrate the "pearl milk tea" freeze-drying method to form porous materials with controllable pore characteristics, which is realized by rapidly freezing the uniformly distributed template-containing precursor solution, followed by freeze-drying and suitable calcination. This general and convenient method has been successfully applied to synthesize various porous phosphate and oxide materials using different templates. The method is promising for the development of tunable porous materials for numerous applications of energy, environment, and catalysis, etc. PMID:27193866

  20. 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. PMID:25191594

  1. Postnatal ontogeny of skeletal muscle protein synthesis in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The neonatal period is characterized by rapid growth and elevated rates of synthesis and accretion of skeletal muscle proteins. The fractional rate of muscle protein synthesis is very high at birth and declines rapidly with age. The elevated capacity for muscle protein synthesis in the neonatal pig ...

  2. Postnatal ontogeny of skeletal muscle protein synthesis in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The neonatal period is characterized by rapid growth and elevated rates of synthesis and accretion of skeletal muscle proteins. The fractional rate of muscle protein synthesis is very high at birth and declines rapidly with development. The elevated capacity for muscle protein synthesis in the neo...

  3. Severe Food Protein-Induced Enterocolitis Syndrome to Cow’s Milk in Infants

    PubMed Central

    Yang, Min; Geng, Lanlan; Xu, Zhaohui; Chen, Peiyu; Friesen, Craig A.; Gong, Sitang; Li, Ding-You

    2015-01-01

    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. PMID:26703722

  4. 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

    2016-01-01

    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. PMID:26703722

  5. Maternal protein reserves and their influence on lactational performance in rats. 3. The effects of dietary protein restriction and stage of lactation on milk composition.

    PubMed

    Pine, A P; Jessop, N S; Oldham, J D

    1994-12-01

    The effects of severe protein restriction following parturition on the changes in rat milk composition during lactation were investigated using multiparous female Sprague-Dawley rats caged individually following mating and offered a high-protein diet (H; 215 g crude protein (N x 6.25; CP)/kg dry matter (DM)) ad lib. until parturition. Following parturition, half the females continued to receive diet H, whilst the remainder were offered a diet low in protein (L; 90 g CP/kg DM) ad lib. On days 2, 4, 8 and 12 of lactation groups of females from both dietary treatments were used to provide a milk sample. Milk samples were analysed for their lactose (enzymically), protein (binding to Coomassie blue), lipid (gravimetrically) and mineral (spectrophotometrically) contents. The milk lactose concentration of group H increased with stage of lactation (r2 0.85, P < 0.001). Such an increase was prevented by diet L, and from day 8 of lactation the milk lactose of group L was lower (P < 0.05) than in group H. Group H milk protein concentration did not change during lactation and averaged 90.7 mg/g. Dietary protein restriction reduced the milk protein concentration of group L so that on days 2, 4 and 12 of lactation it was lower (P < 0.05) than that of group H. On day 8 of lactation the milk protein concentration of group L had increased (P < 0.05) and was comparable with that of group H. For group H, milk lipid averaged 166.8 mg/g and was generally unchanged during lactation. Diet L increased (P < 0.01) the milk lipid concentration (205.5 mg/g) compared with diet H and this was also significant on days 4 and 8 of lactation (P < 0.05). Group L milk lipid concentration also increased between days 4 and 8 of lactation (P < 0.05). Milk Na concentration declined during lactation in both dietary groups (P < 0.01) but was unaffected by dietary treatment. Both milk Ca and P concentrations increased (P < 0.01) during lactation in both dietary groups, whilst protein restriction also

  6. Effects of dietary cottonseed oil and tannin supplements on protein and fatty acid composition of bovine milk.

    PubMed

    Aprianita, Aprianita; Donkor, Osaana N; Moate, Peter J; Williams, S Richard O; Auldist, Martin J; Greenwood, Jae S; Hannah, Murray C; Wales, William J; Vasiljevic, Todor

    2014-05-01

    This experiment was conducted to determine the effects of diets supplemented with cottonseed oil, Acacia mearnsii-condensed tannin extract, and a combination of both on composition of bovine milk. Treatment diets included addition of cottonseed oil (800 g/d; CSO), condensed tannin from Acacia mearnsii (400 g/d; TAN) or a combination of cottonseed oil (800 g/d) and condensed tannin (400 g/d; CPT) with a diet consisting of 6·0 kg dry matter (DM) of concentrates and alfalfa hay ad libitum, which also served as the control diet (CON). Relative to the CON diet, feeding CSO and CPT diets had a minor impact on feed intake and yield of lactose in milk. These diets increased yields of milk and protein in milk. In contrast to the TAN diet, the CSO and CPT diets significantly decreased milk fat concentration and altered milk fatty acid composition by decreasing the proportion of saturated fatty acids but increasing proportions of monounsaturated and polyunsaturated fatty acids. The CPT diet had a similar effect to the CSO diet in modifying fatty acid profile. Overall, reduction in milk fat concentration and changes in milk fatty acid profile were probably due to supplementation of linoleic acid-rich cottonseed oil. The TAN diet had no effect on feed intake, milk yield and milk protein concentration. However, a reduction in the yields of protein and lactose occurred when cows were fed this diet. Supplemented tannin had no significant effect on fat concentration and changes in fatty acid profile in milk. All supplemented diets did not affect protein concentration or composition, nitrogen concentration, or casein to total protein ratio of the resulting milk. PMID:24594257

  7. 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. PMID:26210276

  8. Effects of Different Protein Supplements on Milk Production and Nutrient Utilization in Lactating Dairy Cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sixteen (8 ruminally cannulated) multiparous and 8 primiparous lactating Holstein cows were used in 6 replicated 4 x 4 Latin squares to test the effects of feeding supplemental protein as urea, solvent soybean meal (SSBM), cottonseed meal (CSM), or canola meal (CM) on milk production, nutrient utili...

  9. Low levels of aflatoxin B1, ricin and milk enhance recombinant protein production in mammalian cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. 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. PMID:27179865

  11. Factors affecting application of milk allantoin as an estimator of microbial protein flow to the duodenum under commercial conditions.

    PubMed

    Schager, W M; Harrison, J H; Gaskins, C T; Davidson, D

    2003-05-01

    Three experiments were conducted to determine the effect of diet change, milk sampling technique, and bovine somatotropin (bST) on allantoin output in milk and the use of allantoin as a practical, noninvasive method for estimating microbial protein flow in dairy cattle. In experiment 1, four lactating Holstein cows were used in a 2 x 2 Latin square design with two treatments (ratio of forage to concentrate) and two periods. In experiment 2, six Holstein cows were used in a completely randomized design, and milk was collected by 1) a strip sample collected immediately before milking, 2) a strip sample collected 3 min from start of milking, and 3) a composite sample taken with an autosampler. In experiment three, 10 cows were used in a randomized block design to determine the effect of bST on milk allantoin. Milk samples were taken daily for 21 d, 7 d before, and 14 d after bST administration. In experiment 1, allantoin output (mmol/d) was significantly greater for cows fed the higher ratio of concentrate to forage, and there was a significant change in the amount of allantoin in milk 12 h (first subsequent milking) after a diet change. There was no difference in milk yield or dry matter intake between treatments. In experiment 2, no difference was detected in milk allantoin concentration among the three sampling methods. In experiment 3, milk yield, allantoin concentration, and total allantoin output was significantly increased after bST administration even though dry matter intake (DMI) remained unchanged. During the first 14 d following bST administration, estimates of microbial protein production derived from milk allantoin may be inaccurate due to increased milk production without an increase in DMI. PMID:12778582

  12. Milk digesta and milk protein fractions influence the adherence of Lactobacillus gasseri R and Lactobacillus casei FMP to human cultured cells.

    PubMed

    Volstatova, Tereza; Havlik, Jaroslav; Potuckova, Miroslava; Geigerova, Martina

    2016-08-10

    Adhesion to the intestinal epithelium is considered an important feature of probiotic bacteria, which may increase their persistence in the intestine, allowing them to exert their beneficial health effect or promote the colonisation process. However, this feature might be largely dependent on the host specificity or diet. In the present study, we investigated the effect of selected milks and milk protein fractions on the ability of selected lactobacilli to adhere to the cells of an intestinal model based on co-culture Caco-2/HT29-MTX cell lines. Most milk digesta did not significantly affect bacterial adhesion except for UHT-treated milk and sheep milk. The presence of UHT-treated milk digesta reduced the adhesion of Lactobacillus gasseri R by 61% but not that of Lactobacillus casei FMP. However, sheep milk significantly increased the adherence of L. casei FMP (P < 0.05) but not of L. gasseri R. Among the protein fractions, rennet casein (RCN) and bovine serum albumin (BSA) showed reproducible patterns and strain-specific effects on bacterial adherence. While RCN reduced the adherence of L. gasseri R to <50% compared to the control, it did not have a significant effect on L. casei FMP. In contrast, BSA reduced L. casei FMP adherence to a higher extent than that of L. gasseri R. Whey protein (WH) tended to increase the adherence of both strains by 130%-180%. Recently, interactions between the host diet and its microbiota have attracted considerable interest. Our results may explain one of the aspects of the role of milk in the development of microbiota or support of probiotic supplements. Based on our data, we conclude that the persistence of probiotic strains supplemented as part of dairy food or constitutional microbiota in the gut might be affected negatively or positively by the food matrix through complex strain or concentration dependent effects. PMID:27435508

  13. 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. PMID:24029787

  14. Cumulative Muscle Protein Synthesis and Protein Intake Requirements.

    PubMed

    Simmons, Erin; Fluckey, James D; Riechman, Steven E

    2016-07-17

    Muscle protein synthesis (MPS) fluctuates widely over the course of a day and is influenced by many factors. The time course of MPS responses to exercise and the influence of training and nutrition can only be pieced together from several different investigations and methods, many of which create unnatural experimental conditions. Measurements of cumulative MPS, the sum synthesis over an extended period, using deuterium oxide have been shown to accurately reflect muscle responses and may allow investigations of the response to exercise, total protein intake requirements, and interaction with protein timing in free-living experimental conditions; these factors have yet to be carefully integrated. Such studies could include clinical and athletic populations to integrate nutritional and exercise recommendations and help guide their revisions to optimize the skeletal muscle function that is so important to overall health. PMID:27215586

  15. 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.

  16. 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. PMID:26235579

  17. Chemical characteristics and enhanced hepatoprotective activities of Maillard reaction products derived from milk protein-sugar system.

    PubMed

    Oh, Nam Su; Young Lee, Ji; Lee, Hyun Ah; Joung, Jae Yeon; Shin, Yong Kook; Kim, Sae Hun; Kim, Younghoon; Lee, Kwang Won

    2016-02-01

    The objective of this study was to investigate the characteristics, antioxidative properties, and hepatoprotective effects of Maillard reaction products (MRP) from milk protein reacted with sugars. The MRP were obtained from milk protein, whey protein concentrates and sodium caseinate, using 2 types of sugars, lactose and glucose, by heating the mixture at 55°C for 7d in a sodium phosphate buffer (pH 7.4). Changes in the chemical modification of the milk protein were monitored by measuring the protein-bound carbonyls and PAGE protein profiles. The results showed that the amount of protein-bound carbonyls increased after Maillard reaction (MR). In addition, sodium dodecyl sulfate-PAGE analysis indicated a formation of high-molecular weight complexes through MR. The modification sites induced by MR of milk protein were monitored by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of tryptic-digested gel spots of MRP. As a result, modification and their localization in AA sequence of MRP was identified. Also, the MRP showed higher antioxidant activities than the intact milk protein, and they reduced intracellular reactive oxygen species production and inhibited the depletion of the reduced glutathione concentrations in the HepG2 cells. In particular, glucose-sodium caseinate MRP showed the highest biological activities among all MRP. Therefore, these results suggest that the MRP from milk protein reacting with sugars possess effective antioxidant activity and have a protective ability against oxidative damage. PMID:26627852

  18. 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. PMID:8747343

  19. Effect of protein provision via milk replacer or solid feed on protein metabolism in veal calves.

    PubMed

    Berends, H; van den Borne, J J G C; Røjen, B A; Hendriks, W H; Gerrits, W J J

    2015-02-01

    The current study evaluated the effects of protein provision to calves fed a combination of solid feed (SF) and milk replacer (MR) at equal total N intake on urea recycling and N retention. Nitrogen balance traits and [(15)N2]urea kinetics were measured in 30 calves (23 wk of age, 180±3.7kg of body weight), after being exposed to the following experimental treatments for 11 wk: a low level of SF with a low N content (SF providing 12% of total N intake), a high level of SF with a low N content (SF providing 22% of total N intake), or a high level of SF with a high N content (SF providing 36% of total N intake). The SF mixture consisted of 50% concentrates, 25% corn silage, and 25% straw on a dry matter basis. Total N intake was equalized to 1.8g of N·kg of BW(-0.75)·d(-1) by adjusting N intake via MR. All calves were housed individually on metabolic cages to allow for quantification of a N balance of calves for 5 d, and for the assessment of urea recycling from [(15)N2]urea kinetics. Increasing low-N SF intake at equal total N intake resulted in a shift from urinary to fecal N excretion but did not affect protein retention (0.71g of N·kg of BW(-0.75)·d(-1)). Increasing low-N SF intake increased urea recycling but urea reused for anabolism remained unaffected. Total-tract neutral detergent fiber digestibility decreased (-9%) with increasing low-N SF intake, indicating reduced rumen fermentation. Increasing the N content of SF at equal total N intake resulted in decreased urea production, excretion, and return to ornithine cycle, and increased protein retention by 17%. This increase was likely related to an effect of energy availability on protein retention due to an increase in total-tract neutral detergent fiber digestion (>10%) and due to an increased energy supply via the MR. In conclusion, increasing low-N SF intake at the expense of N intake from MR, did not affect protein retention efficiency in calves. Increasing the N content of SF at equal total N

  20. 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. PMID:23483553

  1. Redox proteomics of fat globules unveils broad protein lactosylation and compositional changes in milk samples subjected to various technological procedures.

    PubMed

    Arena, Simona; Renzone, Giovanni; Novi, Gianfranco; Scaloni, Andrea

    2011-10-19

    The Maillard reaction between lactose and proteins occurs during thermal treatment of milk and lactosylated β-lactoglobulin, α-lactalbumin and caseins have widely been used to monitor the quality of dairy products. We recently demonstrated that a number of other whey milk proteins essential for nutrient delivery, defense against bacteria/virus and cellular proliferation become lactosylated during milk processing. The extent of their modification is associated with the harshness of product manufacturing. Since fat globule proteins are also highly important for the health-beneficial properties of milk, an evaluation of their lactosylation is crucial for a complete understanding of aliment nutritional characteristics. This is more important when milk is the unique dietary source, as in the infant diet. To this purpose, a sequential proteomic procedure involving an optimized milk fat globule (MFG) preparation/electrophoretic resolution, shot-gun analysis of gel portions for protein identification, selective trapping of lactosylated peptides by phenylboronate chromatography and their analysis by nanoLC-ESI-electron transfer dissociation (ETD) tandem MS was used for systematic characterization of fat globule proteins in milk samples subjected to various manufacturing procedures. Significant MFG protein compositional changes were observed between samples, highlighting the progressive adsorption of caseins and whey proteins on the fat globule surface as result of the technological process used. A significant lactosylation of MFG proteins was observed in ultra-high temperature sterilized and powdered for infant nutrition milk preparations, which well paralleled with the harshness of thermal treatment. Globally, this study allowed the identification of novel 157 non-redundant modification sites and 35 MFG proteins never reported so far as being lactosylated, in addition to the 153 ones ascertained here as present on other 21 MFG-adsorbed proteins whose nature was already

  2. Utilization of supercritical carbon dioxide to produce milk protein fractions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. Protein Synthesis in Relation to Ripening of Pome Fruits 1

    PubMed Central

    Frenkel, Chaim; Klein, Isaac; Dilley, D. R.

    1968-01-01

    Protein synthesis by intact Bartlett pear fruits was studied with ripening as measured by flesh softening, chlorophyll degradation, respiration, ethylene synthesis, and malic enzyme activity. Protein synthesis is required for normal ripening, and the proteins synthesized early in the ripening process are, in fact, enzymes required for ripening. 14C-Phenylalanine is differentially incorporated into fruit proteins separated by acrylamide gel electrophoresis of pome fruits taken at successive ripening stages. Capacity for malic enzyme synthesis increases during the early stage of ripening. Fruit ripening and ethylene synthesis are inhibited when protein synthesis is blocked by treatment with cycloheximide at the early-climacteric stage. Cycloheximide became less effective as the climacteric developed. Ethylene did not overcome inhibition of ripening by cycloheximide. The respiratory climacteric is not inhibited by cycloheximide. It is concluded that normal ripening of pome fruits is a highly coordinated process of biochemical differentiation involving directed protein synthesis. PMID:16656897

  4. SDS-PAGE Analysis of Soluble Proteins in Reconstituted Milk Exposed to Different Heat Treatments

    PubMed Central

    Jovanovic, Snezana; Barac, Miroljub; Macej, Ognjen; Vucic, Tanja; Lacnjevac, Caslav

    2007-01-01

    This paper deals with the investigation of the impact of the heat treatment of reconstituted skim milk conducted at different temperatures, and the adding of demineralized whey on the protein solubility, soluble protein composition and interactions involved between proteins in a chemical complex. Commercial skim milk has been reconstituted and heat treated at 75°C, 85°C and 90°C for 20 minutes. Demineralized whey has been added in concentrations of 0.5%, 1.0 and 2.0%. The soluble protein composition has been determined by the polyacrilamide gel electrophoresis (SDS-PAGE) and by the densitometric analysis. Due to the different changes occurred during treatments at different temperatures, proteins of heat-treated samples containing added demineralized whey have had significantly different solubility. At lower temperatures (75°C and 85°C) the adding of demineralized whey decreased the protein solubility by 5.28%-26.41%, while the addition of demineralized whey performed at 90°C increased the soluble protein content by 5.61%-28.89%. Heat treatments, as well as the addition of demineralized whey, have induced high molecular weight complex formation. β-Lg, α-La and κ-casein are involved in high molecular weight complexes. The disulfide interactions between denatured molecules of these proteins are mostly responsible for the formation of coaggregates. The level of their interactions and the soluble protein composition are determined by the degree of temperature.

  5. Technical note: comparing calibration methods for determination of protein in goat milk by ultraviolet spectroscopy.

    PubMed

    Rukke, E O; Olsen, E F; Devold, T; Vegarud, G; Isaksson, T

    2010-07-01

    A rapid spectroscopic method to determine total protein in bovine and buffalo milk using UV spectra of guanidine-hydrochloride mixed milk has previously been reported and validated. The method was based on mixed calibration samples and univariate calibrations of fourth derivative (4D) spectra. In this study the same method was compared and tested for determination of total protein in goat milk. Calculations based on multivariate calibration (partial least squares regression) on full spectra of goat milk were used. The method was tested on 2 UV instruments. The comparison resulted in a significantly more robust (i.e., better) transferability between UV instruments for the partial least squares regression method on full spectra compared with previous univariate calibration of 4D spectra. Local (1 instrument) calibrations gave similar, significantly not different (chi-squared test) cross-validated prediction error results for the 2 methods. It can be concluded that there is no need for fourth derivation. Partial least squares regression on full spectra was equal or superior to using the 4D spectra. PMID:20630209

  6. Thermostable β-galactosidases for the synthesis of human milk oligosaccharides.

    PubMed

    Zeuner, Birgitte; Nyffenegger, Christian; Mikkelsen, Jørn Dalgaard; Meyer, Anne S

    2016-05-25

    Human milk oligosaccharides (HMOs) designate a unique family of bioactive lactose-based molecules present in human breast milk. Using lactose as a cheap donor, some β-galactosidases (EC 3.2.1.23) can catalyze transgalactosylation to form the human milk oligosaccharide lacto-N-neotetraose (LNnT; Gal-β(1,4)-GlcNAc-β(1,3)-Gal-β(1,4)-Glc). In order to reduce reaction times and be able to work at temperatures, which are less welcoming to microbial growth, the current study investigates the possibility of using thermostable β-galactosidases for synthesis of LNnT and N-acetyllactosamine (LacNAc; Gal-β(1,4)-GlcNAc), the latter being a core structure in HMOs. Two hyperthermostable GH 1 β-galactosidases, Ttβ-gly from Thermus thermophilus HB27 and CelB from Pyrococcus furiosus, were codon-optimized for expression in Escherichia coli along with BgaD-D, a truncated version of the GH 42 β-galactosidase from Bacillus circulans showing high transgalactosylation activity at low substrate concentrations. The three β-galactosidases were compared in the current study in terms of their transgalactosylation activity in the formation of LacNAc and LNnT. In all cases, BgaD-D was the most potent transgalactosidase, but both thermostable GH 1 β-galactosidases could catalyze formation of LNnT and LacNAc, with Ttβ-gly giving higher yields than CelB. The thermal stability of the three β-galactosidases was elucidated and the results were used to optimize the reaction efficiency in the formation of LacNAc, resulting in 5-6 times higher reaction yields and significantly shorter reaction times. PMID:26802542

  7. 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.

  8. Effect of prior dietary exposure to cows' milk protein on antigen-specific and nonspecific cellular proliferation in mice.

    PubMed

    Brix, Susanne; Magyar, Orit H; Barkholt, Vibeke; Frøkiaer, Hanne

    2005-05-01

    The impact of dietary components on the immune system is gaining increased attention in the effort to develop safe food products, some even with health-promoting potential, as well as to improve the basic understanding of the immunomodulatory potential of common food components. In such studies, which are mainly based on experiments in vitro, it is important to be able to differentiate nonspecific activation of immune cells induced by dietary components from ex vivo restimulation of antigen-specific cells that might be present in cell cultures owing to prior dietary exposure to the antigens in cell donors. Focusing on the immunostimulatory potential of cows' milk proteins and peptides, we studied the impact of prior dietary exposure to cows' milk on proliferation of murine immune cells upon ex vivo stimulation with bovine milk proteins. Nonspecific proliferation induced by beta-casein peptides was further assessed on cells from mice bred on a cows'-milk-free diet. Regarding the dietary effect, we found that prior oral intake of cows' milk proteins affected cell proliferation induced by culturing with cows' milk proteins in vitro, as spleen cells from mice fed a milk-containing diet showed a significantly greater proliferative response than did cells from mice bred on a cows'-milk-free diet. Studies of immune enhancing potentials of beta-casein peptides showed that some peptides stimulate proliferation of immune cells nonspecifically. In conclusion, these findings stress the importance of employing immune cells from mice unexposed to cows' milk for studies of the immunomodulating capacity of cows' milk proteins and peptides, in order to rule out the interference caused by antigen-specific immune responses. By using such cells, we here show that some beta-casein peptides possess the potential to induce proliferation in immune cells in a nonspecific manner. PMID:15909688

  9. 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. PMID:26613816

  10. 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

  11. 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. PMID:26308444

  12. 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. PMID:10596760

  13. 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. PMID:27157580

  14. Protein oxidative changes in whole and skim milk after ultraviolet or fluorescent light exposure.

    PubMed

    Scheidegger, D; Pecora, R P; Radici, P M; Kivatinitz, S C

    2010-11-01

    We investigated how protein changes occur, at the primary or higher structural levels, when proteins are exposed to UV or fluorescent (FL) light while in the complex matrix, milk. Whole milk (WM) or skim milk (SM) samples were exposed to FL or UV light from 0 to 24h at 4°C. Protein oxidation was evaluated by the formation of protein carbonyls (PC), dityrosine bond (DiTyr), and changes in molecular weight (protein fragmentation and polymerization). Oxidative changes in AA residues were measured by PC. Dityrosine and N'-formylkynurenine (NFK), a carbonylation derivative of Trp, were measured by fluorometry. Protein carbonyls increased as a function of irradiation time for both WM and SM. The initial rate for PC formation by exposure to FL light (0.25 or 0.27 nmol/h for WM and SM, respectively) was slower than that following exposure to UV light (1.95 or 1.20 nmol/h, respectively). The time course of NFK formation resembled that of PC. After 24h of UV exposure, SM had significantly higher levels of NFK than did WM. In contrast, WM samples irradiated with UV had higher levels of DiTyr than did SM samples, indicating different molecular pathways. The formation of intra- or intermolecular DiTyr bonds could be indicative of changes in the tertiary structure or oligomerization of proteins. The existence of NFK suggests the occurrence of protein fragmentation. Thus, proteolysis and oligomerization were analyzed by sodium dodecyl sulfate-PAGE. After 24h of exposing WM to UV or FL light, all the proteins were affected by both types of light, as evidenced by loss of material in most of the bands. Aggregates were produced only by UV irradiation. Hydrolysis by pepsin and enzyme-induced coagulation by rennet were performed to evaluate altered biological properties of the oxidized proteins. No effect on pepsin digestion or rennet coagulation was found in irradiated SM or WM. The oxidative status of proteins in milk and dairy products is of interest to the dairy industry and

  15. 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.

  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. 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

  18. Cows' milk protein-sensitive enteropathy. An important factor in prolonging diarrhoea of acute infective enteritis in early infancy.

    PubMed Central

    Iyngkaran, N; Robinson, M J; Sumithran, E; Lam, S K; Puthucheary, S D; Yadav, M

    1978-01-01

    The possible role of cows' milk protein in prolonging diarrhoea in very young infants with acute infective enteritis was studied in 14 infants, 9 under the age of 2 months and 5 older than 6 months. Bacterial pathogens were isolated from the stools of 4 infants from the younger age group. After appropriate initial treatment the infants were maintained on a cows' milk protein-free formula. 6 weeks later jejunal biopsies were performed before and 24 hours after challenge with a low lactose cows' milk protein formula. The immunoglobulin and complement levels in the serum and duodenal juice were also estimated at these times. Attempts to isolate bacterial and viral pathogens in stools were again made in all patients. The 5 older infants clinically tolerated cows' milk protein and their pre- and postchallenge jejunal biopsies were within normal limits. However, significant histological changes were observed in the postchallenge jejunal biopsies of all 9 infants under 2 months of age. In addition, 5 of these infants developed diarrhoea. This suggests that the jejunal mucosa of very young infants previously fed a cows' milk protein-based formula and who contract infective enteritis suffers damage when rechallenged with cows' milk protein. PMID:646417

  19. 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

  20. Combined effects of soy isoflavones and milk basic protein on bone mineral density in hind-limb unloaded mice.

    PubMed

    Matsumoto, Yu; Tousen, Yuko; Nishide, Yoriko; Tadaishi, Miki; Kato, Ken; Ishimi, Yoshiko

    2016-03-01

    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

  1. Variations in protein and fat contents and their fractions in milk from two species fed different forages.

    PubMed

    Kholif, S M; El-Shewy, A A; Morsy, T A; Abd El-Rahman, H H

    2015-02-01

    This study aimed at determining the variations in milk constituents which could be varied by feed and animal species. To achieve this goal, two groups of homoparity Baladi cows and Egyptian buffaloes (n = 20 per species) were used. Each group was divided into two subgroups (n = 10): subgroup I received legume forage (Egyptian clover) and subgroup II received grass forage (sorghum forage). All experimental animals were fed the diet consisting of concentrate, forage and rice straw as 50, 25 and 25% of dry matter intake respectively. Milk samples were taken for analysis. The trial lasted until the 3rd month of parturition. The main results indicated that lactating cattle fed legume forage significantly (p ≤ 0.01) had more content of casein nitrogen (513 mg/100 ml milk), lower content of glutamic acid (23.56 g/100 g milk protein) and more content of cis-9, trans-11 18:2 conjugated linoleic acid (CLA) (0.77 g/100 g milk fat) compared with 433, 26.67 and 0.53, respectively, for cattle fed grass forage. With regard to the species effect, results showed that buffalo milk appeared to contain significantly higher (p ≤ 0.01) contents of casein nitrogen, phenylalanine, glutamic and arachidonic acid compared with cow's milk. However, the latter was significantly (p ≤ 0.01) more in the cis-9, trans-11CLA (0.59 g/100 g milk fat) than that in buffalo milk (0.47 g/100 g milk fat). The results revealed that not only forage type played a critical role in determining the variations of milk nitrogen distribution, milk amino acids and fatty acids but also animal species had a significant effect on these parameters. PMID:25040448

  2. Short communication: The effect of feeding high protein distillers dried grains on milk production of Holstein cows.

    PubMed

    Hubbard, K J; Kononoff, P J; Gehman, A M; Kelzer, J M; Karges, K; Gibson, M L

    2009-06-01

    The objectives of this study were to evaluate the effects of feeding high-protein distillers dried grains (HPDDG) on rumen degradability, dry matter intake, milk production, and milk composition. Sixteen lactating Holstein cows (12 multiparous and 4 primiparous) averaging 80 +/- 14 d in milk were randomly assigned to 1 of 2 dietary treatments in a 2 x 2 crossover design. A portion of forage and all soy-based protein in the control diet were replaced by HPDDG (20% dry matter). Milk production and dry matter intake were recorded daily and averaged for d 19 to 21 of each 21-d period. Milk samples were collected on d 20 to 21 of each period. Milk yield increased with the inclusion of HPDDG (33.4 vs. 31.6 +/- 2.13 kg/d), and 3.5% FCM was higher for the ration containing HPDDG (36.3 vs. 33.1 +/- 2.24 kg/d). Percentage protein was not affected by treatment (average 3.04 +/- 0.08%), but protein yield increased with inclusion of HPDDG (0.95 to 1.00 +/- 0.05 kg/d). Milk fat concentration was not different between treatments (average 3.95 +/- 0.20%), but fat yield increased for the ration containing HPDDG (1.35 vs. 1.21 +/- 0.09 kg/d). Dry matter intake was not affected and averaged 21.9 +/- 0.80 kg across treatments. Because of greater milk production, feed conversion was improved by the inclusion of HPDDG (1.47 to 1.73 +/- 0.09). Milk urea N was greater for the HPDDG ration than the control (14.5 vs. 12.8 +/- 0.67 mg/dL). This research suggests that HPDDG may effectively replace soy-based protein in lactating dairy cow diets. PMID:19448023

  3. 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

  4. 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. PMID:26374843

  5. 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. PMID:24849657

  6. 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

  7. Disorder in Milk Proteins: α -Lactalbumin. Part A. Structural Properties and Conformational Behavior.

    PubMed

    Permyakov, Eugene A; Permyakov, Serge E; Breydo, Leonid; Redwan, Elrashdy M; Almehdar, Hussein A; Uversky, Vladimir N

    2016-01-01

    This is a first part of the two-part article that continues a series of reviews on the abundance and roles of intrinsic disorder in milk proteins. We introduce here α-lactalbumin, a small (Mr 14 200), simple, acidic (pI 4-5), Ca(2+)-binding protein that might constitute up to 20% of total milk protein. Although function (it is one of the two components of lactose synthase that catalyzes the final step of the lactose biosynthesis in the lactating mammary gland), structure (protein has two domains, a large α -helical domain and a small β -sheet domain connected by a calcium binding loop), and folding mechanisms (α-lactalbumin is well-known as a classic example of the molten globule state) of this model globular protein are relatively well understood, α-lactalbumin continues to surprise researchers and clearly continues to have high discovery potential. The goal of this review is to summarize some recent advances in the field of α-lactalbumin research and to analyze the peculiarities of the "intrinsic disorder code" of this protein. PMID:26956441

  8. Tools for Characterizing Bacterial Protein Synthesis Inhibitors

    PubMed Central

    Orelle, Cédric; Carlson, Skylar; Kaushal, Bindiya; Almutairi, Mashal M.; Liu, Haipeng; Ochabowicz, Anna; Quan, Selwyn; Pham, Van Cuong; Squires, Catherine L.; Murphy, Brian T.

    2013-01-01

    Many antibiotics inhibit the growth of sensitive bacteria by interfering with ribosome function. However, discovery of new protein synthesis inhibitors is curbed by the lack of facile techniques capable of readily identifying antibiotic target sites and modes of action. Furthermore, the frequent rediscovery of known antibiotic scaffolds, especially in natural product extracts, is time-consuming and expensive and diverts resources that could be used toward the isolation of novel lead molecules. In order to avoid these pitfalls and improve the process of dereplication of chemically complex extracts, we designed a two-pronged approach for the characterization of inhibitors of protein synthesis (ChIPS) that is suitable for the rapid identification of the site and mode of action on the bacterial ribosome. First, we engineered antibiotic-hypersensitive Escherichia coli strains that contain only one rRNA operon. These strains are used for the rapid isolation of resistance mutants in which rRNA mutations identify the site of the antibiotic action. Second, we show that patterns of drug-induced ribosome stalling on mRNA, monitored by primer extension, can be used to elucidate the mode of antibiotic action. These analyses can be performed within a few days and provide a rapid and efficient approach for identifying the site and mode of action of translation inhibitors targeting the bacterial ribosome. Both techniques were validated using a bacterial strain whose culture extract, composed of unknown metabolites, exhibited protein synthesis inhibitory activity; we were able to rapidly detect the presence of the antibiotic chloramphenicol. PMID:24041905

  9. A nine-country study of the protein content and amino acid composition of mature human milk

    PubMed Central

    Feng, Ping; Gao, Ming; Burgher, Anita; Zhou, Tian Hui; Pramuk, Kathryn

    2016-01-01

    Background Numerous studies have evaluated protein and amino acid levels in human milk. However, research in this area has been limited by small sample sizes and study populations with little ethnic or racial diversity. Objective Evaluate the protein and amino acid composition of mature (≥30 days) human milk samples collected from a large, multinational study using highly standardized methods for sample collection, storage, and analysis. Design Using a single, centralized laboratory, human milk samples from 220 women (30–188 days postpartum) from nine countries were analyzed for amino acid composition using Waters AccQ-Tag high-performance liquid chromatography and total nitrogen content using the LECO FP-528 nitrogen analyzer. Total protein was calculated as total nitrogen×6.25. True protein, which includes protein, free amino acids, and peptides, was calculated from the total amino acids. Results Mean total protein from individual countries (standard deviation [SD]) ranged from 1,133 (125.5) to 1,366 (341.4) mg/dL; the mean across all countries (SD) was 1,192 (200.9) mg/dL. Total protein, true protein, and amino acid composition were not significantly different across countries except Chile, which had higher total and true protein. Amino acid profiles (percent of total amino acids) did not differ across countries. Total and true protein concentrations and 16 of 18 amino acid concentrations declined with the stage of lactation. Conclusions Total protein, true protein, and individual amino acid concentrations in human milk steadily decline from 30 to 151 days of lactation, and are significantly higher in the second month of lactation compared with the following 4 months. There is a high level of consistency in the protein content and amino acid composition of human milk across geographic locations. The size and diversity of the study population and highly standardized procedures for the collection, storage, and analysis of human milk support the validity and

  10. Preparation of iron bound succinylated milk protein concentrate and evaluation of its stability.

    PubMed

    Shilpashree, B G; Arora, Sumit; Sharma, Vivek; Bajaj, Rajesh Kumar; Tomar, S K

    2016-04-01

    Major problems associated with the fortification of soluble iron salts include chemical reactivity and incompatibility with other components. Milk protein concentrate (MPC) are able to bind significant amount of iron due to the presence of both casein and whey protein. MPC in its native state possess very poor solubility, therefore, succinylated derivatives of MPC (succ. MPC) were also used for the preparation of protein-iron complex. Preparation of the complex involved centrifugation (to remove insoluble iron), ultrafiltration (to remove unbound iron) and lyophilisation (to attain in dry form). Iron binding ability of MPC enhanced significantly (P<0.05) upon succinylation. Stability of bound iron from both varieties of complexes was monitored under different conditions encountered during processing. Higher stability (P<0.05) of bound iron was observed in succ. MPC-iron complex than native protein complex. This method could be adopted for the production of stable iron enriched protein, an organic iron source. PMID:26593557

  11. Relationship between content of crude protein in rations for dairy cows and milk yield, concentration of urea in milk and ammonia emissions.

    PubMed

    Frank, B; Swensson, C

    2002-07-01

    During recent decades, efforts have been made in several countries to diminish the negative environmental influence of dairy production. The main focus has been on nitrogen and phosphorus. Modern dairy production in Western Europe is often based on imported feed-stuffs, mostly protein-rich feeds. In Sweden at least, it is wished that the use of imported feedstuffs in animal production will decrease due to the risk of contamination with Salmonella and the ban of using GMO crops in Swedish dairy production. An experiment was carried out to investigate whether a lower content of crude protein in the diet would decrease the ammonia release from cow manure and whether a well-balanced diet using only feedstuffs of Swedish origin would maintain milk production. Five treatments were arranged in a Latin square design. Two different protein supplements made of ingredients of Swedish origin were each fed at two protein levels, and a fifth imported commercial protein mix was fed at the higher level. The treatments with low protein levels (13.1 to 13.5%) had a significantly lower milk yield, kilograms of ECM, but, on the other hand the net profit, milk income minus feed cost was nearly the same in all treatments except diet C, which had lower feed cost but also lower net profit due to lower milk yield. The content of urea in milk was higher with diets high in crude protein (17%) content. A decreased protein level in the diets did not influence the content of casein or whey protein, but the commercial concentrate showed a tendency to give lower values than the Swedish mixtures. The low protein diets gave significantly lower ammonia release from manure compared with the high protein diets. There were no production differences between the diets of Swedish feeds compared with the imported control. The readily fermentable beet pulp should have helped cows use the higher N diet more efficiently and increased the response. This gives the rumen microbes a possibility to match the

  12. Quantitative proteomic analysis of milk fat globule membrane (MFGM) proteins in human and bovine colostrum and mature milk samples through iTRAQ labeling.

    PubMed

    Yang, Mei; Cong, Min; Peng, Xiuming; Wu, Junrui; Wu, Rina; Liu, Biao; Ye, Wenhui; Yue, Xiqing

    2016-05-18

    Milk fat globule membrane (MFGM) proteins have many functions. To explore the different proteomics of human and bovine MFGM, MFGM proteins were separated from human and bovine colostrum and mature milk, and analyzed by the iTRAQ proteomic approach. A total of 411 proteins were recognized and quantified. Among these, 232 kinds of differentially expressed proteins were identified. These differentially expressed proteins were analyzed based on multivariate analysis, gene ontology (GO) annotation and KEGG pathway. Biological processes involved were response to stimulus, localization, establishment of localization, and the immune system process. Cellular components engaged were the extracellular space, extracellular region parts, cell fractions, and vesicles. Molecular functions touched upon were protein binding, nucleotide binding, and enzyme inhibitor activity. The KEGG pathway analysis showed several pathways, including regulation of the actin cytoskeleton, focal adhesion, neurotrophin signaling pathway, leukocyte transendothelial migration, tight junction, complement and coagulation cascades, vascular endothelial growth factor signaling pathway, and adherens junction. These results enhance our understanding of different proteomes of human and bovine MFGM across different lactation phases, which could provide important information and potential directions for the infant milk powder and functional food industries. PMID:27159491

  13. Milk from different species: Relationship between protein fractions and inflammatory response in infants affected by generalized epilepsy.

