Phosphorylation of Dgk1 Diacylglycerol Kinase by Casein Kinase II Regulates Phosphatidic Acid Production in Saccharomyces cerevisiae*

Science.gov (United States)

Qiu, Yixuan; Hassaninasab, Azam; Han, Gil-Soo; Carman, George M.

2016-01-01

In the yeast Saccharomyces cerevisiae, Dgk1 diacylglycerol (DAG) kinase catalyzes the CTP-dependent phosphorylation of DAG to form phosphatidic acid (PA). The enzyme in conjunction with Pah1 PA phosphatase controls the levels of PA and DAG for the synthesis of triacylglycerol and membrane phospholipids, the growth of the nuclear/endoplasmic reticulum membrane, and the formation of lipid droplets. Little is known about how DAG kinase activity is regulated by posttranslational modification. In this work, we examined the phosphorylation of Dgk1 DAG kinase by casein kinase II (CKII). When phosphate groups were globally reduced using nonspecific alkaline phosphatase, Triton X-100-solubilized membranes from DGK1-overexpressing cells showed a 7.7-fold reduction in DAG kinase activity; the reduced enzyme activity could be increased 5.5-fold by treatment with CKII. Dgk1(1–77) expressed heterologously in Escherichia coli was phosphorylated by CKII on a serine residue, and its phosphorylation was dependent on time as well as on the concentrations of CKII, ATP, and Dgk1(1–77). We used site-specific mutagenesis, coupled with phosphorylation analysis and phosphopeptide mapping, to identify Ser-45 and Ser-46 of Dgk1 as the CKII target sites, with Ser-46 being the major phosphorylation site. In vivo, the S46A and S45A/S46A mutations of Dgk1 abolished the stationary phase-dependent stimulation of DAG kinase activity. In addition, the phosphorylation-deficient mutations decreased Dgk1 function in PA production and in eliciting pah1Δ phenotypes, such as the expansion of the nuclear/endoplasmic reticulum membrane, reduced lipid droplet formation, and temperature sensitivity. This work demonstrates that the CKII-mediated phosphorylation of Dgk1 regulates its function in the production of PA. PMID:27834677

Expression of casein kinase 2 during mouse embryogenesis

DEFF Research Database (Denmark)

Mestres, P; Boldyreff, B; Ebensperger, C

1994-01-01

This paper deals with the expression and distribution of casein kinase 2 (CK-2) subunits in mouse embryos at different developmental stages. Expression was investigated at the mRNA level of CK-2 alpha- and beta-subunits by in situ hybridization and distribution at the protein level by immunohisto......This paper deals with the expression and distribution of casein kinase 2 (CK-2) subunits in mouse embryos at different developmental stages. Expression was investigated at the mRNA level of CK-2 alpha- and beta-subunits by in situ hybridization and distribution at the protein level...

Helicobacter pylori induces cell migration and invasion through casein kinase 2 in gastric epithelial cells.

Science.gov (United States)

Lee, Yeo Song; Lee, Do Yeon; Yu, Da Yeon; Kim, Shin; Lee, Yong Chan

2014-12-01

Chronic infection with Helicobacter pylori (H. pylori) is causally linked with gastric carcinogenesis. Virulent H. pylori strains deliver bacterial CagA into gastric epithelial cells. Induction of high motility and an elongated phenotype is considered to be CagA-dependent process. Casein kinase 2 plays a critical role in carcinogenesis through signaling pathways related to the epithelial mesenchymal transition. This study was aimed to investigate the effect of H. pylori infection on the casein kinase 2-mediated migration and invasion in gastric epithelial cells. AGS or MKN28 cells as human gastric epithelial cells and H. pylori strains Hp60190 (ATCC 49503, CagA(+)) and Hp8822 (CagA(-)) were used. Cells were infected with H. pylori at multiplicity of infection of 100 : 1 for various times. We measured in vitro kinase assay to examine casein kinase 2 activity and performed immunofluorescent staining to observe E-cadherin complex. We also examined β-catenin transactivation through promoter assay and MMP7 expression by real-time PCR and ELISA. H. pylori upregulates casein kinase 2 activity and inhibition of casein kinase 2 in H. pylori-infected cells profoundly suppressed cell invasiveness and motility. We confirmed that casein kinase 2 mediates membranous α-catenin depletion through dissociation of the α-/β-catenin complex in H. pylori-infected cells. We also found that H. pylori induces β-catenin nuclear translocation and increases MMP7 expressions mediated through casein kinase 2. We show for the first time that CagA(+) H. pylori upregulates cellular invasiveness and motility through casein kinase 2. The demonstration of a mechanistic interplay between H. pylori and casein kinase 2 provides important insights into the role of CagA(+) H. pylori in the gastric cancer invasion and metastasis. © 2014 John Wiley & Sons Ltd.

Casein kinase-2 structure-function relationship

DEFF Research Database (Denmark)

Boldyreff, B; Meggio, F; Pinna, L A

1992-01-01

Nine mutants of human casein kinase-2 beta subunit have been created and assayed for their ability to assemble with the catalytic alpha subunit to give, at a 1:1 molar ratio, a fully competent CK-2 holoenzyme as judged by the following criteria: 1) the generation of an active heterotetrameric form...

Phosphorylation of nm23/nucleoside diphosphate kinase by casein kinase 2 in vitro

DEFF Research Database (Denmark)

Engel, M; Issinger, O G; Lascu, I

1994-01-01

We have investigated phosphorylation of human nucleoside diphosphate kinase (NDPK) and of homologous NDPK from different species by human casein kinase 2 (CK-2). The human NDPK isotypes A and B were phosphorylated by CK-2 in vitro both when the purified proteins and total lysate of HL-60 leukemia...

Casein kinase II is required for the spindle assembly checkpoint by regulating Mad2p in fission yeast

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Shimada, Midori [Department of Biochemistry and Cell Biology, Graduate School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan); Yamamoto, Ayumu [Department of Chemistry, Shizuoka University, 836 Ohya, Suruga-ku, Sizuoka 422-8529 (Japan); Murakami-Tonami, Yuko; Nakanishi, Makoto; Yoshida, Takashi [Department of Biochemistry and Cell Biology, Graduate School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan); Aiba, Hirofumi [Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Chikusa-ku, Nagoya 464-8601 (Japan); Murakami, Hiroshi, E-mail: hmura@med.nagoya-cu.ac.jp [Department of Biochemistry and Cell Biology, Graduate School of Medicine, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan)

2009-10-23

The spindle checkpoint is a surveillance mechanism that ensures the fidelity of chromosome segregation in mitosis. Here we show that fission yeast casein kinase II (CK2) is required for this checkpoint function. In the CK2 mutants mitosis occurs in the presence of a spindle defect, and the spindle checkpoint protein Mad2p fails to localize to unattached kinetochores. The CK2 mutants are sensitive to the microtubule depolymerising drug thiabendazole, which is counteracted by ectopic expression of mad2{sup +}. The level of Mad2p is low in the CK2 mutants. These results suggest that CK2 has a role in the spindle checkpoint by regulating Mad2p.

Casein kinase II is required for the spindle assembly checkpoint by regulating Mad2p in fission yeast

International Nuclear Information System (INIS)

Shimada, Midori; Yamamoto, Ayumu; Murakami-Tonami, Yuko; Nakanishi, Makoto; Yoshida, Takashi; Aiba, Hirofumi; Murakami, Hiroshi

2009-01-01

The spindle checkpoint is a surveillance mechanism that ensures the fidelity of chromosome segregation in mitosis. Here we show that fission yeast casein kinase II (CK2) is required for this checkpoint function. In the CK2 mutants mitosis occurs in the presence of a spindle defect, and the spindle checkpoint protein Mad2p fails to localize to unattached kinetochores. The CK2 mutants are sensitive to the microtubule depolymerising drug thiabendazole, which is counteracted by ectopic expression of mad2 + . The level of Mad2p is low in the CK2 mutants. These results suggest that CK2 has a role in the spindle checkpoint by regulating Mad2p.

Cloning and sequencing of the casein kinase 2 alpha subunit from Zea mays

DEFF Research Database (Denmark)

Dobrowolska, G; Boldyreff, B; Issinger, O G

1991-01-01

The nucleotide sequence of the cDNA coding for the alpha subunit of casein kinase 2 of Zea mays has been determined. The cDNA clone contains an open reading frame of 996 nucleotides encoding a polypeptide comprising 332 amino acids. The primary amino acid sequence exhibits 75% identity to the alpha...... subunit and 71% identity to the alpha' subunit of human casein kinase 2....

Casein kinase II is required for proper cell division and acts as a negative regulator of centrosome duplication in Caenorhabditis elegans embryos

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Jeffrey C. Medley

2017-01-01

Full Text Available Centrosomes are the primary microtubule-organizing centers that orchestrate microtubule dynamics during the cell cycle. The correct number of centrosomes is pivotal for establishing bipolar mitotic spindles that ensure accurate segregation of chromosomes. Thus, centrioles must duplicate once per cell cycle, one daughter per mother centriole, the process of which requires highly coordinated actions among core factors and modulators. Protein phosphorylation is shown to regulate the stability, localization and activity of centrosome proteins. Here, we report the function of Casein kinase II (CK2 in early Caenorhabditis elegans embryos. The catalytic subunit (KIN-3/CK2α of CK2 localizes to nuclei, centrosomes and midbodies. Inactivating CK2 leads to cell division defects, including chromosome missegregation, cytokinesis failure and aberrant centrosome behavior. Furthermore, depletion or inhibiting kinase activity of CK2 results in elevated ZYG-1 levels at centrosomes, restoring centrosome duplication and embryonic viability to zyg-1 mutants. Our data suggest that CK2 functions in cell division and negatively regulates centrosome duplication in a kinase-dependent manner.

Casein Kinase 1α Mediates the Degradation of Receptors for Type I and Type II Interferons Caused by Hemagglutinin of Influenza A Virus.

Science.gov (United States)

Xia, Chuan; Wolf, Jennifer J; Vijayan, Madhuvanthi; Studstill, Caleb J; Ma, Wenjun; Hahm, Bumsuk

2018-04-01

Although influenza A virus (IAV) evades cellular defense systems to effectively propagate in the host, the viral immune-evasive mechanisms are incompletely understood. Our recent data showed that hemagglutinin (HA) of IAV induces degradation of type I IFN receptor 1 (IFNAR1). Here, we demonstrate that IAV HA induces degradation of type II IFN (IFN-γ) receptor 1 (IFNGR1), as well as IFNAR1, via casein kinase 1α (CK1α), resulting in the impairment of cellular responsiveness to both type I and II IFNs. IAV infection or transient HA expression induced degradation of both IFNGR1 and IFNAR1, whereas HA gene-deficient IAV failed to downregulate the receptors. IAV HA caused the phosphorylation and ubiquitination of IFNGR1, leading to the lysosome-dependent degradation of IFNGR1. Influenza viral HA strongly decreased cellular sensitivity to type II IFNs, as it suppressed the activation of STAT1 and the induction of IFN-γ-stimulated genes in response to exogenously supplied recombinant IFN-γ. Importantly, CK1α, but not p38 MAP kinase or protein kinase D2, was proven to be critical for HA-induced degradation of both IFNGR1 and IFNAR1. Pharmacologic inhibition of CK1α or small interfering RNA (siRNA)-based knockdown of CK1α repressed the degradation processes of both IFNGR1 and IFNAR1 triggered by IAV infection. Further, CK1α was shown to be pivotal for proficient replication of IAV. Collectively, the results suggest that IAV HA induces degradation of IFN receptors via CK1α, creating conditions favorable for viral propagation. Therefore, the study uncovers a new immune-evasive pathway of influenza virus. IMPORTANCE Influenza A virus (IAV) remains a grave threat to humans, causing seasonal and pandemic influenza. Upon infection, innate and adaptive immunity, such as the interferon (IFN) response, is induced to protect hosts against IAV infection. However, IAV seems to be equipped with tactics to evade the IFN-mediated antiviral responses, although the detailed

Phosphorylation of acidic ribosomal proteins from rabbit reticulocytes by a ribosome-associated casein kinase

DEFF Research Database (Denmark)

Issinger, O G

1977-01-01

Two acidic proteins from 80-S ribosomes were isolated and purified to homogeneity. The purified acidic proteins could be phosphorylated by casein kinase using [gamma-32P]ATP and [gamma-32P]GTP as a phosphoryl donor. The proteins became phosphorylated in situ, too. Sodium dodecyl sulfate polyacryl......Two acidic proteins from 80-S ribosomes were isolated and purified to homogeneity. The purified acidic proteins could be phosphorylated by casein kinase using [gamma-32P]ATP and [gamma-32P]GTP as a phosphoryl donor. The proteins became phosphorylated in situ, too. Sodium dodecyl sulfate...

Casein kinase 1 regulates sterol regulatory element-binding protein (SREBP) to control sterol homeostasis.

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Brookheart, Rita T; Lee, Chih-Yung S; Espenshade, Peter J

2014-01-31

Sterol homeostasis is tightly controlled by the sterol regulatory element-binding protein (SREBP) transcription factor that is highly conserved from fungi to mammals. In fission yeast, SREBP functions in an oxygen-sensing pathway to promote adaptation to decreased oxygen supply that limits oxygen-dependent sterol synthesis. Low oxygen stimulates proteolytic cleavage of the SREBP homolog Sre1, generating the active transcription factor Sre1N that drives expression of sterol biosynthetic enzymes. In addition, low oxygen increases the stability and DNA binding activity of Sre1N. To identify additional signals controlling Sre1 activity, we conducted a genetic overexpression screen. Here, we describe our isolation and characterization of the casein kinase 1 family member Hhp2 as a novel regulator of Sre1N. Deletion of Hhp2 increases Sre1N protein stability and ergosterol levels in the presence of oxygen. Hhp2-dependent Sre1N degradation by the proteasome requires Hhp2 kinase activity, and Hhp2 binds and phosphorylates Sre1N at specific residues. Our results describe a role for casein kinase 1 as a direct regulator of sterol homeostasis. Given the role of mammalian Hhp2 homologs, casein kinase 1δ and 1ε, in regulation of the circadian clock, these findings may provide a mechanism for coordinating circadian rhythm and lipid metabolism.

Selective Inhibition of Casein Kinase 1 epsilon Minimally Alters Circadian Clock Period

Czech Academy of Sciences Publication Activity Database

Walton, K. M.; Fisher, K.; Rubitski, D.; Marconi, M.; Meng, Q.-J.; Sládek, Martin; Adams, J.; Bass, M.; Chandrasekaran, R.; Butler, T.; Griffor, M.; Rajamohan, F.; Serpa, M.; Chen, Y.; Claffey, M.; Hastings, M.; Loudon, A.; Maywood, E.; Ohren, J.; Doran, A.; Wager, T. T.