    PubMed

    Albenzio, M; Santillo, A; Ciliberti, M G; Figliola, L; Caroprese, M; Marino, R; Polito, A N

    2016-07-01

    The present study was undertaken to evaluate the effect of protein fractions from bovine, caprine, and ovine milk on production of cytokines and reactive oxygen species (ROS) and reactive nitrogen species (RNS) by cultured peripheral blood mononuclear cells (PMBC) from infants with generalized epilepsy. Bovine, caprine, and ovine bulk milks were pasteurized and analyzed for chemical composition. Then, PBMC were isolated from 10 patients with generalized epilepsy (5 males; mean age 33.6±5.4mo). Production of tumor necrosis factor-α (TNF-α), IL-10, IL-6, and IL-1β was studied in cultured PBMC (from infants with epilepsy and controls) stimulated by bovine, caprine, and ovine milk and casein and whey protein fractions, and levels of ROS and RNS were measured in the culture supernatant. The ability of PBMC to secrete cytokines in response to milk and protein fraction stimulation may predict the secretion of soluble factor TNF-α in the bloodstream of challenged patients. Bovine, caprine, and ovine bulk milks induced low-level production of IL-10 by cultured PBMC in at least 50% of cases; the same behavior was observed in both casein and whey protein fractions for all species studied. Bovine and ovine milk and their casein fractions induced production of lower levels of IL-1β in 80% of patients, whereas caprine milk and its casein fraction induced the highest levels in 80% of patients. The amount of IL-6 detected after stimulation of PBMC by milk and its fractions for all species was lower than that of other proinflammatory cytokines. In the bovine, total free radicals were higher in bulk milk and lower in the casein fraction, whereas the whey protein fraction showed an intermediate level; in caprine, ROS/RNS levels were not different among milk fractions, whereas ovine had higher levels for bulk milk and casein than the whey protein fraction. Lower levels of ROS/RNS detected in PBMC cultured with caprine milk fraction could be responsible for the lower levels of

  14. Gamma irradiation influence on physical properties of milk proteins

    NASA Astrophysics Data System (ADS)

    Cieśla, K.; Salmieri, S.; Lacroix, M.; Tien, C. Le

    2004-09-01

    Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling.

  15. Effects of the diacylglycerol o-acyltransferase 1 (DGAT1) K232A polymorphism on fatty acid, protein, and mineral composition of dairy cattle milk.

    PubMed

    Bovenhuis, H; Visker, M H P W; Poulsen, N A; Sehested, J; van Valenberg, H J F; van Arendonk, J A M; Larsen, L B; Buitenhuis, A J

    2016-04-01

    Several studies have described associations between the diacylglycerol o-acyltransferase 1 (DGAT1) K232A polymorphism and routinely collected milk production traits but not much is known about effects of the DGAT1 polymorphism on detailed milk composition. The aim of this study was to estimate effects of the DGAT1 polymorphism on milk fatty acid, protein, and mineral composition. We looked for effects that were significant and consistent in Danish Holstein Friesian (HF), Danish Jersey, and Dutch HF as these are likely to be true effects of the DGAT1 K232A polymorphism rather than being effects of linked loci. For fatty acid composition, significant and consistent effects of the DGAT1 polymorphism were detected on C14:0, C16:0, C15:0, C16:1, C18:1 cis-9, conjugated linoleic acid (CLA) cis-9,trans-11, C18:2 cis-9,cis-12, and C18:3 cis-9,cis-12,cis-15 content (percent by weight, wt/wt %). For C16:0, C16:1, and C18:1 cis-9, the DGAT1 polymorphism explained more than 10% of the phenotypic variation. Significant effects on milk protein composition in Dutch HF could not be confirmed in Danish Jersey or Danish HF. For mineral content, significant and consistent effects of the DGAT1 polymorphism on calcium, phosphorus, and zinc were detected. In the Dutch HF population, the contribution of the DGAT1 K232A polymorphism to phenotypic variance was 12.0% for calcium, 8.3% for phosphorus, and 6.1% for zinc. Different from effects on fatty acid composition, effects of the DGAT1 polymorphism on yields of long-chain fatty acids C18:1 cis-9, CLA cis-9,trans-11, C18:2 cis-9,cis-12, and C18:3 cis-9,cis-12,cis-15 were not significant. This indicates that effects of DGAT1 on these fatty acids are indirect, not direct, effects: DGAT1 affects de novo synthesis of fatty acids and, consequently, the contribution of the long-chain fatty acids to total fat is decreased. In addition, effects of the DGAT1 polymorphism on yields of Ca, P, and Zn were not significant, which indicates that effects

  16. 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.

  17. Preventive effect of fermented Maillard reaction products from milk proteins in cardiovascular health.

    PubMed

    Oh, N S; Kwon, H S; Lee, H A; Joung, J Y; Lee, J Y; Lee, K B; Shin, Y K; Baick, S C; Park, M R; Kim, Y; Lee, K W; Kim, S H

    2014-01-01

    The aim of this study was to determine the dual effect of Maillard reaction and fermentation on the preventive cardiovascular effects of milk proteins. Maillard reaction products (MRP) were prepared from the reaction between milk proteins, such as whey protein concentrates (WPC) and sodium caseinate (SC), and lactose. The hydrolysates of MRP were obtained from fermentation by lactic acid bacteria (LAB; i.e., Lactobacillus gasseri H10, L. gasseri H11, Lactobacillus fermentum H4, and L. fermentum H9, where human-isolated strains were designated H1 to H15), which had excellent proteolytic and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities (>20%). The antioxidant activity of MRP was greater than that of intact proteins in assays of the reaction with 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and trivalent ferric ions; moreover, the effect of MRP was synergistically improved by fermentation. The Maillard reaction dramatically increased the level of antithrombotic activity and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) inhibitory effect of milk proteins, but did not change the level of activity for micellar cholesterol solubility. Furthermore, specific biological properties were enhanced by fermentation. Lactobacillus gasseri H11 demonstrated the greatest activity for thrombin and HMGR inhibition in Maillard-reacted WPC, by 42 and 33%, respectively, whereas hydrolysates of Maillard-reacted SC fermented by L. fermentum H9 demonstrated the highest reduction rate for micellar cholesterol solubility, at 52%. In addition, the small compounds that were likely released by fermentation of MRP were identified by size-exclusion chromatography. Therefore, MRP and hydrolysates of fermented MRP could be used to reduce cardiovascular risks. PMID:24731635

  18. Organization and Regulation of Mitochondrial Protein Synthesis.

    PubMed

    Ott, Martin; Amunts, Alexey; Brown, Alan

    2016-06-01

    Mitochondria are essential organelles of endosymbiotic origin that are responsible for oxidative phosphorylation within eukaryotic cells. Independent evolution between species has generated mitochondrial genomes that are extremely diverse, with the composition of the vestigial genome determining their translational requirements. Typically, translation within mitochondria is restricted to a few key subunits of the oxidative phosphorylation complexes that are synthesized by dedicated ribosomes (mitoribosomes). The dramatically rearranged mitochondrial genomes, the limited set of transcripts, and the need for the synthesized proteins to coassemble with nuclear-encoded subunits have had substantial consequences for the translation machinery. Recent high-resolution cryo-electron microscopy has revealed the effect of coevolution on the mitoribosome with the mitochondrial genome. In this review, we place the new structural information in the context of the molecular mechanisms of mitochondrial translation and focus on the novel ways protein synthesis is organized and regulated in mitochondria. PMID:26789594

  19. Susceptibility to denaturation of caseins in milk samples for improving protein conformational study and their identification.

    PubMed

    Pepe, Giacomo; Tenore, Gian Carlo; Conte, Carmine; Russo, Mariateresa; Manfra, Michele; Campiglia, Pietro

    2013-01-01

    Caseins are phosphoproteins kept together by non-covalent interactions to form a highly stabilised dispersion in milk. This study intended to evaluate the different effects of denaturing solvents and solutions on caseins in order to optimise the chromatographic resolution for a better identification of individual casein fractions. The caseins were obtained from bovine skimmed milks by precipitation at pH 4.3, and the proteins were dissolved in water and three different solutions. The casein separation was performed by reversed-phase high-performance liquid chromatography. Each casein was identified by matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry. The best result was achieved by treating the caseins with solution D. PMID:22978643

  20. Food protein-induced enterocolitis syndrome--not only due to cow's milk and soy.

    PubMed

    Levy, Yael; Danon, Yehuda L

    2003-08-01

    Over a of 7-year period, six patients (four males, two females aged 3-12 months) were diagnosed with food protein-induced enterocolitis syndrome (FPIES) triggered by foods other than cow's milk and soy: chicken in four, turkey in two, peas in one, and lentils in one (five patients reacted to more than one food type). All reactions developed within 2 h of ingestion of the allergenic food. To exclude other conditions with similar clinical symptoms, three infants underwent work-up for sepsis, one infant underwent work-up to exclude metabolic defects, and one underwent a barium enema to rule out intussusception. All were negative. Pediatricians should be aware that FPIES may be caused by foods other than cow's milk and soy, mainly chicken, turkey and foods from the legume family, and that it may present also in infants older than 6 months. PMID:12911514

  1. Cell-free protein synthesis: applications come of age.

    PubMed

    Carlson, Erik D; Gan, Rui; Hodgman, C Eric; Jewett, Michael C

    2012-01-01

    Cell-free protein synthesis has emerged as a powerful technology platform to help satisfy the growing demand for simple and efficient protein production. While used for decades as a foundational research tool for understanding transcription and translation, recent advances have made possible cost-effective microscale to manufacturing scale synthesis of complex proteins. Protein yields exceed grams protein produced per liter reaction volume, batch reactions last for multiple hours, costs have been reduced orders of magnitude, and reaction scale has reached the 100-liter milestone. These advances have inspired new applications in the synthesis of protein libraries for functional genomics and structural biology, the production of personalized medicines, and the expression of virus-like particles, among others. In the coming years, cell-free protein synthesis promises new industrial processes where short protein production timelines are crucial as well as innovative approaches to a wide range of applications. PMID:22008973

  2. Staphylococcus aureus proteins differentially produced in ewe gangrenous mastitis or ewe milk.

    PubMed

    Le Maréchal, Caroline; Jardin, Julien; Briard-Bion, Valérie; Rault, Lucie; Berkova, Nadia; Vautor, Eric; Thiéry, Richard; Even, Sergine; Le Loir, Yves

    2013-05-31

    Despite being one of the main pathogens involved in ruminant mastitis, little is known about what proteins Staphylococcus aureus does express, in vivo, during the infection. Here, two S. aureus strains were isolated from curds formed within the udder of two ewes suffering from gangrenous mastitis. Protein samples were prepared from cell fractions and were analyzed using 1D-LC MS/MS. Results were compared to 1D-LC MS/MS analysis of the same S. aureus strains grown in ewe milk. A total of 365 proteins were identified. Most of them were related to cellular metabolism, cellular division and stress response. Half of the proteins were found in both conditions but a substantial number were specifically found in in vivo conditions and gave indications about the active metabolic status and the stresses encountered by S. aureus within the cistern during a gangrenous mastitis. PMID:23415898

  3. Bacteriostasis of a milk-sensitive strain of Escherichia coli by immunoglobulins and iron-binding proteins in association

    PubMed Central

    Spik, Geneviève; Cheron, A.; Montreuil, J.; Dolby, J. M.

    1978-01-01

    The growth of a milk-sensitive strain of Escherichia coli in 1% peptone water can be inhibited for at least 3 h by IgA isolated from human milk or IgG1 from bovine colostrum acting with native iron-binding proteins from milk or serum. The immunoglobulins alone are inactive; the native iron-binding proteins alone are sometimes partially active. All this activity is inconsistent and not always enhanced by the addition of bicarbonate ions. The growth of E. coli in human milk that has been inactivated by heating at 100° is consistently inhibited by IgA or IgG1 acting with native iron-binding proteins. The immunoglobulins are inactive alone but the iron-binding proteins have considerably more activity when added alone to inactivated milk than to peptone water, suggesting that the growth medium is contributing to or stabilising the activity. The addition of bicarbonate ions is without effect. Attempted absorption of antibody with suspensions of E. coli and replacement of bacteriostatic activity by addition of purified milk proteins has not, however, suggested any participants in the bacteriostasis of milk-sensitive strains other than antibody and iron-binding protein. Bacteriostasis is abolished by saturating the transferrins with iron. The iron-free apo-derivatives are not more inhibitory than the native proteins except for human apo-lactotransferrin in peptone water which inhibits growth completely. This latter inhibition is not attributable to the low pH and 10–100 times more iron is needed to abolish this activity than is needed to abolish that of bovine apo-lactotransferrin. PMID:361548

  4. [A CASE OF ANAPHYLAXIS IN THE PEDIATRIC PATIENT WITH MILK ALLERGY DUE TO TRACES OF MILK PROTEIN IN THE LACTOSE USED AS AN EXCIPIENT OF INAVIR INHALATION].

    PubMed

    Morikawa, Miki; Kanemitsu, Yoshitomi; Tsukamoto, Hiroki; Morikawa, Akimasa; Tomioka, Yoshihisa

    2016-05-01

    The patient was a 6-year-old female with milk allergy and persistent asthma. She experienced anaphylactic reactions just after the inhalation of Inavir (Laninamivir Octanoate Hydrate) to treat flu infection. A skin-prick test showed positive reactions for Inavir inhaler powder and lactose used as an excipient but negative for Laninamivir. Same results were obtained in a drug-stimulated basophil activation test. The lactose excipient in Inavir inhaler powder was supposed to contain milk proteins, which caused anaphylactic reactions. To test this possibility, we examined the contamination of allergic milk proteins in the lactose excipient and found the smear band by silver staining, which was identified as β-lactoglobulin (β-LG) by Western blotting using specific monoclonal antibody and patient's sera. The β-LG in Inavir was supposed to be glycosylated with lactose because the molecular weight was slightly higher than β-LG standard reference as seen in mobility. In fact, the incubation with lactose in vitro tended to increase molecular weight. Following these results, we herein report that the trace amounts of β-LG contaminated in the lactose excipient of Inavir could cause immediate allergic reactions. The risk that the lactose-containing dry powder inhalers cause allergic reactions for patients with cow's milk allergy need to be reminded. In particular, the use for flu patients should be paid careful attention because of increased airway hypersensitivity in those patients. PMID:27193929

  5. Use of dry milk protein concentrate in pizza cheese manufactured by culture or direct acidification.

    PubMed

    Shakeel-Ur-Rehman; Farkye, N Y; Yim, B

    2003-12-01

    Milk protein concentrate (MPC) contains high concentrations of casein and calcium and low concentrations of lactose. Enrichment of cheese milk with MPC should, therefore, enhance yields and improve quality. The objectives of this study were: 1) to compare pizza cheese made by culture acidification using standardized whole milk (WM) plus skim milk (SM) versus WM plus MPC; and 2) compare cheese made using WM + MPC by culture acidification to that made by direct acidification. The experimental design is as follows: vat 1 = WM + SM + culture (commercial thermophilic lactic acid bacteria), vat 2 = WM + MPC + culture, and vat 3 = WM + MPC + direct acid (2% citric acid). Each cheese milk was standardized to a protein-to-fat ratio of approximately 1.4. The experiment was repeated three times. Yield and composition of cheeses were determined by standard methods, whereas the proteolysis was assessed by urea polyacrylamide gel electrophoresis (PAGE) and water-soluble N contents. Meltability of the cheeses was determined during 1 mo of storage, in addition to pizza making. The addition of MPC improved the yields from 10.34 +/- 0.57% in vat 1 cheese to 14.50 +/- 0.84% and 16.65 +/- 2.23%, respectively, in vats 2 and 3 and cheeses. The percentage of fat and protein recoveries showed insignificant differences between the treatments, but TS recoveries were in the order, vat 2 > vat 3 > vat 1. Most of the compositional parameters were significantly affected by the different treatments. Vat 2 cheese had the highest calcium and lowest lactose contencentrations. Vat 3 cheese had the best meltability. Vat 1 cheese initially had better meltability than vat 2 cheese; however, the difference became insignificant after 28 d of storage at 4 degrees C. Vat 3 cheese had the softest texture and produced large-sized blisters when baked on pizza. The lowest and highest levels of proteolysis were found in vats 2 and 3 cheeses, respectively. The study demonstrates the use of MPC in pizza cheese

  6. SHORT-TERM MEMORY IS INDEPENDENT OF BRAIN PROTEIN SYNTHESIS

    SciTech Connect

    Davis, Hasker P.; Rosenzweig, Mark R.; Jones, Oliver W.

    1980-09-01

    Male Swiss albino CD-1 mice given a single injection of a cerebral protein synthesis inhibitor, anisomycin (ANI) (1 mg/animal), 20 min prior to single trial passive avoidance training demonstrated impaired retention at tests given 3 hr, 6 hr, 1 day, and 7 days after training. Retention was not significantly different from saline controls when tests were given 0.5 or 1.5 hr after training. Prolonging inhibition of brain protein synthesis by giving either 1 or 2 additional injections of ANI 2 or 2 and 4 hr after training did not prolong short-term retention performance. The temporal development of impaired retention in ANI treated mice could not be accounted for by drug dosage, duration of protein synthesis inhibition, or nonspecific sickness at test. In contrast to the suggestion that protein synthesis inhibition prolongs short-term memory (Quinton, 1978), the results of this experiment indicate that short-term memory is not prolonged by antibiotic drugs that inhibit cerebral protein synthesis. All evidence seems consistent with the hypothesis that short-term memory is protein synthesis independent and that the establishment of long-term memory depends upon protein synthesis during or shortly after training. Evidence for a role of protein synthesis in memory maintenance is discussed.

  7. Understanding Protein Synthesis: An Interactive Card Game Discussion

    ERIC Educational Resources Information Center

    Lewis, Alison; Peat, Mary; Franklin, Sue

    2005-01-01

    Protein synthesis is a complex process and students find it difficult to understand. This article describes an interactive discussion "game" used by first year biology students at the University of Sydney. The students, in small groups, use the game in which the processes of protein synthesis are actioned by the students during a practical…

  8. Short communication: Multi-trait estimation of genetic parameters for milk protein composition in the Danish Holstein.

    PubMed

    Gebreyesus, G; Lund, M S; Janss, L; Poulsen, N A; Larsen, L B; Bovenhuis, H; Buitenhuis, A J

    2016-04-01

    Genetic parameters were estimated for the major milk proteins using bivariate and multi-trait models based on genomic relationships between animals. The analyses included, apart from total protein percentage, αS1-casein (CN), αS2-CN, β-CN, κ-CN, α-lactalbumin, and β-lactoglobulin, as well as the posttranslational sub-forms of glycosylated κ-CN and αS1-CN-8P (phosphorylated). Standard errors of the estimates were used to compare the models. In total, 650 Danish Holstein cows across 4 parities and days in milk ranging from 9 to 481d were selected from 21 herds. The multi-trait model generally resulted in lower standard errors of heritability estimates, suggesting that genetic parameters can be estimated with high accuracy using multi-trait analyses with genomic relationships for scarcely recorded traits. The heritability estimates from the multi-trait model ranged from low (0.05 for β-CN) to high (0.78 for κ-CN). Genetic correlations between the milk proteins and the total milk protein percentage were generally low, suggesting the possibility to alter protein composition through selective breeding with little effect on total milk protein percentage. PMID:26805988

  9. Effects of Forage Sources on Rumen Fermentation Characteristics, Performance, and Microbial Protein Synthesis in Midlactation Cows

    PubMed Central

    Xu, Jun; Hou, Yujie; Yang, Hongbo; Shi, Renhuang; Wu, Caixia; Huo, Yongjiu; Zhao, Guoqi

    2014-01-01

    Eight multiparous Holstein cows (632±12 kg BW; 135±16 DIM) were used in a replicated 4×4 Latin square design to evaluate the effects of forage sources on rumen fermentation characteristics, performance, and microbial protein (MCP) synthesis. The forage portion of the diets contained alfalfa hay (AH), oat hay (OH), Leymus chinensis (LC), or rice straw (RS) as the primary source of fiber. Diets were isonitrogenous and isocaloric, and cows were fed four corn silages based total mixed rations with equivalent nonfiber carbohydrate (NFC) and forage neutral detergent fiber (NDF). Dry matter intake was not affected by the source of dietary forages, ranging from 18.83 to 19.20 kg/d, consequently, milk yield was similar among diets. Because of the numerical differences in milk fat and milk protein concentrations, 4% FCM and ECM yields were unchanged (p>0.05). Mean rumen pH, NH3-N content, and concentrations of volatile fatty acids in the rumen fluid were not affected by the treatments (p>0.05). Dietary treatments did not affect the total tract apparent digestibility of dry matter, organic matter, and crude protein (p>0.05); however, digestibility of NDF and acid detergent fiber in RS diet was higher compared with AH, OH, and LC diets (p<0.05). Total purine derivative excretion was higher in cows fed AH, OH, and LC diets compared with those fed RS diet (p<0.05), consequently, estimated MCP synthesis was 124.35 g/d higher in cows fed AH diet compared with those fed RS diet (p<0.05). The results indicated that cows fed AH, OH, LC, and RS diets with an equivalent forage NDF and NFC have no unfavourable effect on the ruminal fermentation and productive parameters. PMID:25050001

  10. Effects of forage sources on rumen fermentation characteristics, performance, and microbial protein synthesis in midlactation cows.

    PubMed

    Xu, Jun; Hou, Yujie; Yang, Hongbo; Shi, Renhuang; Wu, Caixia; Huo, Yongjiu; Zhao, Guoqi

    2014-05-01

    Eight multiparous Holstein cows (632±12 kg BW; 135±16 DIM) were used in a replicated 4×4 Latin square design to evaluate the effects of forage sources on rumen fermentation characteristics, performance, and microbial protein (MCP) synthesis. The forage portion of the diets contained alfalfa hay (AH), oat hay (OH), Leymus chinensis (LC), or rice straw (RS) as the primary source of fiber. Diets were isonitrogenous and isocaloric, and cows were fed four corn silages based total mixed rations with equivalent nonfiber carbohydrate (NFC) and forage neutral detergent fiber (NDF). Dry matter intake was not affected by the source of dietary forages, ranging from 18.83 to 19.20 kg/d, consequently, milk yield was similar among diets. Because of the numerical differences in milk fat and milk protein concentrations, 4% FCM and ECM yields were unchanged (p>0.05). Mean rumen pH, NH3-N content, and concentrations of volatile fatty acids in the rumen fluid were not affected by the treatments (p>0.05). Dietary treatments did not affect the total tract apparent digestibility of dry matter, organic matter, and crude protein (p>0.05); however, digestibility of NDF and acid detergent fiber in RS diet was higher compared with AH, OH, and LC diets (p<0.05). Total purine derivative excretion was higher in cows fed AH, OH, and LC diets compared with those fed RS diet (p<0.05), consequently, estimated MCP synthesis was 124.35 g/d higher in cows fed AH diet compared with those fed RS diet (p<0.05). The results indicated that cows fed AH, OH, LC, and RS diets with an equivalent forage NDF and NFC have no unfavourable effect on the ruminal fermentation and productive parameters. PMID:25050001

  11. A process efficiency assessment of serum protein removal from milk using ceramic graded permeability microfiltration membrane.

    PubMed

    Tremblay-Marchand, D; Doyen, A; Britten, M; Pouliot, Y

    2016-07-01

    Microfiltration (MF) is a well-known process that can be used in the dairy industry to separate caseins from serum proteins (SP) in skim milk using membranes with a pore diameter of 0.1μm. Graded permeability ceramic membranes have been studied widely as means of improving milk fractionation by overcoming problems encountered with other MF membranes. The ideal operating parameters for process efficiency in terms of membrane selectivity, permeate flux, casein loss, SP transmission, energy consumption, and dilution with water remain to be determined for this membrane. Our objective was to evaluate the effects of transmembrane pressure (TMP), volumetric concentration factor (VCF), and diafiltration on overall process efficiency. Skim milk was processed using a pilot-scale MF system equipped with 0.72-m(2) graded permeability membranes with a pore size of 0.1μm. In the first experiment, in full recycle mode, TMP was set at 124, 152, 179, or 207 kPa by adjusting the permeate pressure at the outlet. Whereas TMP had no significant effect on permeate and retentate composition, 152 kPa was found to be optimal for SP removal during concentration and concentration or diafiltration experiments. When VCF was increased to 3×, SP rejection coefficient increased along with energy consumption and total casein loss, whereas SP removal rate decreased. Diafiltering twice allowed an increase in total SP removal but resulted in a substantial increase in energy consumption and casein loss. It also reduced the SP removal rate by diluting permeate. The membrane surface area required for producing cheese milk by blending whole milk, cream, and MF retentate (at different VCF) was estimated for different cheese milk casein concentrations. For a given casein concentration, the same quantity of permeate and SP would be produced, but less membrane surface area would be needed at a lower retentate VCF. Microfiltration has great potential as a process of adding value to conventional

  12. Inhibition of mammalian mitochondrial protein synthesis by oxazolidinones.

    PubMed

    McKee, E E; Ferguson, M; Bentley, A T; Marks, T A

    2006-06-01

    The effects of a variety of oxazolidinones, with different antibacterial potencies, including linezolid, on mitochondrial protein synthesis were determined in intact mitochondria isolated from rat heart and liver and rabbit heart and bone marrow. The results demonstrate that a general feature of the oxazolidinone class of antibiotics is the inhibition of mammalian mitochondrial protein synthesis. Inhibition was similar in mitochondria from all tissues studied. Further, oxazolidinones that were very potent as antibiotics were uniformly potent in inhibiting mitochondrial protein synthesis. These results were compared to the inhibitory profiles of other antibiotics that function by inhibiting bacterial protein synthesis. Of these, chloramphenicol and tetracycline were significant inhibitors of mammalian mitochondrial protein synthesis while the macrolides, lincosamides, and aminoglycosides were not. Development of future antibiotics from the oxazolidinone class will have to evaluate potential mitochondrial toxicity. PMID:16723564

  13. Heat-induced changes in the properties of modified skim milks with different casein to whey protein ratios.

    PubMed

    Singh, Mandeep Jeswan; Chandrapala, Jayani; Udabage, Punsandani; McKinnon, Ian; Augustin, Mary Ann

    2015-05-01

    The heat-induced changes in pH, Ca activity and viscosity after heating at 90 °C for 10 min of five modified skim milks were studied as a function of the initial pH of the milks at 25 °C. The milks had (i) different ratios of casein : whey protein (0.03, 1.74, 3.97, 5.27 and 7.25), (ii) the same total solids concentration (9% w/w) and (iii) prior to the adjustment of the pH, similar values of pH (6.67-6.74), concentration of serum calcium, and calcium activity, suggesting that the sera have similar mineral composition. The total protein concentrations of the milks differ (2.8-4.0%, w/w). The pH decrease in situ upon heating from 25-90 °C was similar for all the modified skim milks with the same starting pH, suggesting that the pH changes to milk on heating were primarily mediated by the initial mineral composition of the serum and were unaffected by the casein : whey protein ratio or the total protein content of the milk. The heat-induced changes in pH and calcium activity were largely reversible on cooling. The two milks with the lowest ratios of casein to whey protein gelled on heating to 90 °C for 10 min and cooling to 25 °C when the pH was adjusted to pH = 6.2 prior to heating. The viscosities of all other milks with casein to whey protein ratio of 3.97, 5.27 and 7.25 and/or pH ≥6.7 prior to heating did not change significantly. The effect of casein : whey protein ratio and the pH are the dominant factors in controlling the susceptibility to thickening of the milks on heating in this study. PMID:25499614

  14. Changes over lactation in breast milk serum proteins involved in the maturation of immune and digestive system of the infant

    PubMed Central

    Zhang, Lina; de Waard, Marita; Verheijen, Hester; Boeren, Sjef; Hageman, Jos A.; van Hooijdonk, Toon; Vervoort, Jacques; van Goudoever, Johannes B.; Hettinga, Kasper

    2016-01-01

    Here we provide data from shot-gun proteomics, using filtered-aided sample preparation (FASP), dimethyl labeling and LC–MS/MS, to quantify the changes in the repertoire of human milk proteins over lactation. Milk serum proteins were analyzed at week 1, 2, 3 4, 8, 16, and 24 in milk from four individual mothers. A total of 247 proteins were identified, of which 200 proteins were quantified. The data supplied in this article supports the accompanying publication (Zhang et al., 2006) [1]. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (Vizcaíno et al., 2016) [2] via the PRIDE partner repository with the dataset identifier PXD003465. PMID:26977438

  15. 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

    2016-06-01

    Here we provide data from shot-gun proteomics, using filtered-aided sample preparation (FASP), dimethyl labeling and LC-MS/MS, to quantify the changes in the repertoire of human milk proteins over lactation. Milk serum proteins were analyzed at week 1, 2, 3 4, 8, 16, and 24 in milk from four individual mothers. A total of 247 proteins were identified, of which 200 proteins were quantified. The data supplied in this article supports the accompanying publication (Zhang et al., 2006) [1]. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (Vizcaíno et al., 2016) [2] via the PRIDE partner repository with the dataset identifier PXD003465. PMID:26977438

  16. Effect of dietary cation-anion difference on performance of lactating dairy cows and stability of milk proteins.

    PubMed

    Martins, C M M R; Arcari, M A; Welter, K C; Netto, A S; Oliveira, C A F; Santos, M V

    2015-04-01

    Casein micelle stability is negatively correlated with milk concentrations of ionic calcium, which may change according to the metabolic and nutritional status of dairy cows. The present study aimed to evaluate the effect of dietary cation-anion difference (DCAD) on concentrations of casein subunits, whey proteins, ionic calcium, and milk heat and ethanol stability. Sixteen Holstein cows were distributed in 4 contemporary 4 × 4 Latin square designs, which consisted of 4 periods of 21 d and 4 treatments according to DCAD: 290, 192, 98, and -71 mEq/kg of dry matter (DM). The milk concentrations of ionic calcium and κ-casein were reduced as DCAD increased, whereas the milk urea nitrogen and β-lactoglobulin concentrations were increased. As a result of these alterations, the milk ethanol stability and milk stability during heating at 140 °C were increased linearly with increasing DCAD [Y = 74.87 (standard error = 0.87) + 0.01174 (standard error = 0.0025) × DCAD (mEq/kg of DM) and Y = 3.95 (standard error = 1.02) + 0.01234 (standard error = 0.0032) × DCAD (mEq/kg of DM), respectively]. In addition, 3.5% fat-corrected milk and fat, lactose, and total milk solids contents were linearly increased by 13.52, 8.78, 2.5, and 2.6%, respectively, according to DCAD increases from -71 to 290 mEq/kg of DM, whereas crude protein and casein content were linearly reduced by 4.83 and 4.49%, respectively. In conclusion, control of metabolic changes in lactating dairy cows to maintain blood acid-base equilibrium plays an important role in keeping milk stable to ethanol and during heat treatments. PMID:25622868

  17. Iron and exercise induced alterations in antioxidant status. Protection by dietary milk proteins.

    PubMed

    Zunquin, Gautier; Rouleau, Vincent; Bouhallab, Said; Bureau, Francois; Theunynck, Denis; Rousselot, Pierre; Arhan, Pierre; Bougle, Dominique

    2006-05-01

    Lipid peroxidation stress induced by iron supplementation can contribute to the induction of gut lesions. Intensive sports lead to ischemia reperfusion, which increases free radical production. Athletes frequently use heavy iron supplementation, whose effects are unknown. On the other hand, milk proteins have in vitro antioxidant properties, which could counteract these potential side effects. The main aims of the study were: (1) to demonstrate the effects of combined exercise training (ET) and iron overload on antioxidant status; (2) to assess the protective properties of casein in vivo; (3) to study the mechanisms involved in an in vitro model. Antioxidant status was assessed by measuring the activity of antioxidant enzymes (superoxide dismutase (SOD); glutathione peroxidase (GSH-Px)), and on the onset of aberrant crypts (AC) in colon, which can be induced by lipid peroxidation. At day 30, all ET animals showed an increase in the activity of antioxidant enzymes, in iron concentration in colon mucosa and liver and in the number of AC compared to untrained rats. It was found that Casein's milk protein supplementation significantly reduced these parameters. Additional information on protective effect of casein was provided by measuring the extent of TBARS formation during iron/ascorbate-induced oxidation of liposomes. Free casein and casein bound to iron were found to significantly reduce iron-induced lipid peroxidation. The results of the overall study suggest that Iron supplementation during intensive sport training would decrease anti-oxidant status. Dietary milk protein supplementation could at least partly prevent occurrence of deleterious effects to tissue induced by iron overload. PMID:17390518

  18. Proteolytic degradation of ewe milk proteins during fermentation of yoghurts and storage.

    PubMed

    El-Zahar, Khaled; Chobert, Jean-Marc; Sitohy, Mahmoud; Dalgalarrondo, Michèle; Haertlé, Thomas

    2003-06-01

    Yoghurts are mostly produced from cow milk and to a very limited extent from ewe milk. The evolution of caseins and whey proteins in ovine milk submitted to different thermal treatments (63 degrees C/30 min; 73 degrees C/15 min; 85 degrees C/10 min or 96 degrees C/5 min) was followed during fermentation of yoghurts and during their storage up to 14 days, using two different sets of starters. One set of starter LAB was a "ropy" culture (YC-191), which is a well-defined mixed strain culture containing Streptococcus thermophilus ST-143 and Lactobacillus delbrueckii subsp. bulgaricus (LB-18 and LB-CH2). The other set of starter bacteria (YC-460) was a standard yoghurt culture("non-ropy") containing mixed strain culture of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. Contents of free amino groups in produced yoghurts increased gradually during the fermentation, up to a maximal value obtained after 4 h fermentation, then they did not change significantly during storage of yoghurt produced with YC-191 starter. In contrary, a large drop in the amount of free amino groups was observed in the first 24 h of storage in the case of yoghurt made with YC-460 indicating that microorganisms continue still to grow in low temperatures. During fermentation and storage of both yoghurt types, alpha-lactalbumin was hydrolyzed to a slightly bigger extent than beta-lactoglobulin. During fermentation, beta-casein was slightly more degraded than alpha(s)-caseins; however, the opposite was observed during storage up to 14 days. Generally, a more intense heat pretreatment led to a higher degradation of whey proteins and caseins during fermentation and storage. Differences in proteolytic activity between the two starters used (whey proteins more degraded by YC-191; caseins more degraded by YC-460) may lead to improvement in production and formulation of yoghurts differing in their physicochemical and rheological properties. PMID:12866624

  19. Designer milk.

    PubMed

    Sabikhi, Latha

    2007-01-01

    Dairy biotechnology is fast gaining ground in the area of altering milk composition for processing and/or animal and human health by employing nutritional and genetic approaches. Modification of the primary structure of casein, alteration in the lipid profile, increased protein recovery, milk containing nutraceuticals, and replacement for infant formula offer several advantages in the area of processing. Less fat in milk, altered fatty acid profiles to include more healthy fatty acids such as CLA and omega-fats, improved amino acid profiles, more protein, less lactose, and absence of beta-lactoglobulin (beta-LG) are some opportunities of "designing" milk for human health benefits. Transgenic technology has also produced farm animals that secrete in their milk, human lactoferrin, lysozyme, and lipase so as to simulate human milk in terms of quality and quantity of these elements that are protective to infants. Cow milk allergenicity in children could be reduced by eliminating the beta-LG gene from bovines. Animals that produce milk containing therapeutic agents such as insulin, plasma proteins, drugs, and vaccines for human health have been genetically engineered. In order to cater to animal health, transgenic animals that express in their mammary glands, various components that work against mastitis have been generated. The ultimate acceptability of the "designer" products will depend on ethical issues such as animal welfare and safety, besides better health benefits and increased profitability of products manufactured by the novel techniques. PMID:17900499

  20. RNA-Seq reveals 10 novel promising candidate genes affecting milk protein concentration in the Chinese Holstein population

    PubMed Central

    Li, Cong; Cai, Wentao; Zhou, Chenghao; Yin, Hongwei; Zhang, Ziqi; Loor, Juan J.; Sun, Dongxiao; Zhang, Qin; Liu, Jianfeng; Zhang, Shengli

    2016-01-01

    Paired-end RNA sequencing (RNA-Seq) was used to explore the bovine transcriptome from the mammary tissue of 12 Chinese Holstein cows with 6 extremely high and 6 low phenotypic values for milk protein percentage. We defined the differentially expressed transcripts between the two comparison groups, extremely high and low milk protein percentage during the peak lactation (HP vs LP) and during the non-lactating period (HD vs LD), respectively. Within the differentially expressed genes (DEGs), we detected 157 at peak lactation and 497 in the non-lactating period with a highly significant correlation with milk protein concentration. Integrated interpretation of differential gene expression indicated that SERPINA1, CLU, CNTFR, ERBB2, NEDD4L, ANG, GALE, HSPA8, LPAR6 and CD14 are the most promising candidate genes affecting milk protein concentration. Similarly, LTF, FCGR3A, MEGF10, RRM2 and UBE2C are the most promising candidates that in the non-lactating period could help the mammary tissue prevent issues with inflammation and udder disorders. Putative genes will be valuable resources for designing better breeding strategies to optimize the content of milk protein and also to provide new insights into regulation of lactogenesis. PMID:27254118

  1. Milk protein suspensions enriched with three essential minerals: Physicochemical characterization and aggregation induced by a novel enzymatic pool.

    PubMed

    Lombardi, Julia; Spelzini, Darío; Corrêa, Ana Paula Folmer; Brandelli, Adriano; Risso, Patricia; Boeris, Valeria

    2016-04-01

    Structural changes of casein micelles and their aggregation induced by a novel enzymatic pool isolated from Bacillus spp. in the presence of calcium, magnesium or zinc were investigated. The effect of cations on milk protein structure was studied using fluorescence and dynamic light scattering. In the presence of cations, milk protein structure rearrangements and larger casein micelle size were observed. The interaction of milk proteins with zinc appears to be of a different nature than that with calcium or magnesium. Under the experimental conditions assayed, the affinity of each cation for some groups present in milk proteins seems to play an important role, besides electrostatic interaction. On the other hand, the lowest aggregation times were achieved at the highest calcium and zinc concentrations (15 mM and 0.25 mM, respectively). The study found that the faster the aggregation of casein micelles, the less compact the gel matrix obtained. Cation concentrations affected milk protein aggregation kinetics and the structure of the aggregates formed. PMID:26803666

  2. RNA-Seq reveals 10 novel promising candidate genes affecting milk protein concentration in the Chinese Holstein population.