2009-01-01

Roč. 330, č. 2 (2009), s. 430-439 ISSN 0022-3565 Institutional research plan: CEZ:AV0Z50110509 Keywords : circadian clock * casein kinase 1 epsilon * inhibitor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.093, year: 2009

Casein kinase 1-Like 3 is required for abscisic acid regulation of ...

African Journals Online (AJOL)

Casein kinase 1-Like 3 is required for abscisic acid regulation of seed germination, root growth, and gene expression in Arabidopsis. M Wang, D Yu, X Guo, X Li, J Zhang, L Zhao, H Chang, S Hu, C Zhang, J Shi, X Liu ...

Identification of a BET Family Bromodomain/Casein Kinase II/TAF-Containing Complex as a Regulator of Mitotic Condensin Function

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Hyun-Soo Kim

2014-03-01

Full Text Available Condensin is a central regulator of mitotic genome structure with mutants showing poorly condensed chromosomes and profound segregation defects. Here, we identify NCT, a complex comprising the Nrc1 BET-family tandem bromodomain protein (SPAC631.02, casein kinase II (CKII, and several TAFs, as a regulator of condensin function. We show that NCT and condensin bind similar genomic regions but only briefly colocalize during the periods of chromosome condensation and decondensation. This pattern of NCT binding at the core centromere, the region of maximal condensin enrichment, tracks the abundance of acetylated histone H4, as regulated by the Hat1-Mis16 acetyltransferase complex and recognized by the first Nrc1 bromodomain. Strikingly, mutants in NCT or Hat1-Mis16 restore the formation of segregation-competent chromosomes in cells containing defective condensin. These results are consistent with a model where NCT targets CKII to chromatin in a cell-cycle-directed manner in order to modulate the activity of condensin during chromosome condensation and decondensation.

Identification of a BET family bromodomain/casein kinase II/TAF-containing complex as a regulator of mitotic condensin function.

Science.gov (United States)

Kim, Hyun-Soo; Mukhopadhyay, Rituparna; Rothbart, Scott B; Silva, Andrea C; Vanoosthuyse, Vincent; Radovani, Ernest; Kislinger, Thomas; Roguev, Assen; Ryan, Colm J; Xu, Jiewei; Jahari, Harlizawati; Hardwick, Kevin G; Greenblatt, Jack F; Krogan, Nevan J; Fillingham, Jeffrey S; Strahl, Brian D; Bouhassira, Eric E; Edelmann, Winfried; Keogh, Michael-Christopher

2014-03-13

Condensin is a central regulator of mitotic genome structure with mutants showing poorly condensed chromosomes and profound segregation defects. Here, we identify NCT, a complex comprising the Nrc1 BET-family tandem bromodomain protein (SPAC631.02), casein kinase II (CKII), and several TAFs, as a regulator of condensin function. We show that NCT and condensin bind similar genomic regions but only briefly colocalize during the periods of chromosome condensation and decondensation. This pattern of NCT binding at the core centromere, the region of maximal condensin enrichment, tracks the abundance of acetylated histone H4, as regulated by the Hat1-Mis16 acetyltransferase complex and recognized by the first Nrc1 bromodomain. Strikingly, mutants in NCT or Hat1-Mis16 restore the formation of segregation-competent chromosomes in cells containing defective condensin. These results are consistent with a model where NCT targets CKII to chromatin in a cell-cycle-directed manner in order to modulate the activity of condensin during chromosome condensation and decondensation. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

RNA helicase DDX3 is a regulatory subunit of casein kinase 1 in Wnt-beta-catenin signaling

NARCIS (Netherlands)

Cruciat, C.M.; Dolde, C.; de Groot, R.E.; Ohkawara, B.; Reinhard, C.; Korswagen, H.C.; Niehrs, C.

2013-01-01

Casein kinase 1 (CK1) members play key roles in numerous biological processes. They are considered "rogue" kinases, because their enzymatic activity appears unregulated. Contrary to this notion, we have identified the DEAD-box RNA helicase DDX3 as a regulator of the Wnt-beta-catenin network, where

Assignment of casein kinase 2 alpha sequences to two different human chromosomes

DEFF Research Database (Denmark)

Boldyreff, B; Klett, C; Göttert, E

1992-01-01

Human casein kinase 2 alpha gene (CK-2-alpha) sequences have been localized within the human genome by in situ hybridization and somatic cell hybrid analysis using a CK-2 alpha cDNA as a probe. By in situ hybridization, the CK-2 alpha cDNA could be assigned to two different loci, one on 11p15.1-ter...

Protein kinase CK2 in human diseases

DEFF Research Database (Denmark)

Guerra, Barbara; Issinger, Olaf-Georg

2008-01-01

Protein kinase CK2 (formerly referred to as casein kinase II) is an evolutionary conserved, ubiquitous protein kinase. There are two paralog catalytic subunits, i.e. alpha (A1) and alpha' (A2). The alpha and alpha' subunits are linked to two beta subunits to produce a heterotetrameric structure...

Characterization, subcellular localization and nuclear targeting of casein kinase 2 from Zea mays

DEFF Research Database (Denmark)

Peracchia, G; Jensen, A B; Culiáñez-Macià, F A

1999-01-01

We have isolated and characterized the genomic clone of maize casein kinase 2 (CK2) alpha subunit using the previously described alphaCK2-1 cDNA clone as a probe. The genomic clone is 7.5 kb long and contains 10 exons, separated by 9 introns of different size, two larger than 1.5 kb and the others...

Characterization of the alpha and beta subunits of casein kinase 2 by far-UV CD spectroscopy

DEFF Research Database (Denmark)

Issinger, O G; Brockel, C; Boldyreff, B

1992-01-01

Although Chou-Fasman calculations of the secondary structure of recombinant casein kinase 2 subunits alpha and beta suggest they have a similar overall conformation, circular dichroism (CD) studies show that substantial differences in the conformation of the two subunits exist. In addition......, no changes in the far-UV CD spectrum of the alpha subunit are observed in the presence of casein or the synthetic decapeptide substrate RRRDDDSDDD. Furthermore, the alpha-helical structure of the alpha subunit (but not the beta subunit) can be increased in the presence of stoichiometric amounts of heparin...

Pea DNA topoisomerase I is phosphorylated and stimulated by casein kinase 2 and protein kinase C.

Science.gov (United States)

Tuteja, Narendra; Reddy, Malireddy Kodandarami; Mudgil, Yashwanti; Yadav, Badam Singh; Chandok, Meena Rani; Sopory, Sudhir Kumar

2003-08-01

DNA topoisomerase I catalyzes the relaxation of superhelical DNA tension and is vital for DNA metabolism; therefore, it is essential for growth and development of plants. Here, we have studied the phosphorylation-dependent regulation of topoisomerase I from pea (Pisum sativum). The purified enzyme did not show autophosphorylation but was phosphorylated in an Mg(2+)-dependent manner by endogenous protein kinases present in pea nuclear extracts. This phosphorylation was abolished with calf intestinal alkaline phosphatase and lambda phosphatase. It was also phosphorylated by exogenous casein kinase 2 (CK2), protein kinase C (PKC; from animal sources), and an endogenous pea protein, which was purified using a novel phorbol myristate acetate affinity chromatography method. All of these phosphorylations were inhibited by heparin (inhibitor of CK2) and calphostin (inhibitor of PKC), suggesting that pea topoisomerase I is a bona fide substrate for these kinases. Spermine and spermidine had no effect on the CK2-mediated phosphorylation, suggesting that it is polyamine independent. Phospho-amino acid analysis showed that only serine residues were phosphorylated, which was further confirmed using antiphosphoserine antibody. The topoisomerase I activity increased after phosphorylation with exogenous CK2 and PKC. This study shows that these kinases may contribute to the physiological regulation of DNA topoisomerase I activity and overall DNA metabolism in plants.

Reconstitution of normal and hyperactivated forms of casein kinase-2 by variably mutated beta-subunits

DEFF Research Database (Denmark)

Boldyreff, B; Meggio, F; Pinna, L A

1993-01-01

Twenty-one mutants of the noncatalytic beta-subunit of human casein kinase-2 have been created, expressed in Escherichia coli, and purified to homogeneity. They are either modified at the autophosphorylation site (mutants beta delta 1-4 and beta A 5,6) or bear variable deletions in their C...

Casein Kinase 2 Reverses Tail-Independent Inactivation of Kinesin-1

Science.gov (United States)

Xu, Jing

2013-03-01

Kinesin-1 is a plus-end microtubule-based motor, and defects in kinesin-based transport are linked to diseases including neurodegeneration. Kinesin can auto-inhibit via a head-tail interaction, but is believed to be active otherwise. Here we report a tail-independent inactivation of kinesin, reversible by the disease-relevant signalling protein, casein kinase 2 (CK2). The majority of initially active kinesin (native or tail-less) loses its ability to interact with microtubules in vitro, and CK2 reverses this inactivation (approximately fourfold) without altering kinesin's single motor properties. This activation pathway does not require motor phosphorylation, and is independent of head-tail auto-inhibition. In cultured mammalian cells, reducing CK2 expression, but not its kinase activity, decreases the force required to stall lipid droplet transport, consistent with a decreased number of active kinesin motors. Our results (Nat. Commun., 3:754, 2012) provide the first direct evidence of a protein kinase upregulating kinesin-based transport, and suggest a novel pathway for regulating the activity of cargo-bound kinesin. Work supported by NIGMS grants GM64624 to SPG, GM74830-06A1 to LH, GM76516 to LB, NS048501 to SJK, and AHA grant 825278F to JX.

Ribosomal S6 Kinase Cooperates with Casein Kinase 2 to Modulate the Drosophila Circadian Molecular Oscillator

Science.gov (United States)

Akten, Bikem; Tangredi, Michelle M.; Jauch, Eike; Roberts, Mary A.; Ng, Fanny; Raabe, Thomas; Jackson, F. Rob

2009-01-01

There is a universal requirement for post-translational regulatory mechanisms in circadian clock systems. Previous work in Drosophila has identified several kinases, phosphatases and an E3 ligase that are critical for determining the nuclear translocation and/or stability of clock proteins. The present study evaluated the function of p90 ribosomal S6 kinase (RSK) in the Drosophila circadian system. In mammals, RSK1 is a light- and clock-regulated kinase known to be activated by the MAPK pathway, but there is no direct evidence that it functions as a component of the circadian system. Here, we show that Drosophila S6KII RNA displays rhythms in abundance, indicative of circadian control. Importantly, an S6KII null mutant exhibits a short-period circadian phenotype that can be rescued by expression of the wild-type gene in clock neurons, indicating a role for S6KII in the molecular oscillator. Peak PER clock protein expression is elevated in the mutant, indicative of enhanced stability, whereas per mRNA level is decreased, consistent with enhanced feedback repression. Gene reporter assays show that decreased S6KII is associated with increased PER repression. Surprisingly, we demonstrate a physical interaction between S6KII and the Casein Kinase 2 regulatory subunit (CK2β), suggesting a functional relationship between the two kinases. In support of such a relationship, there are genetic interactions between S6KII and CK2 mutations, in vivo, which indicate that CK2 activity is required for S6KII action. We propose that the two kinases cooperate within clock neurons to fine-tune circadian period, improving the precision of the clock mechanism. PMID:19144847

Electrochemiluminescence resonance energy transfer between graphene quantum dots and graphene oxide for sensitive protein kinase activity and inhibitor sensing

Energy Technology Data Exchange (ETDEWEB)

Liang, Ru-Ping; Qiu, Wei-Bin; Zhao, Hui-Fang; Xiang, Cai-Yun; Qiu, Jian-Ding, E-mail: jdqiu@ncu.edu.cn

2016-01-21

Herein, a novel electrochemiluminescence resonance energy transfer (ECL-RET) biosensor using graphene quantum dots (GQDs) as donor and graphene oxide (GO) as acceptor for monitoring the activity of protein kinase was presented for the first time. Anti-phosphoserine antibody conjugated graphene oxide (Ab-GO) nonocomposite could be captured onto the phosphorylated peptide/GQDs modified electrode surface through antibody–antigen interaction in the presence of casein kinase II (CK2) and adenosine 5′-triphosphate (ATP), resulting in ECL from the GQDs quenching by closely contacting GO. This ECL quenching degree was positively correlated with CK2 activity. Therefore, on the basis of ECL-RET between GQDs and GO, the activity of protein kinase can be detected sensitively. This biosensor can also be used for quantitative analysis CK2 activity in serum samples and qualitative screening kinase inhibition, indicating the potential application of the developed method in biochemical fundamental research and clinical diagnosis. - Highlights: • We reported a novel ECL-RET biosensor for sensitive analysis of casein kinase II activity. • The successful ECL-RET between GQDs and GO could be established. • GQDs was employed for casein kinase II activity monitoring and inhibition assay. • Highly sensitive detection of CK2 activity and inhibition was achieved.

The association of lysozyme with casein

NARCIS (Netherlands)

Roos, de A.L.; Walstra, P.; Geurts, T.J.

1998-01-01

The association of hen eggs’ lysozyme with caseins was studied by using three casein substrates: (I) solutions of the various caseins, (II) artificially made casein micelles of various compositions and (III) caseins adsorbed onto soya-oil emulsion droplets. In solution, lysozyme associated most

Hepatocyte Growth Factor Inhibits Apoptosis by the Profibrotic Factor Angiotensin II via Extracellular Signal-regulated Kinase 1/2 in Endothelial Cells and Tissue Explants

Science.gov (United States)

2010-12-01

1 mM sodium fluoride, 0.1 mM sodium orthovanadate, 1 mM tetrasodium pyrophosphate, 2 mM phenylmethylsulfonyl fluoride, 10 g/ml leupeptin, and 10 g...buffer [50 mM Tris-HCl, 1 mM EGTA, 1% (wt/vol) CHAPS, 10% glycerol, 50 mM sodium fluoride, 1 mM sodium orthovanadate, 2 mM phenylmethylsulfonyl fluoride...nucleus, nucleolin can be phosphorylated on serine res- idues by the cell cycle-regulated kinases casein kinase II and cell division cycle 2 protein

Rotavirus NSP1 Requires Casein Kinase II-Mediated Phosphorylation for Hijacking of Cullin-RING Ligases.

Science.gov (United States)

Davis, Kaitlin A; Morelli, Marco; Patton, John T

2017-08-29

The rotavirus nonstructural protein NSP1 repurposes cullin-RING E3 ubiquitin ligases (CRLs) to antagonize innate immune responses. By functioning as substrate adaptors of hijacked CRLs, NSP1 causes ubiquitination and proteasomal degradation of host proteins that are essential for expression of interferon (IFN) and IFN-stimulated gene products. The target of most human and porcine rotaviruses is the β-transducin repeat-containing protein (β-TrCP), a regulator of NF-κB activation. β-TrCP recognizes a phosphorylated degron (DSGΦXS) present in the inhibitor of NF-κB (IκB); phosphorylation of the IκB degron is mediated by IκB kinase (IKK). Because NSP1 contains a C-terminal IκB-like degron (ILD; DSGXS) that recruits β-TrCP, we investigated whether the NSP1 ILD is similarly activated by phosphorylation and whether this modification is required to trigger the incorporation of NSP1 into CRLs. Based on mutagenesis and phosphatase treatment studies, we found that both serine residues of the NSP1 ILD are phosphorylated, a pattern mimicking phosphorylation of IκB. A three-pronged approach using small-molecule inhibitors, small interfering RNAs, and mutagenesis demonstrated that NSP1 phosphorylation is mediated by the constitutively active casein kinase II (CKII), rather than IKK. In coimmunoprecipitation assays, we found that this modification was essential for NSP1 recruitment of β-TrCP and induced changes involving the NSP1 N-terminal RING motif that allowed formation of Cul3-NSP1 complexes. Taken together, our results indicate a highly regulated stepwise process in the formation of NSP1-Cul3 CRLs that is initiated by CKII phosphorylation of NSP1, followed by NSP1 recruitment of β-TrCP and ending with incorporation of the NSP1-β-TrCP complex into the CRL via interactions dependent on the highly conserved NSP1 RING motif. IMPORTANCE Rotavirus is a segmented double-stranded RNA virus that causes severe diarrhea in young children. A primary mechanism used by the

Yeast phospholipase C is required for stability of casein kinase I Yck2p and expression of hexose transporters

Czech Academy of Sciences Publication Activity Database

Zhang, T.; Galdieri, L.; Hašek, Jiří; Vančura, A.

2017-01-01

Roč. 364, č. 22 (2017), č. článku fnx227. ISSN 0378-1097 R&D Projects: GA ČR(CZ) GA16-05497S Institutional support: RVO:61388971 Keywords : phospholipase C * casein kinase I * hexose transporters Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.765, year: 2016

Interactions between Casein kinase Iepsilon (CKIepsilon and two substrates from disparate signaling pathways reveal mechanisms for substrate-kinase specificity.

Directory of Open Access Journals (Sweden)

Caroline Lund Dahlberg

Full Text Available Members of the Casein Kinase I (CKI family of serine/threonine kinases regulate diverse biological pathways. The seven mammalian CKI isoforms contain a highly conserved kinase domain and divergent amino- and carboxy-termini. Although they share a preferred target recognition sequence and have overlapping expression patterns, individual isoforms often have specific substrates. In an effort to determine how substrates recognize differences between CKI isoforms, we have examined the interaction between CKIepsilon and two substrates from different signaling pathways.CKIepsilon, but not CKIalpha, binds to and phosphorylates two proteins: Period, a transcriptional regulator of the circadian rhythms pathway, and Disheveled, an activator of the planar cell polarity pathway. We use GST-pull-down assays data to show that two key residues in CKIalpha's kinase domain prevent Disheveled and Period from binding. We also show that the unique C-terminus of CKIepsilon does not determine Dishevelled's and Period's preference for CKIepsilon nor is it essential for binding, but instead plays an auxillary role in stabilizing the interactions of CKIepsilon with its substrates. We demonstrate that autophosphorylation of CKIepsilon's C-terminal tail prevents substrate binding, and use mass spectrometry and chemical crosslinking to reveal how a phosphorylation-dependent interaction between the C-terminal tail and the kinase domain prevents substrate phosphorylation and binding.The biochemical interactions between CKIepsilon and Disheveled, Period, and its own C-terminus lead to models that explain CKIepsilon's specificity and regulation.

Casein kinase 2 regulates the active uptake of the organic osmolyte taurine in NIH3T3 mouse fibroblasts

DEFF Research Database (Denmark)

Jacobsen, Jack H; Clement, Christian A; Friis, Martin B

2008-01-01

Inhibition of the constitutively active casein kinase 2 (CK2) with 2-dimethyl-amino-4,5,6,7-tetrabromo-1H-benzimidasole stimulates the Na(+)-dependent taurine influx via the taurine transporter TauT in NIH3T3 cells. CK2 inhibition reduces the TauT mRNA level and increases the localization of TauT...

Pharmacological and safety evaluation of CIGB-300, a casein kinase 2 inhibitor peptide, administered intralesionally to patients with cervical cancer stage IB2/II

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Soriano-García JL

2013-08-01

Full Text Available CIGB-300 is a pro-apoptotic casein kinase 2 inhibitor peptide with potential anticancer action. An open-label and dose scaling Phase I trial was carried out to investigate the peptide tumor uptake, pharmacokinetics, toxicity, and levels of a CIGB-300 response biomarker in patients with cervical cancer stage IB2/II. Fourteen patients were included; six of them received 35 mg, 6 received 70 mg and the two remaining patients received 245 mg of CIGB-300 prior chemoradiotherapy. CIGB-300 was applied by intratumor injections during 5-consecutive days. For pharmacokinetic and biodistribution studies, the peptide was radiolabeled with 99mTc in the first administration and whole body gammagraphy and plasma testing were done during 48 h. Data showed that the maximum tolerated dose was 70 mg for CIGB-300 in this clinical setting. Furthermore, an allergic-like syndrome was identified as the dose limiting toxicity, which was well-correlated with plasmatic histamine levels. Importantly, the mean tumor uptake was 14.9 mg and 10.4 mg for CIGB-300 doses of 35 and 70 mg, respectively. Also, the kidneys were the main target organ for drug elimination. Finally, treatment with CIGB-300 significantly reduced the B23/nucleophosmin levels in tumor specimens. CIGB-300 meets potentialities to be tested in future trials in a neoadjuvant setting prior to chemoradiotherapy in cervical cancer.

Restricted growth of U-type infectious haematopoietic necrosis virus (IHNV) in rainbow trout cells may be linked to casein kinase II activity

Science.gov (United States)

Park, J.-W.; Moon, C.H.; Harmache, A.; Wargo, A.R.; Purcell, M.K.; Bremont, M.; Kurath, G.

2011-01-01

casein kinase II (CKII) inhibitor, 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole (DRB), reduced the titre of the U type 8.3-fold at 24 h post-infection. In contrast, 100 μm of the CKII inhibitor reduced the titre of the M type only 1.3-fold at 48 h post-infection. Our data suggest that the different growth of U- and M-type IHNV in RTG-2 cells may be linked to a differential requirement for cellular protein kinases such as CKII for their growth.

Casein genes of Bos taurus. II. Isolation and characterization of the β-casein gene

International Nuclear Information System (INIS)

Gorodetskii, S.I.; Tkach, T.M.; Kapelinskaya, T.V.

1988-01-01

The expression of the casein genes in the cells of the mammary gland is regulated by peptide and steroid hormones. In order to study the controlling mechanisms we have isolated and characterized the β-casein gene. The gene is 8.6 kb long and exceeds by a factor of 7.8 the length of the corresponding mRNA which is encoded by nine exons. The genomic clones incorporate in addition 8.5 kb and 4.5 kb of the 5'- and 3'-flanking regions. We have determined the sequence of the 5- and 3-terminals of the gene and have performed a comparative analysis of the corresponding regions of the rat β-casein gene. Furthermore we have identified the conversed sequences identical or homologous to the potential sections of binding to the nuclear factor CTF/NF-1 by glucocorticoid and progesterone receptors. The regulatory region of the bovine casein gene contains two variants of the TATA signal, flanking the duplication section in the promoter region

Identification of protein tyrosine phosphatase 1B and casein as substrates for 124-v-Mos

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Stabel Silvia

2002-04-01

Full Text Available Abstract Background The mos proto-oncogene encodes a cytoplasmic serine/threonine-specific protein kinase with crucial function during meiotic cell division in vertebrates. Based on oncogenic amino acid substitutions the viral derivative, 124-v-Mos, displays constitutive protein kinase activity and functions independent of unknown upstream effectors of mos protein kinase. We have utilized this property of 124-v-Mos and screened for novel mos substrates in immunocomplex kinase assays in vitro. Results We generated recombinant 124-v-Mos using the baculovirus expression system in Spodoptera frugiperda cells and demonstrated constitutive kinase activity by the ability of 124-v-Mos to auto-phosphorylate and to phosphorylate vimentin, a known substrate of c-Mos. Using this approach we analyzed a panel of acidic and basic substrates in immunocomplex protein kinase assays and identified novel in vitro substrates for 124-v-Mos, the protein tyrosine phosphatase 1B (PTP1B, alpha-casein and beta-casein. We controlled mos-specific phosphorylation of PTP1B and casein in comparative assays using a synthetic kinase-inactive 124-v-Mos mutant and further, tryptic digests of mos-phosphorylated beta-casein identified a phosphopeptide specifically targeted by wild-type 124-v-Mos. Two-dimensional phosphoamino acid analyses showed that 124-v-mos targets serine and threonine residues for phosphorylation in casein at a 1:1 ratio but auto-phosphorylation occurs predominantly on serine residues. Conclusion The mos substrates identified in this study represent a basis to approach the identification of the mos-consensus phosphorylation motif, important for the development of specific inhibitors of the Mos protein kinase.

Protein kinase activity associated with Fcγ/sub 2a/ receptor of a murine macrophage like cell line, P388D1

International Nuclear Information System (INIS)

Hirata, Y.; Suzuki, T.

1987-01-01

The properties of protein kinase activity associated with Fc receptor specific for IgG/sub 2a/(Fcγ/sub 2a/R) of a murine macrophage like cell line, P388D 1 , were investigated. IgG/sub 2a/-binding protein isolated from the detergent lysate of P388D 1 cells by affinity chromatography of IgG-Sepharose was found to contain four distinct proteins of M/sub r/ 50,000, 43,000, 37,000, and 17,000, which could be autophosphorylated upon incubation with [γ- 32 P]ATP. The autophosphorylation of Fcγ/sub 2a/ receptor complex ceased when exogenous phosphate acceptors (casein or histone) were added in the reaction mixture. Phosphorylation of casein catalyzed by Fcγ/sub 2a/ receptor complex was dependent on casein concentration, increased with time or temperature, was dependent on the concentration of ATP and Mg 2+ , and was maximum at pH near 8. Casein phosphorylation was significantly inhibited by a high concentration of Mn 2+ or KCl or by a small amount of heparin and was enhanced about 2-fold by protamine. Casein kinase activity associated with Fcγ/sub 2a/ receptor used ATP as substrate with an apparent K/sub m/ of 2 μM as well as GTP with an apparent K/sub m/ of 10 μM. Prior heating (60 0 C for 15 min) or treatment with protease (trypsin or Pronase) of Fcγ/sub 2a/ receptor complex almost totally abolished casein kinase activity. Thin-layer chromatography of a partial acid hydrolysate of the phosphorylated casein showed that the site of phosphorylation is at a seryl residue. These results suggest that Fcγ 2 /sub a/ receptor forms a molecule complex with protein kinase, whose characteristics resemble those of type II casein kinase but are different from those of cyclic nucleotide dependent protein kinase or from those of C protein kinase

Mini Screening of Kinase Inhibitors Affecting Period-length of Mammalian Cellular Circadian Clock

International Nuclear Information System (INIS)

Yagita, Kazuhiro; Yamanaka, Iori; Koinuma, Satoshi; Shigeyoshi, Yasufumi; Uchiyama, Yasuo

2009-01-01

In mammalian circadian rhythms, the transcriptional-translational feedback loop (TTFL) consisting of a set of clock genes is believed to elicit the circadian clock oscillation. The TTFL model explains that the accumulation and degradation of mPER and mCRY proteins control the period-length (tau) of the circadian clock. Although recent studies revealed that the Casein Kinase Iεδ (CKIεδ) regurates the phosphorylation of mPER proteins and the circadian period-length, other kinases are also likely to contribute the phosphorylation of mPER. Here, we performed small scale screening using 84 chemical compounds known as kinase inhibitors to identify candidates possibly affecting the circadian period-length in mammalian cells. Screening by this high-throughput real-time bioluminescence monitoring system revealed that the several chemical compounds apparently lengthened the cellular circadian clock oscillation. These compounds are known as inhibitors against kinases such as Casein Kinase II (CKII), PI3-kinase (PI3K) and c-Jun N-terminal Kinase (JNK) in addition to CKIεδ. Although these kinase inhibitors may have some non-specific effects on other factors, our mini screening identified new candidates contributing to period-length control in mammalian cells

Role of the beta subunit of casein kinase-2 on the stability and specificity of the recombinant reconstituted holoenzyme

DEFF Research Database (Denmark)

Meggio, F; Boldyreff, B; Marin, O

1992-01-01

Recombinant human alpha subunit from casein kinase-2 (CK-2) was subjected, either alone or in combination with recombinant human beta subunit, to high temperature, tryptic digestion and urea treatment. In all three cases, it was shown that the presence of the beta subunit could drastically reduce...... the autophosphorylation site. It is suggested that the acidic domain of the beta subunit, encompassing residues 55-71, plays a role in the interactions between the beta and alpha subunits....

The autophosphorylation and p34cdc2 phosphorylation sites of casein kinase-2 beta-subunit are not essential for reconstituting the fully-active heterotetrameric holoenzyme

DEFF Research Database (Denmark)

Meggio, F; Boldyreff, B; Issinger, O G

1993-01-01

Two mutants of human casein kinase-2 beta-subunit with short deletions at either their amino (delta 1-4) or carboxy (delta 209-215) terminal side have been created that have lost the capability to undergo autophosphorylation and p34cdc2 mediated phosphorylation, respectively. Both mutants give rise...

Detection of protein kinase activity by renaturation in sodium dodecyl sulfate-polyacrylamide gels

International Nuclear Information System (INIS)

Anostario, M. Jr.; Harrison, M.L.; Geahlen, R.L.

1986-01-01

The authors have developed a procedure for identifying protein kinase activity in protein samples following electrophoresis on SDS-polyacrylamide gels. Proteins are allowed to renature directly in the gel by removal of detergent. The gel is then incubated with [γ- 32 P]ATP to allow renatured protein kinases to autophosphorylate or to phosphorylate various substrates which can be incorporated into the gel. The positions of the radiolabeled proteins can then be detected by autoradiography. With this technique, using purified catalytic subunit of cAMP-dependent protein kinase, enzyme concentrations as low as 0.01 μg can be detected on gels containing 1.0 mg/ml casein. The procedure is also applicable for the determination of active subunits of multisubunit protein kinases. For example, when the two subunits of casein kinase II are separated by SDS-polyacrylamide gel electrophoresis and allowed to renature, only the larger α subunit shows activity. This procedure can also be used to detect and distinguish kinases present in heterogeneous mixtures. Starting with a particulate fraction from LSTRA, a murine T cell lymphoma, several distinct enzymes were detected, including a 30,000 Dalton protein with protein-tyrosine kinase activity. This same enzyme has also been detected in T lymphocytes and other T lymphoid cell lines

Efficient autophosphorylation and phosphorylation of the beta-subunit by casein kinase-2 require the integrity of an acidic cluster 50 residues downstream from the phosphoacceptor site

DEFF Research Database (Denmark)

Boldyreff, B; Meggio, F; Pinna, L A

1994-01-01

Various beta-mutants were investigated either as subunits or as substrates for casein kinase 2 (CK-2), in the absence of presence of polylysine. A total of 21 beta-mutants were characterized for their susceptibility to autophosphorylation, by combining them in equimolar amounts with the recombina...