    PubMed

    Li, Cong; Cai, Wentao; Zhou, Chenghao; Yin, Hongwei; Zhang, Ziqi; Loor, Juan J; Sun, Dongxiao; Zhang, Qin; Liu, Jianfeng; Zhang, Shengli

    2016-01-01

    Paired-end RNA sequencing (RNA-Seq) was used to explore the bovine transcriptome from the mammary tissue of 12 Chinese Holstein cows with 6 extremely high and 6 low phenotypic values for milk protein percentage. We defined the differentially expressed transcripts between the two comparison groups, extremely high and low milk protein percentage during the peak lactation (HP vs LP) and during the non-lactating period (HD vs LD), respectively. Within the differentially expressed genes (DEGs), we detected 157 at peak lactation and 497 in the non-lactating period with a highly significant correlation with milk protein concentration. Integrated interpretation of differential gene expression indicated that SERPINA1, CLU, CNTFR, ERBB2, NEDD4L, ANG, GALE, HSPA8, LPAR6 and CD14 are the most promising candidate genes affecting milk protein concentration. Similarly, LTF, FCGR3A, MEGF10, RRM2 and UBE2C are the most promising candidates that in the non-lactating period could help the mammary tissue prevent issues with inflammation and udder disorders. Putative genes will be valuable resources for designing better breeding strategies to optimize the content of milk protein and also to provide new insights into regulation of lactogenesis. PMID:27254118

  3. Mineral-binding milk proteins and peptides; occurrence, biochemical and technological characteristics.

    PubMed

    Vegarud, G E; Langsrud, T; Svenning, C

    2000-11-01

    Minerals and trace elements in cow's milk occur as inorganic ions and salts or form complexes with proteins and peptides, carbohydrates, fats and small molecules. The main mineral binder or chelators of calcium are the caseins, alphas1-casein, alphas2-casein, beta-casein and kappa-casein, but also whey proteins and lactoferrin bind specific minerals like calcium, magnesium, zinc, iron, sodium and potassium. Less documented is the binding of trace elements. Peptides obtained by in vitro or in vivo hydrolysis act as mineral trappers through specific and non-specific binding sites. They may then function as carriers, chelators, of various minerals and thus enhance or inhibit bioavailability. Peptides from milk proteins have found interesting new applications in the food industry as products with improved functionality or as ingredients of dietary products, or used in pharmaceutical industry. Fortification of foods with minerals in a low concentration has for a long time been used in some countries to overcome mineral deficiency, which is an increasing problem in humans. These types of foods are being used to create a new generation of super foods in the industry today. PMID:11242452

  4. Dissemination of Cronobacter spp. (Enterobacter sakazakii) in a Powdered Milk Protein Manufacturing Facility▿

    PubMed Central

    Mullane, N.; Healy, B.; Meade, J.; Whyte, P.; Wall, P. G.; Fanning, S.

    2008-01-01

    The microbial contamination of air filters and possible links to contaminated product in a powdered milk protein-processing facility were investigated. Over a 10-month period, seven air filters, the environment, and powdered product were analyzed for the presence of Cronobacter spp. The effects of air filter installation, maintenance, and subsequent dissemination of Cronobacter were investigated. A total of 30 isolates were characterized by pulsed-field gel electrophoresis (PFGE). PFGE revealed the presence of three clonal populations distributed throughout the manufacturing site. This study highlights the need for proper installation of air filters to limit the dissemination of microorganisms into processing sites. PMID:18641152

  5. Milk Allergy

    MedlinePlus

    ... the word “Milk” on the label. Read all product labels carefully before purchasing and consuming any item. Ingredients ... following the circled K or U on a product label indicates the presence of milk protein or a ...

  6. Modeling protein synthesis from a physicist's perspective: A toy model

    NASA Astrophysics Data System (ADS)

    Basu, Aakash; Chowdhury, Debashish

    2007-10-01

    Proteins are polymers of amino acids. These macromolecules are synthesized by intracellular machines called ribosomes. Although the experimental investigation of protein synthesis has been a traditional area of research in molecular cell biology, important quantitative models of protein synthesis have been reported in research journals devoted to statistical physics and related interdisciplinary topics. From the perspective of a physicist, protein synthesis is the classical transport of interacting ribosomes on a messenger RNA (mRNA) template that dictates the sequence of the amino acids on the protein. We discuss appropriate simplification of the models and methods. In particular, we develop and analyze a simple toy model using some elementary techniques of nonequilibrium statistical mechanics and predict the average rate of protein synthesis and the spatial organization of the ribosomes in the steady state.

  7. Intestinal threonine utilization for protein and mucin synthesis is decreased in formula-fed preterm pigs.

    PubMed

    Puiman, Patrycja J; Jensen, Mikkel; Stoll, Barbara; Renes, Ingrid B; de Bruijn, Adrianus C J M; Dorst, Kristien; Schierbeek, Henk; Schmidt, Mette; Boehm, Günther; Burrin, Douglas G; Sangild, Per T; van Goudoever, Johannes B

    2011-07-01

    Threonine is an essential amino acid necessary for synthesis of intestinal (glyco)proteins such as mucin MUC2 to maintain adequate gut barrier function. In premature infants, reduced barrier function may contribute to the development of necrotizing enterocolitis (NEC). Human milk protects against NEC compared with infant formula. Therefore, we hypothesized that formula feeding decreases the MUC2 synthesis rate concomitant with a decrease in intestinal first-pass threonine utilization, predisposing the preterm neonate to NEC. Preterm pigs were delivered by caesarian section and received enteral feeding with formula (FORM; n = 13) or bovine colostrum (COL; n = 6) for 2 d following 48 h of total parenteral nutrition. Pigs received a dual stable isotope tracer infusion of threonine to determine intestinal threonine kinetics. NEC developed in 38% of the FORM pigs, whereas none of the COL pigs were affected (P = 0.13). Intestinal fractional first-pass threonine utilization was lower in FORM pigs (49 ± 2%) than in COL pigs (60 ± 4%) (P = 0.02). In FORM pigs compared with COL pigs, protein synthesis (369 ± 31 mg·kg(-1)·d(-1) vs. 615 ± 54 mg·kg(-1)·d(-1); P = 0.003) and MUC2 synthesis (121 ± 17%/d vs. 184 ± 15%/d; P = 0.02) were lower in the distal small intestine (SI). Our results suggest that formula feeding compared with colostrum feeding in preterm piglets reduces mucosal growth with a concomitant decrease in first-pass splanchnic threonine utilization, protein synthesis, and MUC2 synthesis in the distal SI. Hence, decreased intestinal threonine metabolism and subsequently impaired gut barrier function may predispose the formula-fed infant to developing NEC. PMID:21593357

  8. Attachment of Listeria innocua to polystyrene: effects of ionic strength and conditioning films from culture media and milk proteins.

    PubMed

    Robitaille, Gilles; Choinière, Sébastien; Ells, Timothy; Deschènes, Louise; Mafu, Akier Assanta

    2014-03-01

    It is recognized that bacterial adhesion usually occurs on conditioning films made of organic macromolecules absorbed to abiotic surfaces. The objectives of this study were to determine the extent to which milk protein-coated polystyrene (PS) pegs interfere with biofilm formation and the synergistic effect of this conditioning and hypertonic growth media on the bacterial adhesion and biofilm formation of Listeria innocua, used as a nonpathogenic surrogate for Listeria monocytogenes. PS pegs were uncoated (bare PS) or individually coated with whey proteins isolate (WPI), β-lactoglobulin, bovine serum albumin, or tryptic soy broth (TSB) and were incubated in bacterial suspensions in modified Welshimer's broth. After 4 h, the number of adherent cells was dependent on the coating, as follows: TSB (10(7) CFU/ml) > bare PS > β-lactoglobulin > bovine serum albumin ∼ WPI (10(4) CFU/ml). The sessile cell counts increased up to 24 h, reaching > 10(7) CFU per peg for all surfaces (P > 0.1), except for WPI-coated PS; this indicates that the inhibitory effects of milk protein conditioning films are transient, slowing down the adhesion process. The 4-h bacterial adhesion on milk protein-coated PS in modified Welshimer's broth supplemented with salt (0 to 10% [wt/vol]) did not vary (P > 0.1), indicating that conditioning with milk proteins was the major determinant for inhibition of bacterial adhesion and that the synergetic effect of salt and milk proteins on adhesion was minimal. Moreover, the presence of 5 to 10% salt significantly inhibited 24-h biofilm formation on the TSB-coated and bare PS, with a decrease of >3 log at 10% (wt/vol) NaCl and almost completely depleted viable sessile bacteria on the milk protein-coated PS. PMID:24674434

  9. Role of RNA and Protein Synthesis in Abscission

    PubMed Central

    Abeles, F. B.

    1968-01-01

    The cell separation aspect of abscission is thought to involve the action of specific cell wall degrading enzymes. Enzymes represent synthesis which in turn is preceded by the synthesis of specific RNA molecules, and it follows that inhibition of either of these processes would also block abscission. Since abscission is a localized phenomenon usually involving 2 or 3 cell layers, RNA and protein synthesis should also be localized. Manipulations of plant material which either accelerate or retard abscission may be due to the regulation of RNA and protein synthesis. This paper is a review of literature concerned with these and related questions. Images PMID:16657020

  10. Partial calcium depletion during membrane filtration affects gelation of reconstituted milk protein concentrates.

    PubMed

    Eshpari, H; Jimenez-Flores, R; Tong, P S; Corredig, M

    2015-12-01

    Milk protein concentrate powders (MPC) with improved rehydration properties are often manufactured using processing steps, such as acidification and high-pressure processing, and with addition of other ingredients, such as sodium chloride, during their production. These steps are known to increase the amount of serum caseins or modify the mineral equilibrium, hence improving solubility of the retentates. The processing functionality of the micelles may be affected. The aim of this study was to investigate the effects of partial acidification by adding glucono-δ-lactone (GDL) to skim milk during membrane filtration on the structural changes of the casein micelles by observing their chymosin-induced coagulation behavior, as such coagulation is affected by both the supramolecular structure of the caseins and calcium equilibrium. Milk protein concentrates were prepared by preacidification with GDL to pH 6 using ultrafiltration (UF) and diafiltration (DF) followed by spray-drying. Reconstituted UF and DF samples (3.2% protein) treated with GDL showed significantly increased amounts of soluble calcium and nonsedimentable caseins compared with their respective controls, as measured by ion chromatography and sodium dodecyl sulfate-PAGE electrophoresis, respectively. The primary phase of chymosin-induced gelation was not significantly different between treatments as measured by the amount of caseino-macropeptide released. The rheological properties of the reconstituted MPC powders were determined immediately after addition of chymosin, both before and after dialysis against skim milk, to ensure similar serum composition for all samples. Reconstituted samples before dialysis showed no gelation (defined as tan δ=1), and after re-equilibration only control UF and DF samples showed gelation. The gelation properties of reconstituted MPC powders were negatively affected by the presence of soluble casein, and positively affected by the amount of both soluble and insoluble

  11. Effects of Industrial Heating Processes of Milk-Based Enteral Formulas on Site-Specific Protein Modifications and Their Relationship to in Vitro and in Vivo Protein Digestibility.

    PubMed

    Wada, Yasuaki; Lönnerdal, Bo

    2015-08-01

    Heat treatments are applied to milk and dairy products to ensure their microbiological safety and shelf lives. Types of heating processes may have different effects on protein modifications, leading to different protein digestibility. In this study, milk-based liquid nutritional formulas (simulating enteral formulas) were subjected to steam injection ultra-high-temperature treatment or in-can sterilization, and the formulas were investigated by proteomic methods and in vitro and in vivo digestion assays. Proteomic analyses revealed that in-can sterilization resulted in higher signals for N(ε)-carboxymethyllysine and dephosphorylation of Ser residues in major milk proteins than in steam-injected formula, reflecting the more severe thermal process of in-can sterilization. In vitro and in vivo digestion assays indicated that steam injection improved protein digestibility, supposedly by denaturation, while the improvement seemed to be overwhelmed by formation of aggregates that showed resistance to digestion in in-can sterilized formula. Adverse effects of heat treatment on protein digestibility are more likely to be manifested in milk-based formulas than in cow's milk. Although the differences might be of limited significance in terms of amino acid bioavailability, these results emphasize the importance of protein quality of raw materials and selection of heating processes. PMID:26161498

  12. Efficacy of fermented milk and whey proteins in Helicobacter pylori eradication: A review

    PubMed Central

    Sachdeva, Aarti; Rawat, Swapnil; Nagpal, Jitender

    2014-01-01

    Helicobacter pylori (H. pylori) eradication is considered a necessary step in the management of peptic ulcer disease, chronic gastritis, gastric adenocarcinoma and mucosa associated lymphoid tissue lymphoma. Standard triple therapy eradication regimens are inconvenient and achieve unpredictable and often poor results. Eradication rates are decreasing over time with increase in antibiotic resistance. Fermented milk and several of its component whey proteins have emerged as candidates for complementary therapy. In this context the current review seeks to summarize the current evidence available on their role in H. pylori eradication. Pertinent narrative/systematic reviews, clinical trials and laboratory studies on individual components including fermented milk, yogurt, whey proteins, lactoferrin, α-lactalbumin (α-LA), glycomacropeptide and immunoglobulin were comprehensively searched and retrieved from Medline, Embase, Scopus, Cochrane Controlled Trials Register and abstracts/proceedings of conferences up to May 2013. A preponderance of the evidence available on fermented milk-based probiotic preparations and bovine lactoferrin suggests a beneficial effect in Helicobacter eradication. Evidence for α-LA and immunoglobulins is promising while that for glycomacropeptide is preliminary and requires substantiation. The magnitude of the potential benefit documented so far is small and the precise clinical settings are ill defined. This restricts the potential use of this group as a complementary therapy in a nutraceutical setting hinging on better patient acceptability/compliance. Further work is necessary to identify the optimal substrate, fermentation process, dose and the ideal clinical setting (prevention/treatment, first line therapy/recurrence, symptomatic/asymptomatic, gastritis/ulcer diseases etc.). The potential of this group in high antibiotic resistance or treatment failure settings presents interesting possibilities and deserves further exploration. PMID

  13. Effects of Protein Level and Mangosteen Peel Pellets (Mago-pel) in Concentrate Diets on Rumen Fermentation and Milk Production in Lactating Dairy Crossbreds

    PubMed Central

    Norrapoke, T.; Wanapat, M.; Wanapat, S.

    2012-01-01

    Four, lactating dairy crossbreds (50%×50% Holstein Friesian×Native Zebu cattle) were randomly assigned according to a 2×2 factorial arrangement (two protein levels and two levels of mangosteen peel pellets (Mago-pel)) in a 4×4 Latin square design to receive four dietary treatments. All cows received concentrate at a proportion of 1 kg concentrate per 2 kg of milk yield, and urea-treated 5% rice straw (UTRS) was given ad libitum. It was found that total dry matter intakes, nutrient digestibility, ruminal pH and NH3-N concentrations were not affected (p>0.05) by treatments. Concentrations of ruminal pH and NH3-N were not affected by dietary treatments although the concentration of BUN varied significantly (p<0.05) between protein levels (p<0.05). The populations of rumen bacteria and fungal zoospores did not differ among treatments (p>0.05); however, the population of protozoa was decreased (p<0.05) when cows received Mago-pel supplementation. The composition of the population of bacteria, identified by real-time PCR technique, including total bacteria, methanogens, Fibrobacter succinogenes and Ruminococcus albus was similar (p>0.05) among dietary treatments (p>0.05); however, copy numbers of Ruminococcus flavefaciens was increased when protein level increased (p<0.05). Microbial protein synthesis, in terms of both quantity and efficiency, was enriched by Mago-pel supplementation. Milk yield was greatest in cows fed UTRS based diets with concentrate containing protein at 16% CP with Mago-pel, but were lowest without Mago-pel (p<0.05). In addition, protein level and supplementation of Mago-pel did not affect (p>0.05) milk composition except solids-not-fat which was higher in cows fed the diet with 19% CP. Therefore, feeding a concentrate containing 16% CP together with 300 g/hd/d Mago-pel supplementation results in changes in rumen fermentation and microbial population and improvements in milk production in lactating dairy crossbreds fed on UTRS. PMID:25049652

  14. Interrelation between protein synthesis, proteostasis and life span.

    PubMed

    Arnsburg, Kristin; Kirstein-Miles, Janine

    2014-02-01

    The production of newly synthesized proteins is a key process of protein homeostasis that initiates the biosynthetic flux of proteins and thereby determines the composition, stability and functionality of the proteome. Protein synthesis is highly regulated on multiple levels to adapt the proteome to environmental and physiological challenges such as aging and proteotoxic conditions. Imbalances of protein folding conditions are sensed by the cell that then trigger a cascade of signaling pathways aiming to restore the protein folding equilibrium. One regulatory node to rebalance proteostasis upon stress is the control of protein synthesis itself. Translation is reduced as an immediate response to perturbations of the protein folding equilibrium that can be observed in the cytosol as well as in the organelles such as the endoplasmatic reticulum and mitochondria. As reduction of protein synthesis is linked to life span increase, the signaling pathways regu-lating protein synthesis might be putative targets for treatments of age-related diseases. Eukaryotic cells have evolved a complex system for protein synthesis regulation and this review will summarize cellular strategies to regulate mRNA translation upon stress and its impact on longevity. PMID:24653664

  15. Effect of adjusted pH prior to ultrafiltration of skim milk on membrane performance and physical functionality of milk protein concentrate.

    PubMed

    Luo, X; Vasiljevic, T; Ramchandran, L

    2016-02-01

    Processing conditions during ultrafiltration of skim milk influence properties of the casein micelle and thereby the physical properties of milk protein concentrate (MPC). The aim of the study was to establish the effects of pH adjustment of skim milk feed to obtain MPC with desired emulsification properties. The ultrafiltration was conducted using commercially pasteurized skim milk with the pH adjusted to 6.7 (control), 6.3, 5.9, or 5.5 at 15°C until a volume concentration factor of 5 was reached. Effects of pH adjustment on selected physico-chemical properties (Ca content, particle size, ζ-potential) and functionalities (solubility, heat stability, emulsification capacity, and stability) of MPC were determined. Lowering the feed pH solubilized colloidal calcium phosphate that substantially contributed to modifying the properties of casein. This caused a reduction in the particle size while increasing the net negative charge. The structural modifications in proteins were manifested in the Fourier transform infrared spectra. Subsequent concentration did not induce any further protein structural changes. Such modifications to the casein micelles and colloidal calcium phosphate negatively affected the solubility and heat stability of the corresponding MPC powders. However, the emulsion activity index improved only until the pH of the feed was lowered to 5.9 and declined when pH was dropped to 5.5, followed with the loss of stability. Readjusting the pH of MPC powder dispersions to 6.7 restored their surface properties and thereby their functionality. Lowering the feed pH also negatively affected the membrane performance by clogging the membrane pores and lowering the flux, particularly at pH 5.5. Adjusting pH to 5.9 produced MPC with optimum emulsifying properties with minimal influence on membrane performance. PMID:26686705

  16. Systematic microRNAome profiling reveals the roles of microRNAs in milk protein metabolism and quality: insights on low-quality forage utilization

    PubMed Central

    Wang, Diming; Liang, Guanxiang; Wang, Bing; Sun, Huizeng; Liu, Jianxin; Guan, Le Luo

    2016-01-01

    In this study, we investigated the molecular regulatory mechanisms of milk protein production in dairy cows by studying the miRNAomes of five key metabolic tissues involved in protein synthesis and metabolism from dairy cows fed high- and low-quality diets. In total, 340, 338, 337, 330, and 328 miRNAs were expressed in the rumen, duodenum, jejunum, liver, and mammary gland tissues, respectively. Some miRNAs were highly correlated with feed and nitrogen efficiency, with target genes involved in transportation and phosphorylation of amino acid (AA). Additionally, low-quality forage diets (corn stover and rice straw) influenced the expression of feed and nitrogen efficiency-associated miRNAs such as miR-99b in rumen, miR-2336 in duodenum, miR-652 in jejunum, miR-1 in liver, and miR-181a in mammary gland. Ruminal miR-21-3p and liver miR-2285f were predicted to regulate AA transportation by targeting ATP1A2 and SLC7A8, respectively. Furthermore, bovine-specific miRNAs regulated the proliferation and morphology of rumen epithelium, as well as the metabolism of liver lipids and branched-chain AAs, revealing bovine-specific mechanisms. Our results suggest that miRNAs expressed in these five tissues play roles in regulating transportation of AA for downstream milk production, which is an important mechanism that may be associated with low milk protein under low-quality forage feed. PMID:26884323

  17. Evaluation of the synergistic effects of milk proteins in a rapid viscosity analyzer.

    PubMed

    Stephani, Rodrigo; Borges de Souza, Alisson; Leal de Oliveira, Marcone Augusto; Perrone, Ítalo Tuler; Fernandes de Carvalho, Antônio; Cappa de Oliveira, Luiz Fernando

    2015-12-01

    Protein systems (PS) are routinely used by companies from Brazil and around the globe to improve the texture, yield, and palatability of processed foods. Understanding the synergistic behavior among the different protein structures of these systems during thermal treatment under the influence of pH can help to better define optimum conditions for products and processes. The interpretation of the reactions and interactions that occur simultaneously among the protein constituents of these systems as dispersions during thermal processing is still a major challenge. Here, using a rapid viscosity analyzer, we observed the rheological changes in the startup viscosities of 5 PS obtained by combining varying proportions of milk protein concentrate and whey protein concentrate under different conditions of pH (5.0, 6.5, and 7.0) and heat processing (85°C/15min and 95°C/5min). The solutions were standardized to 25% of total solids and 17% of protein. Ten analytical parameters were used to characterize each of the startup-viscosity ramps for 35 experiments conducted in a 2×3 × 5 mixed planning matrix, using principal component analysis to interpret behavioral similarities. The study showed the clear influence of pH 5.5 in the elevation of the initial temperature of the PS startup viscosity by at least 5°C, as well as the effect of different milk protein concentrate:whey protein concentrate ratios above 15:85 at pH 7.0 on the viscographic profile curves. These results suggested that the primary agent driving the changes was the synergism among the reactions and interactions of casein with whey proteins during processing. This study reinforces the importance of the rapid viscosity analyzer as an analytical tool for the simulation of industrial processes involving PS, and the use of the startup viscosity ramp as a means of interpreting the interactions of system components with respect to changes related to the treatment temperature. PMID:26409966

  18. Endogenous Human Milk Peptide Release Is Greater after Preterm Birth than Term Birth123

    PubMed Central

    Dallas, David C; Smink, Christina J; Robinson, Randall C; Tian, Tian; Guerrero, Andres; Parker, Evan A; Smilowitz, Jennifer T; Hettinga, Kasper A; Underwood, Mark A; Lebrilla, Carlito B; German, J Bruce; Barile, Daniela

    2015-01-01

    Background: Hundreds of naturally occurring milk peptides are present in term human milk. Preterm milk is produced before complete maturation of the mammary gland, which could change milk synthesis and secretion processes within the mammary gland, leading to differences in protein expression and enzymatic activity, thereby resulting in an altered peptide profile. Objective: This study examined differences in peptides present between milk from women delivering at term and women delivering prematurely. Methods: Nano-LC tandem mass spectrometry was employed to identify naturally occurring peptides and compare their abundances between term and preterm human milk samples at multiple time points over lactation. Term milk samples were collected from 8 mothers and preterm milk was collected from 14 mothers. The 28 preterm and 32 term human milk samples were divided into 4 groups based on day of collection (<14, 14–28, 29–41, and 42–58 d). Results: Preterm milk peptide counts, ion abundance, and concentration were significantly higher in preterm milk than term milk. Bioinformatic analysis of the cleavage sites for peptides identified suggested that plasmin was more active in preterm milk than term milk and that cytosol aminopeptidase and carboxypeptidase B2 likely contribute to extensive milk protein breakdown. Many identified milk peptides in both term and preterm milk overlapped with known functional peptides, including antihypertensive, antimicrobial, and immunomodulatory peptides. Conclusion: The high protein degradation by endogenous proteases in preterm milk might attenuate problems because of the preterm infant’s immature digestive system. This trial was registered at clinicaltrials.gov as NCT01817127. PMID:25540406

  19. Symposium: Role of the extracellular matrix in mammary development. Regulation of milk protein and basement membrane gene expression: The influence of the extracellular matrix

    SciTech Connect

    Aggeler, J.; Park, C.S.; Bissell, M.J.

    1988-10-01

    Synthesis and secretion of milk proteins ({alpha}-casein, {beta}-casein, {gamma}-casein, and transferrin) by cultured primary mouse mammary epithelial cells is modulated by the extracellular matrix. In cells grown on released or floating type I collagen gels, mRNA for {beta}-casein and transferrin is increased as much as 30-fold over cells grown on plastic. Induction of {beta}-casein expression depends strongly on the presence of lactogenic hormones, especially prolactin, in the culture. When cells are plated onto partially purified reconstituted basement membrane, dramatic changes in morphology and milk protein gene expression are observed. Cells cultured on the matrix for 6 to 8 d in the presence of prolactin, insulin, and hydrocortisone form hollow spheres and duct-like structures that are completely surrounded by matrix. The cells lining these spheres appear actively secretory and are oriented with their apices facing the lumen. Hybridization experiments indicate that mRNA for {beta}-casein can be increased as much as 70-fold in these cultures. Because > 90% of the cultured cells synthesize immunoreactive {beta}-casein, as compared with only 40% of cells in the late pregnant gland, the matrix appears to be able to induce protein expression in previously silent cells. Synthesis of laminin and assembly of a mammary-specific basal lamina by cells cultured on different extracellular matrices also appears to depend on the presence of lactogenic hormones. These studies provide support for the concept of dynamic reciprocity in which complex interactions between extracellular matrix and the cellular cytoskeleton contribute to the induction and maintenance of tissue-specific gene expression in the mammary gland.

  20. The rapid determination of fat and protein content in fresh raw milk using the laser light scattering technology

    NASA Astrophysics Data System (ADS)

    Xin, Qi; Zhi Ling, Hou; Jian Long, Tian; Zhu, Yu

    2006-08-01

    The aim was to develop a simple and rapid method for determination of fat and protein content in milk. Based on the laser light scattering theory, the ratio of the scattered light (at 90±0.05° scattering angles) intensity to the transmitted light intensity, which is called scattered-transmitted-ratio method, is adopted as the optical parameter representing the milk fat content and the protein content. In this way, the influence of the fluctuation of the power of the light source is eliminated and the accuracy of determination is improved accordingly. The system we use is real-time and can satisfy the challenging requirements of dairy farming. Results of this study indicate the feasibility of using this technology for fresh milk fat and protein analysis. The fat contents and protein contents of 50 milk samples determined by this method were consistent with the values obtained by the reference methods based on Rose-Gottlieb method and Kjeldahl determination of N method. In this paper, the operating principle of the instrument is introduced and the influence of the environmental conditions, such as the homogenization pressure and homogenization temperature, etc. on the result of the test is analyzed. Through data analysis, the concrete schemes for testing the fat using the curve fitting and testing the protein using the surface fitting technique are determined. Finally, the difference from the reference values of the test is discussed.

  1. Predictors of Muscle Protein Synthesis after Severe Pediatric Burns

    PubMed Central

    Diaz, Eva C.; Herndon, David N.; Lee, Jinhyung; Porter, Craig; Cotter, Matthew; Suman, Oscar E.; Sidossis, Labros S.; Børsheim, Elisabet

    2015-01-01

    Background Following a major burn, skeletal muscle protein synthesis rate increases, but is often insufficient to compensate for massively elevated muscle protein breakdown rates. Given the long-term nature of the pathophysiologic response to burn injury, we hypothesized that muscle protein synthesis rate would be chronically elevated in severely burned children. The objectives of this study were to characterize muscle protein synthesis rate of burned children over a period of 24 months post-injury, and identify predictors that influence this response. Study design 87 children with ≥40% total body surface area (TBSA) burn were included. Patients participated in stable isotope infusion studies at 1, 2 and ~ 4 weeks post-burn, and at 6, 12 and 24 months post-injury to determine skeletal muscle fractional synthesis rate. Generalized estimating equations with log link normal distribution were applied to account for clustering of patients and control for patient characteristics. Results Patients (8±6 years) had large (62, 51–72% TBSA) and deep (47±21% TBSA third degree) burns. Muscle fractional synthesis rate was elevated throughout the first 12 months post-burn compared to established values from healthy young adults. Muscle fractional synthesis rate was lower in boys, children >3 years old, and when burns were >80% TBSA. Conclusions Muscle protein synthesis is elevated for at least one year after injury, suggesting that greater muscle protein turnover is a component of the long-term pathophysiological response to burn trauma. Muscle protein synthesis is highly affected by gender, age and burn size in severely burned children. These findings may explain the divergence in net protein balance and lean body mass in different populations of burn victims. PMID:25807408

  2. Engineering protein processing of the mammary gland to produce abundant hemophilia B therapy in milk

    PubMed Central

    Zhao, Jianguo; Xu, Weijie; Ross, Jason W.; Walters, Eric M.; Butler, Stephen P.; Whyte, Jeff J.; Kelso, Lindsey; Fatemi, Mostafa; Vanderslice, Nicholas C.; Giroux, Keith; Spate, Lee D.; Samuel, Melissa S.; Murphy, Cliff N.; Wells, Kevin D.; Masiello, Nick C.; Prather, Randall S.; Velander, William H.

    2015-01-01

    Both the low animal cell density of bioreactors and their ability to post-translationally process recombinant factor IX (rFIX) limit hemophilia B therapy to <20% of the world’s population. We used transgenic pigs to make rFIX in milk at about 3,000-fold higher output than provided by industrial bioreactors. However, this resulted in incomplete γ-carboxylation and propeptide cleavage where both processes are transmembrane mediated. We then bioengineered the co-expression of truncated, soluble human furin (rFurin) with pro-rFIX at a favorable enzyme to substrate ratio. This resulted in the complete conversion of pro-rFIX to rFIX while yielding a normal lactation. Importantly, these high levels of propeptide processing by soluble rFurin did not preempt γ-carboxylation in the ER and therefore was compartmentalized to the Trans-Golgi Network (TGN) and also to milk. The Golgi specific engineering demonstrated here segues the ER targeted enhancement of γ-carboxylation needed to biomanufacture coagulation proteins like rFIX using transgenic livestock. PMID:26387706

  3. Engineering protein processing of the mammary gland to produce abundant hemophilia B therapy in milk.

    PubMed

    Zhao, Jianguo; Xu, Weijie; Ross, Jason W; Walters, Eric M; Butler, Stephen P; Whyte, Jeff J; Kelso, Lindsey; Fatemi, Mostafa; Vanderslice, Nicholas C; Giroux, Keith; Spate, Lee D; Samuel, Melissa S; Murphy, Cliff N; Wells, Kevin D; Masiello, Nick C; Prather, Randall S; Velander, William H

    2015-01-01

    Both the low animal cell density of bioreactors and their ability to post-translationally process recombinant factor IX (rFIX) limit hemophilia B therapy to <20% of the world's population. We used transgenic pigs to make rFIX in milk at about 3,000-fold higher output than provided by industrial bioreactors. However, this resulted in incomplete γ-carboxylation and propeptide cleavage where both processes are transmembrane mediated. We then bioengineered the co-expression of truncated, soluble human furin (rFurin) with pro-rFIX at a favorable enzyme to substrate ratio. This resulted in the complete conversion of pro-rFIX to rFIX while yielding a normal lactation. Importantly, these high levels of propeptide processing by soluble rFurin did not preempt γ-carboxylation in the ER and therefore was compartmentalized to the Trans-Golgi Network (TGN) and also to milk. The Golgi specific engineering demonstrated here segues the ER targeted enhancement of γ-carboxylation needed to biomanufacture coagulation proteins like rFIX using transgenic livestock. PMID:26387706

  4. Insulin-like growth factor-I and insulin-like growth factor binding proteins in the bovine mammary gland: Receptors, endogenous secretion, and appearance in milk

    SciTech Connect

    Campbell, P.G.

    1988-01-01

    This is the first study to characterize both insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) in bovine milk, to characterize the IGF-I receptor in the dry and lactating mammary gland, and to report de novo synthesis and secretion of IGF-I and IGFBP from normal mammary tissue. Immunoreactive IGF-I was principally associated with 45 kDa IGFBP in milk. Multiparous cows had a higher IGF-I concentration of 307 ng/ml than primiparous cows at 147 ng/ml. IGF-I concentration on day 56 of lactation was 34 ng/ml for combined parity groups. At parturition, IGF-I mass in blood and milk pools was 1.4 and 1.2 mg, respectively. Binding of {sup 125}I-IGF-I was specific for IGF-I with anIC{sub 50} of 2.2 ng which was a 10- and 1273-fold greater affinity than IGF-II and insulin, respectively. Association constants, as determined by Scatchard analysis, were similar for both pregnant and lactating cows at 3.5 and 4.0 L/nM, respectively. In addition, estimated mean receptor concentration was 0.25 and 0.23 pM/mg protein for pregnant and lactating cows, respectively. In a survey of mammary microscomes prepared from 48 cows, {sup 125}I-IGF-I binding declined with progressing lactation and a similar trend was observed during pregnancy.

  5. Cow's milk protein sensitivity assessed by the mucosal patch technique is related to irritable bowel syndrome in patients with primary Sjögren's syndrome

    PubMed Central

    Lidén, M; Kristjánsson, G; Valtysdottir, S; Venge, P; Hällgren, R

    2008-01-01

    Introduction Patients with primary Sjögren's syndrome (pSS) are reported to have a variety of gastrointestinal symptoms partly attributed to an overrepresentation of celiac disease. We have observed that irritable bowel syndrome (IBS)-like symptoms are frequent complaints in this patient group. Allergic manifestations to various drugs are also common in pSS. A role of food allergy in IBS has been proposed. Objective This study is aimed at evaluating the mucosal response to rectal challenge with cow's milk protein (CM) in patients with pSS and relates possible CM reactivity to their intestinal symptoms. Methods A rectal challenge with CM was performed in 21 patients with pSS and 18 healthy controls. Fifteen hours after challenge the mucosal production of nitric oxide (NO) and the release of myeloperoxidase (MPO) as signs of mucosal inflammatory reaction were measured using the mucosal patch technique. Results Eight out of 21 patients with pSS had a definite increase of mucosal NO synthesis and the luminal release of MPO after rectal CM challenge. This sign of milk sensitivity was not linked to IgG/IgA antibodies to milk proteins. The symptoms for IBS according to Rome III criteria were fulfilled in 13 patients. All patients who were CM sensitive suffered from IBS. In a small open study, patients reactive to CM reported an improvement of intestinal symptoms on a CM-free diet. Conclusion A rectal mucosal inflammatory response after CM challenge is seen in 38% of patients with pSS as a sign of CM sensitivity. IBS-like symptoms were common in pSS, linked to CM sensitivity. PMID:18498540

  6. Effects of sterilization, packaging, and storage on vitamin C degradation, protein denaturation, and glycation in fortified milks.

    PubMed

    Gliguem, H; Birlouez-Aragon, I

    2005-03-01

    Monitoring the nutritional quality of dietetic milk throughout its shelf life is particularly important due to the high susceptibility of some vitamins to oxidation, and the continuous development of the Maillard reaction during storage. The objective of this paper was to evaluate the vitamin C content and protein modification by denaturation and glycation on fortified milk samples (growth milks) destined for 1- to 3-yr-old children. The influences of the sterilization process, formulation, packaging, and storage duration at ambient temperature in the dark were studied. Vitamin C degradation was particularly influenced by type of packaging. The use of a 3-layered opaque bottle was associated with complete oxidation of vitamin C after 1 mo of storage, whereas in the 6-layered opaque bottle, which has an oxygen barrier, the vitamin C content slowly decreased to reach 25% of the initial concentration after 4 mo of storage. However, no significant effect of vitamin C degradation during storage could be observed in terms of Maillard reaction, despite the fact that a probable impact occurred during sterilization. Furosine content and the FAST (fluorescence of advanced Maillard products and soluble tryptophan) index-indicators of the early and advanced Maillard reaction, respectively-were significantly higher in the in-bottle sterilized milk samples compared with UHT samples, and in fortified milk samples compared with cow milk. However, after 1 mo, the impact of storage was predominant, increasing the furosine level and the FAST index at similar levels for the differently processed samples. The early Maillard reaction developed continuously throughout the storage period.In conclusion, only packaging comprising an oxygen and light barrier is compatible with vitamin C fortification of milk. Furthermore, short storage time or low storage temperature is needed to retard vitamin C degradation, protein denaturation, and development of the Maillard reaction. PMID:15738222

  7. Protein chemical synthesis by α-ketoacid-hydroxylamine ligation.

    PubMed

    Harmand, Thibault J; Murar, Claudia E; Bode, Jeffrey W

    2016-06-01

    Total chemical synthesis of proteins allows researchers to custom design proteins without the complex molecular biology that is required to insert non-natural amino acids or the biocontamination that arises from methods relying on overexpression in cells. We describe a detailed procedure for the chemical synthesis of proteins with the α-ketoacid-hydroxylamine (KAHA ligation), using (S)-5-oxaproline (Opr) as a key building block. This protocol comprises two main parts: (i) the synthesis of peptide fragments by standard fluorenylmethoxycarbonyl (Fmoc) chemistry and (ii) the KAHA ligation between fragments containing Opr and a C-terminal peptide α-ketoacid. This procedure provides an alternative to native chemical ligation (NCL) that could be valuable for the synthesis of proteins, particularly targets that do not contain cysteine residues. The ligation conditions-acidic DMSO/H2O or N-methyl-2-pyrrolidinone (NMP)/H2O-are ideally suited for solubilizing peptide segments, including many hydrophobic examples. The utility and efficiency of the protocol is demonstrated by the total chemical synthesis of the mature betatrophin (also called ANGPTL8), a 177-residue protein that contains no cysteine residues. With this protocol, the total synthesis of the betatrophin protein has been achieved in around 35 working days on a multimilligram scale. PMID:27227514

  8. Circulating protein synthesis rates reveal skeletal muscle proteome dynamics.

    PubMed

    Shankaran, Mahalakshmi; King, Chelsea L; Angel, Thomas E; Holmes, William E; Li, Kelvin W; Colangelo, Marc; Price, John C; Turner, Scott M; Bell, Christopher; Hamilton, Karyn L; Miller, Benjamin F; Hellerstein, Marc K

    2016-01-01

    Here, we have described and validated a strategy for monitoring skeletal muscle protein synthesis rates in rodents and humans over days or weeks from blood samples. We based this approach on label incorporation into proteins that are synthesized specifically in skeletal muscle and escape into the circulation. Heavy water labeling combined with sensitive tandem mass spectrometric analysis allowed integrated synthesis rates of proteins in muscle tissue across the proteome to be measured over several weeks. Fractional synthesis rate (FSR) of plasma creatine kinase M-type (CK-M) and carbonic anhydrase 3 (CA-3) in the blood, more than 90% of which is derived from skeletal muscle, correlated closely with FSR of CK-M, CA-3, and other proteins of various ontologies in skeletal muscle tissue in both rodents and humans. Protein synthesis rates across the muscle proteome generally changed in a coordinate manner in response to a sprint interval exercise training regimen in humans and to denervation or clenbuterol treatment in rodents. FSR of plasma CK-M and CA-3 revealed changes and interindividual differences in muscle tissue proteome dynamics. In human subjects, sprint interval training primarily stimulated synthesis of structural and glycolytic proteins. Together, our results indicate that this approach provides a virtual biopsy, sensitively revealing individualized changes in proteome-wide synthesis rates in skeletal muscle without a muscle biopsy. Accordingly, this approach has potential applications for the diagnosis, management, and treatment of muscle disorders. PMID:26657858

  9. Circulating protein synthesis rates reveal skeletal muscle proteome dynamics

    PubMed Central

    Shankaran, Mahalakshmi; King, Chelsea L.; Angel, Thomas E.; Holmes, William E.; Li, Kelvin W.; Colangelo, Marc; Price, John C.; Turner, Scott M.; Bell, Christopher; Hamilton, Karyn L.; Miller, Benjamin F.; Hellerstein, Marc K.

    2015-01-01

    Here, we have described and validated a strategy for monitoring skeletal muscle protein synthesis rates in rodents and humans over days or weeks from blood samples. We based this approach on label incorporation into proteins that are synthesized specifically in skeletal muscle and escape into the circulation. Heavy water labeling combined with sensitive tandem mass spectrometric analysis allowed integrated synthesis rates of proteins in muscle tissue across the proteome to be measured over several weeks. Fractional synthesis rate (FSR) of plasma creatine kinase M-type (CK-M) and carbonic anhydrase 3 (CA-3) in the blood, more than 90% of which is derived from skeletal muscle, correlated closely with FSR of CK-M, CA-3, and other proteins of various ontologies in skeletal muscle tissue in both rodents and humans. Protein synthesis rates across the muscle proteome generally changed in a coordinate manner in response to a sprint interval exercise training regimen in humans and to denervation or clenbuterol treatment in rodents. FSR of plasma CK-M and CA-3 revealed changes and interindividual differences in muscle tissue proteome dynamics. In human subjects, sprint interval training primarily stimulated synthesis of structural and glycolytic proteins. Together, our results indicate that this approach provides a virtual biopsy, sensitively revealing individualized changes in proteome-wide synthesis rates in skeletal muscle without a muscle biopsy. Accordingly, this approach has potential applications for the diagnosis, management, and treatment of muscle disorders. PMID:26657858

  10. Comparative Protein Composition Analysis of Goat Milk Produced by the Alpine and Saanen Breeds in Northeastern Brazil and Related Antibacterial Activities

    PubMed Central

    da Costa, Whyara Karoline Almeida; de Souza, Evandro Leite; Beltrão-Filho, Edvaldo Mesquita; Vasconcelos, Gracy Kelly Vieira; Santi-Gadelha, Tatiane; de Almeida Gadelha, Carlos Alberto; Franco, Octavio Luiz; Magnani, Marciane

    2014-01-01

    The protein composition of goat milk differs between goat breeds and could present regional trends. The aim of this study was to comparatively analyze the protein composition of goat milk produced by the Alpine and Saanen breeds in northeastern Brazil and to evaluate the antibacterial activity of its protein fractions. SDS-PAGE, 2-DE electrophoresis and RP-HPLC analyses revealed the absence of αs1-casein in the milk of both breeds and no differences between the αs2-casein, β-casein, β-lactoglobulin and α-lactalbumin profiles. The amounts of soluble proteins and β-casein hydrolysis residues were higher in Saanen milk. Only the protein fraction containing the largest amounts of casein (F60–90%) inhibited bacterial growth, with MIC values between 50 and 100 mg/mL. This study describe for the first time three important points about the goat milk protein of two Brazilian goat breeders: absence of α-s1 casein in the protein profile, differences between the milk protein composition produced by goats of Alpine and Saanen breeders and antibacterial activity of unbroken proteins (casein-rich fraction) present in these milk. PMID:24675996

  11. Temperature-Regulated Protein Synthesis by Leptospira interrogans

    PubMed Central

    Nally, Jarlath E.; Timoney, John F.; Stevenson, Brian

    2001-01-01

    Leptospira interrogans is an important mammalian pathogen. Transmission from an environmental source requires adaptations to a range of new environmental conditions in the organs and tissues of the infected host. Since many pathogenic bacteria utilize temperature to discern their environment and regulate the synthesis of appropriate proteins, we investigated the effects of temperature on protein synthesis in L. interrogans. Bacteria were grown for several days after culture temperatures were shifted from 30 to 37°C. Triton X-114 cellular fractionation identified several proteins of the cytoplasm, periplasm, and outer membrane for which synthesis was dependent on the culture temperature. Synthesis of a cytoplasmic protein of 20 kDa was switched off at 37°C, whereas synthesis of a 66-kDa periplasmic protein was increased at the higher temperature. Increased synthesis of a 25-kDa outer membrane protein was observed when the organisms were shifted from 30 to 37°C. A 36-kDa protein synthesized at 30 but not at 37°C was identified as LipL36, an outer membrane lipoprotein. In contrast, expression of another lipoprotein, LipL41, was the same at either temperature. Immunoblotting with convalescent equine sera revealed that some proteins exhibiting thermoregulation of synthesis elicited antibody responses during infection. Our results show that sera from horses which aborted as a result of naturally acquired infection with L. interrogans serovar pomona type kennewicki recognize periplasmic and outer membrane proteins which are differentially synthesized in response to temperature and which therefore may be important in the host-pathogen interaction during infection. PMID:11119530

  12. Preheated milk proteins improve the stability of grape skin anthocyanins extracts.

    PubMed

    He, Zhiyong; Xu, Mingzhu; Zeng, Maomao; Qin, Fang; Chen, Jie

    2016-11-01

    The effects of casein and whey proteins, preheated at 40-100°C and 45-60°C for 15min, respectively, on color loss and anthocyanins degradation in grape skin anthocyanins extracts (GSAE) at pH 3.2 and 6.3 were evaluated. Preheating milk proteins effectively improved their protective effects against color loss and anthocyanins degradation in GSAE solutions during thermal treatment (at 80°C for 2h), H2O2 oxidation (0.005% H2O2 for 1h) and illumination (at 5000lx for 5 d). Whey proteins and casein, preheated at 50°C and 60°C for 15min, respectively, demonstrated the optimal protective effects. However, preheated whey proteins had a better protective effect on the thermal, oxidation and photo stability of GSAE, decreasing the thermal, oxidative and photo degradation of anthocyanins in GSAE 71.59%, 32.22% and 56.92% at pH 3.2 and 54.91%, 22.89% and 46.68% at pH 6.3, respectively. PMID:27211641

  13. Identification of Escherichia coli F4ac-binding proteins in porcine milk fat globule membrane.

    PubMed

    Novakovic, Predrag; Huang, Yanyun Y; Lockerbie, Betty; Shahriar, Farshid; Kelly, John; Gordon, John R; Middleton, Dorothy M; Loewen, Matthew E; Kidney, Beverly A; Simko, Elemir

    2015-04-01

    F4ac-positive enterotoxigenic Escherichia coli (ETEC) must attach to the intestinal mucosa to cause diarrhea in piglets. Prevention of bacterial attachment to the intestinal mucosa is the most effective defense against ETEC-induced diarrhea. Porcine milk fat globule membranes (MFGM) were shown to be able to inhibit attachment of ETEC to the intestinal brush border; however, the specific components of porcine MFGM that inhibited attachment of ETEC to enterocytes were not identified. Accordingly, the purpose of this study was to identify F4ac-binding MFGM proteins by overlay Western blot and affinity chromatography. The proteome of porcine MFGM was characterized and the following F4ac-binding proteins were detected by overlay Western blot and affinity chromatography: lactadherin, butyrophilin, adipophilin, acyl-CoA synthetase 3, and fatty acid-binding protein 3. The biological function of these proteins was not investigated but it is possible that their interaction with F4ac fimbria interferes with bacterial attachment and colonization. PMID:25852227

  14. Identification of Escherichia coli F4ac-binding proteins in porcine milk fat globule membrane

    PubMed Central

    Novakovic, Predrag; Huang, Yanyun Y.; Lockerbie, Betty; Shahriar, Farshid; Kelly, John; Gordon, John R.; Middleton, Dorothy M.; Loewen, Matthew E.; Kidney, Beverly A.; Simko, Elemir

    2015-01-01

    F4ac-positive enterotoxigenic Escherichia coli (ETEC) must attach to the intestinal mucosa to cause diarrhea in piglets. Prevention of bacterial attachment to the intestinal mucosa is the most effective defense against ETEC-induced diarrhea. Porcine milk fat globule membranes (MFGM) were shown to be able to inhibit attachment of ETEC to the intestinal brush border; however, the specific components of porcine MFGM that inhibited attachment of ETEC to enterocytes were not identified. Accordingly, the purpose of this study was to identify F4ac-binding MFGM proteins by overlay Western blot and affinity chromatography. The proteome of porcine MFGM was characterized and the following F4ac-binding proteins were detected by overlay Western blot and affinity chromatography: lactadherin, butyrophilin, adipophilin, acyl-CoA synthetase 3, and fatty acid-binding protein 3. The biological function of these proteins was not investigated but it is possible that their interaction with F4ac fimbria interferes with bacterial attachment and colonization. PMID:25852227

  15. Freeze-drying of “pearl milk tea”: A general strategy for controllable synthesis of porous materials

    NASA Astrophysics Data System (ADS)

    Zhou, Yingke; Tian, Xiaohui; Wang, Pengcheng; Hu, Min; Du, Guodong

    2016-05-01

    Porous materials have been widely used in many fields, but the large-scale synthesis of materials with controlled pore sizes, pore volumes, and wall thicknesses remains a considerable challenge. Thus, the controllable synthesis of porous materials is of key general importance. Herein, we demonstrate the “pearl milk tea” freeze-drying method to form porous materials with controllable pore characteristics, which is realized by rapidly freezing the uniformly distributed template-containing precursor solution, followed by freeze-drying and suitable calcination. This general and convenient method has been successfully applied to synthesize various porous phosphate and oxide materials using different templates. The method is promising for the development of tunable porous materials for numerous applications of energy, environment, and catalysis, etc.

  16. Freeze-drying of “pearl milk tea”: A general strategy for controllable synthesis of porous materials

    PubMed Central

    Zhou, Yingke; Tian, Xiaohui; Wang, Pengcheng; Hu, Min; Du, Guodong

    2016-01-01

    Porous materials have been widely used in many fields, but the large-scale synthesis of materials with controlled pore sizes, pore volumes, and wall thicknesses remains a considerable challenge. Thus, the controllable synthesis of porous materials is of key general importance. Herein, we demonstrate the “pearl milk tea” freeze-drying method to form porous materials with controllable pore characteristics, which is realized by rapidly freezing the uniformly distributed template-containing precursor solution, followed by freeze-drying and suitable calcination. This general and convenient method has been successfully applied to synthesize various porous phosphate and oxide materials using different templates. The method is promising for the development of tunable porous materials for numerous applications of energy, environment, and catalysis, etc. PMID:27193866

  17. Comparison of analytical and predictive methods for water, protein, fat, sugar, and gross energy in marine mammal milk.

    PubMed

    Oftedal, O T; Eisert, R; Barrell, G K

    2014-01-01

    Mammalian milks may differ greatly in composition from cow milk, and these differences may affect the performance of analytical methods. High-fat, high-protein milks with a preponderance of oligosaccharides, such as those produced by many marine mammals, present a particular challenge. We compared the performance of several methods against reference procedures using Weddell seal (Leptonychotes weddellii) milk of highly varied composition (by reference methods: 27-63% water, 24-62% fat, 8-12% crude protein, 0.5-1.8% sugar). A microdrying step preparatory to carbon-hydrogen-nitrogen (CHN) gas analysis slightly underestimated water content and had a higher repeatability relative standard deviation (RSDr) than did reference oven drying at 100°C. Compared with a reference macro-Kjeldahl protein procedure, the CHN (or Dumas) combustion method had a somewhat higher RSDr (1.56 vs. 0.60%) but correlation between methods was high (0.992), means were not different (CHN: 17.2±0.46% dry matter basis; Kjeldahl 17.3±0.49% dry matter basis), there were no significant proportional or constant errors, and predictive performance was high. A carbon stoichiometric procedure based on CHN analysis failed to adequately predict fat (reference: Röse-Gottlieb method) or total sugar (reference: phenol-sulfuric acid method). Gross energy content, calculated from energetic factors and results from reference methods for fat, protein, and total sugar, accurately predicted gross energy as measured by bomb calorimetry. We conclude that the CHN (Dumas) combustion method and calculation of gross energy are acceptable analytical approaches for marine mammal milk, but fat and sugar require separate analysis by appropriate analytic methods and cannot be adequately estimated by carbon stoichiometry. Some other alternative methods-low-temperature drying for water determination; Bradford, Lowry, and biuret methods for protein; the Folch and the Bligh and Dyer methods for fat; and enzymatic and reducing

  18. The origin of polynucleotide-directed protein synthesis

    NASA Technical Reports Server (NTRS)

    Orgel, Leslie E.

    1989-01-01

    If protein synthesis evolved in an RNA world it was probably preceded by simpler processes by means of which interaction with amino acids conferred selective advantage on replicating RNA molecules. It is suggested that at first the simple attachment of amino acids to the 2'(3') termini of RNA templates favored initiation of replication at the end of the template rather than at internal positions. The second stage in the evolution of protein synthesis would probably have been the association of pairs of charged RNA adaptors in such a way as to favor noncoded formation of peptides. Only after this process had become efficient could coded synthesis have begun.

  19. EFFECTS OF ATRAZINE AND AN ATRAZINE METABOLITE MIXTURE ON DIFFERENTIATED MAMMARY EPITHELIAL CELL MILK PROTEIN PRODUCTION IN CULTURE

    EPA Science Inventory

    Effects of Atrazine and an Atrazine Metabolite Mixture on Differentiated Mammary Epithelial Cell Milk Protein Production in Culture

    E.P. Hines, R. Barbee, M. Blanton, M.S. Pooler, and S.E. Fenton. US EPA, ORD/NHEERL, RTD, RTP, NC, 27711, USA.

    Previous studies have ...

  20. Clinical course of cow's milk protein allergy/intolerance and atopic diseases in childhood.

    PubMed

    Høst, Arne; Halken, Susanne; Jacobsen, Hans P; Christensen, Anne E; Herskind, Anne M; Plesner, Karin

    2002-01-01

    A cohort of 1,749 newborns from the municipality of Odense, born during 1995 at the Odense University Hospital, were followed up prospectively for the development of cow's milk protein allergy/intolerance (CMPA/I) during the first year of life. Once a diagnosis of CMPA/I was confirmed, a milk-free diet was continued until a new milk challenge had shown development of tolerance. All infants with CMPA/I were rechallenged at 12 months of age and, in the event of continued clinical sensitivity to cow's milk protein, controlled rechallenges were performed every 6 months up to 3 years of age; and thereafter every 12 months until the age of 15 years. From the same birth cohort, 276 infants were randomly selected at birth for prospective non-interventional follow-up in order to investigate the natural course of sensitization and development of atopic disease during childhood. Standardized questionnaires on atopic heredity, environmental factors and presence of atopic symptoms were answered at 0, 6, 12 and 18 months and at 5, 10 and 15 years of age. Interviews on atopic history and environmental factors as well as physical examination were carried out at 18 months, 5, 10 and 15 years of age. Skin prick test and specific sIgE (Pharmacia CAP) testing were performed at 18 months, 5, 10 and 15 years of age against a panel of inhalant allergens (birch, grass, mugwort, dog, cat, horse, Dermatophagoidespteronyssinus, Dermatophagoides farinae, alternaria and cladosporium herbarum). Furthermore, lung function measurements were performed in children when 10 and 15 years of age. Based on controlled milk elimination and challenge procedures, the diagnosis of CMPA/I was confirmed in 39 out of 117 infants, with symptoms suggestive of CMPA/I, thus resulting in a 1-year incidence of CMPA/I of 2.2%. The overall prognosis of CMPA/I was good, with a total recovery of 56% at 1 year, 77% at 2 years, 87% at 3 years, 92% at 5 and 10 years and 97% at 15 years of age. In children younger than 10

  1. Textural performance of crosslinked or reduced-calcium milk protein ingredients in model high-protein nutrition bars.

    PubMed

    Banach, J C; Clark, S; Metzger, L E; Lamsal, B P

    2016-08-01

    Transglutaminase (Tgase) crosslinking and calcium reduction were investigated as ways to improve the texture and storage stability of high-protein nutrition (HPN) bars formulated with milk protein concentrate (MPC) and micellar casein concentrate (MCC). The MPC and MCC crosslinked at none, low, and high levels, and a reduced-calcium MPC (RCMPC) were each formulated into model HPN bars. Hardness, crumbliness, moisture content, pH, color, and water activity of the HPN bars were measured during accelerated storage. The HPN bars prepared with MPC were harder and more cohesive than those prepared with MCC. Higher levels of Tgase crosslinking improved HPN bar cohesiveness and decreased hardening during storage. The RCMPC produced softer, yet crumblier HPN bars. Small textural differences were observed for the HPN bars formulated with the transglutaminase crosslinked proteins or RCMPC when compared with their respective controls. However, modification only slightly improved protein ingredient ability to slow hardening while balancing cohesion and likely requires further improvement for increased applicability in soft-texture HPN bars. PMID:27236767

  2. Nontargeted detection of adulteration of skim milk powder with foreign proteins using UHPLC-UV.

    PubMed

    Jablonski, Joseph E; Moore, Jeffrey C; Harnly, James M

    2014-06-01

    Chromatographic profiles of skim milk powder (SMP) and mixtures of SMP with soy (SPI), pea (PPI), brown rice (BRP), and hydrolyzed wheat protein (HWPI) isolates were obtained by ultrahigh-performance liquid chromatography (UHPLC) with 215 nm detection. Two data analysis approaches were compared for their utility to classify samples as authentic or adulterated. The t test approach evaluated data points exceeding the 99% confidence limit of the mean authentic SMP chromatogram and used data points from the entire chromatogram. The other approach used the multivariate Q statistic from a SIMCA model of authentic samples to determine adulteration and used a selected retention window to obtain best classifications. Q-Statistic and t test correctly classified adulteration of SMP with SPI at the 1% and 3% levels, respectively, while minimizing false classifications of authentic SMP. Detection of SMP adulterated with PPI, BRP, and HWPI was possible at higher adulteration levels. PMID:24811490

  3. Adeno-associated virus rep protein synthesis during productive infection

    SciTech Connect

    Redemann, B.E.; Mendelson, E.; Carter, B.J.

    1989-02-01

    Adeno-associated virus (AAV) Rep proteins mediate viral DNA replication and can regulate expression from AAV genes. The authors studied the kinetics of synthesis of the four Rep proteins, Rep78, Rep68, Rep52, and Rep40, during infection of human 293 or KB cells with AAV and helper adenovirus by in vivo labeling with (/sup 35/S)methionine, immunoprecipitation, and immunoblotting analyses. Rep78 and Rep52 were readily detected concomitantly with detection of viral monomer duplex DNA replicating about 10 to 12 h after infection, and Rep68 and Rep40 were detected 2 h later. Rep78 and Rep52 were more abundant than Rep68 and Rep40 owing to a higher synthesis rate throughout the infectious cycle. In some experiments, very low levels of Rep78 could be detected as early as 4 h after infection. The synthesis rates of Rep proteins were maximal between 14 and 24 h and then decreased later after infection. Isotopic pulse-chase experiments showed that each of the Rep proteins was synthesized independently and was stable for at least 15 h. A slower-migrating, modified form of Rep78 was identified late after infection. AAV capsid protein synthesis was detected at 10 to 12 h after infection and also exhibited synthesis kinetics similar to those of the Rep proteins. AAV DNA replication showed at least two clearly defined stages. Bulk duplex replicating DNA accumulation began around 10 to 12 h and reached a maximum level at about 20 h when Rep and capsid protein synthesis was maximal. Progeny single-stranded DNA accumulation began about 12 to 13 h, but most of this DNA accumulated after 24 h when Rep and capsid protein synthesis had decreased.

  4. Identification of a functional SNP in the 3'-UTR of caprine MTHFR gene that is associated with milk protein levels.

    PubMed

    An, Xiaopeng; Song, Yuxuan; Hou, Jinxing; Wang, Shan; Gao, Kexin; Cao, Binyun

    2016-08-01

    Xinong Saanen (n = 305) and Guanzhong (n = 317) dairy goats were used to detect SNPs in the caprine MTHFR 3'-UTR by DNA sequencing. One novel SNP (c.*2494G>A) was identified in the said region. Individuals with the AA genotype had greater milk protein levels than did those with the GG genotype at the c.*2494 G>A locus in both dairy goat breeds (P < 0.05). Functional assays indicated that the MTHFR:c.2494G>A substitution could increase the binding activity of bta-miR-370 with the MTHFR 3'-UTR. In addition, we observed a significant increase in the MTHFR protein level of AA carriers relative to that of GG carriers. These altered levels of MTHFR protein may account for the association of the SNP with milk protein level. PMID:27062401

  5. Genetic parameters for test-day yield of milk, fat and protein in buffaloes estimated by random regression models.

    PubMed

    Aspilcueta-Borquis, Rúsbel R; Araujo Neto, Francisco R; Baldi, Fernando; Santos, Daniel J A; Albuquerque, Lucia G; Tonhati, Humberto

    2012-08-01

    The test-day yields of milk, fat and protein were analysed from 1433 first lactations of buffaloes of the Murrah breed, daughters of 113 sires from 12 herds in the state of São Paulo, Brazil, born between 1985 and 2007. For the test-day yields, 10 monthly classes of lactation days were considered. The contemporary groups were defined as the herd-year-month of the test day. Random additive genetic, permanent environmental and residual effects were included in the model. The fixed effects considered were the contemporary group, number of milkings (1 or 2 milkings), linear and quadratic effects of the covariable cow age at calving and the mean lactation curve of the population (modelled by third-order Legendre orthogonal polynomials). The random additive genetic and permanent environmental effects were estimated by means of regression on third- to sixth-order Legendre orthogonal polynomials. The residual variances were modelled with a homogenous structure and various heterogeneous classes. According to the likelihood-ratio test, the best model for milk and fat production was that with four residual variance classes, while a third-order Legendre polynomial was best for the additive genetic effect for milk and fat yield, a fourth-order polynomial was best for the permanent environmental effect for milk production and a fifth-order polynomial was best for fat production. For protein yield, the best model was that with three residual variance classes and third- and fourth-order Legendre polynomials were best for the additive genetic and permanent environmental effects, respectively. The heritability estimates for the characteristics analysed were moderate, varying from 0·16±0·05 to 0·29±0·05 for milk yield, 0·20±0·05 to 0·30±0·08 for fat yield and 0·18±0·06 to 0·27±0·08 for protein yield. The estimates of the genetic correlations between the tests varied from 0·18±0·120 to 0·99±0·002; from 0·44±0·080 to 0·99±0·004; and from 0·41±0·080 to

  6. Cell-free protein synthesis in microfluidic array devices.

    PubMed

    Mei, Qian; Fredrickson, Carl K; Simon, Andrew; Khnouf, Ruba; Fan, Z Hugh

    2007-01-01

    We report the development of a microfluidic array device for continuous-exchange, cell-free protein synthesis. The advantages of protein expression in the microfluidic array include (1) the potential to achieve high-throughput protein expression, matching the throughput of gene discovery; (2) more than 2 orders of magnitude reduction in reagent consumption, decreasing the cost of protein synthesis; and (3) the possibility to integrate with detection for rapid protein analysis, eliminating the need to harvest proteins. The device consists of an array of units, and each unit can be used for production of an individual protein. The unit comprises a tray chamber for in vitro protein expression and a well chamber as a nutrient reservoir. The tray is nested in the well, and they are separated by a dialysis membrane and connected through a microfluidic connection that provides a means to supply nutrients and remove the reaction byproducts. The device is demonstrated by synthesis of green fluorescent protein, chloramphenicol acetyl-transferase, and luciferase. Protein expression in the device lasts 5-10 times longer and the production yield is 13-22 times higher than in a microcentrifuge tube. In addition, we studied the effects of the operation temperature and hydrostatic flow on the protein production yield. PMID:17924644

  7. Multiple Post-translational Modifications Affect Heterologous Protein Synthesis*

    PubMed Central

    Tokmakov, Alexander A.; Kurotani, Atsushi; Takagi, Tetsuo; Toyama, Mitsutoshi; Shirouzu, Mikako; Fukami, Yasuo; Yokoyama, Shigeyuki

    2012-01-01

    Post-translational modifications (PTMs) are required for proper folding of many proteins. The low capacity for PTMs hinders the production of heterologous proteins in the widely used prokaryotic systems of protein synthesis. Until now, a systematic and comprehensive study concerning the specific effects of individual PTMs on heterologous protein synthesis has not been presented. To address this issue, we expressed 1488 human proteins and their domains in a bacterial cell-free system, and we examined the correlation of the expression yields with the presence of multiple PTM sites bioinformatically predicted in these proteins. This approach revealed a number of previously unknown statistically significant correlations. Prediction of some PTMs, such as myristoylation, glycosylation, palmitoylation, and disulfide bond formation, was found to significantly worsen protein amenability to soluble expression. The presence of other PTMs, such as aspartyl hydroxylation, C-terminal amidation, and Tyr sulfation, did not correlate with the yield of heterologous protein expression. Surprisingly, the predicted presence of several PTMs, such as phosphorylation, ubiquitination, SUMOylation, and prenylation, was associated with the increased production of properly folded soluble proteins. The plausible rationales for the existence of the observed correlations are presented. Our findings suggest that identification of potential PTMs in polypeptide sequences can be of practical use for predicting expression success and optimizing heterologous protein synthesis. In sum, this study provides the most compelling evidence so far for the role of multiple PTMs in the stability and solubility of heterologously expressed recombinant proteins. PMID:22674579

  8. Genome-wide association of coagulation properties, curd firmness modeling, protein percentage, and acidity in milk from Brown Swiss cows.

    PubMed

    Dadousis, C; Biffani, S; Cipolat-Gotet, C; Nicolazzi, E L; Rossoni, A; Santus, E; Bittante, G; Cecchinato, A

    2016-05-01

    Cheese production is increasing in many countries, and a desire toward genetic selection for milk coagulation properties in dairy cattle breeding exists. However, measurements of individual cheesemaking properties are hampered by high costs and labor, whereas traditional single-point milk coagulation properties (MCP) are sometimes criticized. Nevertheless, new modeling of the entire curd firmness and syneresis process (CFt equation) offers new insight into the cheesemaking process. Moreover, identification of genomic regions regulating milk cheesemaking properties might enhance direct selection of individuals in breeding programs based on cheese ability rather than related milk components. Therefore, the objective of this study was to perform genome-wide association studies to identify genomic regions linked to traditional MCP and new CFt parameters, milk acidity (pH), and milk protein percentage. Milk and DNA samples from 1,043 Italian Brown Swiss cows were used. Milk pH and 3 MCP traits were grouped together to represent the MCP set. Four CFt equation parameters, 2 derived traits, and protein percentage were considered as the second group of traits (CFt set). Animals were genotyped with the Illumina SNP50 BeadChip v.2 (Illumina Inc., San Diego, CA). Multitrait animal models were used to estimate variance components. For genome-wide association studies, the genome-wide association using mixed model and regression-genomic control approach was used. In total, 106 significant marker traits associations and 66 single nucleotide polymorphisms were identified on 12 chromosomes (1, 6, 9, 11, 13, 15, 16, 19, 20, 23, 26, and 28). Sharp peaks were detected at 84 to 88 Mbp on Bos taurus autosome (BTA) 6, with a peak at 87.4 Mbp in the region harboring the casein genes. Evidence of quantitative trait loci at 82.6 and 88.4 Mbp on the same chromosome was found. All chromosomes but BTA6, BTA11, and BTA28 were associated with only one trait. Only BTA6 was in common between MCP

  9. Optical backscatter method for determining thermal denaturation of β-lactoglobulin and other whey proteins in milk.

    PubMed

    Lamb, Alisa; Payne, Fred; Xiong, Youling L; Castillo, Manuel

    2013-03-01

    The heat denaturation of whey proteins affects the functional properties of milk. Correlations of β-lactoglobulin (β-LG) denaturation to gelation time, gel firmness, and gel moisture content have been widely documented. Currently, no technique is available for quantifying β-LG denaturation in milk without altering its native composition or requiring a laborious procedure. The goal of this study was to establish if an optical backscatter response of whey protein denaturation during milk heat treatment could be determined that would be the basis for an inline optical measurement technology. The experimental design consisted of 1 factor (time at 80°C) and 6 levels (0, 3, 5, 7, 12, and 25 min). Physicochemical analysis performed indicated that β-LG denaturation followed a first-order response during thermal treatment. The light backscatter response, measured as a ratio of two 25-nm wave bands (832.5 nm/382.5 nm), significantly correlated to β-LG denaturation and had a 14% increase for milk with 75% β-LG denaturation. The strength of the optical response at the proposed wave bands and their correlation to denaturation suggests that light backscatter could potentially be used to measure β-LG and other whey protein denaturation inline. PMID:23357014

  10. Genetic parameters for lactation traits of milking ewes: protein content and composition, fat, somatic cells and individual laboratory cheese yield

    PubMed Central

    Othmane, Med Houcine; Carriedo, Juan Antonio; San Primitivo, Fermin; De la Fuente, Luis Fernando

    2002-01-01

    The effects of some environmental variation factors and the genetic parameters for total milk traits (fat content, protein content, casein content, serum protein content, lactation mean of individual laboratory cheese yield (LILCY), lactation mean of somatic cell count (LSCC), and milk yield) were estimated from the records of 1 111 Churra ewes. Genetic parameters were estimated by multivariate REML. Heritability for fat content was low (0.10) as is usually found in the Churra breed. Heritabilities for protein content, casein content, serum protein content, LILCY, milk yield and somatic cell count were 0.31, 0.30, 0.22, 0.09, 0.26 and 0.11, respectively. The highest heritability estimates were for protein and casein contents. Casein content is not advisable as an alternative to protein content as a selection criterion for cheese yield improvement; it does not have any compelling advantages and its measurement is costly. Our results for LSCC indicated that efforts should focus on improving the level of management rather than selecting for somatic cells, in the actual conditions of the Churra breed. PMID:12427387

  11. Monitoring protein synthesis in single live cancer cells.

    PubMed

    Tu, Chengyi; Santo, Loredana; Mishima, Yuko; Raje, Noopur; Smilansky, Zeev; Zoldan, Janet

    2016-05-16

    Protein synthesis is generally under sophisticated and dynamic regulation to meet the ever-changing demands of a cell. Global up or down-regulation of protein synthesis and the shift of protein synthesis location (as shown, for example, during cellular stress or viral infection) are recognized as cellular responses to environmental changes such as nutrient/oxygen deprivation or to alterations such as pathological mutations in cancer cells. Monitoring protein synthesis in single live cells can be a powerful tool for cancer research. Here we employed a microfluidic platform to perform high throughput delivery of fluorescent labeled tRNAs into multiple myeloma cells with high transfection efficiency (∼45%) and high viability (>80%). We show that the delivered tRNAs were actively recruited to the ER for protein synthesis and that treatment with puromycin effectively disrupted this process. Interestingly, we observed the scattered distribution of tRNAs in cells undergoing mitosis, which has not been previously reported. Fluorescence lifetime analysis detected extensive FRET signals generated from tRNAs labeled as FRET pairs, further confirming that the delivered tRNAs were used by active ribosomes for protein translation. Our work demonstrates that the microfluidic delivery of FRET labeled tRNAs into living cancer cells can provide new insights into basic cancer metabolism and has the potential to serve as a platform for drug screening, diagnostics, or personalized medication. PMID:26956582

  12. Regulation of protein synthesis during early limitation of Saccharomyces cerevisiae.

    PubMed Central

    Swedes, J S; Dial, M E; McLaughlin, C S

    1979-01-01

    Arsenate, a competitive inhibitor with phosphate in phosphorylation reactions, has been used to lower adenine and guanine nucleotide levels in Saccharomyces cerevisiae to study nucleotide effects on protein synthesis. By measuring polysome levels, we have shown that initiation of protein synthesis is much more sensitive than elongation or termination to inhibition when the ATP/ADP, GTP/GDP ratios are low. When the arsenate-phosphate molar ratio was 0.27, protein synthesis was inhibited by about 85% and the kinetics of polysome decay was similar to that observed with the initiation inhibitor, verrucarin-76, or with the protein synthesis initiation mutant, ts187, at the restrictive temperature. With this level of arsenate, the adenylate energy charge dropped from 0.9 to 0.7 and the ATP/ADP and GTP/GDP ratios dropped from 6 to 2. The observed correlations between nucleotide ratio changes and inhibition of protein synthesis suggest that the former may be a control signal for the latter. The significance of these in vivo correlations will have to be tested with an in vitro protein synthesizing system. Higher arsenate levels resulted in even lower ATP/ADP, GTP/GDP ratios and in a slower decay of polysomes, implying that, eventually, elongation (in addition to initiation) was being inhibited. PMID:374362

  13. Energizing eukaryotic cell-free protein synthesis with glucose metabolism.

    PubMed

    Anderson, Mark J; Stark, Jessica C; Hodgman, C Eric; Jewett, Michael C

    2015-07-01

    Eukaryotic cell-free protein synthesis (CFPS) is limited by the dependence on costly high-energy phosphate compounds and exogenous enzymes to power protein synthesis (e.g., creatine phosphate and creatine kinase, CrP/CrK). Here, we report the ability to use glucose as a secondary energy substrate to regenerate ATP in a Saccharomyces cerevisiae crude extract CFPS platform. We observed synthesis of 3.64±0.35 μg mL(-1) active luciferase in batch reactions with 16 mM glucose and 25 mM phosphate, resulting in a 16% increase in relative protein yield (μg protein/$ reagents) compared to the CrP/CrK system. Our demonstration provides the foundation for development of cost-effective eukaryotic CFPS platforms. PMID:26054976

  14. Leucine-Enriched Essential Amino Acids Augment Mixed Protein Synthesis, But Not Collagen Protein Synthesis, in Rat Skeletal Muscle after Downhill Running.

    PubMed

    Kato, Hiroyuki; Suzuki, Hiromi; Inoue, Yoshiko; Suzuki, Katsuya; Kobayashi, Hisamine

    2016-01-01

    Mixed and collagen protein synthesis is elevated for as many as 3 days following exercise. Immediately after exercise, enhanced amino acid availability increases synthesis of mixed muscle protein, but not muscle collagen protein. However, the potential for synergic effects of amino acid ingestion with exercise on both mixed and collagen protein synthesis remains unclear. We investigated muscle collagen protein synthesis in rats following post-exercise ingestion of leucine-enriched essential amino acids. We determined fractional protein synthesis rates (FSR) at different time points following exercise. Mixed protein and collagen protein FSRs in skeletal muscle were determined by measuring protein-bound enrichments of hydroxyproline and proline, and by measuring the intracellular enrichment of proline, using injections of flooding d₃-proline doses. A leucine-enriched mixture of essential amino acids (or distilled water as a control) was administrated 30 min or 1 day post-exercise. The collagen protein synthesis in the vastus lateralis was elevated for 2 days after exercise. Although amino acid administration did not increase muscle collagen protein synthesis, it did lead to augmented mixed muscle protein synthesis 1 day following exercise. Thus, contrary to the regulation of mixed muscle protein synthesis, muscle collagen protein synthesis is not affected by amino acid availability after damage-inducing exercise. PMID:27367725

  15. Leucine-Enriched Essential Amino Acids Augment Mixed Protein Synthesis, But Not Collagen Protein Synthesis, in Rat Skeletal Muscle after Downhill Running

    PubMed Central

    Kato, Hiroyuki; Suzuki, Hiromi; Inoue, Yoshiko; Suzuki, Katsuya; Kobayashi, Hisamine

    2016-01-01

    Mixed and collagen protein synthesis is elevated for as many as 3 days following exercise. Immediately after exercise, enhanced amino acid availability increases synthesis of mixed muscle protein, but not muscle collagen protein. However, the potential for synergic effects of amino acid ingestion with exercise on both mixed and collagen protein synthesis remains unclear. We investigated muscle collagen protein synthesis in rats following post-exercise ingestion of leucine-enriched essential amino acids. We determined fractional protein synthesis rates (FSR) at different time points following exercise. Mixed protein and collagen protein FSRs in skeletal muscle were determined by measuring protein-bound enrichments of hydroxyproline and proline, and by measuring the intracellular enrichment of proline, using injections of flooding d3-proline doses. A leucine-enriched mixture of essential amino acids (or distilled water as a control) was administrated 30 min or 1 day post-exercise. The collagen protein synthesis in the vastus lateralis was elevated for 2 days after exercise. Although amino acid administration did not increase muscle collagen protein synthesis, it did lead to augmented mixed muscle protein synthesis 1 day following exercise. Thus, contrary to the regulation of mixed muscle protein synthesis, muscle collagen protein synthesis is not affected by amino acid availability after damage-inducing exercise. PMID:27367725

  16. Glucose Synthesis in a Protein-Based Artificial Photosynthesis System.

    PubMed

    Lu, Hao; Yuan, Wenqiao; Zhou, Jack; Chong, Parkson Lee-Gau

    2015-09-01

    The objective of this study was to understand glucose synthesis of a protein-based artificial photosynthesis system affected by operating conditions, including the concentrations of reactants, reaction temperature, and illumination. Results from non-vesicle-based glyceraldehyde-3-phosphate (GAP) and glucose synthesis showed that the initial concentrations of ribulose-1,5-bisphosphate (RuBP) and adenosine triphosphate (ATP), lighting source, and temperature significantly affected glucose synthesis. Higher initial concentrations of RuBP and ATP significantly enhanced GAP synthesis, which was linearly correlated to glucose synthesis, confirming the proper functions of all catalyzing enzymes in the system. White fluorescent light inhibited artificial photosynthesis and reduced glucose synthesis by 79.2 % compared to in the dark. The reaction temperature of 40 °C was optimum, whereas lower or higher temperature reduced glucose synthesis. Glucose synthesis in the vesicle-based artificial photosynthesis system reconstituted with bacteriorhodopsin, F 0 F 1 ATP synthase, and polydimethylsiloxane-methyloxazoline-polydimethylsiloxane triblock copolymer was successfully demonstrated. This system efficiently utilized light-induced ATP to drive glucose synthesis, and 5.2 μg ml(-1) glucose was synthesized in 0.78-ml reaction buffer in 7 h. Light-dependent reactions were found to be the bottleneck of the studied artificial photosynthesis system. PMID:26170084

  17. Perinatal protein restriction affects milk free amino acid and fatty acid profile in lactating rats: potential role on pup growth and metabolic status.