Functional analysis of Casein Kinase 1 in a minimal circadian system.

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Gerben van Ooijen

Full Text Available The Earth's rotation has driven the evolution of cellular circadian clocks to facilitate anticipation of the solar cycle. Some evidence for timekeeping mechanism conserved from early unicellular life through to modern organisms was recently identified, but the components of this oscillator are currently unknown. Although very few clock components appear to be shared across higher species, Casein Kinase 1 (CK1 is known to affect timekeeping across metazoans and fungi, but has not previously been implicated in the circadian clock in the plant kingdom. We now show that modulation of CK1 function lengthens circadian rhythms in Ostreococcustauri, a unicellular marine algal species at the base of the green lineage, separated from humans by ~1.5 billion years of evolution. CK1 contributes to timekeeping in a phase-dependent manner, indicating clock-mediated gating of CK1 activity. Label-free proteomic analyses upon overexpression as well as inhibition revealed CK1-responsive phosphorylation events on a set of target proteins, including highly conserved potentially clock-relevant cellular regulator proteins. These results have major implications for our understanding of cellular timekeeping and can inform future studies in any circadian organism.

Intake of Hydrolyzed Casein is Associated with Reduced Body Fat Accretion and Enhanced Phase II Metabolism in Obesity Prone C57BL/6J Mice

Science.gov (United States)

Clausen, Morten Rahr; Zhang, Xumin; Yde, Christian C.; Ditlev, Ditte B.; Lillefosse, Haldis H.; Madsen, Lise; Kristiansen, Karsten; Liaset, Bjørn; Bertram, Hanne C.

2015-01-01

The amount and form of dietary casein have been shown to affect energy metabolism and lipid accumulation in mice, but the underlying mechanisms are not fully understood. We investigated 48 hrs urinary metabolome, hepatic lipid composition and gene expression in male C57BL/6J mice fed Western diets with 16 or 32 energy% protein in the form of extensively hydrolyzed or intact casein. LC-MS based metabolomics revealed a very strong impact of casein form on the urinary metabolome. Evaluation of the discriminatory metabolites using tandem mass spectrometry indicated that intake of extensively hydrolyzed casein modulated Phase II metabolism associated with an elevated urinary excretion of glucuronic acid- and sulphate conjugated molecules, whereas glycine conjugated molecules were more abundant in urine from mice fed the intact casein diets. Despite the differences in the urinary metabolome, we observed no differences in hepatic expression of genes involved in Phase II metabolism, but it was observed that expression of Abcc3 encoding ATP binding cassette c3 (transporter of glucuronic acid conjugates) was increased in livers of mice fed hydrolyzed casein. As glucuronic acid is derived from glucose and sulphate is derived from cysteine, our metabolomic data provided evidence for changes in carbohydrate and amino acid metabolism and we propose that this modulation of metabolism was associated with the reduced glucose and lipid levels observed in mice fed the extensively hydrolyzed casein diets. PMID:25738501

Casein Kinase I Isoform Hrr25 Is a Negative Regulator of Haa1 in the Weak Acid Stress Response Pathway in Saccharomyces cerevisiae.

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Collins, Morgan E; Black, Joshua J; Liu, Zhengchang

2017-07-01

Haa1 is a transcription factor that adapts Saccharomyces cerevisiae cells to weak organic acid stresses by activating the expression of various genes. Many of these genes encode membrane proteins, such as TPO2 and YRO2 How Haa1 is activated by weak acids is not clear. Here, we show that casein kinase I isoform Hrr25 is an important negative regulator of Haa1. Haa1 is known to be multiply phosphorylated. We found that mutations in HRR25 lead to reduced Haa1 phosphorylation and increased expression of Haa1 target genes and that Hrr25 interacts with Haa1. The other three casein kinase I isoforms, Yck1, Yck2, and Yck3, do not seem to play critical roles in Haa1 regulation. Hrr25 has a 200-residue C-terminal region, including a proline- and glutamine-rich domain. Our data suggest that the C-terminal region of Hrr25 is required for normal inhibition of expression of Haa1 target genes TPO2 and YRO2 and is important for cell growth but is not required for cell morphogenesis. We propose that Hrr25 is an important regulator of cellular adaptation to weak acid stress by inhibiting Haa1 through phosphorylation. IMPORTANCE Our study has revealed the casein kinase I protein Hrr25 to be a negative regulator of Haa1, a transcription factor mediating the cellular response to stresses caused by weak acids. Many studies have focused on the target genes of Haa1 and their roles in weak acid stress responses, but little has been reported on the regulatory mechanism of Haa1. Weak acids, such as acetic acid, have long been used for food preservation by slowing down the growth of fungal species, including S. cerevisiae In the biofuel industry, acetic acid in the lignocellulosic hydrolysates limits the production of ethanol, which is undesirable. By understanding how Haa1 is regulated, we can make advances in the field of food sciences to better preserve food and engineer acetic acid-resistant strains that will increase productivity in the biofuel industry. Copyright © 2017 American

The Rho kinases I and II regulate different aspects of myosin II activity

DEFF Research Database (Denmark)

Yoneda, Atsuko; Multhaupt, Hinke A B; Couchman, John R

2005-01-01

The homologous mammalian rho kinases (ROCK I and II) are assumed to be functionally redundant, based largely on kinase construct overexpression. As downstream effectors of Rho GTPases, their major substrates are myosin light chain and myosin phosphatase. Both kinases are implicated in microfilament...... bundle assembly and smooth muscle contractility. Here, analysis of fibroblast adhesion to fibronectin revealed that although ROCK II was more abundant, its activity was always lower than ROCK I. Specific reduction of ROCK I by siRNA resulted in loss of stress fibers and focal adhesions, despite...

CK2(beta)tes gene encodes a testis-specific isoform of the regulatory subunit of casein kinase 2 in Drosophila melanogaster

DEFF Research Database (Denmark)

Kalmykova, Alla I; Shevelyov, Yuri Y; Polesskaya, Oksana O

2002-01-01

An earlier described CK2(beta)tes gene of Drosophila melanogaster is shown to encode a male germline specific isoform of regulatory beta subunit of casein kinase 2. Western-analysis using anti-CK2(beta)tes Ig revealed CK2(beta)tes protein in Drosophila testes extract. Expression of a CK2(beta...... and coimmunoprecipitation analysis of protein extract from Drosophila testes, we demonstrated an association between CK2(beta)tes and CK2alpha. Northern-analysis has shown that another regulatory (beta') subunit found recently in D. melanogaster genome is also testis-specific. Thus, we describe the first example of two...

Main: 1M2Q [RPSD[Archive

Lifescience Database Archive (English)

Full Text Available 1M2Q トウモロコシ Corn Zea mays L. Casein Kinase Ii, Alpha Chain Name=Ack2; Zea Mays Mole...cule: Casein Kinase Ii, Alpha Chain; Chain: A; Fragment: Catlytic Subunit; Synonym: Ckii; Engineered: Yes Tr...ansferase 2.7.1.37 (Casein Kinase Ii, Alpha Chain) E.De Moliner, S.Sarno, S.Moro, G.Zagotto, G.Zanotti, L.A....=2-326.|PDB; 1M2Q; X-ray; A=2-328.|PDB; 1M2R; X-ray; A=2-328.|PDB; 1OM1; X-ray; A=1-332.|Mai

Casein polymorphism heterogeneity influences casein micelle size in milk of individual cows.

Science.gov (United States)

Day, L; Williams, R P W; Otter, D; Augustin, M A

2015-06-01

Milk samples from individual cows producing small (148-155 nm) or large (177-222 nm) casein micelles were selected to investigate the relationship between the individual casein proteins, specifically κ- and β-casein phenotypes, and casein micelle size. Only κ-casein AA and β-casein A1A1, A1A2 and A2A2 phenotypes were found in the large casein micelle group. Among the small micelle group, both κ-casein and β-casein phenotypes were more diverse. κ-Casein AB was the dominant phenotype, and 3 combinations (AA, AB, and BB) were present in the small casein micelle group. A considerable mix of β-casein phenotypes was found, including B and I variants, which were only found in the small casein micelle group. The relative amount of κ-casein to total casein was significantly higher in the small micelle group, and the nonglycosylated and glycosylated κ-casein contents were higher in the milks with small casein micelles (primarily with κ-casein AB and BB variants) compared with the large micelle group. The ratio of glycosylated to nonglycosylated κ-casein was higher in the milks with small casein micelles compared with the milks with large casein micelles. This suggests that although the amount of κ-casein (both glycosylated and nonglycosylated) is associated with micelle size, an increased proportion of glycosylated κ-casein could be a more important and favorable factor for small micelle size. This suggests that the increased spatial requirement due to addition of the glycosyl group with increasing extent of glycosylation of κ-casein is one mechanism that controls casein micelle assembly and growth. In addition, increased electrostatic repulsion due to the sialyl residues on the glycosyl group could be a contributory factor. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Complexes of lutein with bovine and caprine caseins and their impact on lutein chemical stability in emulsion systems: Effect of arabinogalactan.

Science.gov (United States)

Mora-Gutierrez, A; Attaie, R; Núñez de González, M T; Jung, Y; Woldesenbet, S; Marquez, S A

2018-01-01

Lutein is an important xanthophyll carotenoid with many benefits to human health. Factors affecting the application of lutein as a functional ingredient in low-fat dairy-like beverages (pH 6.0-7.0) are not well understood. The interactions of bovine and caprine caseins with hydrophobic lutein were studied using UV/visible spectroscopy as well as fluorescence. Our studies confirmed that the aqueous solubility of lutein is improved after binding with bovine and caprine caseins. The rates of lutein solubilization by the binding to bovine and caprine caseins were as follows: caprine α S1 -II-casein 34%, caprine α S1 -I-casein 10%, and bovine casein 7% at 100 μM lutein. Fluorescence of the protein was quenched on binding supporting complex formation. The fluorescence experiments showed that the binding involves tryptophan residues and some nonspecific interactions. Scatchard plots of lutein binding to the caseins demonstrated competitive binding between the caseins and their sites of interaction with lutein. Competition experiments suggest that caprine α S1 -II casein will bind a larger number of lutein molecules with higher affinity than other caseins. The chemical stability of lutein was largely dependent on casein type and significant increases occurred in the chemical stability of lutein with the following pattern: caprine α S1 -II-casein > caprine α S1 -I-casein > bovine casein. Addition of arabinogalactan to lutein-enriched emulsions increases the chemical stability of lutein-casein complexes during storage under accelerated photo-oxidation conditions at 25°C. Therefore, caprine α S1 -II-casein alone and in combination with arabinogalactan can have important applications in the beverage industry as carrier of this xanthophyll carotenoid (lutein). Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

In vitro phosphorylation of the movement protein of tomato mosaic tobamovirus by a cellular kinase.

Science.gov (United States)

Matsushita, Y; Hanazawa, K; Yoshioka, K; Oguchi, T; Kawakami, S; Watanabe, Y; Nishiguchi, M; Nyunoya, H

2000-08-01

The movement protein (MP) of tomato mosaic virus (ToMV) was produced in E. coli as a soluble fusion protein with glutathione S-transferase. When immobilized on glutathione affinity beads, the recombinant protein was phosphorylated in vitro by incubating with cell extracts of Nicotiana tabacum and tobacco suspension culture cells (BY-2) in the presence of [gamma-(32)P]ATP. Phosphorylation occurred even after washing the beads with a detergent-containing buffer, indicating that the recombinant MP formed a stable complex with some protein kinase(s) during incubation with the cell extract. Phosphoamino acid analysis revealed that the MP was phosphorylated on serine and threonine residues. Phosphorylation of the MP was decreased by addition of kinase inhibitors such as heparin, suramin and quercetin, which are known to be effective for casein kinase II (CK II). The phosphorylation level was not changed by other types of inhibitor. In addition, as shown for animal and plant CK II, [gamma-(32)P]GTP was efficiently used as a phosphoryl donor. Phosphorylation was not affected by amino acid replacements at serine-37 and serine-238, but was completely inhibited by deletion of the carboxy-terminal 9 amino acids, including threonine-256, serine-257, serine-261 and serine-263. These results suggest that the MP of ToMV could be phosphorylated in plant cells by a host protein kinase that is closely related to CK II.

Serotonin suppresses β-casein expression via PTP1B activation in human mammary epithelial cells.

Science.gov (United States)

Chiba, Takeshi; Maeda, Tomoji; Sanbe, Atsushi; Kudo, Kenzo

2016-04-22

Serotonin (5-hydroxytriptamine, 5-HT) has an important role in milk volume homeostasis within the mammary gland during lactation. We have previously shown that the expression of β-casein, a differentiation marker in mammary epithelial cells, is suppressed via 5-HT-mediated inhibition of signal transduction and activator of transcription 5 (STAT5) phosphorylation in the human mammary epithelial MCF-12A cell line. In addition, the reduction of β-casein in turn was associated with 5-HT7 receptor expression in the cells. The objective of this study was to determine the mechanisms underlying the 5-HT-mediated suppression of β-casein and STAT5 phosphorylation. The β-casein level and phosphorylated STAT5 (pSTAT5)/STAT5 ratio in the cells co-treated with 5-HT and a protein kinase A (PKA) inhibitor (KT5720) were significantly higher than those of cells treated with 5-HT alone. Exposure to 100 μM db-cAMP for 6 h significantly decreased the protein levels of β-casein and pSTAT5 and the pSTAT5/STAT5 ratio, and significantly increased PTP1B protein levels. In the cells co-treated with 5-HT and an extracellular signal-regulated kinase1/2 (ERK) inhibitor (FR180294) or Akt inhibitor (124005), the β-casein level and pSTAT5/STAT5 ratio were equal to those of cells treated with 5-HT alone. Treatment with 5-HT significantly induced PTP1B protein levels, whereas its increase was inhibited by KT5720. In addition, the PTP1B inhibitor sc-222227 increased the expression levels of β-casein and the pSTAT5/STAT5 ratio. Our observations indicate that PTP1B directly regulates STAT5 phosphorylation and that its activation via the cAMP/PKA pathway downstream of the 5-HT7 receptor is involved in the suppression of β-casein expression in MCF-12A cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Casein Micelle Dispersions under Osmotic Stress

Science.gov (United States)

Bouchoux, Antoine; Cayemitte, Pierre-Emerson; Jardin, Julien; Gésan-Guiziou, Geneviève; Cabane, Bernard

2009-01-01

Abstract Casein micelles dispersions have been concentrated and equilibrated at different osmotic pressures using equilibrium dialysis. This technique measured an equation of state of the dispersions over a wide range of pressures and concentrations and at different ionic strengths. Three regimes were found. i), A dilute regime in which the osmotic pressure is proportional to the casein concentration. In this regime, the casein micelles are well separated and rarely interact, whereas the osmotic pressure is dominated by the contribution from small residual peptides that are dissolved in the aqueous phase. ii), A transition range that starts when the casein micelles begin to interact through their κ-casein brushes and ends when the micelles are forced to get into contact with each other. At the end of this regime, the dispersions behave as coherent solids that do not fully redisperse when osmotic stress is released. iii), A concentrated regime in which compression removes water from within the micelles, and increases the fraction of micelles that are irreversibly linked to each other. In this regime the osmotic pressure profile is a power law of the residual free volume. It is well described by a simple model that considers the micelle to be made of dense regions separated by a continuous phase. The amount of water in the dense regions matches the usual hydration of proteins. PMID:19167314

Chymosin-induced hydrolysis of caseins: Influence of degree of phosphorylation of alpha-s1-casein and genetic variants of beta-casein

NARCIS (Netherlands)

Bijl, E.; Valenberg, van H.J.F.; Sikkes, S.; Jumelet, S.; Sala, G.; Olieman, K.; Hooijdonk, van A.C.M.; Huppertz, T.

2014-01-01

The objective of this study was to investigate the impact of natural variations in aS1-casein and b-casein composition of milk on chymosin-induced hydrolysis of these caseins in milk gels and in sodium caseinate solutions. At 50% casein degradation, 15% more of aS1-casein with eight phosphate groups

MAP kinase-independent signaling in angiotensin II regulation of neuromodulation in SHR neurons.

Science.gov (United States)

Yang, H; Raizada, M K

1998-09-01

Angiotensin II (Ang II), via its interaction with the angiotensin type 1 (AT1) receptor subtype, causes enhanced stimulation of norepinephrine (NE) neuromodulation. This involves increased transcription of NE transporter, tyrosine hydroxylase, and dopamine ss-hydroxylase genes in Wistar-Kyoto rat (WKY) brain neurons. AT1 receptor-mediated regulation of certain signaling events (such as activation of the Ras-Raf-1-mitogen activated protein (MAP) kinase signaling pathway, nuclear translocation of transcription factors such as Fos and Jun, and the interactions of these factors with AP-1 binding sites) is involved in this NE neuromodulation (Lu et al. J Cell Biol. 1996;135:1609-1617). The aim of this study was to compare the signal transduction mechanism of Ang II regulation of NE neuromodulation in WKY and spontaneously hypertensive rat (SHR) brain neurons, in view of the fact that AT1 receptor expression and Ang II stimulation of NE neuromodulation are higher in SHR neurons compared with WKY neurons. Despite this hyperactivity, Ang II stimulation of Ras, Raf-1, and MAP kinase activities was comparable between the neurons from WKY and SHR. Similarly, central injections of Ang II caused a comparable stimulation of MAP kinase in the hypothalamic and brain stem areas of adult WKY and SHR. Inhibition of MAP kinase by either an MAP kinase kinase inhibitor (PD98059) or an MAP kinase antisense oligonucleotide completely attenuated the stimulatory effects of Ang II on [3H]-NE uptake, NE transporter mRNA, and tyrosine hydroxylase mRNA levels in WKY neurons. These treatments resulted in only 43% to 50% inhibition of [3H]-NE uptake and NE transporter and tyrosine hydroxylase mRNAs in SHR neurons. Thus, Ang II stimulation of NE neuromodulation was completely blocked by MAP kinase inhibition in WKY neurons and only partially blocked in the SHR neurons. These observations suggest the presence of an additional signal transduction pathway involved in NE neuromodulation in SHR neurons

Angiotensin II regulation of neuromodulation: downstream signaling mechanism from activation of mitogen-activated protein kinase.

Science.gov (United States)

Lu, D; Yang, H; Raizada, M K

1996-12-01

Angiotensin II (Ang II) stimulates expression of tyrosine hydroxylase and norepinephrine transporter genes in brain neurons; however, the signal-transduction mechanism is not clearly defined. This study was conducted to determine the involvement of the mitogen-activated protein (MAP) kinase signaling pathway in Ang II stimulation of these genes. MAP kinase was localized in the perinuclear region of the neuronal soma. Ang II caused activation of MAP kinase and its subsequent translocation from the cytoplasmic to nuclear compartment, both effects being mediated by AT1 receptor subtype. Ang II also stimulated SRE- and AP1-binding activities and fos gene expression and its translocation in a MAP kinase-dependent process. These observations are the first demonstration of a downstream signaling pathway involving MAP kinase in Ang II-mediated neuromodulation in noradrenergic neurons.

Role of casein kinase 1A1 in the biology and targeted therapy of del(5q) MDS

Science.gov (United States)

Schneider, Rebekka K.; Ademà, Vera; Heckl, Dirk; Järås, Marcus; Mallo, Mar; Lord, Allegra M.; Chu, Lisa P.; McConkey, Marie E.; Kramann, Rafael; Mullally, Ann; Bejar, Rafael; Solé, Francesc; Ebert, Benjamin L.

2014-01-01

Summary The Casein kinase 1A1 gene (CSNK1A1) is a putative tumor suppressor gene located in the common deleted region for del(5q) myelodysplastic syndrome (MDS). We generated a murine model with conditional inactivation of Csnk1a1 and found that Csnk1a1 haploinsufficiency induces hematopoietic stem cell expansion and a competitive repopulation advantage whereas homozygous deletion induces hematopoietic stem cell failure. Based on this finding, we found that heterozygous inactivation of Csnk1a1 sensitizes cells to a CSNK1 inhibitor relative to cells with two intact alleles. In addition, we identified recurrent somatic mutations in CSNK1A1 on the non-deleted allele of patients with del(5q) MDS. These studies demonstrate that CSNK1A1 plays a central role in the biology of del(5q) MDS and is a promising therapeutic target. PMID:25242043

Crystal structure of human protein kinase CK2

DEFF Research Database (Denmark)

Niefind, K; Guerra, B; Ermakowa, I

2001-01-01

The crystal structure of a fully active form of human protein kinase CK2 (casein kinase 2) consisting of two C-terminally truncated catalytic and two regulatory subunits has been determined at 3.1 A resolution. In the CK2 complex the regulatory subunits form a stable dimer linking the two catalyt...... as a docking partner for various protein kinases. Furthermore it shows an inter-domain mobility in the catalytic subunit known to be functionally important in protein kinases and detected here for the first time directly within one crystal structure.......The crystal structure of a fully active form of human protein kinase CK2 (casein kinase 2) consisting of two C-terminally truncated catalytic and two regulatory subunits has been determined at 3.1 A resolution. In the CK2 complex the regulatory subunits form a stable dimer linking the two catalytic...... subunits, which make no direct contact with one another. Each catalytic subunit interacts with both regulatory chains, predominantly via an extended C-terminal tail of the regulatory subunit. The CK2 structure is consistent with its constitutive activity and with a flexible role of the regulatory subunit...

Casein Kinase 1δ Is an APC/CCdh1 Substrate that Regulates Cerebellar Granule Cell Neurogenesis

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Clara Penas

2015-04-01

Full Text Available Although casein kinase 1δ (CK1δ is at the center of multiple signaling pathways, its role in the expansion of CNS progenitor cells is unknown. Using mouse cerebellar granule cell progenitors (GCPs as a model for brain neurogenesis, we demonstrate that the loss of CK1δ or treatment of GCPs with a highly selective small molecule inhibits GCP expansion. In contrast, CK1δ overexpression increases GCP proliferation. Thus, CK1δ appears to regulate GCP neurogenesis. CK1δ is targeted for proteolysis via the anaphase-promoting complex/cyclosome (APC/CCdh1 ubiquitin ligase, and conditional deletion of the APC/CCdh1 activator Cdh1 in cerebellar GCPs results in higher levels of CK1δ. APC/CCdh1 also downregulates CK1δ during cell-cycle exit. Therefore, we conclude that APC/CCdh1 controls CK1δ levels to balance proliferation and cell-cycle exit in the developing CNS. Similar studies in medulloblastoma cells showed that CK1δ holds promise as a therapeutic target.

Main: 1LR4 [RPSD[Archive

Lifescience Database Archive (English)

Full Text Available 1LR4 トウモロコシ Corn Zea mays L. Casein Kinase Ii, Alpha Chain Name=Ack2; Zea Mays Mole...cule: Protein Kinase Ck2; Chain: A; Synonym: Casein Kinase Ii, Alpha Chain; Engineered: Yes Transferase 2.7....ray; A=2-326.|PDB; 1M2Q; X-ray; A=2-328.|PDB; 1M2R; X-ray; A=2-328.|PDB; 1OM1; X-ray; A=1-332.|Mai

Production of calcium- and magnesium-enriched caseins and caseinates by an ecofriendly technology.

Science.gov (United States)

Masson, Félix-André; Mikhaylin, Sergey; Bazinet, Laurent

2018-05-09

Finding new green ways of producing proteins has never been of such critical public interest, both to meet consumers' needs and to preserve the environment. Milk proteins are among the most attractive protein types due to their high nutritional value and attractive functional properties. In this work, the separation of caseins by conventional chemical acidification was compared with electrodialysis with bipolar membrane coupled to an ultrafiltration module (EDBM-UF), a green process that allows the precipitation of caseins by H + generated in situ by the bipolar membrane and, simultaneously, the production of a separated NaOH stream from OH - electrogenerated by the bipolar membrane. Caseinate production using this NaOH stream by-product and the quantity of NaOH needed to produce caseinates from both methods were also investigated. Hence, the purity and composition of caseins and caseinates were compared in terms of protein, ash, and lactose contents as well as mineral composition. The results showed for the first time that caseinates can be produced by solubilizing caseins with NaOH stream from the EDBM process. Furthermore, the caseins and caseinates produced by EDBM-UF were equivalent in terms of lactose and protein contents to their respective caseins and caseinates that were chemically produced but presented slightly lower sodium content and 3 to 4 times higher magnesium and calcium contents. The fact that calcium and magnesium are likely bound to milk caseins would ensure their favorable absorbability. These caseins or caseinates from the new EDBM-UF process could be suitable as an improved protein-based calcium or magnesium supplement, both for their enhanced nutritional quality and because they are produced by a green process. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Bovine β-casein

NARCIS (Netherlands)

Atamer, Zeynep; Post, Antonie E.; Schubert, Thomas; Holder, Aline; Boom, Remko Marcel; Hinrichs, Jörg

2017-01-01

In recent years there has been an increasing interest in pure casein fractions, particularly β-casein due to its physiochemical properties as well as its bio- and techno-functional properties. A range of methods has been developed for the fractionation of casein into its individual proteins. The

Inhibition of casein kinase 2 modulates XBP1-GRP78 arm of unfolded protein responses in cultured glial cells.

Directory of Open Access Journals (Sweden)

Toru Hosoi

Full Text Available Stress signals cause abnormal proteins to accumulate in the endoplasmic reticulum (ER. Such stress is known as ER stress, which has been suggested to be involved in neurodegenerative diseases, diabetes, obesity and cancer. ER stress activates the unfolded protein response (UPR to reduce levels of abnormal proteins by inducing the production of chaperon proteins such as GRP78, and to attenuate translation through the phosphorylation of eIF2α. However, excessive stress leads to apoptosis by generating transcription factors such as CHOP. Casein kinase 2 (CK2 is a serine/threonine kinase involved in regulating neoplasia, cell survival and viral infections. In the present study, we investigated a possible linkage between CK2 and ER stress using mouse primary cultured glial cells. 4,5,6,7-tetrabromobenzotriazole (TBB, a CK2-specific inhibitor, attenuated ER stress-induced XBP-1 splicing and subsequent induction of GRP78 expression, but was ineffective against ER stress-induced eIF2α phosphorylation and CHOP expression. Similar results were obtained when endogenous CK2 expression was knocked-down by siRNA. Immunohistochemical analysis suggested that CK2 was present at the ER. These results indicate CK2 to be linked with UPR and to resist ER stress by activating the XBP-1-GRP78 arm of UPR.

Yeast casein kinase 2 governs morphology, biofilm formation, cell wall integrity, and host cell damage of Candida albicans.

Science.gov (United States)

Jung, Sook-In; Rodriguez, Natalie; Irrizary, Jihyun; Liboro, Karl; Bogarin, Thania; Macias, Marlene; Eivers, Edward; Porter, Edith; Filler, Scott G; Park, Hyunsook

2017-01-01

The regulatory networks governing morphogenesis of a pleomorphic fungus, Candida albicans are extremely complex and remain to be completely elucidated. This study investigated the function of C. albicans yeast casein kinase 2 (CaYck2p). The yck2Δ/yck2Δ strain displayed constitutive pseudohyphae in both yeast and hyphal growth conditions, and formed enhanced biofilm under non-biofilm inducing condition. This finding was further supported by gene expression analysis of the yck2Δ/yck2Δ strain which showed significant upregulation of UME6, a key transcriptional regulator of hyphal transition and biofilm formation, and cell wall protein genes ALS3, HWP1, and SUN41, all of which are associated with morphogenesis and biofilm architecture. The yck2Δ/yck2Δ strain was hypersensitive to cell wall damaging agents and had increased compensatory chitin deposition in the cell wall accompanied by an upregulation of the expression of the chitin synthase genes, CHS2, CHS3, and CHS8. Absence of CaYck2p also affected fungal-host interaction; the yck2Δ/yck2Δ strain had significantly reduced ability to damage host cells. However, the yck2Δ/yck2Δ strain had wild-type susceptibility to cyclosporine and FK506, suggesting that CaYck2p functions independently from the Ca+/calcineurin pathway. Thus, in C. albicans, Yck2p is a multifunctional kinase that governs morphogenesis, biofilm formation, cell wall integrity, and host cell interactions.

Characterisation of monotreme caseins reveals lineage-specific expansion of an ancestral casein locus in mammals.

Science.gov (United States)

Lefèvre, Christophe M; Sharp, Julie A; Nicholas, Kevin R

2009-01-01

Using a milk-cell cDNA sequencing approach we characterised milk-protein sequences from two monotreme species, platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus) and found a full set of caseins and casein variants. The genomic organisation of the platypus casein locus is compared with other mammalian genomes, including the marsupial opossum and several eutherians. Physical linkage of casein genes has been seen in the casein loci of all mammalian genomes examined and we confirm that this is also observed in platypus. However, we show that a recent duplication of beta-casein occurred in the monotreme lineage, as opposed to more ancient duplications of alpha-casein in the eutherian lineage, while marsupials possess only single copies of alpha- and beta-caseins. Despite this variability, the close proximity of the main alpha- and beta-casein genes in an inverted tail-tail orientation and the relative orientation of the more distant kappa-casein genes are similar in all mammalian genome sequences so far available. Overall, the conservation of the genomic organisation of the caseins indicates the early, pre-monotreme development of the fundamental role of caseins during lactation. In contrast, the lineage-specific gene duplications that have occurred within the casein locus of monotremes and eutherians but not marsupials, which may have lost part of the ancestral casein locus, emphasises the independent selection on milk provision strategies to the young, most likely linked to different developmental strategies. The monotremes therefore provide insight into the ancestral drivers for lactation and how these have adapted in different lineages.