    PubMed

    Martin Agnoux, Aurore; Antignac, Jean-Philippe; Boquien, Clair-Yves; David, Agnes; Desnots, Emmanuelle; Ferchaud-Roucher, Veronique; Darmaun, Dominique; Parnet, Patricia; Alexandre-Gouabau, Marie-Cécile

    2015-07-01

    Perinatal undernutrition affects not only fetal and neonatal growth but also adult health outcome, as suggested by the metabolic imprinting concept. Although maternal milk is the only channel through which nutrients are transferred from mother to offspring during the postnatal period, the impact of maternal undernutrition on milk composition is poorly understood. The present study investigates, in a rat model of nutritional programming, the effects of feeding an isocaloric, low-protein diet throughout gestation and lactation on milk composition and its possible consequences on offspring's growth and metabolic status. We used an integrated methodological approach that combined targeted analyses of macronutrients, free amino acid and fatty acid content throughout lactation, with an untargeted mass-spectrometric-based metabolomic phenotyping. Whereas perinatal dietary protein restriction failed to alter milk protein content, it dramatically decreased the concentration of most free amino acids at the end of lactation. Interestingly, a decrease of several amino acids involved in insulin secretion or gluconeogenesis was observed, suggesting that maternal protein restriction during the perinatal period may impact the insulinotrophic effect of milk, which may, in turn, account for the slower growth of the suckled male offspring. Besides, the decrease in sulfur amino acids may alter redox status in the offspring. Maternal undernutrition was also associated with an increase in milk total fatty acid content, with modifications in their pattern. Altogether, our results show that milk composition is clearly influenced by maternal diet and suggest that alterations in milk composition may play a role in offspring growth and metabolic programming. PMID:25935308

  18. Acetaldehyde inhibition of protein synthesis in isolated rat pancreatic acini

    SciTech Connect

    Majumdar, A.P.; Haiman, M.J.; Zylbert, B.A.; Billy, H.T.; Vesenka, G.D.; Geokas, M.C.

    1986-03-30

    Exposure of isolated dispersed pancreatic acini to increasing concentrations of ethanol (5 to 500 mM) or acetaldehyde (0.5 to 100 mM) produced a progressive inhibition of (3H)leucine incorporation into both cellular (those remaining in the cell) and secretory (those released into the medium) proteins. Whereas 500 mM ethanol caused 90-95% inhibition in the synthesis of cellular and secretory proteins, the concentration of acetaldehyde needed to produce a similar inhibition was found to be 50 mM. All subsequent experiments were performed with 12.5 mM acetaldehyde, a concentration that consistently inhibited acinar protein synthesis by about 50%. The acetaldehyde-mediated inhibition of acinar protein synthesis was partially normalized when this metabolite was removed after 30 min during a 90-min incubation period. In the presence of acetaldehyde, the secretion of 3H-pulse-labeled proteins, but not amylase, trypsinogen, or chymotrypsinogen, was greatly depressed. Acetaldehyde also caused a marked reduction in (3H)uridine incorporation into acinar RNA. The entry of (3H)uridine, (3H)leucine, and (3H)aminoisobutyric acid into isolated acini was found to be slightly (15-25%) decreased by acetaldehyde. It is concluded that acetaldehyde exerts a direct toxic effect on isolated dispersed pancreatic acini as evidenced by diminution of both protein and RNA synthesis and decreased secretion of the newly synthesized proteins. This inhibitory effect of acetaldehyde could be partially reversed.

  19. His6 tag-assisted chemical protein synthesis

    NASA Astrophysics Data System (ADS)

    Bang, Duhee; Kent, Stephen B. H.

    2005-04-01

    To make more practical the total chemical synthesis of proteins by the ligation of unprotected peptide building blocks, we have developed a method to facilitate the isolation and handling of intermediate products. The synthetic technique makes use of a His6 tag at the C terminus of the target polypeptide chain, introduced during the synthesis of the C-terminal peptide segment building block. The presence of a His6 tag enables the isolation of peptide or protein products directly from ligation reaction mixtures by Ni-NTA affinity column purification. This simple approach enables facile buffer exchange to alternate reaction conditions and is compatible with direct analytical control by protein MS of the multiple ligation steps involved in protein synthesis. We used syntheses of crambin and a modular tetratricopeptide repeat protein of 17 kDa as models to examine the utility of this affinity purification approach. The results show that His6 tag-assisted chemical protein synthesis is a useful method that substantially reduces handling losses and provides for rapid chemical protein syntheses. affinity purification | native chemical ligation

  20. Protein synthesis rates in atrophied gastrocnemius muscles after limb immobilization

    NASA Technical Reports Server (NTRS)

    Tucker, K. R.; Seider, M. J.; Booth, F. W.

    1981-01-01

    Noting that protein synthesis declines in the gastrocnemius 6 hr after immobilization, the study sought to detect an increase of protein synthesis when the limb was freed, and to examine the effects of exercise on the rate of increase. Rats were used as subjects, with their hind legs in plaster of Paris in plantar flexion to eliminate strain on the gastrocnemius. Periods of immobilization were varied and samples of blood from the muscle were taken to track protein synthesis rates for different groups in immobilization and exercise regimens (running and weightlifting). Synthesis rates declined 3.6% during time in the cast, then increased 6.3%/day after the casts were removed. Both running and weightlifting were found to increase the fractional rate of protein formation in the gastrocnemius muscle when compared with contralateral muscles that were not exercised and were used as controls, suggesting that the mechanism controlling protein synthesis in skeletal muscles is rapidly responsive to changes in muscular contractile activity.

  1. Regulation of protein synthesis during sea urchin early development

    SciTech Connect

    Kelso, L.C.

    1989-01-01

    Fertilization of the sea urchin egg results in a 20-40 fold increase in the rate of protein synthesis. The masked message hypothesis proposes that mRNAs are masked or unavailable for translation in the egg. We devised an in vivo assay to test this hypothesis. Our results show that masked mRNAs limit protein synthesis in the unfertilized egg. In addition, we show that protein synthesis is also regulated at the level of translational machinery. Following fertilization is a period of rapid cell divisions. This period, known as the rapid cleavage stage, is characterized by the transient synthesis of a novel set of proteins. The synthesis of these proteins is programmed by maternal mRNAs stored in the unfertilized egg. To study the behavior of these mRNAs, we prepared a cDNA library from polysomal poly (A+) RNA from 2-hour embryos. ({sup 32}P) labeled probes, prepared from the cDNA library, were used to monitor the levels of individual mRNAs in polysomes at fertilization and during early development.

  2. Update on protein intake: importance of milk proteins for health status of the elderly.

    PubMed

    Wolfe, Robert R

    2015-08-01

    Loss of lean body mass that occurs with aging is the primary endpoint with which sarcopenia is defined. Furthermore, loss of muscle mass is central to the development of many adverse health issues in the elderly. Consequently, the response of lean body mass to nutritional interventions, particularly to dietary protein, has been a commonly measured endpoint. However, increased protein intake has been associated with improved markers for cardiovascular health, improved bone health, management of weight and metabolic diseases, and reduced all-cause mortality. Strength, rather than lean body mass, may be a more accurate indicator of health, especially in the elderly. The recommended dietary allowance for protein has been set at 0.8 g/kg/day. Because the average protein intake in the United States is approximately 1.2 g/kg/day, it appears that the average protein intake is above the recommended dietary allowance but below the low end of the acceptable macronutrient distribution range recommended by expert committees of the National Academy of Sciences and below the dietary intake levels suggested by the US Department of Agriculture in the Dietary Guidelines. PMID:26175489

  3. Caecal fermentation, putrefaction and microbiotas in rats fed milk casein, soy protein or fish meal.

    PubMed

    An, Choa; Kuda, Takashi; Yazaki, Takahiro; Takahashi, Hajime; Kimura, Bon

    2014-03-01

    To clarify the effect of soy protein (SP) and fish meal (FM), compared to milk casein (MC), on the intestinal environment, we examined caecal environment of rats fed the test diets. Four-week-old rats were fed AIN-76-based diet containing 20 %, w/w MC, SP or FM for 16 days. Caecal organic acids were analysed by HPLC. Caecal putrefactive compounds (indole, phenol, H2S and ammonia) were analysed by colorimetric assays. Caecal microflora was determined by 16S rRNA gene-DGGE and pyrosequencing with bar-coded primers targeting the bacterial 16S rRNA gene. n-Butyric and lactic acid levels were high in rats fed SP and FM, respectively. Butyrate-producing bacteria, such as Oscillibacter, and lactate-producing bacteria, such as Lactobacillus, were detected in each diet group. Also, the putrefactive compound contents were high in rats fed SP and FM. In this study, both DGGE and pyrosequencing analyses were able to evaluate the dynamics of the intestinal microbiota. The results indicate that dietary proteins can alter the intestinal environment, affecting fermentation by the intestinal microbiota and the generation of putrefactive compounds. PMID:24113824

  4. Preparation and characterization of milk protein films and their application for packaging of Cheddar cheese.

    PubMed

    Wagh, Y R; Pushpadass, Heartwin A; Emerald, F Magdaline Eljeeva; Nath, B Surendra

    2014-12-01

    Casein and whey protein concentrate (WPC) films, plasticized with glycerol and sorbitol independently, were prepared by casting. The film thickness, water vapour and oxygen permeation and tensile and moisture sorption properties of the films were determined. The tensile strength (TS), tensile strain (TE) and elastic modulus (EM) of the films ranged from 0.71 to 4.58 MPa, 19.22 to 66.63 % and 2.05 to 6.93 MPa, respectively. The film properties were influenced by the type of biopolymer (casein and whey protein concentrate), plasticizer and its concentration. Increasing the plasticizer concentration, increased the film thickness, TE and water vapour permeability (WVP), but decreased the TS and EM. As the concentration of plasticizer increased to the highest level, the film thickness increased from 0.168 to 0.305 mm for glycerol-plasticized films and from 0.251 to 0.326 mm for sorbitol-plasticized films. The film thickness increased because the amount of plasticizer in the film network increased and the amount of biopolymer remained same. Casein films showed superior tensile properties as compared to WPC films. The WVP of both casein and WPC films lied between 3.87 and 13.97 g.mm./(m(2).h.kPa). The moisture sorption isotherms of both films were typical of high-protein material, and were adequately described by the GAB model. The oxygen permeability of casein films was relatively lower than that of WPC films, regardless of the plasticizer used. The sensory data revealed that the organoleptic quality of Cheddar cheese was unaffected by milk-protein film packaging. PMID:25477643

  5. Instrumental and Sensory Texture Attributes of High-Protein Nutrition Bars Formulated with Extruded Milk Protein Concentrate.

    PubMed

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

    2016-05-01

    Previous instrumental study of high-protein nutrition (HPN) bars formulated with extruded milk protein concentrate (MPC) indicated slower hardening compared to bars formulated with unmodified MPC. However, hardness, and its change during storage, insufficiently characterizes HPN bar texture. In this study, MPC80 was extruded at 2 different conditions and model HPN bars were prepared. A trained sensory panel and instrumental techniques were used to measure HPN bar firmness, crumbliness, fracturability, hardness, cohesiveness, and other attributes to characterize texture change during storage. Extrusion modification, storage temperature, and storage time significantly affected the instrumental and sensory panel measured texture attributes. The HPN bars became firmer and less cohesive during storage. When evaluated at the same storage conditions, the texture attributes of the HPN bars formulated with the different extrudates did not differ significantly from each other. However, textural differences were noted most of the time between the control and the HPN bars formulated with extruded MPC80. An adapted HPN bar crumbliness measurement technique produced results that were correlated with sensory panel measured crumbliness (r = 0.85) and cohesiveness (r = -0.84). Overall, the HPN bars formulated with extruded MPC80 were significantly softer, less crumbly, and more cohesive than the control during storage. PMID:27037608

  6. The Role of Protein Synthesis in the Senescence of Leaves

    PubMed Central

    Martin, Colin; Thimann, Kenneth V.

    1972-01-01

    The senescence of oat leaves has been studied by following the loss of chlorophyll and protein and the increase of α-amino nitrogen, after detachment and darkening. Protein synthesis and the amounts of proteolytic enzymes in the leaves have been determined directly. The process of senescence is shown to be a sequential one in which protein synthesis,most probably the formation of a proteolytic enzyme with l-serine in its active center, is of prime importance. The evidence is as follows. Firstly, l-serine specifically enhances senescence, especially in presence of kinetin. Secondly, cycloheximide, which inhibits protein synthesis in other systems, delays senescence and prevents the serine enhancement. Although requiring higher concentrations, cycloheximide can be as effective as kinetin in inhibiting senescence. It is shown directly that cycloheximide prevents protein synthesis in oat leaves under the same conditions as when it prevents senescence. Thirdly, leaves have been shown to contain two proteinases, with pH optima at 3 and 7.5, whose activity increases during senescence, even though the total leaf protein is decreasing. The amounts of both these enzymes present after 3 days are clearly increased by serine, and are greatly decreased by cycloheximide or by kinetin. The role of kinetin in delaying senescence thus may rest on its ability to suppress protease formation. PMID:16657898

  7. DNA Nanoparticles for Improved Protein Synthesis In Vitro

    PubMed Central

    Galinis, Robertas; Stonyte, Greta; Kiseliovas, Vaidotas; Zilionis, Rapolas; Studer, Sabine; Hilvert, Donald; Janulaitis, Arvydas

    2016-01-01

    Abstract The amplification and digital quantification of single DNA molecules are important in biomedicine and diagnostics. Beyond quantifying DNA molecules in a sample, the ability to express proteins from the amplified DNA would open even broader applications in synthetic biology, directed evolution, and proteomics. Herein, a microfluidic approach is reported for the production of condensed DNA nanoparticles that can serve as efficient templates for in vitro protein synthesis. Using phi29 DNA polymerase and a multiple displacement amplification reaction, single DNA molecules were converted into DNA nanoparticles containing up to about 104 clonal gene copies of the starting template. DNA nanoparticle formation was triggered by accumulation of inorganic pyrophosphate (produced during DNA synthesis) and magnesium ions from the buffer. Transcription–translation reactions performed in vitro showed that individual DNA nanoparticles can serve as efficient templates for protein synthesis in vitro. PMID:26821778

  8. Prolonged inhibition of bacterial protein synthesis abolishes Salmonella invasion.

    PubMed Central

    MacBeth, K J; Lee, C A

    1993-01-01

    We have found that prolonged inhibition of bacterial protein synthesis abolishes the ability of Salmonella typhimurium to enter HEp-2 cells. Our results suggest that an essential invasion factor has a functional half-life that is seen as a gradual loss of invasiveness in the absence of protein synthesis. Therefore, Salmonella invasiveness appears to be a transient phenotype that is lost unless protein synthesis is maintained. This finding may explain why salmonellae grown to stationary phase lose their ability to enter cultured cells. In addition, a short-lived capacity to enter cells may be important during infection so that bacterial invasiveness is limited to certain times and host sites during pathogenesis. PMID:8454361

  9. Bacterial Protein Synthesis as a Target for Antibiotic Inhibition.

    PubMed

    Arenz, Stefan; Wilson, Daniel N

    2016-01-01

    Protein synthesis occurs on macromolecular machines, called ribosomes. Bacterial ribosomes and the translational machinery represent one of the major targets for antibiotics in the cell. Therefore, structural and biochemical investigations into ribosome-targeting antibiotics provide not only insight into the mechanism of action and resistance of antibiotics, but also insight into the fundamental process of protein synthesis. This review summarizes the recent advances in our understanding of protein synthesis, particularly with respect to X-ray and cryoelectron microscopy (cryo-EM) structures of ribosome complexes, and highlights the different steps of translation that are targeted by the diverse array of known antibiotics. Such findings will be important for the ongoing development of novel and improved antimicrobial agents to combat the rapid emergence of multidrug resistant pathogenic bacteria. PMID:27481773

  10. Proteomics data in support of the quantification of the changes of bovine milk proteins during mammary gland involution.

    PubMed

    Boggs, Irina; Hine, Brad; Smolenksi, Grant; Hettinga, Kasper; Zhang, Lina; Wheeler, Thomas T

    2016-09-01

    Here we provide data from three proteomics techniques; two-dimensional electrophoresis (2-DE) followed by identification of selected spots using PSD MALDI-TOF MS/MS, one-dimensional gel electrophoresis followed by LC-MS/MS analysis of gel slices (GeLC) and dimethyl isotopic labelling of tryptic peptides followed by Orbitrap MS/MS (DML), to quantify the changes in the repertoire of bovine milk proteins that occurs after drying off. We analysed skim milk and whey sampled at day 0 and either day 3 or day 8 after drying off. These analyses identified 45 spots by MALDI-TOF, 51 proteins by GeLC and 161 proteins by DML, for which the detailed data work-up is presented as three Excel files. The data supplied in this article supports the accompanying publication "Changes in the repertoire of bovine milk proteins during mammary involution" (Boggs et al., 2015) [1]. Data are available via ProteomeXchange with identifiers ProteomeXchange: PXD003110 and ProteomeXchange: PXD003011. PMID:27274532

  11. Quantifying elongation rhythm during full-length protein synthesis.

    PubMed

    Rosenblum, Gabriel; Chen, Chunlai; Kaur, Jaskiran; Cui, Xiaonan; Zhang, Haibo; Asahara, Haruichi; Chong, Shaorong; Smilansky, Zeev; Goldman, Yale E; Cooperman, Barry S

    2013-07-31

    Pauses regulate the rhythm of ribosomal protein synthesis. Mutations disrupting even minor pauses can give rise to improperly formed proteins and human disease. Such minor pauses are difficult to characterize by ensemble methods, but can be readily examined by single-molecule (sm) approaches. Here we use smFRET to carry out real-time monitoring of the expression of a full-length protein, the green fluorescent protein variant Emerald GFP. We demonstrate significant correlations between measured elongation rates and codon and isoacceptor tRNA usage, and provide a quantitative estimate of the effect on elongation rate of replacing a codon recognizing an abundant tRNA with a synonymous codon cognate to a rarer tRNA. Our results suggest that tRNA selection plays an important general role in modulating the rates and rhythms of protein synthesis, potentially influencing simultaneous co-translational processes such as folding and chemical modification. PMID:23822614

  12. Selective memory generalization by spatial patterning of protein synthesis

    PubMed Central

    O’Donnell, Cian; Sejnowski, Terrence J.

    2014-01-01

    Summary Protein synthesis is crucial for both persistent synaptic plasticity and long-term memory. De novo protein expression can be restricted to specific neurons within a population, and to specific dendrites within a single neuron. Despite its ubiquity, the functional benefits of spatial protein regulation for learning are unknown. We used computational modeling to study this problem. We found that spatially patterned protein synthesis can enable selective consolidation of some memories but forgetting of others, even for simultaneous events that are represented by the same neural population. Key factors regulating selectivity include the functional clustering of synapses on dendrites, and the sparsity and overlap of neural activity patterns at the circuit level. Based on these findings we proposed a novel two-step model for selective memory generalization during REM and slow-wave sleep. The pattern-matching framework we propose may be broadly applicable to spatial protein signaling throughout cortex and hippocampus. PMID:24742462

  13. Cyclin B synthesis and rapamycin-sensitive regulation of protein synthesis during starfish oocyte meiotic divisions.

    PubMed

    Lapasset, Laure; Pradet-Balade, Bérengère; Vergé, Valérie; Lozano, Jean-Claude; Oulhen, Nathalie; Cormier, Patrick; Peaucellier, Gérard

    2008-11-01

    Translation of cyclin mRNAs represents an important event for proper meiotic maturation and post-fertilization mitoses in many species. Translational control of cyclin B mRNA has been described to be achieved through two separate but related mechanisms: translational repression and polyadenylation. In this paper, we evaluated the contribution of global translational regulation by the cap-dependent translation repressor 4E-BP (eukaryotic initiation factor 4E-binding protein) on the cyclin B protein synthesis during meiotic maturation of the starfish oocytes. We used the immunosupressant drug rapamycin, a strong inhibitor of cap-dependent translation, to check for the involvement of this protein synthesis during this physiological process. Rapamycin was found to prevent dissociation of 4E-BP from the initiation factor eIF4E and to suppress correlatively a burst of global protein synthesis occurring at the G2/M transition. The drug had no effect on first meiotic division but defects in meiotic spindle formation prevented second polar body emission, demonstrating that a rapamycin-sensitive pathway is involved in this mechanism. While rapamycin affected the global protein synthesis, the drug altered neither the specific translation of cyclin B mRNA nor the expression of the Mos protein. The expression of these two proteins was correlated with the phosphorylation and the dissociation of the cytoplasmic polyadenylation element-binding protein from eIF4E. PMID:18361417

  14. Cell-free protein synthesis and assembly on a biochip

    NASA Astrophysics Data System (ADS)

    Heyman, Yael; Buxboim, Amnon; Wolf, Sharon G.; Daube, Shirley S.; Bar-Ziv, Roy H.

    2012-06-01

    Biologically active complexes such as ribosomes and bacteriophages are formed through the self-assembly of proteins and nucleic acids. Recapitulating these biological self-assembly processes in a cell-free environment offers a way to develop synthetic biodevices. To visualize and understand the assembly process, a platform is required that enables simultaneous synthesis, assembly and imaging at the nanoscale. Here, we show that a silicon dioxide grid, used to support samples in transmission electron microscopy, can be modified into a biochip to combine in situ protein synthesis, assembly and imaging. Light is used to pattern the biochip surface with genes that encode specific proteins, and antibody traps that bind and assemble the nascent proteins. Using transmission electron microscopy imaging we show that protein nanotubes synthesized on the biochip surface in the presence of antibody traps efficiently assembled on these traps, but pre-assembled nanotubes were not effectively captured. Moreover, synthesis of green fluorescent protein from its immobilized gene generated a gradient of captured proteins decreasing in concentration away from the gene source. This biochip could be used to create spatial patterns of proteins assembled on surfaces.

  15. Milk-derived ribonuclease 5 preparations induce myogenic differentiation in vitro and muscle growth in vivo.

    PubMed

    Knight, Matthew I; Tester, Angus M; McDonagh, Matthew B; Brown, Andrew; Cottrell, Jeremy; Wang, Jianghui; Hobman, Peter; Cocks, Benjamin G

    2014-12-01

    Ribonuclease 5, also known as angiogenin, is a stable and abundant ribonuclease in milk whey protein, which is able to regulate several cellular functions, including capillary formation, neuron survival, and epithelial cell growth. Ribonuclease 5 is important for protein synthesis directly stimulating rRNA synthesis in the nucleolus. Here, we show that biologically active RNase5 can be purified from bovine milk. Furthermore, we show that milk-derived RNase5 directly stimulates muscle cell differentiation in vitro, inducing C2C12 cell differentiation and myogenesis. When supplemented into the diet of healthy adult mice, milk-derived RNase5 preparations promoted muscle weight gain and grip strength. Collectively, these data indicate that milk-derived RNase5 preparations exhibit a novel role in skeletal muscle cell function. PMID:25282415

  16. Is it possible to screen for milk or whey protein adulteration with melamine, urea and ammonium sulphate, combining Kjeldahl and classical spectrophotometric methods?

    PubMed

    Finete, Virgínia de Lourdes Mendes; Gouvêa, Marcos Martins; Marques, Flávia Ferreira de Carvalho; Netto, Annibal Duarte Pereira

    2013-12-15

    The Kjeldahl method and four classic spectrophotometric methods (Biuret, Lowry, Bradford and Markwell) were applied to evaluate the protein content of samples of UHT whole milk deliberately adulterated with melamine, ammonium sulphate or urea, which can be used to defraud milk protein and whey contents. Compared with the Kjeldahl method, the response of the spectrophotometric methods was unaffected by the addition of the nitrogen compounds to milk or whey. The methods of Bradford and Markwell were most robust and did not exhibit interference subject to composition. However, the simultaneous interpretation of results obtained using these methods with those obtained using the Kjeldahl method indicated the addition of nitrogen-rich compounds to milk and/or whey. Therefore, this work suggests a combination of results of Kjeldahl and spectrophotometric methods should be used to screen for milk adulteration by these compounds. PMID:23993532

  17. Characterisation of a New Fungal Immunomodulatory Protein from Tiger Milk mushroom, Lignosus rhinocerotis

    PubMed Central

    Pushparajah, V.; Fatima, A.; Chong, C. H.; Gambule, T. Z.; Chan, C. J.; Ng, S. T.; Tan, C. S.; Fung, S. Y.; Lee, S. S.; Tan, N. H.; Lim, R. L. H.

    2016-01-01

    Lignosus rhinocerotis (Tiger milk mushroom) is an important folk medicine for indigenous peoples in Southeast Asia. We previously reported its de novo assembled 34.3 Mb genome encoding a repertoire of proteins including a putative bioactive fungal immunomodulatory protein. Here we report the cDNA of this new member (FIP-Lrh) with a homology range of 54–64% to FIPs from other mushroom species, the closest is with FIP-glu (LZ-8) (64%) from Ganoderma lucidum. The FIP-Lrh of 112 amino acids (12.59 kDa) has a relatively hydrophobic N-terminal. Its predicted 3-dimensional model has identical folding patterns to FIP-fve and contains a partially conserved and more positively charged carbohydrates binding pocket. Docking predictions of FIP-Lrh on 14 glycans commonly found on cellular surfaces showed the best binding energy of −3.98 kcal/mol to N-acetylgalactosamine and N-acetylglucosamine. Overexpression of a 14.9 kDa soluble 6xHisFIP-Lrh was achieved in pET-28a(+)/BL21 and the purified recombinant protein was sequence verified by LC-MS/MS (QTOF) analysis. The ability to haemagglutinate both mouse and human blood at concentration ≥0.34 μM, further demonstrated its lectin nature. In addition, the cytotoxic effect of 6xHisFIP-Lrh on MCF-7, HeLa and A549 cancer cell lines was detected at IC50 of 0.34 μM, 0.58 μM and 0.60 μM, respectively. PMID:27460640

  18. Characterisation of a New Fungal Immunomodulatory Protein from Tiger Milk mushroom, Lignosus rhinocerotis.

    PubMed

    Pushparajah, V; Fatima, A; Chong, C H; Gambule, T Z; Chan, C J; Ng, S T; Tan, C S; Fung, S Y; Lee, S S; Tan, N H; Lim, R L H

    2016-01-01

    Lignosus rhinocerotis (Tiger milk mushroom) is an important folk medicine for indigenous peoples in Southeast Asia. We previously reported its de novo assembled 34.3 Mb genome encoding a repertoire of proteins including a putative bioactive fungal immunomodulatory protein. Here we report the cDNA of this new member (FIP-Lrh) with a homology range of 54-64% to FIPs from other mushroom species, the closest is with FIP-glu (LZ-8) (64%) from Ganoderma lucidum. The FIP-Lrh of 112 amino acids (12.59 kDa) has a relatively hydrophobic N-terminal. Its predicted 3-dimensional model has identical folding patterns to FIP-fve and contains a partially conserved and more positively charged carbohydrates binding pocket. Docking predictions of FIP-Lrh on 14 glycans commonly found on cellular surfaces showed the best binding energy of -3.98 kcal/mol to N-acetylgalactosamine and N-acetylglucosamine. Overexpression of a 14.9 kDa soluble 6xHisFIP-Lrh was achieved in pET-28a(+)/BL21 and the purified recombinant protein was sequence verified by LC-MS/MS (QTOF) analysis. The ability to haemagglutinate both mouse and human blood at concentration ≥0.34 μM, further demonstrated its lectin nature. In addition, the cytotoxic effect of 6xHisFIP-Lrh on MCF-7, HeLa and A549 cancer cell lines was detected at IC50 of 0.34 μM, 0.58 μM and 0.60 μM, respectively. PMID:27460640

  19. Semi-synthesis of labeled proteins for spectroscopic applications.

    PubMed

    De Rosa, Lucia; Russomanno, Anna; Romanelli, Alessandra; D'Andrea, Luca Domenico

    2013-01-01

    Since the introduction of SPPS by Merrifield in the 60s, peptide chemists have considered the possibility of preparing large proteins. The introduction of native chemical ligation in the 90s and then of expressed protein ligation have opened the way to the preparation of synthetic proteins without size limitations. This review focuses on semi-synthetic strategies useful to prepare proteins decorated with spectroscopic probes, like fluorescent labels and stable isotopes, and their biophysical applications. We show that expressed protein ligation, combining the advantages of organic chemistry with the easy and size limitless recombinant protein expression, is an excellent strategy for the chemical synthesis of labeled proteins, enabling a single protein to be functionalized at one or even more distinct positions with different probes. PMID:23282535

  20. Milk yield differences between 1x and 4x milking are associated with changes in mammary mitochondrial number and milk protein gene expression, but not mammary cell apoptosis or "SOCS" gene expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Milking frequency is known to affect milk production and lactation persistence in dairy cows. Despite this, the mechanisms underlying this effect are only partially understood. Previous work in dairy cows examining increases in milk yield due to increased milking frequency have identified changes in...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 two-...

  2. Greater mortality and mordidity in extremely preterm infants fed a diet containing cow milk protein products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Provision of human milk has important implications for the health and outcomes of extremely preterm (EP) infants. This study evaluated the effects of an exclusive human milk diet on the health of EP infants during their stay in the neonatal intensive care unit. EP infants <1,250 g birth weight recei...

  3. Thyroid hormone stimulation of plasma protein synthesis in cultured hepatocytes.

    PubMed

    Hertzberg, K M; Pindyck, J; Mosesson, M W; Grieninger, G

    1981-01-25

    The direct effect of thyroid hormones on hepatocellular plasma protein synthesis has been studied in primary monolayer cultures derived from chick embryo liver. The chemically defined medium used for plating and maintaining the cultures contained no other hormones, protein, or serum supplement. Addition of physiological concentrations (10 nM) of triiodothyronine or thyroxine produced 3-fold or greater increases in the rates of synthesis of fibrinogen and three other major secreted proteins. By comparison albumin, transferrin, and total protein synthesis were not substantially increased. The enhanced synthesis of selected plasma proteins could be detected 6 h after initial addition of triiodothyronine. Exposure of the cells to the hormone for only 30 min was nearly as effective as continuous exposure in eliciting the ultimate response. Triiodothyronine exerted its half-maximal effect at a concentration of 1 nM. Diminished potency was associated with less iodination of the hormone; a marked reduction was noted with di-iodinated thyronine and no stimulatory activity at all with either mono- or non-iodinated thyronine. PMID:7451459

  4. Can milk proteins be a useful tool in the management of cardiometabolic health? An updated review of human intervention trials.

    PubMed

    Fekete, Ágnes A; Givens, D Ian; Lovegrove, Julie A

    2016-08-01

    The prevalence of cardiometabolic diseases is a significant public health burden worldwide. Emerging evidence supports the inverse association between greater dairy consumption and reduced risk of cardiometabolic diseases. Dairy proteins may have an important role in the favourable impact of dairy on human health such as blood pressure (BP), blood lipid and glucose control. The purpose of this review is to update and critically evaluate the evidence on the impacts of casein and whey protein in relation to metabolic function. Evidence from short-term clinical studies assessing postprandial responses to milk protein ingestion suggests benefits on vascular function independent of BP, as well as improvement in glycaemic homeostasis. Long-term interventions have been less conclusive, with some showing benefits and others indicating a lack of improvement in vascular function. During chronic consumption BP appears to be lowered and both dyslipidaemia and hyperglacaemia seem to be controlled. Limited number of trials investigated the effects of dairy proteins on oxidative stress and inflammation. Although the underlying mechanisms of milk proteins on cardiometabolic homeostasis remains to be elucidated, the most likely mechanism is to improve insulin resistance. The incorporation of meals enriched with dairy protein in the habitual diet may result in the beneficial effects on cardiometabolic health. Nevertheless, future well-designed, controlled studies are needed to investigate the relative effects of both casein and whey protein on BP, vascular function, glucose homeostasis and inflammation. PMID:27150497

  5. Insulin accelerates global and mitochondrial protein synthesis rates in neonatal muscle during sepsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In neonatal pigs, sepsis decreases protein synthesis in skeletal muscle by decreasing translation initiation. However, insulin stimulates muscle protein synthesis despite persistent repression of translation initiation signaling. To determine whether the insulin-induced increase in global rates of m...

  6. A Working Model of Protein Synthesis Using Lego(TM) Building Blocks.

    ERIC Educational Resources Information Center

    Templin, Mark A.; Fetters, Marcia K.

    2002-01-01

    Uses Lego building blocks to improve the effectiveness of teaching about protein synthesis. Provides diagrams and pictures for a 2-3 day student activity. Discusses mRNA, transfer RNA, and a protein synthesis model. (MVL)

  7. Effect of high pressures on the enzymatic activity of commercial milk protein coagulants

    NASA Astrophysics Data System (ADS)

    Wiśniewska, Krystyna; Reps, Arnold; Jankowska, Agnieszka

    2014-04-01

    This study was aimed at determining the effect of high pressures in the range of 100-1000 MPa/15 min, applied in 100 MPa increments, on the coagulating and proteolytic activity of commercial coagulants produced with genetic engineering methods: Maxiren, Chymogen, Chymax and of a natural rennin preparation, Hala. The coagulating activity of Hala preparation differed compared with the other preparations, due to greater resistance to high pressures, especially in the range of 500-600 MPa. The preparations produced with genetic engineering methods lost their capability for milk protein coagulation by 500 MPa. Pressurization at 200 MPa contributed to their reduced capability for casein macroproteolysis. In contrast, an increase in Chymax, Chymogen, Maxiren and Hala preparations' hydrolytic capability for the macroproteolysis of isoelectric casein was observed upon pressure treatment at 100 and 400 MPa and for microproteolysis after pressure treatment at 200 MPa. Storage (48 h/5°C) of the pressurized preparations had an insignificant effect on their coagulating and proteolytic activities.

  8. Middle East Consensus Statement on the Prevention, Diagnosis, and Management of Cow's Milk Protein Allergy

    PubMed Central

    Abuabat, Ahmed; Al-Hammadi, Suleiman; Aly, Gamal Samy; Miqdady, Mohamad S; Shaaban, Sanaa Youssef; Torbey, Paul-Henri

    2014-01-01

    Presented are guidelines for the prevention, diagnosis, and treatment of cow's milk protein allergy (CMPA) which is the most common food allergy in infants. It manifests through a variety of symptoms that place a burden on both the infant and their caregivers. The guidelines were formulated by evaluation of existing evidence-based guidelines, literature evidence and expert clinical experience. The guidelines set out practical recommendations and include algorithms for the prevention and treatment of CMPA. For infants at risk of allergy, appropriate prevention diets are suggested. Breastfeeding is the best method for prevention; however, a partially hydrolyzed formula should be used in infants unable to be breastfed. In infants with suspected CMPA, guidelines are presented for the appropriate diagnostic workup and subsequent appropriate elimination diet for treatment. Exclusive breastfeeding and maternal dietary allergen avoidance are the best treatment. In infants not exclusively breastfed, an extensively hydrolyzed formula should be used with amino acid formula recommended if the symptoms are life-threatening or do not resolve after extensively hydrolyzed formula. Adherence to these guidelines should assist healthcare practitioners in optimizing their approach to the management of CMPA and decrease the burden on infants and their caregivers. PMID:25061580

  9. Bioactive proteins and energy value of okara as a byproduct in hydrothermal processing of soy milk.

    PubMed

    Stanojevic, Sladjana P; Barac, Miroljub B; Pesic, Mirjana B; Jankovic, Vanja S; Vucelic-Radovic, Biljana V

    2013-09-25

    The nutritional properties of raw okara obtained as a byproduct from six soybean varieties during hydrothermal cooking (HTC) of soy milk were assessed. The composition and residual activity (rTIA) of trypsin inhibitors (TIs), contents of lectin, proteins, fats, and carbohydrates, and energy values (EV) were correlated with the respective physicochemical properties of soybean and okara. Kunitz (KTI) and Bowman-Birk (BBI) TIs both comprised okara rTIA. TIs content was higher in okara (5.19-14.40%) than in soybean (3.10-12.17%), which additionally enriched okara by cysteine. Contents of KTI (r = 1.00;p < 0.05) and BBI (r = 0.89;p < 0.05) as well as BBI monomeric (r = 0.89;p < 0.05) and polymeric forms (r = 0.95;p < 0.05) in okara and in soybean were strongly correlated. Low urease index activity indicated that okara was heated adequately to inactivate antinutritional factors. The proximate composition of raw okara, advantageous rTIA, and a very low EV (2.74-3.78 kJ/g) qualify this byproduct for potential application in food preparation as a functional ingredient in dietary products. PMID:23978042

  10. Low-fat meat sausages with fish oil: optimization of milk proteins and carrageenan contents using response surface methodology.

    PubMed

    Marchetti, L; Andrés, S C; Califano, A N

    2014-03-01

    Response surface methodology was used to analyze the effect of milk proteins and 2:1 κ:ι-carrageenans on cooking loss (CL), weight lost by centrifugation (WLC) and texture attributes of low-fat meat sausages with pre-emulsified fish oil. A central-composite design was used to develop models for the objective responses. Changes in carrageenans affected more the responses than milk proteins levels. Convenience functions were calculated for CL, WLC, hardness, and springiness of the product. Responses were optimized simultaneously minimizing CL and WLC; ranges for hardness and springiness corresponded to commercial products (20 g of pork fat/100 g). The optimum corresponded to 0.593 g of carrageenans/100 g and 0.320 g of milk proteins and its total lipid content was 6.3 g/100 g. This formulation was prepared and evaluated showing a good agreement between predicted and experimental responses. These additives could produce low-fat meat sausages with pre-emulsified fish oil with good nutritional quality and similar characteristics than traditional ones. PMID:24342180

  11. Efficacy of coating activated carbon with milk proteins to prevent binding of bacterial cells from foods for PCR detection.

    PubMed

    Opet, Nathan J; Levin, Robert E

    2013-08-01

    Foods contaminated with pathogens are common sources of illness. Currently, the most common and sensitive rapid detection method involves the PCR. However, food matrices are complex and contain inhibitors that limit the sensitivity of the PCR. The use of coated activated carbon can effectively facilitate the removal of PCR inhibitors without binding targeted bacterial cells from food samples. With the use of activated carbon coated with milk proteins, a cell recovery at pH 7.0 of 95.7%±2.0% was obtained, compared to control uncoated activated carbon, which yielded a cell recovery of only 1.1%±0.8%. In addition, the milk protein coated activated carbon was able to absorb similar amounts of soluble compounds as uncoated activated carbon, with the exception of bovine hemoglobin. This suggests that the use of milk proteins to coat activated carbon may therefore serve as a suitable replacement for bentonite in the coating of activated carbon, which has previously been used for the removal of PCR inhibitors from food. PMID:23680231

  12. Effects of milk proteins on release properties and particle morphology of β-carotene emulsions during in vitro digestion.

    PubMed

    Liu, Yuwei; Lei, Fei; Yuan, Fang; Gao, Yanxiang

    2014-11-01

    In the present study, β-lactoglobulin, sodium caseinate, lactalbumin and lactoferrin were used to prepare β-carotene emulsions. The milk protein-stabilized emulsions were explored using an in vitro release model to elucidate the effects of different milk proteins on β-carotene release properties in the stomach, duodenum and small intestine, respectively. Notable changes in the droplet size and size distribution were observed among these four oil-in-water (O/W) milk protein emulsions. In the gastric environment, the highest β-carotene release rate (2.9%) was achieved in β-lactoglobulin emulsion with a remarkable change in the particle size. In the simulated intestine, the best β-carotene micellarization potency (92%) was observed in β-lactoglobulin emulsion and its droplet diameter moderately increased from 215 nm to 471 nm. Moreover, substantial release of β-carotene was found in the small intestine for the four types of emulsions. It was concluded that β-carotene release in different digestive stages was characterized by the emulsion interfacial composition. PMID:25215854

  13. Thymol nanoemulsified by whey protein-maltodextrin conjugates: the enhanced emulsifying capacity and antilisterial properties in milk by propylene glycol.