Protein kinase CK2 in health and disease: Protein kinase CK2: from structures to insights

DEFF Research Database (Denmark)

Niefind, K; Raaf, J; Issinger, Olaf-Georg

2009-01-01

the critical region of CK2alpha recruitment is pre-formed in the unbound state. In CK2alpha the activation segment - a key element of protein kinase regulation - adapts invariably the typical conformation of the active enzymes. Recent structures of human CK2alpha revealed a surprising plasticity in the ATP......Within the last decade, 40 crystal structures corresponding to protein kinase CK2 (former name 'casein kinase 2'), to its catalytic subunit CK2alpha and to its regulatory subunit CK2beta were published. Together they provide a valuable, yet by far not complete basis to rationalize the biochemical...

Developmental distribution of CaM kinase II in the antennal lobe of the sphinx moth Manduca sexta.

Science.gov (United States)

Lohr, Christian; Bergstein, Sandra; Hirnet, Daniela

2007-01-01

The antennal lobe (primary olfactory center of insects) is completely reorganized during metamorphosis. This reorganization is accompanied by changing patterns of calcium signaling in neurons and glial cells. In the present study, we investigated the developmental distribution of a major calcium-dependent protein, viz., calcium/calmodulin-dependent protein kinase II (CaM kinase II), in the antennal lobe of the sphinx moth Manduca sexta by using a monoclonal antibody. During synaptogenesis (developmental stages 6-10), we found a redistribution of CaM kinase II immunoreactivity, from a homogeneous distribution in the immature neuropil to an accumulation in the neuropil of the glomeruli. CaM kinase II immunoreactivity was less intense in olfactory receptor axons of the antennal nerve and antennal lobe glial cells. Western blot analysis revealed a growing content of CaM kinase II in antennal lobe tissue throughout metamorphosis. Injection of the CaM kinase inhibitor KN-93 into pupae resulted in a reduced number of antennal lobe glial cells migrating into the neuropil to form borders around glomeruli. The results suggest that CaM kinase II is involved in glial cell migration.

The effect of polylysine on casein-kinase-2 activity is influenced by both the structure of the protein/peptide substrates and the subunit composition of the enzyme

DEFF Research Database (Denmark)

Meggio, F; Boldyreff, B; Marin, O

1992-01-01

, moreover, is variably accounted for by changes in Vmax and/or Km, depending on the structure of the peptide substrate. Maximum stimulation with all protein/peptide substrates tested requires the presence of the beta subunit, since the recombinant alpha subunit is much less responsive than CK2 holoenzyme......The mechanism by which polybasic peptides stimulate the activity of casein kinase 2 (CK2) has been studied by comparing the effect of polylysine on the phosphorylation of a variety of protein and peptide substrates by the native CK2 holoenzyme and by its recombinant catalytic alpha subunit, either...

Natural variation in casein composition of milk

NARCIS (Netherlands)

Bijl, E.

2014-01-01

Bovine milk contains 3-4 % protein and almost 80% of the milk protein fraction consist of four caseins; α_s1-casein, β-casein, α_s2-casein and κ-casein. Most of the caseins in milk are assembled in casein micelles, which consist of several thousands of individual casein

Natural variation in casein composition of milk

OpenAIRE

Bijl, E.

2014-01-01

Bovine milk contains 3-4 % protein and almost 80% of the milk protein fraction consist of four caseins; αs1-casein, β-casein, αs2-casein and κ-casein. Most of the caseins in milk are assembled in casein micelles, which consist of several thousands of individual casein molecules and salts. The unique structure of casein micelles allows the delivery of large amounts of calcium and phosphate to the neonate. Considerable natural variation in casein content and composition exists between milk sam...

Absolute Quantification of Human Milk Caseins and the Whey/Casein Ratio during the First Year of Lactation.

Science.gov (United States)

Liao, Yalin; Weber, Darren; Xu, Wei; Durbin-Johnson, Blythe P; Phinney, Brett S; Lönnerdal, Bo

2017-11-03

Whey proteins and caseins in breast milk provide bioactivities and also have different amino acid composition. Accurate determination of these two major protein classes provides a better understanding of human milk composition and function, and further aids in developing improved infant formulas based on bovine whey proteins and caseins. In this study, we implemented a LC-MS/MS quantitative analysis based on iBAQ label-free quantitation, to estimate absolute concentrations of α-casein, β-casein, and κ-casein in human milk samples (n = 88) collected between day 1 and day 360 postpartum. Total protein concentration ranged from 2.03 to 17.52 with a mean of 9.37 ± 3.65 g/L. Casein subunits ranged from 0.04 to 1.68 g/L (α-), 0.04 to 4.42 g/L (β-), and 0.10 to 1.72 g/L (α-), with β-casein having the highest average concentration among the three subunits. Calculated whey/casein ratio ranged from 45:55 to 97:3. Linear regression analyses show significant decreases in total protein, β-casein, κ-casein, total casein, and a significant increase of whey/casein ratio during the course of lactation. Our study presents a novel and accurate quantitative analysis of human milk casein content, demonstrating a lower casein content than earlier believed, which has implications for improved infants formulas.

Label-free quantitative analysis of the casein kinase 2-responsive phosphoproteome of the marine minimal model species Ostreococcus tauri.

Science.gov (United States)

Le Bihan, Thierry; Hindle, Matthew; Martin, Sarah F; Barrios-Llerena, Martin E; Krahmer, Johanna; Kis, Katalin; Millar, Andrew J; van Ooijen, Gerben

2015-12-01

Casein kinase 2 (CK2) is a protein kinase that phosphorylates a plethora of cellular target proteins involved in processes including DNA repair, cell cycle control, and circadian timekeeping. CK2 is functionally conserved across eukaryotes, although the substrate proteins identified in a range of complex tissues are often different. The marine alga Ostreococcus tauri is a unicellular eukaryotic model organism ideally suited to efficiently study generic roles of CK2 in the cellular circadian clock. Overexpression of CK2 leads to a slow circadian rhythm, verifying functional conservation of CK2 in timekeeping. The proteome was analysed in wild-type and CK2-overexpressing algae at dawn and dusk, revealing that differential abundance of the global proteome across the day is largely unaffected by overexpression. However, CK2 activity contributed more strongly to timekeeping at dusk than at dawn. The phosphoproteome of a CK2 overexpression line and cells treated with CK2 inhibitor was therefore analysed and compared to control cells at dusk. We report an extensive catalogue of 447 unique CK2-responsive differential phosphopeptide motifs to inform future studies into CK2 activity in the circadian clock of more complex tissues. All MS data have been deposited in the ProteomeXchange with identifier PXD000975 (http://proteomecentral.proteomexchange.org/dataset/PXD000975). © 2015 The Authors. PROTEOMICS Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Casein kinase 1 alpha regulates chromosome congression and separation during mouse oocyte meiotic maturation and early embryo development.

Directory of Open Access Journals (Sweden)

Lu Wang

Full Text Available Casein kinase I alpha (CK1α is a member of serine/threonine protein kinase, generally present in all eukaryotes. In mammals, CK1α regulates the transition from interphase to metaphase in mitosis. However, little is known about its role in meiosis. Here we examined Ck1α mRNA and protein expression, as well as its subcellular localization in mouse oocytes from germinal vesicle to the late 1-cell stage. Our results showed that the expression level of CK1α was increased in metaphase. Immunostaining results showed that CK1α colocalized with condensed chromosomes during oocyte meiotic maturation and early embryo development. We used the loss-of-function approach by employing CK1α specific morpholino injection to block the function of CK1α. This functional blocking leads to failure of polar body 1 (PB1 extrusion, chromosome misalignment and MII plate incrassation. We further found that D4476, a specific and efficient CK1 inhibitor, decreased the rate of PB1 extrusion. Moreover, D4476 resulted in giant polar body extrusion, oocyte pro-MI arrest, chromosome congression failure and impairment of embryo developmental potential. In addition, we employed pyrvinium pamoate (PP, an allosteric activator of CK1α, to enhance CK1α activity in oocytes. Supplementation of PP induced oocyte meiotic maturation failure, severe congression abnormalities and misalignment of chromosomes. Taken together, our study for the first time demonstrates that CK1α is required for chromosome alignment and segregation during oocyte meiotic maturation and early embryo development.

Immunohistochemical and Proteomic Evaluation of Nuclear Ubiquitous Casein and Cyclin-Dependent Kinases Substrate in Invasive Ductal Carcinoma of the Breast

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Piotr Ziółkowski

2009-01-01

Full Text Available Nuclear ubiquitous casein and cyclin-dependent kinases substrate (NUCKS is 27 kDa chromosomal protein of unknown function. Its amino acid composition as well as structure of its DNA binding domain resembles that of high-mobility group A, HMGA proteins. HMGA proteins are associated with various malignancies. Since changes in expression of HMGA are considered as marker of tumor progression, it is possible that similar changes in expression of NUCKS could be useful tool in diagnosis and prognosis of breast cancer. For identification and analysis of NUCKS we used proteomic and histochemical methods. Analysis of patient-matched samples of normal and breast cancer by mass spectrometry revealed elevated levels of NUCKS in protein extracts from ductal breast cancers. We elicited specific antibodies against NUCKS and used them for immunohistochemistry in invasive ductal carcinoma of breast. We found high expression of NUCKS in 84.3% of cancer cells. We suggest that such overexpression of NUCKS can play significant role in breast cancer biology.

Glycation Reactions of Casein Micelles.

Science.gov (United States)

Moeckel, Ulrike; Duerasch, Anja; Weiz, Alexander; Ruck, Michael; Henle, Thomas

2016-04-13

After suspensions of micellar casein or nonmicellar sodium caseinate had been heated, respectively, in the presence and absence of glucose for 0-4 h at 100 °C, glycation compounds were quantitated. The formation of Amadori products as indicators for the "early" Maillard reaction were in the same range for both micellar and nonmicellar caseins, indicating that reactive amino acid side chains within the micelles are accessible for glucose in a comparable way as in nonmicellar casein. Significant differences, however, were observed concerning the formation of the advanced glycation end products (AGEs), namely, N(ε)-carboxymethyllysine (CML), pyrraline, pentosidine, and glyoxal-lysine dimer (GOLD). CML could be observerd in higher amounts in nonmicellar casein, whereas in the micelles the pyrraline formation was increased. Pentosidine and GOLD were formed in comparable amounts. Furthermore, the extent of protein cross-linking was significantly higher in the glycated casein micelles than in the nonmicellar casein samples. Dynamic light scattering and scanning electron microscopy showed that glycation has no influence on the size of the casein micelles, indicating that cross-linking occurs only in the interior of the micelles, but altered the surface morphology. Studies on glycation and nonenzymatic cross-linking can contribute to the understanding of the structure of casein micelles.

The cyclin-dependent kinase 8 module sterically blocks Mediator interactions with RNA polymerase II

DEFF Research Database (Denmark)

Elmlund, Hans; Baraznenok, Vera; Lindahl, Martin

2006-01-01

CDK8 (cyclin-dependent kinase 8), along with CycC, Med12, and Med13, form a repressive module (the Cdk8 module) that prevents RNA polymerase II (pol II) interactions with Mediator. Here, we report that the ability of the Cdk8 module to prevent pol II interactions is independent of the Cdk8......-dependent kinase activity. We use electron microscopy and single-particle reconstruction to demonstrate that the Cdk8 module forms a distinct structural entity that binds to the head and middle region of Mediator, thereby sterically blocking interactions with pol II....

Phosphorylation of inhibitor-2 and activation of MgATP-dependent protein phosphatase by rat skeletal muscle glycogen synthase kinase

International Nuclear Information System (INIS)

Hegazy, M.G.; Reimann, E.M.; Thysseril, T.J.; Schlender, K.K.

1986-01-01

Rat skeletal muscle contains a glycogen synthase kinase (GSK-M) which is not stimulated by Ca 2+ or cAMP. This kinase has an apparent Mr of 62,000 and uses ATP but not GTP as a phosphoryl donor. GSK-M phosphorylated glycogen synthase at sites 2 and 3. It phosphorylated ATP-citrate lyase and activated MgATP-dependent phosphatase in the presence of ATP but not GTP. As expected, the kinase also phosphorylated phosphatase inhibitor 2 (I-2). Phosphatase incorporation reached approximately 0.3 mol/mol of I-2. Phosphopeptide maps were obtained by digesting 32 P-labeled I-2 with trypsin and separating the peptides by reversed phase HPLC. Two partially separated 32 P-labeled peaks were obtained when I-2 was phosphorylated with either GSK-M or glycogen synthase kinase 3 (GSK-3) and these peptides were different from those obtained when I-2 was phosphorylated with the catalytic subunit of cAMP-dependent protein kinase (CSU) or casein kinase II (CK-II). When I-2 was phosphorylated with GSK-M or GSK-3 and cleaved by CNBr, a single radioactive peak was obtained. Phosphoamino acid analysis showed that I-2 was phosphorylated by GSK-M or GSK-3 predominately in Thr whereas CSU and CK-II phosphorylated I-2 exclusively in Ser. These results indicate that GSK-M is similar to GSK-3 and to ATP-citrate lyase kinase. However, it appears to differ in Mr from ATP-citrate lyase kinase and it differs from GSK-3 in that it phosphorylates glycogen synthase at site 2 and it does not use GTP as a phosphoryl donor

Comparison of the orogenic displacement of sodium caseinate with the caseins from the air-water interface by nonionic surfactants.

Science.gov (United States)

Woodward, N C; Gunning, A P; Mackie, A R; Wilde, P J; Morris, V J

2009-06-16

Displacement of sodium caseinate from the air-water interface by nonionic surfactants Tween 20 and Tween 60 was observed by atomic force microscopy (AFM). The interfacial structure was sampled by Langmuir-Blodgett deposition onto freshly cleaved mica substrates. Protein displacement occurred through an orogenic mechanism: it involved the nucleation and growth of surfactant domains within the protein network, followed by failure of the protein network. The surface pressure at which failure of the protein network occurred was essentially independent of the type of surfactant. The major component of sodium caseinate is beta-casein, and previous studies at the air-water interface have shown that beta-casein networks are weak, failing at surface pressures below that observed for sodium caseinate. The other components of sodium caseinate are alpha(s)- and kappa-caseins. Studies of the displacement of alpha(s)-caseins from air-water interfaces show that these proteins also form weak networks that fail at surface pressures below that observed for sodium caseinate. However, kappa-casein was found to form strong networks that resisted displacement and failed at surface pressures comparable to those observed for sodium caseinate. The AFM images of the displacement suggest that, despite kappa-casein being a minor component, it dominates the failure of sodium caseinate networks: alpha(s)-casein and beta-casein are preferentially desorbed at lower surface pressures, allowing the residual kappa-casein to control the breakdown of the sodium caseinate network at higher surface pressures.

Electrochemiluminescence resonance energy transfer between graphene quantum dots and graphene oxide for sensitive protein kinase activity and inhibitor sensing.

Science.gov (United States)

Liang, Ru-Ping; Qiu, Wei-Bin; Zhao, Hui-Fang; Xiang, Cai-Yun; Qiu, Jian-Ding

2016-01-21

Herein, a novel electrochemiluminescence resonance energy transfer (ECL-RET) biosensor using graphene quantum dots (GQDs) as donor and graphene oxide (GO) as acceptor for monitoring the activity of protein kinase was presented for the first time. Anti-phosphoserine antibody conjugated graphene oxide (Ab-GO) nonocomposite could be captured onto the phosphorylated peptide/GQDs modified electrode surface through antibody-antigen interaction in the presence of casein kinase II (CK2) and adenosine 5'-triphosphate (ATP), resulting in ECL from the GQDs quenching by closely contacting GO. This ECL quenching degree was positively correlated with CK2 activity. Therefore, on the basis of ECL-RET between GQDs and GO, the activity of protein kinase can be detected sensitively. This biosensor can also be used for quantitative analysis CK2 activity in serum samples and qualitative screening kinase inhibition, indicating the potential application of the developed method in biochemical fundamental research and clinical diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Invited review: Caseins and the casein micelle: their biological functions, structures, and behavior in foods.

Science.gov (United States)

Holt, C; Carver, J A; Ecroyd, H; Thorn, D C

2013-10-01

A typical casein micelle contains thousands of casein molecules, most of which form thermodynamically stable complexes with nanoclusters of amorphous calcium phosphate. Like many other unfolded proteins, caseins have an actual or potential tendency to assemble into toxic amyloid fibrils, particularly at the high concentrations found in milk. Fibrils do not form in milk because an alternative aggregation pathway is followed that results in formation of the casein micelle. As a result of forming micelles, nutritious milk can be secreted and stored without causing either pathological calcification or amyloidosis of the mother's mammary tissue. The ability to sequester nanoclusters of amorphous calcium phosphate in a stable complex is not unique to caseins. It has been demonstrated using a number of noncasein secreted phosphoproteins and may be of general physiological importance in preventing calcification of other biofluids and soft tissues. Thus, competent noncasein phosphoproteins have similar patterns of phosphorylation and the same type of flexible, unfolded conformation as caseins. The ability to suppress amyloid fibril formation by forming an alternative amorphous aggregate is also not unique to caseins and underlies the action of molecular chaperones such as the small heat-shock proteins. The open structure of the protein matrix of casein micelles is fragile and easily perturbed by changes in its environment. Perturbations can cause the polypeptide chains to segregate into regions of greater and lesser density. As a result, the reliable determination of the native structure of casein micelles continues to be extremely challenging. The biological functions of caseins, such as their chaperone activity, are determined by their composition and flexible conformation and by how the casein polypeptide chains interact with each other. These same properties determine how caseins behave in the manufacture of many dairy products and how they can be used as functional

A CK2 site is reversibly phosphorylated in the photosystem II subunit CP29.

Science.gov (United States)

Testi, M G; Croce, R; Polverino-De Laureto, P; Bassi, R

1996-12-16

Protein phosphorylation is a major mechanism in the regulation of protein function. In chloroplast thylakoids several photosystem II subunits, including the major antenna light-harvesting complex II and several core complex components, are reversibly phosphorylated depending on the redox state of the electron carriers. A previously unknown reversible phosphorylation event has recently been described on the CP29 subunit which leads to conformational changes and protection from cold stress (Bergantino, E., Dainese, P., Cerovic, Z. Sechi, S. and Bassi, R. (1995) J. Biol Chem. 270, 8474-8481). In this study, we have identified the phosphorylation site on the N-terminal, stroma-exposed domain, showing that it is located in a sequence not homologous to the other members of the Lhc family. The phosphorylated sequence is unique in chloroplast membranes since it meets the requirements for CK2 (casein kinase II) kinases. The possibility that this phosphorylation is involved in a signal transduction pathway is discussed.

Phosphorylation of the cytoplasmic tail of the 300-kDa mannose 6-phosphate receptor is required for the interaction with a cytosolic protein

DEFF Research Database (Denmark)

Rosorius, O; Issinger, O G; Braulke, T

1993-01-01

The cytoplasmic tail of the human 300-kDa mannose 6-phosphate receptor (MPR 300-CT) is an excellent substrate for casein kinase II in vitro. The phosphorylated MPR 300-CT was cross-linked by means of bis(sulfosuccinimidyl)suberate mainly to a cytosolic protein of 35 kDa (referred to as TIP 35...... with TIP 35 is phosphorylation-specific. Furthermore, TIP 35 was only cross-linked to the MPR 300-CT phosphorylated by casein kinase II whereas the MPR 300-CT phosphorylated by protein kinase A failed to cross-link to TIP 35. These results indicate that the cytoplasmic tail of the MPR 300 interacts...

Short communication: separation and quantification of caseins and casein macropeptide using ion-exchange chromatography.

Science.gov (United States)

Holland, B; Rahimi Yazdi, S; Ion Titapiccolo, G; Corredig, M

2010-03-01

The aim of this work was to improve an existing method to separate and quantify the 4 major caseins from milk samples (i.e., containing whey proteins) using ion-exchange chromatography. The separation process was carried out using a mini-preparative cation exchange column (1 or 5mL of column volume), using urea acetate as elution buffer at pH 3.5 with a NaCl gradient. All 4 major caseins were separated, and the purity of each peak was assessed using sodium dodecyl sulfate-PAGE. Purified casein fractions were also added to raw milk to confirm their elution volumes. The quantification was carried out using purified caseins in buffer as well as added directly to fresh skim milk. This method can also be employed to determine the decrease in kappa-casein and the release of the casein-macropeptide during enzymatic hydrolysis using rennet. In this case, the main advantage of using this method is the lack of organic solvents compared with the conventional method for separation of macropeptide (using reversed phase HPLC).

Role of phosphatidylinositol 3-kinase in angiotensin II regulation of norepinephrine neuromodulation in brain neurons of the spontaneously hypertensive rat.

Science.gov (United States)

Yang, H; Raizada, M K

1999-04-01

Chronic stimulation of norepinephrine (NE) neuromodulation by angiotensin II (Ang II) involves activation of the Ras-Raf-MAP kinase signal transduction pathway in Wistar Kyoto (WKY) rat brain neurons. This pathway is only partially responsible for this heightened action of Ang II in the spontaneously hypertensive rat (SHR) brain neurons. In this study, we demonstrate that the MAP kinase-independent signaling pathway in the SHR neuron involves activation of PI3-kinase and protein kinase B (PKB/Akt). Ang II stimulated PI3-kinase activity in both WKY and SHR brain neurons and was accompanied by its translocation from the cytoplasmic to the nuclear compartment. Although the magnitude of stimulation by Ang II was comparable, the stimulation was more persistent in the SHR neuron compared with the WKY rat neuron. Inhibition of PI3-kinase had no significant effect in the WKY rat neuron. However, it caused a 40-50% attenuation of the Ang II-induced increase in norepinephrine transporter (NET) and tyrosine hydroxylase (TH) mRNAs and [3H]-NE uptake in the SHR neuron. In contrast, inhibition of MAP kinase completely attenuated Ang II stimulation of NET and TH mRNA levels in the WKY rat neuron, whereas it caused only a 45% decrease in the SHR neuron. However, an additive attenuation was observed when both kinases of the SHR neurons were inhibited. Ang II also stimulated PKB/Akt activity in both WKY and SHR neurons. This stimulation was 30% higher and lasted longer in the SHR neuron compared with the WKY rat neuron. In conclusion, these observations demonstrate an exclusive involvement of PI3-kinase-PKB-dependent signaling pathway in a heightened NE neuromodulatory action of Ang II in the SHR neuron. Thus, this study offers an excellent potential for the development of new therapies for the treatment of centrally mediated hypertension.

The chaperone action of bovine milk αS1- and αS2-caseins and their associated form αS-casein.

Science.gov (United States)

Treweek, Teresa M; Thorn, David C; Price, William E; Carver, John A

2011-06-01

α(S)-Casein, the major milk protein, comprises α(S1)- and α(S2)-casein and acts as a molecular chaperone, stabilizing an array of stressed target proteins against precipitation. Here, we report that α(S)-casein acts in a similar manner to the unrelated small heat-shock proteins (sHsps) and clusterin in that it does not preserve the activity of stressed target enzymes. However, in contrast to sHsps and clusterin, α-casein does not bind target proteins in a state that facilitates refolding by Hsp70. α(S)-Casein was also separated into α- and α-casein, and the chaperone abilities of each of these proteins were assessed with amorphously aggregating and fibril-forming target proteins. Under reduction stress, all α-casein species exhibited similar chaperone ability, whereas under heat stress, α-casein was a poorer chaperone. Conversely, α(S2)-casein was less effective at preventing fibril formation by modified κ-casein, whereas α- and α(S1)-casein were comparably potent inhibitors. In the presence of added salt and heat stress, α(S1)-, α- and α(S)-casein were all significantly less effective. We conclude that α(S1)- and α-casein stabilise each other to facilitate optimal chaperone activity of α(S)-casein. This work highlights the interdependency of casein proteins for their structural stability. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of temperature and pH on the solubility of caseins: environmental influences on the dissociation of α(S)- and β-casein.

Science.gov (United States)

Post, A E; Arnold, B; Weiss, J; Hinrichs, J

2012-04-01

Selective precipitation is a common method for the isolation of β-casein, using the different calcium sensitivities of the individual caseins and the selective solubility of β-casein at a low temperature. In previous studies, it has been indicated that the β-casein yield depends on the physicochemical characteristics of the casein raw material used for fractionation. The objective of this study was to evaluate and compare the solubility of α(S)- and β-casein in solutions of micellar casein, sodium caseinate, and calcium caseinate as a function of pH and temperature. Additionally, the solubility of isolated α(S)- and β-casein fractions in demineralized water, ultrafiltration permeate, and a calcium-depleted milk salt solution was investigated depending on the pH and temperature. Furthermore, micellar casein, sodium caseinate, and calcium caseinate were subjected to a calcium chloride-precipitation process to determine the solubility of α(S)- and β-casein in calcium chloride precipitate, which is produced during selective precipitation, as a function of temperature and pH. Generally, the temperature had only a marginal influence on the α(S)-casein solubility compared with the β-casein solubility, whereas the solubility was shown to be strongly influenced by the pH. Our results suggest that the yield of β-casein obtained during isolation by means of selective precipitation may be a result of the solubility characteristics of α(S)- and β-casein in calcium chloride precipitate. Manufacturers may consider a simple solubility experiment before the β-casein isolation process by means of selective precipitation to predict β-casein yield. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Endothelial microparticle formation by angiotensin II is mediated via Ang II receptor type I/NADPH oxidase/ Rho kinase pathways targeted to lipid rafts.

Science.gov (United States)

Burger, Dylan; Montezano, Augusto C; Nishigaki, Nobuhiro; He, Ying; Carter, Anthony; Touyz, Rhian M

2011-08-01

Circulating microparticles are increased in cardiovascular disease and may themselves promote oxidative stress and inflammation. Molecular mechanisms underlying their formation and signaling are unclear. We investigated the role of reactive oxygen species (ROS), Rho kinase, and lipid rafts in microparticle formation and examined their functional significance in endothelial cells (ECs). Microparticle formation from angiotensin II (Ang II)-stimulated ECs and apolipoprotein E(-/-) mice was assessed by annexin V or by CD144 staining and electron microscopy. Ang II promoted microparticle formation and increased EC O(2)(-) generation and Rho kinase activity. Ang II-stimulated effects were inhibited by irbesartan (Ang II receptor type I blocker) and fasudil (Rho kinase inhibitor). Methyl-β-cyclodextrin and nystatin, which disrupt lipid rafts/caveolae, blocked microparticle release. Functional responses, assessed in microparticle-stimulated ECs, revealed increased O(2)(-) production, enhanced vascular cell adhesion molecule/platelet-EC adhesion molecule expression, and augmented macrophage adhesion. Inhibition of epidermal growth factor receptor blocked the prooxidative and proinflammatory effects of microparticles. In vitro observations were confirmed in apolipoprotein E(-/-) mice, which displayed vascular inflammation and high levels of circulating endothelial microparticles, effects that were reduced by apocynin. We demonstrated direct actions of Ang II on endothelial microparticle release, mediated through NADPH oxidase, ROS, and Rho kinase targeted to lipid rafts. Microparticles themselves stimulated endothelial ROS formation and inflammatory responses. Our findings suggest a feedforward system whereby Ang II promotes EC injury through its own endothelial-derived microparticles.

Use of calcium caseinate in association with lecithin for masking the bitterness of acetaminophen--comparative study with sodium caseinate.

Science.gov (United States)

Hoang Thi, Thanh Huong; Lemdani, Mohamed; Flament, Marie-Pierre

2013-11-18

Owing to a variety of structural and functional properties, milk proteins are steadily studied for food and pharmaceutical applications. In the present study, calcium caseinate in association with lecithin was firstly investigated in order to encapsulate the acetaminophen through spray-drying for taste-masking purpose for pediatric medicines. A 2(4)-full factorial design revealed that the spray flow, the calcium caseinate amount and the lecithin amount had significant effects on the release of drug during the first 2 min. Indeed, increasing the spray flow and/or the calcium caseinate amount led to increase the released amount, whereas increasing the lecithin amount decreased the released amount. The "interaction" between the calcium caseinate amount and the lecithin amount was also shown to be statistically significant. The second objective was to compare the efficiency of two caseinate-based formulations, i.e. sodium caseinate and calcium caseinate, on the taste-masking effect. The characteristics of spray-dried powders determined by SEM and DSC were shown to depend on the caseinate/lecithin proportion rather than the type of caseinate. Interestingly, calcium caseinate-based formulations were found to lower the released amount of drug during the early time to a higher extent than sodium caseinate-based formulations, which indicates better taste-masking efficiency. Copyright © 2013 Elsevier B.V. All rights reserved.

The beta subunit of casein kinase II

DEFF Research Database (Denmark)

Boldyreff, B; Piontek, K; Schmidt-Spaniol, I

1991-01-01

cDNAs encoding the beta subunit of pig and mouse CKII were isolated. The porcine cDNA was expressed as a fusion protein in Escherichia coli and used for the production of anti-CKII-beta subunit specific antibodies....

Use of surface plasmon resonance (SPR) to study the dissociation and polysaccharide binding of casein micelles and caseins.