    PubMed

    Xue, Jia; Davidson, P Michael; Zhong, Qixin

    2013-12-26

    The objective of this research was to enhance the capability of whey protein isolate-maltodextrin conjugates in nanoemulsifying thymol using propylene glycol to improve antilisterial properties in milk. Thymol was predissolved in PG and emulsified in 7% conjugate solution. Transparent dispersions with mean diameters of <30 nm were observed up to 1.5%w/v thymol. In skim and 2% reduced fat milk, Listeria monocytogenes Scott A was reduced from ∼5 log CFU/mL to below the detection limit in 6 h by 0.1% w/v and 0.45% w/v nanoemulsified thymol, respectively, contrasting with gradual reductions to 1.15 and 2.26 log CFU/mL after 48 h by same levels of free thymol. In full fat milk, L. monocytogenes was gradually reduced to be undetectable after 48 h by 0.6% w/v nanoemulsified thymol, contrasting with the insignificant reduction by free thymol. The improved antilisterial activities of nanoemulsified thymol resulted from the increased solubility in milk and synergistic activity with propylene glycol. PMID:24328082

  14. Tinkering with Translation: Protein Synthesis in Virus-Infected Cells

    PubMed Central

    Walsh, Derek; Mathews, Michael B.; Mohr, Ian

    2013-01-01

    Viruses are obligate intracellular parasites, and their replication requires host cell functions. Although the size, composition, complexity, and functions encoded by their genomes are remarkably diverse, all viruses rely absolutely on the protein synthesis machinery of their host cells. Lacking their own translational apparatus, they must recruit cellular ribosomes in order to translate viral mRNAs and produce the protein products required for their replication. In addition, there are other constraints on viral protein production. Crucially, host innate defenses and stress responses capable of inactivating the translation machinery must be effectively neutralized. Furthermore, the limited coding capacity of the viral genome needs to be used optimally. These demands have resulted in complex interactions between virus and host that exploit ostensibly virus-specific mechanisms and, at the same time, illuminate the functioning of the cellular protein synthesis apparatus. PMID:23209131

  15. Does trans-10, cis-12 conjugated linoleic acid affect the intermediary glucose and energy expenditure of dairy cows due to repartitioning of milk component synthesis?

    PubMed

    Benninghoff, Jens; Metzger-Petersen, Katrin; Tröscher, Arnulf H A; Südekum, Karl-Heinz

    2015-11-01

    The overall goal of this study was to evaluate if intermediary energy metabolism of cows fed with trans-10, cis-12 conjugated linoleic acid (CLA) was modified such that milk-energy compounds were produced with less intermediary energy expenditure as compared to control cows. Published data on supplemented CLA were assembled. The extent was calculated to which the trans-10, cis-12 CLA isomer has an impact on glucose and energy conversion in the mammary gland by modifying glucose equivalent supply and energy required for fatty acid (FA) and fat synthesis, and if this will eventually lead to an improved glucose and energy status of CLA-supplemented high-yielding dairy cows. A possible relationship between CLA supplementation level and milk energy yield response was also studied. Calculations were conducted separately for orally and abomasally administered CLA and based on energy required for supply of glucose equivalents, i.e. lactose, glycerol and NADPH2. Further, modifications of milk FA profile due to CLA supplementation were considered when energy expenditures for FA and fat synthesis were quantified. Differences in yields between control and CLA groups were transformed into glucose energy equivalents. Only abomasal infusion (r(2) = 0.31) but not oral CLA administration (r(2) = 0.11) supplementation to dairy cow diets resulted in less glucose equivalent energy. Modifications of milk FA profiles also saved energy but the relationship with CLA supplementation was weaker for abomasal infusion (r(2) = 0.06) than oral administration (r(2) = 0.38). On average, 10 g/d of abomasally infused trans-10, cis-12 CLA saved 1.1 to 2.3 MJ net energy expressed as glucose equivalents, whereas both positive and negative values were observed when the trans-10, cis-12 CLA was fed to the cows. This study revealed a weak to moderate dose-dependent relationship between the amount of trans-10, cis-12 CLA administered and the amount of energy in glucose equivalents and energy for the

  16. The role of casein-specific IgA and TGF-β in children with Food Protein-Induced Enterocolitis Syndrome to milk

    PubMed Central

    Konstantinou, George N.; Bencharitiwong, Ramon; Grishin, Alexander; Caubet, Jean-Christoph; Bardina, Luda; Sicherer, Scott H.; Sampson, Hugh A.; Nowak-Węgrzyn, Anna

    2014-01-01

    Background Food protein-induced enterocolitis syndrome (FPIES) is a gastrointestinal hypersensitivity disorder with a poorly understood pathophysiology and no biomarkers to aid in diagnosis. Objective To investigate humoral and cellular responses to casein in children with milk-FPIES, including the role of casein-specific (cs) IgA and T-cell mediated TGF-β responses. Patients and methods Thirty-one children previously diagnosed with milk-FPIES were challenged with milk. Twelve age-matched children with FPIES to other foods and 6 milk-tolerant children without a history of FPIES were used as controls. Casein-specific IgE, IgG, IgG4 and IgA were measured in serum and TGF-β levels in supernatants of casein-stimulated PBMCs. Result Twenty-six children with milk-FPIES reacted (active milk-FPIES) and five tolerated milk (milk-FPIES-resolved) during food challenge. All of them had significantly lower levels of csIgG, csIgG4 and csIgA than control children (p-value<0.001). There were no TGF-β responses in supernatants of active milk-FPIES children. Conclusion Children with milk-FPIES have low levels of csIgG, csIgG4 and csIgA. In particular, children with active FPIES to cow’s milk have deficient T-cell mediated TGF-β responses to casein, rendering TGF-β a promising biomarker in identifying children who are likely to experience FPIES reactions to this allergen. Prospective studies are needed to validate these findings, elucidate their role in FPIES pathophysiology and establish the diagnostic utility of TGF-β in milk-induced FPIES. PMID:25283440

  17. The effect of G protein-coupled receptor kinase 2 (GRK2) on lactation and on proliferation of mammary epithelial cells from dairy cows.

    PubMed

    Hou, Xiaoming; Hu, Hongliu; Lin, Ye; Qu, Bo; Gao, Xuejun; Li, Qingzhang

    2016-07-01

    Milk protein is an important component of milk and a nutritional source for human consumption. To better understand the molecular events underlying synthesis of milk proteins, the global gene expression patterns in mammary glands of dairy cow with high-quality milk (>3% milk protein; >3.5% milk fat) and low-quality milk (<3% milk protein; <3.5% milk fat) were examined via digital gene expression study. A total of 139 upregulated and 66 downregulated genes were detected in the mammary tissues of lactating cows with high-quality milk compared with the tissues of cows with low-quality milk. A pathway enrichment study of these genes revealed that the top 5 pathways that were differentially affected in the tissues of cows with high- versus low-quality milk involved metabolic pathways, cancer, cytokine-cytokine receptor interactions, regulation of the actin cytoskeleton, and insulin signaling. We also found that the G protein-coupled receptor kinase 2 (GRK2) was one of the most highly upregulated genes in lactating mammary tissue with low-quality milk compared with tissue with high-quality milk. The knockdown of GRK2 in cultured bovine mammary epithelial cells enhanced CSN2 expression and activated signaling molecules related to translation, including protein kinase B, mammalian target of rapamycin, and p70 ribosomal protein S6 kinase 1 (S6K1), whereas overexpression of GRK2 had the opposite effects. However, expression of genes involved in the mitogen-activated protein kinase pathway was positively regulated by GRK2. Therefore, GRK2 seems to act as a negative mediator of milk-protein synthesis via the protein kinase B-mammalian target of rapamycin signaling axis. Furthermore, GRK2 may negatively control milk-protein synthesis by activating the mitogen-activated protein kinase pathway in dairy cow mammary epithelial cells. PMID:27132107

  18. Synthesis and application of cephalexin imprinted polymer for solid phase extraction in milk.

    PubMed

    Lata, Kiran; Sharma, Rajan; Naik, Laxmana; Rajput, Y S; Mann, Bimlesh

    2015-10-01

    Molecular imprinted polymer (MIP) against cephalexin was synthesized by co-polymerization of functional monomer, cross-linker, radical initiator, along with target molecule (cephalexin) in a porogenic material. Binding of cephalexin towards prepared MIP was studied in different solvents (water, methanol, 1M NaCl, acetone and acetonitrile) and best binding was observed in methanol. Partition coefficient and selectivity of prepared imprint and non-imprint was also studied. Cross reactivity in terms of binding efficiency was also assessed with other antibiotics. Chromatographic study of MIP was carried out by packing prepared imprint into glass column. MIP was used as matrix in solid phase extraction (SPE) for recovery of cephalexin from spiked milk samples for further estimation by high performance liquid chromatography. No interference was observed from milk components after elution of cephalexin from MIP, indicating selectivity and affinity of MIP. On the other hand, interference was observed in eluate obtained from C18 SPE column. PMID:25872441

  19. Dehulling reduces toxicity and improves in vivo biological value of proteins in vegetal milk derived from two mucuna (Mucuna pruriens L.) seeds varieties.

    PubMed

    Mang, Yannick Dimitry; Njintang, Yanou Nicolas; Abdou, Bouba Armand; Scher, Joel; Bernard, Clémence; Mbofung, Moses C

    2016-06-01

    The present work was carried out to evaluate the nutritive quality (proximate and antinutrients composition) of vegetable milks prepared from whole and dehulled mucuna bean flours. Casein and mucuna milk diets were fed to rats (four weeks old; n = 8 per group) for 28 days to determine protein efficiency ratio (PER), net protein efficiency ratio (NPER), true and apparent digestibility (TD and AD, respectively), organ-to-body weight ratios and hematological parameters. The experimental design was a factorial design with two variety of mucuna (cochinchinensis and veracruz) and two treatments (whole and dehulled beans). Protein, total sugar, dry matter and ash-content of mucuna milks ranged from 6.40 to 12.13 g/100 mL, 10.52 to 13.08 g/100 mL, 8.59 to 12.88 g/100 g and 0.31 to 0.92 g/100 g, respectively. Milks from dehulled flours had lower contents of tannins (80-87.08 %), phytates (76.67-78.16 %) and L-Dopamine (44.45-66.66 %) than that from whole flours. The PER of dehulled mucuna diets were 22.76-21.74 %, but negative PER and low NPER was observed for whole mucuna milk diets. TD for dehulled mucuna milk (85.15-85.96 %) were higher and similar to casein when compared to that of whole mucuna milk (47.87-51.17 %). Rats fed with diets containing whole mucuna milk lost weight and had higher kidney weight. In addition, the rats fed with milk from whole mucuna flours showed significantly lower levels of lymphocytes, granulocytes, red blood cells, hemoglobin and hematocrit than that fed with dehulled mucuna milk. PMID:27478210

  20. Leucine acts as a nutrient signal to stimulate protein synthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The postprandial rise in amino acids and insulin independently stimulates protein synthesis in skeletal muscle of piglets. Leucine is an important mediator of the response to amino acids. We have shown that the postprandial rise in leucine, but not isoleucine or valine, acutely stimulates muscle pro...

  1. The Teaching of Protein Synthesis--A Microcomputer Based Method.

    ERIC Educational Resources Information Center

    Goodridge, Frank

    1983-01-01

    Describes two computer programs (BASIC for 32K Commodore PET) for teaching protein synthesis. The first is an interactive test of base-pairing knowledge, and the second generates random DNA nucleotide sequences, with instructions for substitution, insertion, and deletion printed out for each student. (JN)

  2. Problem-Solving Test: The Mechanism of Protein Synthesis

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2009-01-01

    Terms to be familiar with before you start to solve the test: protein synthesis, ribosomes, amino acids, peptides, peptide bond, polypeptide chain, N- and C-terminus, hemoglobin, [alpha]- and [beta]-globin chains, radioactive labeling, [[to the third power]H] and [[to the fourteenth power]C]leucine, cytosol, differential centrifugation, density…

  3. The Development of an Interactive Videodisc Program on Protein Synthesis.

    ERIC Educational Resources Information Center

    Hazan, Charlene Corey

    An interactive videodisk (IVD) program was developed to reinforce learning of the biological concept of protein synthesis for high school students. The laser videodisc "The Living Textbook Life Science" was the source of frames, and the authoring system of G. Smith was used to create the disc. The interactive program was designed to make the…

  4. Protein Synthesis Inhibition Blocks Consolidation of an Acrobatic Motor Skill

    ERIC Educational Resources Information Center

    Kaelin-Lang, Alain; Dichgans, Johannes; Schulz, Jorg B.; Luft, Andreas R.; Buitrago, Manuel M.

    2004-01-01

    To investigate whether motor skill learning depends on de novo protein synthesis, adult rats were trained in an acrobatic locomotor task (accelerating rotarod) for 7 d. Animals were systemically injected with cycloheximide (CHX, 0.5 mg/kg, i.p.) 1 h before sessions 1 and 2 or sessions 2 and 3. Control rats received vehicle injections before…

  5. Transcriptional profiling of mammary gland in Holstein cows with extremely different milk protein and fat percentage using RNA sequencing

    PubMed Central

    2014-01-01

    Background Recently, RNA sequencing (RNA-seq) has rapidly emerged as a major transcriptome profiling system. Elucidation of the bovine mammary gland transcriptome by RNA-seq is essential for identifying candidate genes that contribute to milk composition traits in dairy cattle. Results We used massive, parallel, high-throughput, RNA-seq to generate the bovine transcriptome from the mammary glands of four lactating Holstein cows with extremely high and low phenotypic values of milk protein and fat percentage. In total, we obtained 48,967,376–75,572,578 uniquely mapped reads that covered 82.25% of the current annotated transcripts, which represented 15549 mRNA transcripts, across all the four mammary gland samples. Among them, 31 differentially expressed genes (p < 0.05, false discovery rate q < 0.05) between the high and low groups of cows were revealed. Gene ontology and pathway analysis demonstrated that the 31 differently expressed genes were enriched in specific biological processes with regard to protein metabolism, fat metabolism, and mammary gland development (p < 0.05). Integrated analysis of differential gene expression, previously reported quantitative trait loci, and genome-wide association studies indicated that TRIB3, SAA (SAA1, SAA3, and M-SAA3.2), VEGFA, PTHLH, and RPL23A were the most promising candidate genes affecting milk protein and fat percentage. Conclusions This study investigated the complexity of the mammary gland transcriptome in dairy cattle using RNA-seq. Integrated analysis of differential gene expression and the reported quantitative trait loci and genome-wide association study data permitted the identification of candidate key genes for milk composition traits. PMID:24655368

  6. The Level of Protein in Milk Formula Modifies Ileal Sensitivity to LPS Later in Life in a Piglet Model

    PubMed Central

    Gras-Le Guen, Christèle; Lallès, Jean-Paul; Le Huërou-Luron, Isabelle; Boudry, Gaëlle

    2011-01-01

    Background Milk formulas have higher protein contents than human milk. This high protein level could modify the development of intestinal microbiota, epithelial barrier and immune functions and have long-term consequences. Methodology/Principal findings We investigated the effect of a high protein formula on ileal microbiota and physiology during the neonatal period and later in life. Piglets were fed from 2 to 28 days of age either a normoprotein (NP, equivalent to sow milk) or a high protein formula (HP, +40% protein). Then, they received the same solid diet until 160 days. During the formula feeding period ileal microbiota implantation was accelerated in HP piglets with greater concentrations of ileal bacteria at d7 in HP than NP piglets. Epithelial barrier function was altered with a higher permeability to small and large probes in Ussing chambers in HP compared to NP piglets without difference in bacterial translocation. Infiltration of T cells was increased in HP piglets at d28. IL-1β and NF-κB sub-units mRNA levels were reduced in HP piglets at d7 and d28 respectively; plasma haptoglobin also tended to be reduced at d7. Later in life, pro-inflammatory cytokines secretion in response to high doses of LPS in explants culture was reduced in HP compared to NP piglets. Levels of mRNA coding the NF-κB pathway sub-units were increased by the challenge with LPS in NP piglets, but not HP ones. Conclusions/Significance A high protein level in formula affects the postnatal development of ileal microbiota, epithelial barrier and immune function in piglets and alters ileal response to inflammatory mediators later in life. PMID:21573022

  7. Enhanced skeletal muscle protein synthesis rates in pigs treated with somatotropin requires fed amino acids levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chronic somatotropin (pST) treatment in pigs increases skeletal muscle protein synthesis and circulating insulin, a known promoter of protein synthesis. Previously, we showed that the pST-mediated rise in insulin alone could not account for the pST-induced increase in protein synthesis. This study...

  8. AMINO ACIDS AUGMENT MUSCLE PROTEIN SYNTHESIS IN NEONATAL PIGS DURING ENDOTOXEMIA BY MODULATING TRANSLATION INITIATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In adults, sepsis reduces protein synthesis in skeletal muscle by restraining translation. The effect of sepsis on amino acid-stimulated muscle protein synthesis has not been determined in neonates, a population who is highly anabolic and whose muscle protein synthesis rates are uniquely sensitive ...

  9. The effect of a partially hydrolysed formula based on rice protein in the treatment of infants with cow’s milk protein allergy

    PubMed Central

    Reche, M; Pascual, C; Fiandor, A; Polanco, I; Rivero-Urgell, M; Chifre, R; Johnston, S; Martín-Esteban, M

    2010-01-01

    Reche M, Pascual C, Fiandor A, Polanco I, Rivero-Urgell M, Chifre R, Johnston S, Martín-Esteban M. The effect of a partially hydrolysed formula based on rice protein in the treatment of infants with cow’s milk protein allergy. Pediatr Allergy Immunol 2010: 21: 577–585. © 2010 John Wiley & Sons A/S Infants diagnosed with allergy to cow’s milk protein (CMP) are fed extensively hydrolysed cow’s milk formulas, modified soy formulas or even amino acid-based formulas. Hydrolysed rice protein infant formulas have become available and have been shown to be well tolerated by these infants. A prospective open, randomized clinical study to compare the clinical tolerance of a new hydrolysed rice protein formula (HRPF) with an extensively hydrolysed CMP formula (EHF) in the feeding of infants with IgE-mediated cow’s milk allergy. Ninety-two infants (46 boys and 46 girls, mean age 4.3 months, range 1.1–10.1 months) diagnosed with IgE-mediated cow’s milk allergy were enrolled in the study. Clinical tolerance to the formula products was tested. Clinical evaluation included skin prick tests with whole cow’s milk, soya and rice as well as antigens of CMP (beta-lactoglobulin, alpha-lactalbumin, casein and bovine seroalbumin), HRPF and EHF and specific IgE determinations to CMP using CAP technology. Patients were randomized to receive either an EHF based on CMP or a new HRPF. Follow-up was at 3, 6, 12, 18 and 24 months. Growth parameters were measured at each visit. One infant showed immediate allergic reaction to EHF, but no reaction was shown by any infant in the HRPF group. The number of infants who did not become tolerant to CMP during the study was not statistically different between the two groups. Measurement of IgE levels of infants allergic to CMP during the study showed no significant differences between the two formula groups. Growth parameters were in the normal range and similar between groups. In this study, the HRPF was well tolerated by infants with

  10. Ultrafiltration of skimmed goat milk increases its nutritional value by concentrating nonfat solids such as proteins, Ca, P, Mg, and Zn.

    PubMed

    Moreno-Montoro, Miriam; Olalla, Manuel; Giménez-Martínez, Rafael; Bergillos-Meca, Triana; Ruiz-López, María Dolores; Cabrera-Vique, Carmen; Artacho, Reyes; Navarro-Alarcón, Miguel

    2015-11-01

    Goat milk has been reported to possess good nutritional and health-promoting properties. Usually, it must be concentrated before fermented products can be obtained. The aim of this study was to compare physicochemical and nutritional variables among raw (RM), skimmed (SM), and ultrafiltration-concentrated skimmed (UFM) goat milk. The density, acidity, ash, protein, casein, whey protein, Ca, P, Mg, and Zn values were significantly higher in UFM than in RM or SM. Dry extract and fat levels were significantly higher in UFM than in SM, and Mg content was significantly higher in UFM than in RM. Ultrafiltration also increased the solubility of Ca and Mg, changing their distribution in the milk. The higher concentrations of minerals and proteins, especially caseins, increase the nutritional value of UFM, which may therefore be more appropriate for goat milk yogurt manufacturing in comparison to RM or SM. PMID:26342988

  11. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults.

    PubMed

    Mamerow, Madonna M; Mettler, Joni A; English, Kirk L; Casperson, Shanon L; Arentson-Lantz, Emily; Sheffield-Moore, Melinda; Layman, Donald K; Paddon-Jones, Douglas

    2014-06-01

    The RDA for protein describes the quantity that should be consumed daily to meet population needs and to prevent deficiency. Protein consumption in many countries exceeds the RDA; however, intake is often skewed toward the evening meal, whereas breakfast is typically carbohydrate rich and low in protein. We examined the effects of protein distribution on 24-h skeletal muscle protein synthesis in healthy adult men and women (n = 8; age: 36.9 ± 3.1 y; BMI: 25.7 ± 0.8 kg/m2). By using a 7-d crossover feeding design with a 30-d washout period, we measured changes in muscle protein synthesis in response to isoenergetic and isonitrogenous diets with protein at breakfast, lunch, and dinner distributed evenly (EVEN; 31.5 ± 1.3, 29.9 ± 1.6, and 32.7 ± 1.6 g protein, respectively) or skewed (SKEW; 10.7 ± 0.8, 16.0 ± 0.5, and 63.4 ± 3.7 g protein, respectively). Over 24-h periods on days 1 and 7, venous blood samples and vastus lateralis muscle biopsy samples were obtained during primed (2.0 μmol/kg) constant infusion [0.06 μmol/(kg⋅min)] of l-[ring-(13)C6]phenylalanine. The 24-h mixed muscle protein fractional synthesis rate was 25% higher in the EVEN (0.075 ± 0.006%/h) vs. the SKEW (0.056 ± 0.006%/h) protein distribution groups (P = 0.003). This pattern was maintained after 7 d of habituation to each diet (EVEN vs. SKEW: 0.077 ± 0.006 vs. 0.056 ± 0.006%/h; P = 0.001). The consumption of a moderate amount of protein at each meal stimulated 24-h muscle protein synthesis more effectively than skewing protein intake toward the evening meal. PMID:24477298

  12. Optimization of protein fractionation by skim milk microfiltration: Choice of ceramic membrane pore size and filtration temperature.

    PubMed

    Jørgensen, Camilla Elise; Abrahamsen, Roger K; Rukke, Elling-Olav; Johansen, Anne-Grethe; Schüller, Reidar B; Skeie, Siv B

    2016-08-01

    The objective of this study was to investigate how ceramic membrane pore size and filtration temperature influence the protein fractionation of skim milk by cross flow microfiltration (MF). Microfiltration was performed at a uniform transmembrane pressure with constant permeate flux to a volume concentration factor of 2.5. Three different membrane pore sizes, 0.05, 0.10, and 0.20µm, were used at a filtration temperature of 50°C. Furthermore, at pore size 0.10µm, 2 different filtration temperatures were investigated: 50 and 60°C. The transmission of proteins increased with increasing pore size, giving the permeate from MF with the 0.20-µm membrane a significantly higher concentration of native whey proteins compared with the permeates from the 0.05- and 0.10-µm membranes (0.50, 0.24, and 0.39%, respectively). Significant amounts of caseins permeated the 0.20-µm membrane (1.4%), giving a permeate with a whitish appearance and a casein distribution (αS2-CN: αS1-CN: κ-CN: β-CN) similar to that of skim milk. The 0.05- and 0.10-µm membranes were able to retain all caseins (only negligible amounts were detected). A permeate free from casein is beneficial in the production of native whey protein concentrates and in applications where transparency is an important functional characteristic. Microfiltration of skim milk at 50°C with the 0.10-µm membrane resulted in a permeate containing significantly more native whey proteins than the permeate from MF at 60°C. The more rapid increase in transmembrane pressure and the significantly lower concentration of caseins in the retentate at 60°C indicated that a higher concentration of caseins deposited on the membrane, and consequently reduced the native whey protein transmission. Optimal protein fractionation of skim milk into a casein-rich retentate and a permeate with native whey proteins were obtained by 0.10-µm MF at 50°C. PMID:27265169

  13. An oxygen-regulated switch in the protein synthesis machinery

    PubMed Central

    Uniacke, James; Holterman, Chet E.; Lachance, Gabriel; Franovic, Aleksandra; Jacob, Mathieu D.; Fabian, Marc R.; Payette, Josianne; Holcik, Martin; Pause, Arnim; Lee, Stephen

    2016-01-01

    SUMMARY Protein synthesis involves the translation of ribonucleic acid information into proteins, the building blocks of life. The initial step of protein synthesis consists of the eukaryotic translation initiation factor 4E (eIF4E) binding to the 7-methylguanosine (m7-GpppG) 5′cap of mRNAs1,2. Low oxygen tension (hypoxia) represses cap-mediated translation by sequestering eIF4E through mammalian target of rapamycin (mTOR)-dependent mechanisms3–6. While the internal ribosome entry site is an alternative translation initiation mechanism, this pathway alone cannot account for the translational capacity of hypoxic cells7,8. This raises a fundamental question in biology as to how proteins are synthesized in periods of oxygen scarcity and eIF4E inhibition9. Here, we uncover an oxygen-regulated translation initiation complex that mediates selective cap-dependent protein synthesis. Hypoxia stimulates the formation of a complex that includes the oxygen-regulated hypoxia-inducible factor 2α (HIF-2α), the RNA binding protein RBM4 and the cap-binding eIF4E2, an eIF4E homologue. PAR-CLIP10 analysis identified an RNA hypoxia response element (rHRE) that recruits this complex to a wide array mRNAs, including the epidermal growth factor receptor (EGFR). Once assembled at the rHRE, HIF-2α/RBM4/eIF4E2 captures the 5′cap and targets mRNAs to polysomes for active translation thereby evading hypoxia-induced repression of protein synthesis. These findings demonstrate that cells have evolved a program whereby oxygen tension switches the basic translation initiation machinery. PMID:22678294

  14. Variability of the caprine whey protein genes and their association with milk yield, composition and renneting properties in the Sarda breed: 2. The BLG gene.

    PubMed

    Dettori, Maria Luisa; Pazzola, Michele; Pira, Emanuela; Puggioni, Ornella; Vacca, Giuseppe Massimo

    2015-11-01

    The variability of the promoter region and the 3'UTR (exon-7) of the BLG gene, encoding the β-lactoglobulin, was investigated by sequencing in 263 lactating Sarda goats in order to assess its association with milk traits. Milk traits included: milk yield, fat, total protein and lactose content, pH, daily fat and protein yield (DFPY), freezing point, milk energy, somatic cell count, total microbial mesophilic count, rennet coagulation time (RCT), curd firming rate (k20) and curd firmness (a30). A total of 7 polymorphic sites were detected and the sequence analysed was given accession number KM817769. Only three SNPs (c.-381C>T, c.-323C>T and c.*420C>A) had minor allele frequency higher than 0.05. The effects of farm, stage of lactation and the interaction farm × stage of lactation significantly influenced all the milk traits (P T and c.*420C>A (P T (P < 0.001). The c.-381TT homozygous goats showed lower pH, RCT and k20 than c.-381CT (P < 0.05). In conclusion the polymorphism of the goat BLG gene did not affect the total protein content of the Sarda goat milk, and only weakly influenced RCT and k20. On the other hand, an interesting effect on milk yields and DFPY emerged in two SNPs. This information might be useful in dairy goat breeding programs. PMID:26373476

  15. Separation and quantification of milk casein from different buffalo breeds.

    PubMed

    Li, Shanshan; Li, Ling; Zeng, Qingkun; Liu, Jianxin; Ren, Daxi

    2016-08-01

    Understanding the milk protein expression profile in different buffalo breeds plays an important role in improving hybrid selection and determining the effects on milk protein synthesis. The aim of this research is to compare the differences in milk protein content, composition and distribution between River buffalo and their crossbreeds for hybrid screening. Four groups of milk samples that included Nili-Ravi (N), Murrah (M), a Nili-Ravi-Murrah crossbreed (M-N), and a crossbreed of river buffalo with local swamp buffalo (C) were collected. The protein composition of the buffalo milk was determined by RP-HPLC. A gel-based proteomic approach consisting of two-dimensional gel electrophoresis coupled with mass spectrometry was utilised for the detailed protein characterisation of milk from different breeds. The results of this analysis showed that the river/swamp buffalo crossbreed (C) displayed the highest content of total protein (4·46%) and κ-casein (11·14%) but the lowest content of α-lactalbumin (6·79%). By selecting 23 different protein spots among the four types of milk that contained the most spots corresponding to κ-casein, β-casein and αs1-casein, correlations between the crossbreeds, protein polymorphism and phosphorylation could be made. The results of this study indicate that crossbreeding a swamp buffalo with a river buffalo has a notable effect on the protein content and composition that may be exploited for producing high-quality raw milk in food technology applications and dairy food production. PMID:27600966

  16. Inhibition of human carcinoma cell growth and DNA synthesis by silibinin, an active constituent of milk thistle: comparison with silymarin.

    PubMed

    Bhatia, N; Zhao, J; Wolf, D M; Agarwal, R

    1999-12-01

    Several studies from our laboratory have shown the cancer chemopreventive and anti-carcinogenic effects of silymarin, a flavonoid antioxidant isolated from milk thistle, in long-term tumorigenesis models and in human prostate, breast and cervical carcinoma cells. Since silymarin is composed mainly of silibinin with small amounts of other stereoisomers of silibinin, in the present communication, studies were performed to assess whether the cancer preventive and anti-carcinogenic effects of silymarin are due to its major component silibinin. Treatment of different prostate, breast, and cervical human carcinoma cells with silibinin resulted in a highly significant inhibition of both cell growth and DNA synthesis in a time-dependent manner with large loss of cell viability only in case of cervical carcinoma cells. When compared with silymarin, these effects of silibinin were consistent and comparable in terms of cell growth and DNA synthesis inhibition, and loss of cell viability. Based on the comparable results of silibinin and silymarin, we suggest that the cancer chemopreventive and anti-carcinogenic effects of silymarin reported earlier are due to the main constituent silibinin. PMID:10660092

  17. Transcriptional regulation of decreased protein synthesis during skeletal muscle unloading

    NASA Technical Reports Server (NTRS)

    Howard, G.; Steffen, J. M.; Geoghegan, T. E.

    1989-01-01

    The regulatory role of transcriptional alterations in unloaded skeletal muscles was investigated by determining levels of total muscle RNA and mRNA fractions in soleus, gastrocnemius, and extensor digitorum longus (EDL) of rats subjected to whole-body suspension for up to 7 days. After 7 days, total RNA and mRNA contents were lower in soleus and gastrocnemius, compared with controls, but the concentrations of both RNAs per g muscle were unaltered. Alpha-actin mRNA (assessed by dot hybridization) was significantly reduced in soleus after 1, 3, and 7 days of suspension and in gastrocnemius after 3 and 7 days, but was unchanged in EDL. Protein synthesis directed by RNA extracted from soleus and EDL indicated marked alteration in mRNAs coding for several small proteins. Results suggest that altered transcription and availability of specific mRNAs contribute significantly to the regulation of protein synthesis during skeletal muscle unloading.

  18. Potential of the Virion-Associated Peptidoglycan Hydrolase HydH5 and Its Derivative Fusion Proteins in Milk Biopreservation

    PubMed Central

    Rodríguez-Rubio, Lorena; Martínez, Beatriz; Donovan, David M.; García, Pilar; Rodríguez, Ana

    2013-01-01

    Bacteriophage lytic enzymes have recently attracted considerable interest as novel antimicrobials against Gram-positive bacteria. In this work, antimicrobial activity in milk of HydH5 [a virion-associated peptidoglycan hydrolase (VAPGH) encoded by the Staphylococcus aureus bacteriophage vB_SauS-phiIPLA88], and three different fusion proteins created between HydH5 and lysostaphin has been assessed. The lytic activity of the five proteins (HydH5, HydH5Lyso, HydH5SH3b, CHAPSH3b and lysostaphin) was confirmed using commercial whole extended shelf-life milk (ESL) in challenge assays with 104 CFU/mL of the strain S. aureus Sa9. HydH5, HydH5Lyso and HydH5SH3b (3.5 µM) kept the staphylococcal viable counts below the control cultures for 6 h at 37°C. The effect is apparent just 15 minutes after the addition of the lytic enzyme. Of note, lysostaphin and CHAPSH3b showed the highest staphylolytic protection as they were able to eradicate the initial staphylococcal challenge immediately or 15 min after addition, respectively, at lower concentration (1 µM) at 37°C. CHAPSH3b showed the same antistaphyloccal effect at room temperature (1.65 µM). No re-growth was observed for the remainder of the experiment (up to 6 h). CHAPSH3b activity (1.65 µM) was also assayed in raw (whole and skim) and pasteurized (whole and skim) milk. Pasteurization of milk clearly enhanced CHAPSH3b staphylolytic activity in both whole and skim milk at both temperatures. This effect was most dramatic at room temperature as this protein was able to reduce S. aureus viable counts to undetectable levels immediately after addition with no re-growth detected for the duration of the experiment (360 min). Furthermore, CHAPSH3b protein is known to be heat tolerant and retained some lytic activity after pasteurization treatment and after storage at 4°C for 3 days. These results might facilitate the use of the peptidoglycan hydrolase HydH5 and its derivative fusions, particularly CHAPSH3b, as biocontrol agents

  19. Whey protein gel composites in the diet of goats increased the omega-3 and omega-6 content of milk fat.

    PubMed

    Weinstein, J A; Taylor, S J; Rosenberg, M; DePeters, E J

    2016-08-01

    Previously, feeding whey protein gels containing polyunsaturated fatty acids (PUFA) reduced their rumen biohydrogenation and increased their concentration in milk fat of Holstein cows. Our objective was to test the efficacy of whey protein isolate (WPI) gels produced in a steam tunnel as a method to alter the fatty acid (FA) composition of the milk lipids. Four primiparous Lamancha goats in midlactation were fed three diets in a 3 × 4 Latin square design. The WPI gels were added to a basal concentrate mix that contained one of three lipid sources: (i) 100% soya bean oil (S) to create (WPI/S), (ii) a 1:1 (wt/wt) mixture of S and linseed (L) oil to create (WPI/SL), or (iii) 100% L to create (WPI/L). Periods were 22 days with the first 10 days used as an adjustment phase followed by a 12-day experimental phase. During the adjustment phase, all goats received a rumen available source of lipid, yellow grease, to provide a baseline for milk FA composition. During the experimental phase, each goat received its assigned WPI. Milk FA concentration of C18:2 n-6 and C18:3 n-3 reached 9.3 and 1.64 g/100 g FA, respectively, when goats were fed WPI/S. Feeding WPI/SL increased the C18:2 n-6 and C18:3 n-3 concentration to 6.22 and 4.36 g/100 g FA, and WPI/L increased C18:2 n-6 and C18:3 n-3 to 3.96 and 6.13 g/100 g FA respectively. The adjusted transfer efficiency (%) of C18:3 n-3 to milk FA decreased significantly as dietary C18:3 n-3 intake increased. Adjusted transfer efficiency for C18:2 n-6 did not change with increasing intake of C18:2 n-6. The WPI gels were effective at reducing rumen biohydrogenation of PUFA; however, we observed a change in the proportion increase of C18:3 n-3 in milk FA suggesting possible regulation of n-3 FA to the lactating caprine mammary gland. PMID:26249647

  20. [Application of infrared spectroscopy technique to protein content fast measurement in milk powder based on support vector machines].

    PubMed

    Wu, Di; Cao, Fang; Feng, Shui-Juan; He, Yong

    2008-05-01

    In the present study, the JASCO Model FTIR-4 000 fourier transform infrared spectrometer (Japan) was used, with a valid range of 7 800-350 cm(-1). Seven brands of milk powder were bought in a local supermarket. Milk powder was compressed into a uniform tablet with a diameter of 5 mm and a thickness of 2 mm, and then scanned by the spectrometer. Each sample was scanned 40 times and the data were averaged. About 60 samples were measured for each brand, and data for 409 samples were obtained. NIRS analysis was based on the range of 4 000 to 6 666 cm(-1), while MIRS analysis was between 400 and 4 000 cm(-1). The protein content was determined by kjeldahl method and the factor 6.38 was used to convert the nitrogen values to protein. The protein content value is the weight of protein per 100 g of milk powder. The NIR data of the milk powder exhibited slight differences. Univariate analysis was not really appropriate for analyzing the data sets. From NIRS region, it could be observed that the trend of different curves is similar. The one around 4 312 cm(-1) embodies the vibration of protein. From MIRS region, it could be determined that there are many differences between transmission value curves. Two troughs around 1 545 and 1 656 cm(-1) stand for the vibration of amide I and II bands of protein. The smoothing way of Savitzky-Golay with 3 segments and zero polynomials and multiplicative scatter correction (MSC) were applied for denoising. First 8 important principle components (PCs), which were obtained from principle component analysis (PCA), were the optimal input feature subset. Least-squares support vector machines was applied to build the protein prediction model based on infrared spectral transmission value. The prediction result was better than that of traditional PLS regression model as the determination coefficient for prediction (R(p)2) is 0.951 7 and root mean square error for prediction (RMSEP) is 0.520 201. These indicate that LS-SVM is a powerful tool for

  1. Predicting grass dry matter intake, milk yield and milk fat and protein yield of spring calving grazing dairy cows during the grazing season.

    PubMed

    O'Neill, B F; Lewis, E; O'Donovan, M; Shalloo, L; Galvin, N; Mulligan, F J; Boland, T M; Delagarde, R

    2013-08-01

    Predicting the grass dry matter intake (GDMI), milk yield (MY) or milk fat and protein yield (milk solids yield (MSY)) of the grazing dairy herd is difficult. Decisions with regard to grazing management are based on guesstimates of the GDMI of the herd, yet GDMI is a critical factor influencing MY and MSY. A data set containing animal, sward, grazing management and concentrate supplementation variables recorded during weeks of GDMI measurement was used to develop multiple regression equations to predict GDMI, MY and MSY. The data set contained data from 245 grazing herds from 10 published studies conducted at Teagasc, Moorepark. A forward stepwise multiple regression technique was used to develop the multiple regression equations for each of the dependent variables (GDMI, MY, MSY) for three periods during the grazing season: spring (SP; 5 March to 30 April), summer (SU; 1 May to 31 July) and autumn (AU; 1 August to 31 October). The equations generated highlighted the importance of different variables associated with GDMI, MY and MSY during the grazing season. Peak MY was associated with an increase in GDMI, MY and MSY during the grazing season with the exception of GDMI in SU when BW accounted for more of the variation. A higher body condition score (BCS) at calving was associated with a lower GDMI in SP and SU and a lower MY and MSY in all periods. A higher BCS was associated with a higher GDMI in SP and SU, a higher MY in SU and AU and a higher MSY in all periods. The pre-grazing herbage mass of the sward (PGHM) above 4 cm was associated with a quadratic effect on GDMI in SP, on MY in SP and SU and on MSY in SU. An increase in daily herbage allowance (DHA) above 4 cm was associated with an increase in GDMI in AU, an increase in MY in SU and AU and MSY in AU. Supplementing grazing dairy cows with concentrate reduced GDMI and increased MY and MSY in all periods. The equations generated can be used by the Irish dairy industry during the grazing season to predict the

  2. Mastitomics, the integrated omics of bovine milk in an experimental model of Streptococcus uberis mastitis: 1. High abundance proteins, acute phase proteins and peptidomics.

    PubMed

    Thomas, Funmilola Clara; Mullen, William; Tassi, Riccardo; Ramírez-Torres, Adela; Mudaliar, Manikhandan; McNeilly, Tom N; Zadoks, Ruth N; Burchmore, Richard; David Eckersall, P

    2016-08-16

    A peptidomic investigation of milk from an experimental model of Streptococcus uberis mastitis in dairy cows has incorporated a study of milk high abundance and acute phase (APP) proteins as well as analysis of low molecular weight peptide biomarkers. Intramammary infection (IMI) with S. uberis caused a shift in abundance from caseins, β-lactoglobulin and α-lactalbumin to albumin, lactoferrin and IgG with the increase in lactoferrin occurring last. The APP response of haptoglobin, mammary associated serum amyloid A3 and C-reactive protein occurred between 30-48 hours post challenge with peak concentrations of APPs at 72-96 hours post challenge and declined thereafter at a rate resembling the fall in bacterial count rather than the somatic cell count. A peptide biomarker panel for IMI based on capillary electrophoresis and mass spectrometry was developed. It comprised 77 identified peptides (IMI77) composed mainly of casein derived peptides but also including peptides of glycosylation dependent cell adhesion molecule and serum amyloid A. The panel had a biomarker classification score that increased from 36 hour to 81 hour post challenge, significantly differentiating infected from non-infected milk, thus suggesting potential as a peptide biomarker panel of bovine mastitis and specifically that of S. uberis origin. The use of omic technology has shown a multifactorial cross system reaction in high and low abundance proteins and their peptide derivatives with changes of over a thousand fold in analyte levels in response to S. uberis infection. PMID:27412456

  3. An extensively hydrolysed rice protein-based formula in the management of infants with cow's milk protein allergy: preliminary results after 1 month

    PubMed Central

    Vandenplas, Yvan; De Greef, Elisabeth; Hauser, Bruno

    2014-01-01

    Background Guidelines recommend extensively hydrolysed cow's milk protein formulas (eHF) in the treatment of infants diagnosed with cow's milk protein allergy (CMPA). Extensively hydrolysed rice protein infant formulas (eRHFs) have recently become available, and could offer a valid alternative. Methods A prospective trial was performed to evaluate the clinical tolerance of a new eRHF in infants with a confirmed CMPA. Patients were followed for 1 month. Clinical tolerance of the eRHF was evaluated with a symptom-based score (SBS) and growth (weight and length) was monitored. Results Thirty-nine infants (mean age 3.4 months, range 0.5–6 months) diagnosed with CMPA were enrolled. All infants tolerated the eRHF and experienced a normal growth. Conclusions In accordance with current guidelines, this eRHF is tolerated by more than 90% of children with proven CMPA with a 95% CI, and is an adequate alternative to cow's milk-based eHF. Trial registration number ClinicalTrials.gov NCT01998074. PMID:24914098

  4. Comparative 2D-DIGE proteomic analysis of bovine mammary epithelial cells during lactation reveals protein signatures for lactation persistency and milk yield.

    PubMed

    Janjanam, Jagadeesh; Singh, Surender; Jena, Manoj K; Varshney, Nishant; Kola, Srujana; Kumar, Sudarshan; Kaushik, Jai K; Grover, Sunita; Dang, Ajay K; Mukesh, Manishi; Prakash, B S; Mohanty, Ashok K

    2014-01-01

    Mammary gland is made up of a branching network of ducts that end with alveoli which surrounds the lumen. These alveolar mammary epithelial cells (MEC) reflect the milk producing ability of farm animals. In this study, we have used 2D-DIGE and mass spectrometry to identify the protein changes in MEC during immediate early, peak and late stages of lactation and also compared differentially expressed proteins in MEC isolated from milk of high and low milk producing cows. We have identified 41 differentially expressed proteins during lactation stages and 22 proteins in high and low milk yielding cows. Bioinformatics analysis showed that a majority of the differentially expressed proteins are associated in metabolic process, catalytic and binding activity. The differentially expressed proteins were mapped to the available biological pathways and networks involved in lactation. The proteins up-regulated during late stage of lactation are associated with NF-κB stress induced signaling pathways and whereas Akt, PI3K and p38/MAPK signaling pathways are associated with high milk production mediated through insulin hormone signaling. PMID:25111801

  5. Comparative 2D-DIGE Proteomic Analysis of Bovine Mammary Epithelial Cells during Lactation Reveals Protein Signatures for Lactation Persistency and Milk Yield

    PubMed Central

    Janjanam, Jagadeesh; Singh, Surender; Jena, Manoj K.; Varshney, Nishant; Kola, Srujana; Kumar, Sudarshan; Kaushik, Jai K.; Grover, Sunita; Dang, Ajay K.; Mukesh, Manishi; Prakash, B. S.; Mohanty, Ashok K.

    2014-01-01

    Mammary gland is made up of a branching network of ducts that end with alveoli which surrounds the lumen. These alveolar mammary epithelial cells (MEC) reflect the milk producing ability of farm animals. In this study, we have used 2D-DIGE and mass spectrometry to identify the protein changes in MEC during immediate early, peak and late stages of lactation and also compared differentially expressed proteins in MEC isolated from milk of high and low milk producing cows. We have identified 41 differentially expressed proteins during lactation stages and 22 proteins in high and low milk yielding cows. Bioinformatics analysis showed that a majority of the differentially expressed proteins are associated in metabolic process, catalytic and binding activity. The differentially expressed proteins were mapped to the available biological pathways and networks involved in lactation. The proteins up-regulated during late stage of lactation are associated with NF-κB stress induced signaling pathways and whereas Akt, PI3K and p38/MAPK signaling pathways are associated with high milk production mediated through insulin hormone signaling. PMID:25111801

  6. Short communication: Changes in fluorescence intensity induced by soybean soluble polysaccharide-milk protein interactions during acidification.

    PubMed

    Li, Y H; Wang, W J; Xu, X J; Meng, Y C; Zhang, L W; Chen, J; Qiu, R

    2015-12-01

    Interactions between stabilizer and milk protein are believed to influence the stabilizing behavior of the milk system. We investigated changes in fluorescence intensity induced by interactions of soybean soluble polysaccharide (SSPS) and milk protein (Mp) during acidification. The fluorescence intensity (If) of Mp increased as pH decreased from 6.8 to 5.2. Compared with Mp alone, If of SSPS-Mp mixtures increased as the pH decreased from 6.8 to 5.2. We found that the If of the SSPS-Mp mixture decreased in a pH range from 5.2 to 3.6, which indicated a change in the polarity microenvironment around the Trp residues. We also found that the maximum emission wavelength (λmax) shifted from 337 to 330nm as pH decreased from 6.8 to 3.6, in further support of SSPS interacting with the polar portion of Mp during acidification. Furthermore, an excited monomeric molecule (pyrene exciplex) was found as a ground-state pyrene formed and a broad band was shown at about 450nm. The intensity ratio of the first peak to the third peak (I1:I3) of Mp increased slightly, and the ratio of intensity of pyrene exciplex to monomer (Ie:Im) decreased because pyrene molecules were located in a less hydrophobic microenvironment during acidification. However, the ratio of I1:I3 decreased clearly at pH below 5.6 and the ratio of Ie:Im showed the opposite trend in the SSPS-Mp mixture. Changes in intrinsic and exogenous fluorescence intensity confirmed that interactions of SSPS and Mp could change the polarity of the microenvironment and that SSPS probably interacted with the polar portion of Mp. These results could give insight into the behavior of stabilizers in acid milk products. PMID:26476946

  7. Functionalized milk-protein-coated magnetic nanoparticles for MRI-monitored targeted therapy of pancreatic cancer.

    PubMed

    Huang, Jing; Qian, Weiping; Wang, Liya; Wu, Hui; Zhou, Hongyu; Wang, Andrew Yongqiang; Chen, Hongbo; Yang, Lily; Mao, Hui

    2016-01-01

    Engineered nanocarriers have emerged as a promising platform for cancer therapy. However, the therapeutic efficacy is limited by low drug loading efficiency, poor passive targeting to tumors, and severe systemic side effects. Herein, we report a new class of nanoconstructs based on milk protein (casein)-coated magnetic iron oxide (CNIO) nanoparticles for targeted and image-guided pancreatic cancer treatment. The tumor-targeting amino-terminal fragment (ATF) of urokinase plasminogen activator and the antitumor drug cisplatin (CDDP) were engineered on this nanoplatform. High drug loading (~25 wt%) and sustained release at physiological conditions were achieved through the exchange and encapsulation strategy. These ATF-CNIO-CDDP nanoparticles demonstrated actively targeted delivery of CDDP to orthotopic pancreatic tumors in mice. The effective accumulation and distribution of ATF-CNIO-CDDP was evidenced by magnetic resonance imaging, based on the T2-weighted contrast resulting from the specific accumulation of ATF-CNIO-CDDP in the tumor. Actively targeted delivery of ATF-CNIO-CDDP led to improved therapeutic efficacy in comparison with free CDDP and nontargeted CNIO-CDDP treatment. Meanwhile, less systemic side effects were observed in the nanocarrier-treated groups than that in the group treated with free CDDP. Hematoxylin and Eosin and Sirius Red staining of tumor sections revealed the possible disruption of stroma during the treatment with ATF-CNIO-CDDP. Overall, our results suggest that ATF-CNIO-CDDP can be an effective theranostic platform for active targeting-enhanced and image-guided cancer treatment while simultaneously reducing the systemic toxicity. PMID:27462153

  8. Functionalized milk-protein-coated magnetic nanoparticles for MRI-monitored targeted therapy of pancreatic cancer

    PubMed Central

    Huang, Jing; Qian, Weiping; Wang, Liya; Wu, Hui; Zhou, Hongyu; Wang, Andrew Yongqiang; Chen, Hongbo; Yang, Lily; Mao, Hui

    2016-01-01

    Engineered nanocarriers have emerged as a promising platform for cancer therapy. However, the therapeutic efficacy is limited by low drug loading efficiency, poor passive targeting to tumors, and severe systemic side effects. Herein, we report a new class of nanoconstructs based on milk protein (casein)-coated magnetic iron oxide (CNIO) nanoparticles for targeted and image-guided pancreatic cancer treatment. The tumor-targeting amino-terminal fragment (ATF) of urokinase plasminogen activator and the antitumor drug cisplatin (CDDP) were engineered on this nanoplatform. High drug loading (~25 wt%) and sustained release at physiological conditions were achieved through the exchange and encapsulation strategy. These ATF-CNIO-CDDP nanoparticles demonstrated actively targeted delivery of CDDP to orthotopic pancreatic tumors in mice. The effective accumulation and distribution of ATF-CNIO-CDDP was evidenced by magnetic resonance imaging, based on the T2-weighted contrast resulting from the specific accumulation of ATF-CNIO-CDDP in the tumor. Actively targeted delivery of ATF-CNIO-CDDP led to improved therapeutic efficacy in comparison with free CDDP and nontargeted CNIO-CDDP treatment. Meanwhile, less systemic side effects were observed in the nanocarrier-treated groups than that in the group treated with free CDDP. Hematoxylin and Eosin and Sirius Red staining of tumor sections revealed the possible disruption of stroma during the treatment with ATF-CNIO-CDDP. Overall, our results suggest that ATF-CNIO-CDDP can be an effective theranostic platform for active targeting-enhanced and image-guided cancer treatment while simultaneously reducing the systemic toxicity. PMID:27462153

  9. Ribosomal History Reveals Origins of Modern Protein Synthesis

    PubMed Central

    Harish, Ajith; Caetano-Anollés, Gustavo

    2012-01-01

    The origin and evolution of the ribosome is central to our understanding of the cellular world. Most hypotheses posit that the ribosome originated in the peptidyl transferase center of the large ribosomal subunit. However, these proposals do not link protein synthesis to RNA recognition and do not use a phylogenetic comparative framework to study ribosomal evolution. Here we infer evolution of the structural components of the ribosome. Phylogenetic methods widely used in morphometrics are applied directly to RNA structures of thousands of molecules and to a census of protein structures in hundreds of genomes. We find that components of the small subunit involved in ribosomal processivity evolved earlier than the catalytic peptidyl transferase center responsible for protein synthesis. Remarkably, subunit RNA and proteins coevolved, starting with interactions between the oldest proteins (S12 and S17) and the oldest substructure (the ribosomal ratchet) in the small subunit and ending with the rise of a modern multi-subunit ribosome. Ancestral ribonucleoprotein components show similarities to in vitro evolved RNA replicase ribozymes and protein structures in extant replication machinery. Our study therefore provides important clues about the chicken-or-egg dilemma associated with the central dogma of molecular biology by showing that ribosomal history is driven by the gradual structural accretion of protein and RNA structures. Most importantly, results suggest that functionally important and conserved regions of the ribosome were recruited and could be relics of an ancient ribonucleoprotein world. PMID:22427882

  10. Accelerated chemical synthesis of peptides and small proteins

    PubMed Central

    Miranda, Les P.; Alewood, Paul F.

    1999-01-01

    The chemical synthesis of peptides and small proteins is a powerful complementary strategy to recombinant protein overexpression and is widely used in structural biology, immunology, protein engineering, and biomedical research. Despite considerable improvements in the fidelity of peptide chain assembly, side-chain protection, and postsynthesis analysis, a limiting factor in accessing polypeptides containing greater than 50 residues remains the time taken for chain assembly. The ultimate goal of this work is to establish highly efficient chemical procedures that achieve chain-assembly rates of approximately 10–15 residues per hour, thus underpinning the rapid chemical synthesis of long polypeptides and proteins, including cytokines, growth factors, protein domains, and small enzymes. Here we report Boc chemistry that employs O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU)/dimethyl sulfoxide in situ neutralization as the coupling agent and incorporates a protected amino acid residue every 5 min to produce peptides of good quality. This rapid coupling chemistry was successfully demonstrated by synthesizing several small to medium peptides, including the “difficult” C-terminal sequence of HIV-1 proteinase (residues 81–99); fragment 65–74 of the acyl carrier protein; conotoxin PnIA(A10L), a potent neuronal nicotinic receptor antagonist; and the pro-inflammatory chemotactic protein CP10, an 88-residue protein, by means of native chemical ligation. The benefits of this approach include enhanced ability to identify and characterize “difficult couplings,” rapid access to peptides for biological and structure–activity studies, and accelerated synthesis of tailored large peptide segments (<50 residues) for use in chemoselective ligation methods. PMID:9989998

  11. Directed Evolution of Proteins through In Vitro Protein Synthesis in Liposomes

    PubMed Central

    Nishikawa, Takehiro; Sunami, Takeshi; Matsuura, Tomoaki; Yomo, Tetsuya

    2012-01-01

    Directed evolution of proteins is a technique used to modify protein functions through “Darwinian selection.” In vitro compartmentalization (IVC) is an in vitro gene screening system for directed evolution of proteins. IVC establishes the link between genetic information (genotype) and the protein translated from the information (phenotype), which is essential for all directed evolution methods, by encapsulating both in a nonliving microcompartment. Herein, we introduce a new liposome-based IVC system consisting of a liposome, the protein synthesis using recombinant elements (PURE) system and a fluorescence-activated cell sorter (FACS) used as a microcompartment, in vitro protein synthesis system, and high-throughput screen, respectively. Liposome-based IVC is characterized by in vitro protein synthesis from a single copy of a gene in a cell-sized unilamellar liposome and quantitative functional evaluation of the synthesized proteins. Examples of liposome-based IVC for screening proteins such as GFP and β-glucuronidase are described. We discuss the future directions for this method and its applications. PMID:22957209

  12. The effect of replacing lactose by starch on protein and fat digestion in milk-fed veal calves.

    PubMed

    Pluschke, A M; Gilbert, M S; Williams, B A; van den Borne, J J G C; Schols, H A; Gerrits, W J J

    2016-08-01

    Replacing dairy components from milk replacer (MR) with vegetable products has been previously associated with decreased protein and fat digestibility in milk-fed calves resulting in lower live weight gain. In this experiment, the major carbohydrate source in MR, lactose, was partly replaced with gelatinized corn starch (GCS) to determine the effect on protein and fat digestibility in milk-fed calves. In total, 16 male Holstein-Friesian calves received either MR with lactose as the carbohydrate source (control) or 18% GCS at the expense of lactose. In the adaptation period, calves were exposed to an increasing dose of GCS for 14 weeks. The indigestible marker cobalt ethylenediaminetetraacetic acid was incorporated into the MR for calculating apparent nutrient digestibility, whereas a pulse dose of chromium (Cr) chloride was fed with the last MR meal 4 h before slaughter as an indicator of passage rates. The calves were anesthetized and exsanguinated at 30 weeks of age. The small intestine was divided in three; small intestine 1 and 2 (SI1 and SI2, respectively) and the terminal ileum (last ~100 cm of small intestine) and samples of digesta were collected. Small intestinal digesta was analysed for α-amylase, lipase and trypsin activity. Digestibility of protein was determined for SI1, SI2, ileum and total tract, whereas digestibility of fat was determined for SI1, SI2 and total tract. Apparent protein digestibility in the small intestine did not differ between treatments but was higher in control calves at total tract level. Apparent crude fat digestibility tended to be increased in SI1 and SI2 for GCS calves, but no difference was found at total tract level. Activity of α-amylase in SI2 and lipase in both SI1 and SI2 was higher in GCS calves. Activity of trypsin tended to be higher in control calves and was higher in SI1 compared with SI2. A lower recovery of Cr in SI2 and a higher recovery of Cr in the large intestine suggest an increased rate of passage for GCS

  13. Selective hydrolysis of milk proteins to facilitate the elimination of the ABBOS epitope of bovine serum albumin and other immunoreactive epitopes.

    PubMed

    Alting, A C; Meijer, R J; van Beresteijn, E C

    1998-08-01

    Milk proteins are hydrolyzed to prevent immunological reactions, but immunoreactive epitopes, including the ABBOS epitope of bovine serum albumin (BSA), can still be detected in commercially available milk protein hydrolysates. We used lactococcal cell-envelope proteinase (CEP) for the hydrolysis of the individual milk proteins and of mixtures thereof, or for the hydrolysis of sodium caseinate (contaminated with whey proteins). CEP exclusively degraded casein, leaving the four major whey proteins intact. This property facilitated the removal of the intact whey proteins from the casein fragments by ultrafiltration. Depending on the molecular mass of the whey protein to be removed, membranes with cutoff values between 3 and 30 kDa were used, resulting in casein hydrolysates free of protein fragments with cross-reactive whey-protein-specific IgE (immunoglobulin E) or ABBOS antibody-binding sites. Even the casein itself was degraded in such a way by CEP that cross-reactive casein-specific IgE antibody-binding sites could be eliminated. The product could find application in infant formulas for therapeutic and preventive treatment of children with cow's milk allergy; in addition, the preventive use of such formulas in children genetically susceptible to the development of insulin-dependent diabetes mellitus (IDDM) should be considered if a relationship between the consumption of BSA and IDDM were to become more apparent. The method is also applicable for preparing casein-free whey protein preparations. PMID:9713762

  14. Milk Leptin Surge and Biological Rhythms of Leptin and Other Regulatory Proteins in Breastmilk

    PubMed Central

    Nozhenko, Yuriy; Asnani-Kishnani, Madhu; Rodríguez, Ana M.; Palou, Andreu

    2015-01-01

    A significant number of chronic diseases are linked to perinatal nutrition, and prevention may be associated to naturally occurring components of breast milk. One key hormone in breast milk is leptin, related with the protection from obesity in the adulthood, thus knowing its changes through the day or lactation is crucial. We aimed to investigate the daily rhythms in the milk levels of leptin, together with other two related hormones, ghrelin and adiponectin, during lactation (days 5, 10 and 15) in rat dams, and the relation with morphometric parameters (dams and pups). Summarizing the main results, the existence of biological rhythms, but not daily and maybe circasemidian, was confirmed for the three hormones at the earliest period of lactation. The correlations performed generally showed a possible dependence of milk hormone levels on plasma levels at the early phase of lactation, while with the progression of lactation this dependence may fade and the hormone levels are suggested to be more dependent on mammary gland production/maturation. There was also a correlation between milk leptin and adiponectin levels, especially in the first half of lactation, suggesting a possible parallel regulation. Interestingly, we describe a milk leptin surge around the mid of lactation (at day 10) which may be related with pup´s growth (males and females) and with the well-known (in the literature) plasma leptin surge in pups. All this knowledge may be crucial for future applications in the development of formula milk and in relation with the role of leptin surge during lactation. PMID:26680765

  15. Responses to Starch Infusion on Milk Synthesis in Low Yield Lactating Dairy Cows

    PubMed Central

    Zou, Yang; Yang, Zhanshan; Guo, Yongqing; Li, Shengli; Cao, Zhijun

    2015-01-01

    The effect of starch infusion on production, metabolic parameters and relative mRNA abundance was investigated in low yield lactating cows from 86 days in milk. Six Holstein cows fitted with permanent ruminal cannulas were arranged into one of two complete 3×3 Latin squares and infused with a starch solution containing 800 grams starch for 16 days. The three treatments were: i) ruminal and abomasal infusion with water (Control); ii) ruminal infusion with cornstarch solution and abomasal infusion with water (Rumen); iii) ruminal infusion with water and abomasal infusion with cornstarch solution (Abomasum). There were no significant differences (p>0.05) among the three treatments with low yield lactating cows in feed and energy intake, milk yield and composition, plasma metabolism, or even on gene expression. However, cows receiving starch through rumen performed better than directly through the abomasum during the glucose tolerance test procedure with a higher area under the curve (AUC; p = 0.08) and shorter half-time (t1/2; p = 0.11) of plasma insulin, therefore, it increased glucose disposal, which stated a lipid anabolism other than mobilization after energy supplementation. In conclusion, extra starch infusion at concentration of 800 g/d did not enhance energy supplies to the mammary gland and improve the lactating performance in low yield lactating cows. PMID:26194224

  16. Reduced protein synthesis in schizophrenia patient-derived olfactory cells

    PubMed Central

    English, J A; Fan, Y; Föcking, M; Lopez, L M; Hryniewiecka, M; Wynne, K; Dicker, P; Matigian, N; Cagney, G; Mackay-Sim, A; Cotter, D R

    2015-01-01

    Human olfactory neurosphere-derived (ONS) cells have the potential to provide novel insights into the cellular pathology of schizophrenia. We used discovery-based proteomics and targeted functional analyses to reveal reductions in 17 ribosomal proteins, with an 18% decrease in the total ribosomal signal intensity in schizophrenia-patient-derived ONS cells. We quantified the rates of global protein synthesis in vitro and found a significant reduction in the rate of protein synthesis in schizophrenia patient-derived ONS cells compared with control-derived cells. Protein synthesis rates in fibroblast cell lines from the same patients did not differ, suggesting cell type-specific effects. Pathway analysis of dysregulated proteomic and transcriptomic data sets from these ONS cells converged to highlight perturbation of the eIF2α, eIF4 and mammalian target of rapamycin (mTOR) translational control pathways, and these pathways were also implicated in an independent induced pluripotent stem cell-derived neural stem model, and cohort, of schizophrenia patients. Analysis in schizophrenia genome-wide association data from the Psychiatric Genetics Consortium specifically implicated eIF2α regulatory kinase EIF2AK2, and confirmed the importance of the eIF2α, eIF4 and mTOR translational control pathways at the level of the genome. Thus, we integrated data from proteomic, transcriptomic, and functional assays from schizophrenia patient-derived ONS cells with genomics data to implicate dysregulated protein synthesis for the first time in schizophrenia. PMID:26485547

  17. Secretion of three enzymes for fatty acid synthesis into mouse milk in association with fat globules, and rapid decrease of the secreted enzymes by treatment with rapamycin.

    PubMed

    Moriya, Hitomi; Uchida, Kana; Okajima, Tetsuya; Matsuda, Tsukasa; Nadano, Daita

    2011-04-01

    The mammary epithelium produces numerous lipid droplets during lactation and secretes them in plasma membrane-enclosed vesicles known as milk fat globules. The biogenesis of such fat globules is considered to provide a model for clarifying the mechanisms of lipogenesis in mammals. In the present study, we identified acetyl coenzyme A carboxylase, ATP citrate lyase, and fatty acid synthase in mouse milk. Fractionation of milk showed that these three enzymes were located predominantly in milk fat globules. The three enzymes were resistant to trypsin digestion without Triton X-100, indicating that they were not located on the outer surface of the globules and thus associated with the precursors of the globules before secretion. When a low dose of rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), was injected into lactating mice, the levels of the three enzymes in milk were decreased within 3h after injection. Since the protein levels of the three enzymes in tissues were not obviously altered by this short-term treatment, known transcriptional control by mTOR signaling was unlikely to account for this decrease in their levels in milk. Our findings suggest a new, putatively mTOR-dependent localization of the three enzymes for de novo lipogenesis. PMID:21281598

  18. Protein level for alfalfa and corn silage-based diets: I. Lactational response and milk urea nitrogen.

    PubMed

    Wattiaux, M A; Karg, K L

    2004-10-01

    This study was designed to evaluate lactational responses of cows fed corn silage (CS) or alfalfa silage (AS) as primary forage source when the diet was balanced for recommended (RP) or excessive (HP) amounts of rumen degradable protein (RDP) and undegradable protein (RUP) according to the recommendations of the National Research Council (NRC). A second objective was to evaluate different sources of variations in milk urea N (MUN). The total mixed rations included 55% forage on a dry matter (DM) basis as either 14% CS and 41% AS or 14% AS and 41% CS. Diets were offered to 48 multiparous Holstein cows (body weight = 652 kg) that were assigned randomly to treatments arranged as a 2 x 2 factorial in 12 complete blocks based on calving date. Data collected during wk 4 to 12 of lactation were adjusted to those obtained from a pretreatment diet fed during wk 1 to 3. Crude protein (CP) averaged 16.5, 18.0, 16.2, and 17.1% of DM in the AS-RP; AS-HP; CS-RP; and CS-HP diets, respectively. Overall DM intake (DMI) was 1.5 kg/d lower than predicted by NRC (24.6 vs. 26.1 kg/d), but 3.5% fat-corrected milk (FCM) was higher than expected (46.1 vs. 45.0 kg/d). The responses to a reduction in dietary protein were independent of primary forage source, except for milk true protein (TP) percentage. Primary forage source did not influence DMI, 3.5% FCM, TP yield, or MUN. However, compared with the AS-based diets, cows fed CS-based diets produced more milk (49.0 vs. 46.4 kg/d), less fat (3.07% vs. 3.54% and 1500 vs. 1651 g/d), and tended to gain more body weight. There were no benefits to feeding diets above NRC protein recommendations, regardless of forage source. Reducing CP from 17.5 to 16.4% of diet DM did not alter milk yield (47.7 kg/d) or milk TP yield (1293 g/d), but lowered N intake by 65 g/d (700 vs. 635 g/d) and lowered MUN by 1 unit (12.7 vs. 11.7 mg/dL). A positive correlation between MUN and production efficiency (3.5% FCM/DMI) on wk 3 of lactation suggested that body

  19. Synthesis of Hydrogen-Bond Surrogate α-helices as Inhibitors of Protein-Protein Interactions

    PubMed Central

    Miller, Stephen E.; Thomson, Paul F.; Arora, Paramjit S.

    2014-01-01

    The α-helix is a prevalent secondary structure in proteins and critical in mediating protein-protein interactions (PPIs). Peptide mimetics that adopt stable helices have become powerful tools for the modulation of PPIs in vitro and in vivo. Hydrogen-bond surrogate (HBS) α-helices utilize a covalent bond in place of an N-terminal i to i+4 hydrogen bond and have been used to target and disrupt PPIs that become dysregulated in disease states. These compounds have improved conformational stability and cellular uptake as compared to their linear peptide counterparts. The protocol presented here describes current methodology for the synthesis of HBS α-helical mimetics. The solid phase synthesis of HBS helices involves solid phase peptide synthesis with three key steps involving incorporation of N-allyl functionality within the backbone of the peptide, coupling of a secondary amine, and a ring-closing metathesis step. PMID:24903885

  20. Modulation by estrogen of synthesis of specific uterine proteins.

    PubMed

    Skipper, J K; Eakle, S D; Hamilton, T H

    1980-11-01

    The contemporary procedure for high resolution two dimensional gel electrophoresis was extended to include an initial nondenaturing dimension of electrophoresis. Use of the resulting three dimensional procedure revealed that the previously described single peak of estrogen-induced protein in the uterus of the rat contains at least three distinct proteins whose rates of synthesis are regulated by estrogen. These proteins were localized within partial protein maps, thereby providing definitive operational definitions for the detection and identification of each. It was unambiguously demonstrated that each of the three proteins is continuously synthesized in control uteri. These findings cast doubt on the simplistic hypothesis that estrogen induces a single key protein that triggers a "cascade" of sequential transcriptional events in the uterus. Our finding that the major uterine protein induced by estrogen is also synthesized in liver and muscle cells is significant in that it points to a more general cellular function for the protein, rather than a unique role within uterine cells. Finally, our procedure for three dimensional gel electrophoresis opens new avenues for the detection of minor proteins in heterogeneous protein mixtures, such as those from the tissues of higher animals. PMID:7428041

  1. Disorder in Milk Proteins: α-Lactalbumin. Part B. A Multifunctional Whey Protein Acting as an Oligomeric Molten Globular "Oil Container" in the Anti-Tumorigenic Drugs, Liprotides.

    PubMed

    Uversky, Vladimir N; Permyakov, Serge E; Breydo, Leonid; Redwan, Elrashdy M; Almehdar, Hussein A; Permyakov, Eugene A

    2016-07-15

    This is a second part of the three-part article from a series of reviews on the abundance and roles of intrinsic disorder in milk proteins. We continue to describe α-lactalbumin, a small globular Ca2+-binding protein, which besides being one of the two components of lactose synthase that catalyzes the final step of the lactose biosynthesis in the lactating mammary gland, possesses a multitude of other functions. In fact, recent studies indicated that some partially folded forms of this protein possess noticeable bactericidal activity and other forms might be related to induction of the apoptosis of tumor cells. In its anti-tumorigenic function, oligomeric α-lactalbumin serves as a founding member of a new family of anticancer drugs termed liprotides (for lipids and partially denatured proteins), where an oligomeric molten globular protein acts as an "oil container" or cargo for the delivery of oleic acid to the cell membranes. PMID:26916155

  2. Antibiotics in development targeting protein synthesis.

    PubMed

    Sutcliffe, Joyce A

    2011-12-01

    The resolution of antibiotic-ribosomal subunit complexes and antibacterial-protein complexes at the atomic level has provided new insights into modifications of clinically relevant antimicrobials and provided new classes that target the protein cellular apparatus. New chemistry platforms that use fragment-based drug design or allow novel modifications in known structural classes are being used to design new antibiotics that overcome known resistance mechanisms and extend spectrum and potency by circumventing ubiquitous efflux pumps. This review provides details on seven antibiotics in development for treatment of moderate-to-severe community-acquired bacterial pneumonia and/or acute bacterial skin and skin structure infections: solithromycin, cethromycin, omadacycline, CEM-102, GSK1322322, radezolid, and tedizolid. Two antibiotics of the oxazolidinone class, PF-02341272 and AZD5847, are being developed as antituberculosis agents. Only three antibiotics that target the protein cellular machinery, TP-434, GSK2251052, and plazomicin, have a spectrum that encompasses multidrug-resistant Gram-negative pathogens. These compounds provide hope for treating key pathogens that cause serious disease in both the community and the hospital. PMID:22191530

  3. Polyaromatic compounds alter placental protein synthesis in pregnant rats

    SciTech Connect

    Shiverick, K.T.; Ogilvie, S.; Medrano, T. )

    1991-03-15

    The administration of the polyaromatic compounds {beta}-naphthoflavone ({beta}NF) and 3-methylcholanthrene (3MC) to pregnant rats during mid-gestation has been shown to produce marked feto-placental growth retardation. This study examined secretory protein synthesis in placental tissue from rats following administration of {beta}NF on gestation days (gd) 11-14 or 3MC on gd 12-14. Explants of placental basal zone tissue were cultured for 24 hours in serum-free medium in the presence of ({sup 3}H)leucine. Secreted proteins were analyzed by two-dimensional SDS-polyacrylamide gel electrophoresis followed by either fluorography or immunostaining. Total incorporation of ({sup 3}H)leucine into secreted proteins was not altered in BZ explants from {beta}NF or 3MC-treated animals. However a selective decrease was observed in ({sup 3}H)leucine incorporation into a major complex of proteins with apparent molecular weight of 25-30,000 and isoelectric point between 5.3 to 5.7. This group of proteins has been further identified as being related to rat pituitary growth hormone (GH) using N-terminal amino acid microsequencing of individual spots from 2-D SDS-PA gels. This is the first report that synthesis of GH-related proteins by rat placenta is decreased following {beta}NF and 3MC administration, a change which may underlie the feto-placental growth retardation associated with these polyaromatic compounds.

  4. Milk demystified by chemistry.

    PubMed

    Obladen, Michael

    2014-09-01

    This article traces the decline of milk from a heavenly elixir to a tradeable food. Early cultures regarded milk not as a simple nutrient, but a living fluid. Heroes and gods were believed to have been nurtured by animals after being abandoned. Character traits were assumed to be transmitted by milk; infantile diseases were attributed to "bad milk", whereas "good milk" was used as a remedy. With chemical methods developed at the end of the 18th century, it became known that human milk was higher in sugar and lower in protein than cow's milk. During the 19th century, "scientific" feeding emerged that meant modifying cow's milk to imitate the proportion of nutrients in human milk. In Boston from 1893, Rotch initiated the "percentage" method, requiring a physician's prescription. In Paris from 1894, Budin sterilized bottled infant milk. In Berlin in 1898, Rubner measured oxygen and energy uptake by calorimetry, prompting feeding by calories, and Czerny introduced regulated feeding by the clock. These activities ignored the emotional dimension of infant nutrition and the anti-infective properties of human milk. They may have also enhanced the decline in breastfeeding, which reached an all-time low in 1971. Milk's demystification made artificial nutrition safer, but paved the way for commercially produced infant formula. PMID:24558227

  5. Overexpression of SREBP1 (sterol regulatory element binding protein 1) promotes de novo fatty acid synthesis and triacylglycerol accumulation in goat mammary epithelial cells.

    PubMed

    Xu, H F; Luo, J; Zhao, W S; Yang, Y C; Tian, H B; Shi, H B; Bionaz, M

    2016-01-01

    Sterol regulatory element binding protein 1 (SREBP1; gene name SREBF1) is known to be the master regulator of lipid homeostasis in mammals, including milk fat synthesis. The major role of SREBP1 in controlling milk fat synthesis has been demonstrated in bovine mammary epithelial cells. Except for a demonstrated role in controlling the expression of FASN, a regulatory role of SREBP1 on milk fat synthesis is very likely, but has not yet been demonstrated in goat mammary epithelial cells (GMEC). To explore the regulatory function of SREBP1 on de novo fatty acids and triacylglycerol synthesis in GMEC, we overexpressed the mature form of SREBP1 (active NH2-terminal fragment) in GMEC using a recombinant adenovirus vector (Ad-nSREBP1), with Ad-GFP (recombinant adenovirus of green fluorescent protein) as control, and infected the GMEC for 48 h. In infected cells, we assessed the expression of 20 genes related to milk fat synthesis using real time-quantitative PCR, the protein abundance of SREBP1 and FASN by Western blot, the production of triacylglycerol, and the fatty acid profile. Expression of SREBF1 was modest in mammary compared with the other tissues in dairy goats but its expression increased approximately 30-fold from pregnancy to lactation. The overexpression of the mature form of SREBP1 was confirmed by >200-fold higher expression of SREBF1 in Ad-nSREBP1 compared with Ad-GFP. We observed no changes in amount of the precursor form of SREBP1 protein but a >10-fold increase of the mature form of SREBP1 protein with Ad-nSREBP1. Compared with Ad-GFP cells (control), Ad-nSREBP1 cells had a significant increase in expression of genes related to long-chain fatty acid activation (ACSL1), transport (FABP3), desaturation (SCD1), de novo synthesis of fatty acids (ACSS2, ACLY, IDH1, ACACA, FASN, and ELOVL6), and transcriptional factors (NR1H3 and PPARG). We observed a >10-fold increase in expression of INSIG1 but SCAP was downregulated by Ad-nSREBP1. Among genes related to

  6. A novel technique for differentiation of proteins in the development of acid gel structure from control and heat treated milk using confocal scanning laser microscopy.

    PubMed

    Dubert-Ferrandon, Alix; Niranjan, Keshaven; Grandison, Alistair S

    2006-11-01

    The incorporation of caseins and whey proteins into acid gels produced from unheated and heat treated skimmed milk was studied by confocal scanning laser microscopy (CSLM) using fluorescent labelled proteins. Bovine casein micelles were labelled using Alexa Fluor 594, while whey proteins were labelled using Alexa Fluor 488. Samples of the labelled protein solutions were introduced into aliquots of pasteurised skim milk, and skim milk heated to 90 degrees C for 2 min and 95 degrees C for 8 min. The milk was acidified at 40 degrees C to a final pH of 4.4 using 20 g glucono-delta-lactone/l (GDL). The formation of gels was observed with CSLM at two wavelengths (488 nm and 594 nm), and also by visual and rheological methods. In the control milk, as pH decreased distinct casein aggregates appeared, and as further pH reduction occurred, the whey proteins could be seen to coat the casein aggregates. With the heated milks, the gel structure was formed of continuous strands consisting of both casein and whey protein. The formation of the gel network was correlated with an increase in the elastic modulus for all three treatments, in relation to the severity of heat treatment. This model system allows the separate observation of the caseins and whey proteins, and the study of the interactions between the two protein fractions during the formation of the acid gel structure, on a real-time basis. The system could therefore be a valuable tool in the study of structure formation in yoghurt and other dairy protein systems. PMID:16834815

  7. Effect of microfiltration concentration factor on serum protein removal from skim milk using spiral-wound polymeric membranes.

    PubMed

    Beckman, S L; Barbano, D M

    2013-10-01

    Our objective was to determine the effect of concentration factor (CF) on the removal of serum protein (SP) from skim milk during microfiltration (MF) at 50 °C using a 0.3-μm-pore-size spiral-wound (SW) polymeric polyvinylidene fluoride (PVDF) membrane. Pasteurized (72°C for 16 s) skim milk was MF (50 °C) at 3 CF (1.50, 2.25, and 3.00×), each on a separate day of processing starting with skim milk. Two phases of MF were used at each CF, with an initial startup-stabilization phase (40 min in full recycle mode) to achieve the desired CF, followed by a steady-state phase (90-min feed-and-bleed with recycle) where data was collected. The experiment was replicated 3 times, and SP removal from skim milk was quantified at each CF. System pressures, flow rates, CF, and fluxes were monitored during the 90-min run. Permeate flux increased (12.8, 15.3, and 19.0 kg/m(2) per hour) with decreasing CF from 3.00 to 1.50×, whereas fouled water flux did not differ among CF, indicating that the effect of membrane fouling on hydraulic resistance of the membrane was similar at all CF. However, the CF used when microfiltering skim milk (50°C) with a 0.3-μm polymeric SW PVDF membrane did affect the percentage of SP removed. As CF increased from 1.50 to 3.00×, the percentage of SP removed from skim milk increased from 10.56 to 35.57%, in a single stage bleed-and-feed MF system. Percentage SP removal from skim milk was lower than the theoretical value. Rejection of SP during MF of skim milk with SW PVDF membranes was caused by fouling of the membrane, not by the membrane itself and differences in the foulant characteristic among CF influenced SP rejection more than it influenced hydraulic resistance. We hypothesize that differences in the conditions near the surface of the membrane and within the pores during the first few minutes of processing, when casein micelles pass through the membrane, influenced the rejection of SP because more pore size narrowing and plugging occurred at

  8. An Herbal Galactagogue Mixture Increases Milk Production and Aquaporin Protein Expression in the Mammary Glands of Lactating Rats

    PubMed Central

    Liu, Haibin; Hua, Ying; Luo, Hui; Shen, Zhaojun; Tao, Xuejiao

    2015-01-01

    Background. Herbal galactagogues have been increasingly used to treat postpartum hypogalactia. The mechanism of action of herbal galactagogues remains unclear. The purpose of this study was to investigate the effect of an herbal galactagogue mixture on milk production and aquaporin (AQP) expression in lactating rats. Methods. Thirty female Sprague Dawley rats were randomized into virgin, lactating + H2O, and lactating + galactagogue groups (n = 10 per group). Lactating rats were administered the decoction of an herbal galactagogue mixture by oral gavage or the same amount of distilled water. Results. The herbal decoction significantly increased milk production in lactating rats (P < 0.05). Both immunohistochemical staining and western blot showed that protein levels of AQP-3 and AQP-5 were significantly increased during lactation compared with virgin stage and the herbal decoction further elevated their expression (P < 0.05). AQP-1 was predominantly expressed in the capillaries whereas AQP-3 and AQP-5 were mainly detected in the epithelial cells and ducts of the mammary glands. Conclusion. The expression of AQPs in the mammary glands of rats was developmentally regulated. Herbal galactagogues might have increased milk secretion by regulating the expression and function of AQPs in the mammary glands. PMID:26075000

  9. Question 7: Optimized Energy Consumption for Protein Synthesis

    NASA Astrophysics Data System (ADS)

    Szaflarski, Witold; Nierhaus, Knud H.

    2007-10-01

    In our previous contribution (Nierhaus, Orig Life Evol Biosph, this volume, 2007) we mentioned that life had solved the problem of energy supply in three major steps, and that these steps also mark major stages during the development of life. We further outlined a possible scenario concerning a minimal translational apparatus focusing on the essential components necessary for protein synthesis. Here we continue that consideration by addressing on one of the main problems of early life, namely avoiding wasteful energy loss. With regard to the limiting energy supply of early living systems, i.e. those of say more than 3,000 Ma, a carefully controlled and product oriented energy consumption was in demand. In recent years we learned how a bacterial cell avoids energy drain, thus being able to pump most of the energy into protein synthesis. These lessons must be followed by the design of a minimal living system, which is surveyed in this short article.

  10. Global protein synthesis in human trophoblast is resistant to inhibition by hypoxia

    PubMed Central

    Williams, S.F.; Fik, E.; Zamudio, S.; Illsley, N.P.

    2012-01-01

    Placental growth and function depend on syncytial cell processes which require the continuing synthesis of cellular proteins. The substantial energy demands of protein synthesis are met primarily from oxidative metabolism. Although the responses of individual proteins produced by the syncytiotrophoblast to oxygen deprivation have been investigated previously, there is no information available on global protein synthesis in syncytiotrophoblast under conditions of hypoxia. These studies were designed to test the hypothesis that syncytial protein synthesis is decreased in a dose-dependent manner by hypoxia. Experiments were performed to measure amino acid incorporation into proteins in primary syncytiotrophoblast cells exposed to oxygen concentrations ranging from 0 to 10%. Compared to cells exposed to normoxia (10% O2), no changes were observed following exposure to 5% or 3% O2, but after exposure to 1% O2, protein synthesis after 24 and 48 h decreased by 24% and 23% and with exposure to 0% O2, by 65% and 50%. As a consequence of these results, we hypothesized that global protein synthesis in conditions of severe hypoxia was being supported by glucose metabolism. Additional experiments were performed therefore to examine the role of glucose in supporting protein synthesis. These demonstrated that at each oxygen concentration there was a significant, decreasing linear trend in protein synthesis as glucose concentration was reduced. Under conditions of near-anoxia and in the absence of glucose, protein synthesis was reduced by >85%. Even under normoxic conditions (defined as 10% O2) and in the presence of oxidative substrates, reductions in glucose were accompanied by decreases in protein synthesis. These experiments demonstrate that syncytiotrophoblast cells are resistant to reductions in protein synthesis at O2 concentrations greater than 1%. This could be explained by our finding that a significant fraction of protein synthesis in the syncytiotrophoblast is

  11. Short communication: Comparison of protocols to estimate twenty-four-hour fat and protein percentages for herds with a robotic milking system.

    PubMed

    Hand, K J; Lazenby, D; Miglior, F; Kelton, D F

    2006-05-01

    Currently, different protocols are used in various countries to estimate the 24-h fat and protein percentages for dairy cows that are milked with an automatic milking system. These protocols include estimating 24-h fat and protein percentages from 1) single samples from all animals in the herd; 2) single samples of fat adjusted for covariates and single samples of protein unadjusted for covariates; or 3) all samples (adjusted and unadjusted) collected on test days where test days vary in length from 10 to 18 h. The accuracy of estimated component percentages in predicting observed percentages was determined via agreement analysis for four protocols. Analysis of the data suggests collecting all samples (unadjusted for covariates) during a sampling period of at least 16 h on test day to be the most accurate protocol when estimating 24-h fat and protein percentages in herds with automatic milking systems. PMID:16606743

  12. Concurrent protein synthesis is required for in vivo chitin synthesis in postmolt blue crabs

    SciTech Connect

    Horst, M.N. )

    1990-12-01

    Chitin synthesis in crustaceans involves the deposition of a protein-polysaccharide complex at the apical surface of epithelial cells which secrete the cuticle or exoskeleton. The present study involves an examination of in vivo incorporation of radiolabeled amino acids and amino sugars into the cuticle of postmolt blue crabs, Callinectes sapidus. Rates of incorporation of both 3H leucine and 3H threonine were linear with respect to time of incubation. Incorporation of 3H threonine into the endocuticle was inhibited greater than 90% in the presence of the protein synthesis inhibitor, puromycin. Linear incorporation of 14C glucosamine into the cuticle was also demonstrated; a significant improvement of radiolabeling was achieved by using 14C-N-acetylglucosamine as the labeled precursor. Incorporation of 3H-N-acetylglucosamine into the cuticle of postmolt blue crabs was inhibited 89% by puromycin, indicating that concurrent protein synthesis is required for the deposition of chitin in the blue crab. Autoradiographic analysis of control vs. puromycin-treated crabs indicates that puromycin totally blocks labeling of the new endocuticle with 3H glucosamine. These results are consistent with the notion that crustacean chitin is synthesized as a protein-polysaccharide complex. Analysis of the postmolt and intermolt blue crab cuticle indicates that the exoskeleton contains about 60% protein and 40% chitin. The predominant amino acids are arginine, glutamic acid, alanine, aspartic acid, and threonine.

  13. Controlled trial of the effects of milk basic protein (MBP) supplementation on bone metabolism in healthy adult women.

    PubMed

    Aoe, S; Toba, Y; Yamamura, J; Kawakami, H; Yahiro, M; Kumegawa, M; Itabashi, A; Takada, Y

    2001-04-01

    Milk has more beneficial effects on bone health compared to other food sources. Recent in vitro and in vivo studies showed that milk whey protein, especially its basic protein fraction, contains several components capable of both promoting bone formation and inhibiting bone resorption. However, the effects of milk basic protein (MBP) on bone metabolism of humans are not known. The object of this study was to examine the effects of MBP on bone metabolism of healthy adult women. Thirty-three normal healthy women were randomly assigned to treatment with either placebo or MBP (40 mg per day) for six months. The bone mineral density (BMD) of the left calcaneus of each subject was measured at the beginning of the study and after six months of treatment, by dual-energy x-ray absorptiometry. Serum and urine indices of bone metabolism were measured at the base line, three-month intervals, and the end of the study. Daily intake of nutrients was monitored by a three-day food record made at three and six months. The mean (+/- SD) rate of left calcaneus BMD gain of women in the MBP group (3.42 +/- 2.05%) was significantly higher than that of women in the placebo group (2.01 +/- 1.75%, P = 0.042). As compared with the placebo group, urinary cross-linked N-teleopeptides of type-I collagen/creatinine and deoxypyridinoline/creatinine were significantly decreased in the MBP group (p < 0.05), while no significant differences between the two groups were observed in serum osteocalcin and bone-specific alkaline phosphatase concentrations. A daily MBP supplementation of 40 mg in healthy adult women can significantly increase their BMD independent of dietary intake of minerals and vitamins. This increase in BMD might be primarily mediated through inhibition of osteoclast-mediated bone resorption by the MBP supplementation. PMID:11388472

  14. A controlled trial of the effect of milk basic protein (MBP) supplementation on bone metabolism in healthy menopausal women.

    PubMed

    Aoe, Seiichiro; Koyama, Takao; Toba, Yasuhiro; Itabashi, Akira; Takada, Yukihiro

    2005-12-01

    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 metabolism of healthy menopausal women. Thirty-two healthy menopausal 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 indices of bone metabolism were measured at 0, 3 and 6 months. Twenty-seven subjects who completed the study in accordance with the protocol were included in the analysis. The mean rate of gain of lumbar BMD in the MBP group (1.21%) was significantly higher than in the placebo group (-0.66%, P=0.046). When compared with the placebo group, urinary cross-linked N-telopeptides of type-I collagen (NTx) were significantly decreased in the MBP group at 6 months, but no significant difference in serum osteocalcin was observed between the two groups. The urinary NTx excretion was found to be related to serum osteocalcin in the MBP group at 3 and 6 months, indicating that MBP maintained the balance of bone remodeling. These results suggested that MBP supplementation was effective in preventing bone loss in menopausal women and that this improvement in BMD may be primarily mediated through the inhibition of bone resorption while maintaining the balance of bone remodeling by MBP supplementation. PMID:16133638

  15. Clinical and pH-metric characteristics of gastro-oesophageal reflux secondary to cows' milk protein allergy.

    PubMed Central

    Cavataio, F; Iacono, G; Montalto, G; Soresi, M; Tumminello, M; Carroccio, A

    1996-01-01

    AIMS: The primary aim was to assess whether there were differences in symptoms, laboratory data, and oesophageal pH-metry between infants with primary gastro-oesophageal reflux and those with reflux secondary to cows' milk protein allergy (CMPA). PATIENTS AND METHODS: 96 infants (mean(SD) age 7.8(2.0) months) with either primary gastro-oesophageal reflux, reflux with CMPA, CMPA only, or none of these (controls) were studied. Symptoms, immunochemical data, and oesophageal pH were compared between the four groups and the effect of a cows' milk protein-free diet on the severity of symptoms was also assessed. RESULTS: 14 out of 47(30%) infants with gastro-oesophageal reflux had CMPA. These infants had similar symptoms to those with primary gastro-oesophageal reflux but higher concentrations of total IgE and circulating eosinophils (p < 0.005) and IgG anti-beta lactoglobulin (p < 0.003). A progressive constant reduction in oesophageal pH at the end of a feed, which continued up to the next feed, was seen in 12 out of 14 patients with gastro-oesophageal reflux secondary to CMPA and in 24 of 25 infants with CMPA only. No infants with primary gastro-oesophageal reflux and none of the controls had this pattern. A cows' milk protein-free diet was associated with a significant improvement in symptoms only in infants with gastro-oesophageal reflux with CMPA. CONCLUSION: A characteristic oesophageal pH pattern is useful in distinguishing infants with gastro-oesophageal reflux associated with CMPA. PMID:8813871

  16. Impact of protein coingestion on muscle protein synthesis during continuous endurance type exercise.

    PubMed

    Beelen, Milou; Zorenc, Antoine; Pennings, Bart; Senden, Joan M; Kuipers, Harm; van Loon, Luc J C

    2011-06-01

    This study investigates the impact of protein coingestion with carbohydrate on muscle protein synthesis during endurance type exercise. Twelve healthy male cyclists were studied during 2 h of fasted rest followed by 2 h of continuous cycling at 55% W(max). During exercise, subjects received either 1.0 g·kg(-1)·h(-1) carbohydrate (CHO) or 0.8 g·kg(-1)·h(-1) carbohydrate with 0.2 g·kg(-1)·h(-1) protein hydrolysate (CHO+PRO). Continuous intravenous infusions with l-[ring-(13)C(6)]phenylalanine and l-[ring-(2)H(2)]tyrosine were applied, and blood and muscle biopsies were collected to assess whole body protein turnover and muscle protein synthesis rates at rest and during exercise conditions. Protein coingestion stimulated whole body protein synthesis and oxidation rates during exercise by 22 ± 3 and 70 ± 17%, respectively (P < 0.01). Whole body protein breakdown rates did not differ between experiments. As a consequence, whole body net protein balance was slightly negative in CHO and positive in the CHO+PRO treatment (-4.9 ± 0.3 vs. 8.0 ± 0.3 μmol Phe·kg(-1)·h(-1), respectively, P < 0.01). Mixed muscle protein fractional synthetic rates (FSR) were higher during exercise compared with resting conditions (0.058 ± 0.006 vs. 0.035 ± 0.006%/h in CHO and 0.070 ± 0.011 vs. 0.038 ± 0.005%/h in the CHO+PRO treatment, respectively, P < 0.05). FSR during exercise did not differ between experiments (P = 0.46). We conclude that muscle protein synthesis is stimulated during continuous endurance type exercise activities when carbohydrate with or without protein is ingested. Protein coingestion does not further increase muscle protein synthesis rates during continuous endurance type exercise. PMID:21364122

  17. Synthesis of Nanogel-Protein Conjugates

    PubMed Central

    Chacko, Reuben T.; Maynard, Heather D.; Thayumanavan, S.

    2014-01-01

    The covalent conjugation of bovine serum albumin (BSA) to disulfide cross-linked polymeric nanogels is reported. Polymeric nanogel precursors were synthesized via a reversible addition-fragmentation chain transfer (RAFT) random copolymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and pyridyl disulfide methacrylate (PDSMA). Reaction of the p(PEGMA-co-PDSMA) with dithiothreitol resulted in the formation of nanogels. PDSMA serves as both a crosslinking agent and a reactive handle for the surface modification of the nanogels. Lipophilic dye, DiI, was sequestered within the nanogels by performing the crosslinking reaction in the presence of the hydrophobic molecule. Thiol-enriched BSA was conjugated to nanogels loaded with DiI via a disulfide reaction between the BSA and the surface exposed nanogel pyridyl disulfides. Conjugation was confirmed by fast protein liquid chromatography, dynamic light scattering, and agarose and polyacrylamide gel electrophoresis. We expect that this methodology is generally applicable to the preparation of nanogel-protein therapeutics. PMID:24761162

  18. Synthesis of Nanogel-Protein Conjugates.

    PubMed

    Matsumoto, Nicholas M; González-Toro, Daniella C; Chacko, Reuben T; Maynard, Heather D; Thayumanavan, S

    2013-04-21

    The covalent conjugation of bovine serum albumin (BSA) to disulfide cross-linked polymeric nanogels is reported. Polymeric nanogel precursors were synthesized via a reversible addition-fragmentation chain transfer (RAFT) random copolymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and pyridyl disulfide methacrylate (PDSMA). Reaction of the p(PEGMA-co-PDSMA) with dithiothreitol resulted in the formation of nanogels. PDSMA serves as both a crosslinking agent and a reactive handle for the surface modification of the nanogels. Lipophilic dye, DiI, was sequestered within the nanogels by performing the crosslinking reaction in the presence of the hydrophobic molecule. Thiol-enriched BSA was conjugated to nanogels loaded with DiI via a disulfide reaction between the BSA and the surface exposed nanogel pyridyl disulfides. Conjugation was confirmed by fast protein liquid chromatography, dynamic light scattering, and agarose and polyacrylamide gel electrophoresis. We expect that this methodology is generally applicable to the preparation of nanogel-protein therapeutics. PMID:24761162

  19. An evaluation of protein/fat ratio in first DHI test milk for prediction of subsequent displaced abomasum in dairy cows.

    PubMed Central

    Geishauser, T D; Leslie, K E; Duffield, T F; Edge, V L

    1998-01-01

    First DHI test milk that was sampled prior to displaced abomasum (DA) diagnosis was used to evaluate milk protein/fat ratio (PFR) for prediction of subsequent DA in dairy cows. Odds ratio, sensitivity, specificity, and likelihood ratio were determined. Twenty-seven DA cases were matched to 3 controls per case by herd and calving date. Milk was tested at a median of 19 d after calving, which was 8 d prior to the median time of DA diagnosis. Adjusted for parity and days in milk, a protein/fat ratio < or = 0.72 was 8.2 times more likely to come from a cow subsequently diagnosed with DA than a protein/fat ratio > 0.72. Using the cut off value of 0.72, the sensitivity of PFR for DA was 80% and the specificity was 68%. A receiver operating characteristics curve indicated that the minimum sum of false negative and false positive results was at a PFR cut off value of 0.72. The likelihood ratio indicated that protein/fat ratios < or = 0.62 are 3.8 times more likely to come from cows that are diagnosed subsequently with DA than from cows without DA. The protein/fat ratio in 1st DHI test milk may predict subsequent DA in dairy cows. PMID:9553715

  20. Interfacial dilational properties of tea polyphenols and milk proteins with gut epithelia and the role of mucus in nutrient adsorption.

    PubMed

    Guri, Anilda; Li, Yang; Corredig, Milena

    2015-12-01

    By interacting with nutrients, the mucus layer covering the intestinal epithelium may mediate absorption. This study aimed to determine possible interactions between epigallocatechin-3-gallate (EGCG), skim milk proteins or their complexes with human intestinal mucin films. The films were extracted from postconfluent monolayers of HT29-MTX, a human intestinal cell line, and a model system was created using drop shape tensiometry. The EGCG uptake tested in vitro on postconfluent Caco-2 cells or co-cultures of Caco-2/HT29-MTX (mucus producing) showed recovery of bioavailable EGCG only for Caco-2 cell monolayers, suggesting an effect of mucus on absorption. Interfacial dilational rheology was employed to characterize the properties of the interface mixed with mucus dispersion. Adsorption of polyphenols greatly enhanced the viscoelastic modulus of the mucus film, showing the presence of interactions between the nutrient molecules and mucus films. On the other hand, in situ digestion of milk proteins using trypsin showed higher surface activities as a result of protein unfolding and competitive adsorption of the hydrolyzed products. There was an increase of viscoelastic modulus over the drop ageing time for the mixed interfaces, indicating the formation of a stiffer interfacial network. These results bring new insights into the role of the mucus layer in nutrient absorption and the interactions of mucus and dairy products. PMID:26328543

  1. Hydrocolloids Decrease the Digestibility of Corn Starch, Soy Protein, and Skim Milk and the Antioxidant Capacity of Grape Juice.

    PubMed

    Yi, Yue; Jeon, Hyeong-Ju; Yoon, Sun; Lee, Seung-Min

    2015-12-01

    Hydrocolloids have many applications in foods including their use in dysphagia diets. We aimed to evaluate whether hydrocolloids in foods affect the digestibility of starch and protein, and their effects on antioxidant capacity. The thickening hydrocolloids: locust bean gum and carboxymethyl cellulose, and the gel-forming agents: agar agar, konjac-glucomannan, and Hot & Soft Plus were blended with corn starch and soy protein, skim milk, or grape juice and were examined for their in vitro-digestability by comparing the reducing sugar and trichloroacetic acid (TCA)-soluble peptide, for antioxidant capacity by total polyphenol contents and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. The hydrocolloids resulted in a decrease in starch digestibility with the gel-forming agents. Hydrocolloids diminished TCA-soluble peptides in skim milk compared to soy protein with the exception of locust bean gum and decreased free radical scavenging capacities and total phenolic contents in grape juice. Our findings may provide evidence for the use of hydro-colloids for people at risk of nutritional deficiencies such as dysphagia patients. PMID:26770915

  2. Hydrocolloids Decrease the Digestibility of Corn Starch, Soy Protein, and Skim Milk and the Antioxidant Capacity of Grape Juice

    PubMed Central

    Yi, Yue; Jeon, Hyeong-Ju; Yoon, Sun; Lee, Seung-Min

    2015-01-01

    Hydrocolloids have many applications in foods including their use in dysphagia diets. We aimed to evaluate whether hydrocolloids in foods affect the digestibility of starch and protein, and their effects on antioxidant capacity. The thickening hydrocolloids: locust bean gum and carboxymethyl cellulose, and the gel-forming agents: agar agar, konjac-glucomannan, and Hot & Soft Plus were blended with corn starch and soy protein, skim milk, or grape juice and were examined for their in vitro-digestability by comparing the reducing sugar and trichloroacetic acid (TCA)-soluble peptide, for antioxidant capacity by total polyphenol contents and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. The hydrocolloids resulted in a decrease in starch digestibility with the gel-forming agents. Hydrocolloids diminished TCA-soluble peptides in skim milk compared to soy protein with the exception of locust bean gum and decreased free radical scavenging capacities and total phenolic contents in grape juice. Our findings may provide evidence for the use of hydro-colloids for people at risk of nutritional deficiencies such as dysphagia patients. PMID:26770915

  3. Voluntary Exercise Regionally Augments Rates of Cerebral Protein Synthesis

    PubMed Central

    Nadel, Jeffrey; Huang, Tianjian; Xia, Zengyan; Burlin, Thomas; Zametkin, Alan; Smith, Carolyn Beebe

    2016-01-01

    Exercise is a natural form of neurophysiologic stimulation that has known benefits for mental health, maintenance of cerebral function, and stress reduction. Exercise is known to induce an upregulation of brain-derived neurotrophic factor and this is thought to be involved in associated increases in neural plasticity. Protein synthesis is also an essential component of adaptive plasticity. We hypothesized that exercise may stimulate changes in brain protein synthesis as part of its effects on plasticity. Here, we applied the quantitative autoradiographic L-[1-14C] leucine method to the in vivo determination of regional rates of cerebral protein synthesis (rCPS) in adult rats following a seven day period of voluntary wheel-running and their sedentary counterparts. In four of 21 brain regions examined, the mean values of rCPS in the exercised rats were statistically significantly higher than in sedentary controls; regions affected were paraventricular hypothalamic nucleus, ventral hippocampus as a whole, CA1 pyramidal cell layer in ventral hippocampus, and frontal cortex. Increases in rCPS approached statistical significance in dentate gyrus of the ventral hippocampus. Our results affirm the value of exercise in encouraging hippocampal and possibly cortical neuroplasticity, and also suggest that exercise may modulate stimulation of stress-response pathways. Ultimately, our study indicates that measurement of rCPS with PET might be used as a marker of brain response to exercise in human subjects. PMID:24016692

  4. Eukaryotic protein synthesis inhibitors identified by comparison of cytotoxicity profiles

    PubMed Central

    CHAN, JENNY; KHAN, SHAKILA N.; HARVEY, ISABELLE; MERRICK, WILLIAM; PELLETIER, JERRY

    2004-01-01

    The National Cancer Institute (NCI) Human Tumor Cell Line Anti-Cancer Drug Screen has evaluated the cytotoxicity profiles of a large number of synthetic compounds, natural products, and plant extracts on 60 different cell lines. The data for each compound/extract can be assessed for similarity of cytotoxicity pattern, relative to a given test compound, using an algorithm called COMPARE. In applying a chemical biology approach to better understand the mechanism of eukaryotic protein synthesis, we used these resources to search for novel inhibitors of translation. The cytotoxicity profiles of 31 known protein synthesis inhibitors were used to identify compounds from the NCI database with similar activity profiles. Using this approach, two natural products, phyllanthoside and nagilactone C, were identified and characterized as novel protein synthesis inhibitors. Both compounds are specific for the eukaryotic translation apparatus, function in vivo and in vitro, and interfere with translation elongation. Our results demonstrate the feasibility of utilizing cytotoxicity profiles to identify new inhibitors of translation. PMID:14970397

  5. Protein synthesis in liposomes with a minimal set of enzymes.

    PubMed

    Murtas, Giovanni; Kuruma, Yutetsu; Bianchini, Paolo; Diaspro, Alberto; Luisi, Pier Luigi

    2007-11-01

    In a significant step towards the construction of the semi-synthetic minimal cell, a protein expression system with a minimal set of pure and specific enzymes is required. A novel cell-free transcription and translation system named PURESYSTEM (PS), consisting of a specified set of 36 enzymes and ribosomes, has been entrapped in POPC liposomes for protein synthesis. The PS has been used to transcribe and translate an Enhanced Green Fluorescent Protein (EGFP) gene from plasmid DNA. The synthesis is confirmed by the EGFP fluorescence emitting liposomes on fluorometric analysis and on confocal microscopy analysis. Furthermore the PS encapsulated into POPC liposomes can drive the expression of the plsB and plsC genes encoding for the sn-glycerol-3-phosphate acyltransferase (GPAT) and 1-acyl-sn-glycerol-3-phosphate acyltransferase (LPAAT) involved in the first step of the "salvage pathway" for synthesis of POPC. The expression of GPAT and LPAAT in liposomes would in principle allow the production of the cell boundary from within. PMID:17850764

  6. The impact of milk proteins and peptides on blood pressure and vascular function: a review of evidence from human intervention studies.

    PubMed

    Fekete, Ágnes A; Givens, D Ian; Lovegrove, Julie A

    2013-12-01

    CVD are the leading cause of death worldwide. Hypertension, a major controllable risk factor of CVD, is intimately associated with vascular dysfunction, a defect which is also now recognised to be a major, modifiable risk factor for the development of CVD. The purpose of the present review was to critically evaluate the evidence for the effects of milk proteins and their associated peptides on blood pressure (BP) and vascular dysfunction. After a detailed literature search, the number of human trials evaluating the antihypertensive effects of casein-derived peptides (excluding isoleucine-proline-proline and valine-proline-proline) was found to be limited; the studies were preliminary with substantial methodological limitations. Likewise, the data from human trials that examined the effects of whey protein and peptides were also scarce and inconsistent. To date, only one study has conducted a comparative investigation on the relative effects of the two main intact milk proteins on BP and vascular function. While both milk proteins were shown to reduce BP, only whey protein improved measures of arterial stiffness. In contrast, a growing number of human trials have produced evidence to support beneficial effects of both milk proteins and peptides on vascular health. However, comparison of the relative outcomes from these trials is difficult owing to variation in the forms of assessment and measures of vascular function. In conclusion, there is an accumulating body of evidence to support positive effects of milk proteins in improving and/or maintaining cardiovascular health. However, the variable quality of the studies that produced this evidence, and the lack of robust, randomised controlled intervention trials, undermines the formulation of firm conclusions on the potential benefits of milk proteins and peptides on vascular health. PMID:24135454

  7. Ultrafast sonochemical synthesis of protein-inorganic nanoflowers

    PubMed Central

    Batule, Bhagwan S; Park, Ki Soo; Kim, Moon Il; Park, Hyun Gyu

    2015-01-01

    We developed a simple but efficient method to synthesize protein-inorganic hybrid nanostructures with a flower-like shape (nanoflowers), which relies on sonication to facilitate the synthesis of the nanoflowers. With this technique, we synthesized nanoflowers containing laccase as a model protein and copper phosphate within 5 minutes at room temperature. The resulting laccase nanoflowers yielded greatly enhanced activity, stability, and reusability, and their usefulness was successfully demonstrated by applying them in the colorimetric detection of epinephrine. The strategy developed could be used to rapidly synthesize nanoflowers for various applications in biosensor and enzyme catalysis and would expand the utilization of nanoflowers in diverse fields of biotechnology. PMID:26346235

  8. Effects of dietary crude protein and rumen-degradable protein concentrations on urea recycling, nitrogen balance, omasal nutrient flow, and milk production in dairy cows.

    PubMed

    Mutsvangwa, T; Davies, K L; McKinnon, J J; Christensen, D A

    2016-08-01

    The objective of this study was to determine how interactions between dietary crude protein (CP) and rumen-degradable protein (RDP) concentrations alter urea-nitrogen recycling, nitrogen (N) balance, omasal nutrient flow, and milk production in lactating Holstein cows. Eight multiparous Holstein cows (711±21kg of body weight; 91±17d in milk at the start of the experiment) were used in a replicated 4×4 Latin square design with a 2×2 factorial arrangement of dietary treatments and 29-d experimental periods. Four cows in one Latin square were fitted with ruminal cannulas to allow ruminal and omasal sampling. The dietary treatment factors were CP (14.9 vs. 17.5%; dry matter basis) and RDP (63 vs. 69% of CP) contents. Dietary RDP concentration was manipulated by including unprocessed or micronized canola meal. Diet adaptation (d 1-20) was followed by 8d (d 21-29) of sample and data collection. Continuous intrajugular infusions of [(15)N(15)N]-urea (220mg/d) were conducted for 4d (d 25-29) with concurrent total collections of urine and feces to estimate N balance and whole-body urea kinetics. Proportions of [(15)N(15)N]- and [(14)N(15)N]-urea in urinary urea, and (15)N enrichment in feces were used to calculate urea kinetics. For the low-CP diets, cows fed the high-RDP diet had a greater DM intake compared with those fed the low-RDP diet, but the opposite trend was observed for cows fed the high-CP diets. Dietary treatment had no effect on milk yield. Milk composition and milk component yields were largely unaffected by dietary treatment; however, on the low-CP diets, milk fat yield was greater for cows fed the low-RDP diet compared with those fed the high-RDP diet, but it was unaffected by RDP concentration on the high-CP diets. On the high-CP diets, milk urea nitrogen concentration was greater in cows fed the high-RDP diet compared with those fed the low-RDP diet, but it was unaffected by RDP concentration on the low-CP diets. Ruminal NH3-N concentration tended to

  9. Quantitating protein synthesis, degradation, and endogenous antigen processing.

    PubMed

    Princiotta, Michael F; Finzi, Diana; Qian, Shu-Bing; Gibbs, James; Schuchmann, Sebastian; Buttgereit, Frank; Bennink, Jack R; Yewdell, Jonathan W

    2003-03-01

    Using L929 cells, we quantitated the macroeconomics of protein synthesis and degradation and the microeconomics of producing MHC class I associated peptides from viral translation products. To maintain a content of 2.6 x 10(9) proteins, each cell's 6 x 10(6) ribosomes produce 4 x 10(6) proteins min(-1). Each of the cell's 8 x 10(5) proteasomes degrades 2.5 substrates min(-1), creating one MHC class I-peptide complex for each 500-3000 viral translation products degraded. The efficiency of complex formation is similar in dendritic cells and macrophages, which play a critical role in activating T cells in vivo. Proteasomes create antigenic peptides at different efficiencies from two distinct substrate pools: rapidly degraded newly synthesized proteins that clearly represent defective ribosomal products (DRiPs) and a less rapidly degraded pool in which DRiPs may also predominate. PMID:12648452

  10. Feed intake, milk production and composition of crossbred cows fed with insect-protected Bollgard II® cottonseed containing Cry1Ac and Cry2Ab proteins.

    PubMed

    Singhal, K K; Tyagi, A K; Rajput, Y S; Singh, M; Kaur, H; Perez, T; Hartnell, G F

    2011-09-01

    Twenty crossbred lactating multiparous cows were used in a 28-day study to compare dry matter intake (DMI), milk yield, milk composition and Bacillus thuringiensis (Bt) protein concentrations in plasma when fed diets containing Bollgard II(®) cottonseed (BGII) or a control non-genetically modified isogenic cottonseed (CON). Bollgard II cottonseed contains the Cry1Ac and Cry2Ab insecticidal proteins that protect cotton plants from feeding damage caused by certain lepidopteran insects. Cows were assigned randomly to the BGII or CON treatments after a 2-week adjustment period. Cows consumed a concentrate containing 40% crushed cottonseed according to milk yield and green maize forage ad libitum. All cows received the same diet but with different crushed cottonseed sources. Cottonseed was included to provide approximately 2.9 kg per cow daily (dry matter basis). The ingredient composition of the concentrate was 40% crushed cottonseed, 15% groundnut cake, 20% corn, 22% wheat bran, 1% salt and 2% mineral mixture. Milk and blood plasma were analyzed for Cry1Ac and Cry2Ab proteins. DMI, BW, milk yield and milk components did not differ between cows on the BGII and CON treatments. Although milk yield and milk fat percentage were not affected by treatment, 4% fat-corrected milk (FCM) production and FCM/kg DMI for cows on the BGII treatment (14.0 kg/cow per day, 1.12 kg/kg) were significantly improved compared with cows on the CON treatment (12.1 kg/cow per day, 0.97 kg/kg). Gossypol contents in BGII cottonseed and conventional cottonseed were similar. Cry1Ac and Cry2Ab2 proteins in Bollgard II cottonseed were 5.53 and 150.8 μg/g, respectively, and were not detected in the milk or plasma samples. The findings suggested that Bollgard II cottonseed can replace conventional cottonseed in dairy cattle diets with no adverse effects on performance and milk composition. PMID:22440417

  11. Fluorinated proteins: from design and synthesis to structure and stability.

    PubMed

    Marsh, E Neil G

    2014-10-21

    Fluorine is all but absent from biology; however, it has proved to be a remarkably useful element with which to modulate the activity of biological molecules and to study their mechanism of action. Our laboratory's interest in incorporating fluorine into proteins was stimulated by the unusual physicochemical properties exhibited by perfluorinated small molecules. These include extreme chemical inertness and thermal stability, properties that have made them valuable as nonstick coatings and fire retardants. Fluorocarbons also exhibit an unusual propensity to phase segregation. This phenomenon, which has been termed the "fluorous effect", has been effectively exploited in organic synthesis to purify compounds from reaction mixtures by extracting fluorocarbon-tagged molecules into fluorocarbon solvents. As biochemists, we were curious to explore whether the unusual physicochemical properties of perfluorocarbons could be engineered into proteins. To do this, we developed a synthesis of a highly fluorinated amino acid, hexafluoroleucine, and designed a model 4-helix bundle protein, α4H, in which the hydrophobic core was packed exclusively with leucine. We then investigated the effects of repacking the hydrophobic core of α4H with various combinations of leucine and hexafluoroleucine. These initial studies demonstrated that fluorination is a general and effective strategy for enhancing the stability of proteins against chemical and thermal denaturation and proteolytic degradation. We had originally envisaged that the "fluorous interactions", postulated from the self-segregating properties of fluorous solvents, might be used to mediate specific protein-protein interactions orthogonal to those of natural proteins. However, various lines of evidence indicate that no special, favorable fluorine-fluorine interactions occur in the core of the fluorinated α4 protein. This makes it unlikely that fluorinated amino acids can be used to direct protein-protein interactions. More

  12. Milk production and composition responds to dietary neutral detergent fiber and starch ratio in dairy cows.

    PubMed

    Zhao, Meng; Bu, Dengpan; Wang, Jiaqi; Zhou, Xiaoqiao; Zhu, Dan; Zhang, Ting; Niu, Junli; Ma, Lu

    2016-06-01

    This study was designed to investigate whether dietary neutral detergent fiber (NDF) : starch ratio could be considered as a nutritional indicator to evaluate carbohydrate composition and manipulate milk production and composition synthesis. Eight primiparous dairy cows were assigned to four total mixed rations with NDF : starch ratios of 0.86, 1.18, 1.63 and 2.34 from T1 to T4 in a replicated 4 × 4 Latin square design. Dry matter intake and milk production were decreased from T1 to T4. Digestibility of dry matter, organic matter, NDF and crude protein were linearly decreased from T1 to T4. As NDF : starch ratio increased, milk protein content and production, and milk lactose content and production were linearly reduced. However, milk fat content was linearly increased from T1 to T4. Quadratic effect was observed on milk fat production with the highest level in T3. Averaged rumen pH was linearly increased from T1 to T4, and subacute rumen acidosis occurred in T1. Ruminal propionate and butyrate concentration were linearly decreased, and microbial crude protein and metabolizable protein decreased from T1 to T4. It is concluded that NDF : starch ratio can be considered as a potential indicator to evaluate dietary carbohydrate composition and manipulate milk production and composition synthesis. PMID:26712573

  13. Short communication: predictive ability of Fourier-transform mid-infrared spectroscopy to assess CSN genotypes and detailed protein composition of buffalo milk.

    PubMed

    Bonfatti, V; Cecchinato, A; Carnier, P

    2015-09-01

    The aim of this work was to test the applicability of Fourier-transform mid-infrared spectroscopy (FT-MIR) for the prediction of the contents of casein (CN) and whey protein fractions in buffalo milk. Buffalo milk samples spectra were collected using a MilkoScan FT2 (Foss, Hillerød, Denmark) over the spectral range from 5,000 to 900 wavenumber × cm(-1). Contents of protein fractions, as well as CSN1S1 and CSN3 genotypes, were assessed by reversed phase HPLC. The highest coefficients of determination in cross-validation (1 - VR) were obtained for the contents (g/L of milk) of total protein and CN (1 - VR=0.92), followed by the content of β-CN, total whey protein, and αS2-CN (1 - VR of 0.87, 0.77, and 0.63, respectively). Conversely, contents of αS1-CN, γ-CN, glycosylated-κ-CN, total κ-CN, and whey protein fractions were predicted with poor accuracy (1 - VR <0.51). When protein fractions were expressed as percentages to total protein, 1 - VR values were never greater than 0.61 (β-CN). Only 56 and 70% of the observations were correctly classified by discriminant analysis in each of 2 groups of CSN1S1 and CSN3 genotypes, respectively. Results showed that FT-MIR spectroscopy is not applicable when prediction of detailed milk protein composition with high accuracy is required. Predictions may play a role as indicator traits in selective breeding, if the genetic correlation between FT-MIR predictions and measures of milk protein composition are high enough and predictions of protein fraction contents are sufficiently independent from the predicted total protein content. PMID:26188571