Science.gov (United States)

Thompson, Abby K; Singh, Harjinder; Dalgleish, Douglas G

2010-11-24

Tests were made to determine whether surface plasmon resonance (SPR) could be used as a technique to study the dissociation properties of bovine casein micelles or of sodium caseinate and the interactions between these protein particles and different polysaccharides. Surfaces of bound micelles or caseinate were made, and the changes in refractive index of these layers were used to define changes in the structures of the chemisorbed material. The technique appears to have some potential for studying details of the dissociation of casein micelles and of the binding of different polysaccharides to caseins.

Effects of hydrolysed casein, intact casein and intact whey protein on energy expenditure and appetite regulation

DEFF Research Database (Denmark)

Bendtsen, Line Quist; Lorenzen, Janne Kunchel; Gomes, Sisse

2014-01-01

Casein and whey differ in amino acid composition and in the rate of absorption; however, the absorption rate of casein can be increased to mimic that of whey by exogenous hydrolysis. The objective of the present study was to compare the effects of hydrolysed casein (HC), intact casein (IC......) and intact whey (IW) on energy expenditure (EE) and appetite regulation, and thereby to investigate the influence of amino acid composition and the rate of absorption. In the present randomised cross-over study, twenty-four overweight and moderately obese young men and women consumed three isoenergetic...

Analysis of casein biopolymers adsorption to lignocellulosic biomass as a potential cellulase stabilizer.

Science.gov (United States)

Eckard, Anahita Dehkhoda; Muthukumarappan, Kasiviswanathan; Gibbons, William

2012-01-01

Although lignocellulosic materials have a good potential to substitute current feedstocks used for ethanol production, conversion of these materials to fermentable sugars is still not economical through enzymatic hydrolysis. High cost of cellulase has prompted research to explore techniques that can prevent from enzyme deactivation. Colloidal proteins of casein can form monolayers on hydrophobic surfaces that alleviate the de-activation of protein of interest. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FT-IR), capillary electrophoresis (CE), and Kjeldahl and BSA protein assays were used to investigate the unknown mechanism of action of induced cellulase activity during hydrolysis of casein-treated biomass. Adsorption of casein to biomass was observed with all of the analytical techniques used and varied depending on the pretreatment techniques of biomass. FT-IR analysis of amides I and II suggested that the substructure of protein from casein or skim milk were deformed at the time of contact with biomass. With no additive, the majority of one of the cellulase mono-component, 97.1 ± 1.1, was adsorbed to CS within 24 h, this adsorption was irreversible and increased by 2% after 72 h. However, biomass treatment with skim-milk and casein reduced the adsorption to 32.9% ± 6.0 and 82.8% ± 6.0, respectively.

The catalytic subunit of human protein kinase CK2 structurally deviates from its maize homologue in complex with the nucleotide competitive inhibitor emodin

DEFF Research Database (Denmark)

Raaf, Jennifer; Klopffleisch, Karsten; Issinger, Olaf-Georg

2008-01-01

The Ser/Thr kinase CK2 (former name: casein kinase 2) is a heterotetrameric enzyme composed of two catalytic chains (CK2alpha) attached to a dimer of noncatalytic subunits. Together with the cyclin-dependent kinases and the mitogen-activated protein kinases, CK2alpha belongs to the CMGC family of...

Milk Intolerance, Beta-Casein and Lactose.

Science.gov (United States)

Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

2015-08-31

True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows' milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows' milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows' milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

Milk Intolerance, Beta-Casein and Lactose

Directory of Open Access Journals (Sweden)

Sebely Pal

2015-08-01

Full Text Available True lactose intolerance (symptoms stemming from lactose malabsorption is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows’ milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows’ milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

Complexation of lysozyme with sodium caseinate and micellar casein in aqueous buffered solutions

NARCIS (Netherlands)

Antonov, Y.A.; Moldenaers, P.; Cardinaels, R.M.

We present an extended structural and morphological study of the complexation of lysozyme (Lys) with sodium caseinate (SC) and micellar casein (MC) by means of turbidity measurements, phase analysis, dynamic, static and electrophoretic light scattering, bright-field and confocal laser scanning

Genetic variability of the equine casein genes.

Science.gov (United States)

Brinkmann, J; Jagannathan, V; Drögemüller, C; Rieder, S; Leeb, T; Thaller, G; Tetens, J

2016-07-01

The casein genes are known to be highly variable in typical dairy species, such as cattle and goat, but the knowledge about equine casein genes is limited. Nevertheless, mare milk production and consumption is gaining importance because of its high nutritive value, use in naturopathy, and hypoallergenic properties with respect to cow milk protein allergies. In the current study, the open reading frames of the 4 casein genes CSN1S1 (αS1-casein), CSN2 (β-casein), CSN1S2 (αS2-casein), and CSN3 (κ-casein) were resequenced in 253 horses of 14 breeds. The analysis revealed 21 nonsynonymous nucleotide exchanges, as well as 11 synonymous nucleotide exchanges, leading to a total of 31 putative protein isoforms predicted at the DNA level, 26 of which considered novel. Although the majority of the alleles need to be confirmed at the transcript and protein level, a preliminary nomenclature was established for the equine casein alleles. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Interactions of casein micelles with calcium phosphate particles.

Science.gov (United States)

Tercinier, Lucile; Ye, Aiqian; Anema, Skelte G; Singh, Anne; Singh, Harjinder

2014-06-25

Insoluble calcium phosphate particles, such as hydroxyapatite (HA), are often used in calcium-fortified milks as they are considered to be chemically unreactive. However, this study showed that there was an interaction between the casein micelles in milk and HA particles. The caseins in milk were shown to bind to the HA particles, with the relative proportions of bound β-casein, αS-casein, and κ-casein different from the proportions of the individual caseins present in milk. Transmission electron microscopy showed no evidence of intact casein micelles on the surface of the HA particles, which suggested that the casein micelles dissociated either before or during binding. The HA particles behaved as ion chelators, with the ability to bind the ions contained in the milk serum phase. Consequently, the depletion of the serum minerals disrupted the milk mineral equilibrium, resulting in dissociation of the casein micelles in milk.

Casein maps: Effect of ethanol, pH, temperature, and CaCl2 on the particle size of reconstituted casein micelles

Science.gov (United States)

Ye, Ran; Harte, Federico

2015-01-01

Although conditions favoring casein micelle aggregation are well known, factors promoting the dissociation of the casein micelle are not fully understood. It was our objective to investigate the ethanol-induced dissociation of micellar casein as affected by temperature and a wide range of pH, along with the concentrations of calcium and casein. Two different concentrations of casein micelles were dispersed in imidazole buffer with 0 to 80% ethanol (vol/vol) and 2 and 10 mM calcium. Apparent micelle size was determined by dynamic light scattering at 5, 30, and 60°C. In the absence of ethanol, casein precipitation occurred at pH 4.6 in imidazole buffer. Ten to forty percent ethanol promoted casein aggregation (>1,000 nm) and higher temperature (30 and 60°C) enhanced this effect. Higher ethanol concentrations at 50 to 80% induced the dissociation (casein micelle upon acidification (pH 8) in imidazole buffer. In addition, higher concentrations of casein (0.25 mg/mL) and calcium (20 mM) caused the formation of larger aggregates (>1,000 nm) in the presence of ethanol when comparing with the initial lower concentrations of casein (0.1 mg/mL) and calcium (2 mM). Casein micelle dissociation can be achieved near the isoelectric pH by modifying the solvent composition and temperature. PMID:23200467

Sensitizing capacity and allergenicity of enzymatically cross-linked sodium caseinate in comparison to sodium caseinate in a mouse model for cow's milk allergy.

Science.gov (United States)

van Esch, Betty C A M; Gros-van Hest, Marjan; Westerbeek, Hans; Garssen, Johan

2013-03-27

A transglutaminase cross-linked caseinate was designed for use in dairy products to increase the viscosity of food matrices. The difference in structure of cross-linked caseinate might have implications for the risk of developing cow's milk allergy. The sensitizing capacity and the allergenicity (the potency to induce an allergic effector response) of cross-linked sodium caseinate was investigated using a mouse model for cow's milk allergy. Mice were orally sensitized with cross-linked caseinate or caseinate using cholera toxin as adjuvant. Anaphylactic shock reactions, change in body temperature, acute allergic skin response, caseinate-, cross-linked caseinate-IgE and mMCP-1 concentrations were determined after challenge with cross-linked caseinate or caseinate. Sensitization with cross-linked caseinate did not result in anaphylactic shock symptoms, drop in body temperature or release of serum mMCP-1. A tendency toward decreased casein-specific IgE levels was observed. The allergenicity did not differ between both products. These results indicate that in already caseinate-sensitized mice, cross-linked caseinate did not provoke more pronounced allergenic reactions compared to sodium caseinate. On top of that, reduced sensitization to cross-linked caseinate was observed. Cross-linked caseinate might therefore be an interesting new dietary concept for humans at risk for food allergy although more mechanistic studies and clinical trials are needed for validation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Factors influencing casein micelle size in milk of individual cows: Genetic variants and glycosylation of k-casein

NARCIS (Netherlands)

Bijl, E.; Vries, de R.F.M.; Valenberg, van H.J.F.; Huppertz, T.; Hooijdonk, van A.C.M.

2014-01-01

The average casein micelle size varies widely between milk samples of individual cows. The factors that cause this variation in size are not known but could provide more insight into casein micelle structure and into the physiology of casein micelle formation. The objective of this research was

21 CFR 582.1748 - Sodium caseinate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium caseinate. 582.1748 Section 582.1748 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1748 Sodium caseinate. (a) Product. Sodium caseinate. (b) Conditions of use. This substance...

21 CFR 182.1748 - Sodium caseinate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium caseinate. 182.1748 Section 182.1748 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1748 Sodium caseinate. (a) Product. Sodium caseinate. (b) Conditions of use. This substance...

The adsorption of orthophosphate onto casein-iron precipitates.

Science.gov (United States)

Mittal, Vikas A; Ellis, Ashling; Ye, Aiqian; Edwards, Patrick J B; Singh, Harjinder

2018-01-15

This study explored the interactions of orthophosphate with casein-iron precipitates. Casein-iron precipitates were formed by adding ferric chloride at ≥10mM to sodium caseinate solutions ranging in concentration from 1 to 3%(w/v). The addition of different concentrations of orthophosphate solution to the casein-iron precipitates resulted in gradual adsorption of the orthophosphate, causing re-dispersion of the casein-iron complexes. The interactions of added orthophosphate with iron in the presence and absence of caseins are postulated, and new mechanisms are proposed. The re-dispersed soluble complexes of casein-iron-orthophosphate generated using this process could be used as novel iron fortificants. Copyright © 2017 Elsevier Ltd. All rights reserved.

αS1-casein, which is essential for efficient ER-to-Golgi casein transport, is also present in a tightly membrane-associated form

Science.gov (United States)

2010-01-01

Background Caseins, the main milk proteins, aggregate in the secretory pathway of mammary epithelial cells into large supramolecular structures, casein micelles. The role of individual caseins in this process and the mesostructure of the casein micelle are poorly known. Results In this study, we investigate primary steps of casein micelle formation in rough endoplasmic reticulum-derived vesicles prepared from rat or goat mammary tissues. The majority of both αS1- and β-casein which are cysteine-containing casein was dimeric in the endoplasmic reticulum. Saponin permeabilisation of microsomal membranes in physico-chemical conditions believed to conserve casein interactions demonstrated that rat immature β-casein is weakly aggregated in the endoplasmic reticulum. In striking contrast, a large proportion of immature αS1-casein was recovered in permeabilised microsomes when incubated in conservative conditions. Furthermore, a substantial amount of αS1-casein remained associated with microsomal or post-ER membranes after saponin permeabilisation in non-conservative conditions or carbonate extraction at pH11, all in the presence of DTT. Finally, we show that protein dimerisation via disulfide bond is involved in the interaction of αS1-casein with membranes. Conclusions These experiments reveal for the first time the existence of a membrane-associated form of αS1-casein in the endoplasmic reticulum and in more distal compartments of the secretory pathway of mammary epithelial cells. Our data suggest that αS1-casein, which is required for efficient export of the other caseins from the endoplasmic reticulum, plays a key role in early steps of casein micelle biogenesis and casein transport in the secretory pathway. PMID:20704729

Valsartan Upregulates Kir2.1 in Rats Suffering from Myocardial Infarction via Casein Kinase 2.

Science.gov (United States)

Li, Xinran; Hu, Hesheng; Wang, Ye; Xue, Mei; Li, Xiaolu; Cheng, Wenjuan; Xuan, Yongli; Yin, Jie; Yang, Na; Yan, Suhua

2015-06-01

Myocardial infarction (MI) results in an increased susceptibility to ventricular arrhythmias, due in part to decreased inward-rectifier K+ current (IK1), which is mediated primarily by the Kir2.1 protein. The use of renin-angiotensin-aldosterone system antagonists is associated with a reduced incidence of ventricular arrhythmias. Casein kinase 2 (CK2) binds and phosphorylates SP1, a transcription factor of KCNJ2 that encodes Kir2.1. Whether valsartan represses CK2 activation to ameliorate IK1 remodeling following MI remains unclear. Wistar rats suffering from MI received either valsartan or saline for 7 days. The protein levels of CK2 and Kir2.1 were each detected via a Western blot analysis. The mRNA levels of CK2 and Kir2.1 were each examined via quantitative real-time PCR. CK2 expression was higher at the infarct border; and was accompanied by a depressed IK1/Kir2.1 protein level. Additionally, CK2 overexpression suppressed KCNJ2/Kir2.1 expression. By contrast, CK2 inhibition enhanced KCNJ2/Kir2.1 expression, establishing that CK2 regulates KCNJ2 expression. Among the rats suffering from MI, valsartan reduced CK2 expression and increased Kir2.1 expression compared with the rats that received saline treatment. In vitro, hypoxia increased CK2 expression and valsartan inhibited CK2 expression. The over-expression of CK2 in cells treated with valsartan abrogated its beneficial effect on KCNJ2/Kir2.1. AT1 receptor antagonist valsartan reduces CK2 activation, increases Kir2.1 expression and thereby ameliorates IK1 remodeling after MI in the rat model.

Analysis of Casein Biopolymers Adsorption to Lignocellulosic Biomass as a Potential Cellulase Stabilizer

Directory of Open Access Journals (Sweden)

Anahita Dehkhoda Eckard

2012-01-01

Full Text Available Although lignocellulosic materials have a good potential to substitute current feedstocks used for ethanol production, conversion of these materials to fermentable sugars is still not economical through enzymatic hydrolysis. High cost of cellulase has prompted research to explore techniques that can prevent from enzyme deactivation. Colloidal proteins of casein can form monolayers on hydrophobic surfaces that alleviate the de-activation of protein of interest. Scanning electron microscope (SEM, fourier transform infrared spectroscopy (FT-IR, capillary electrophoresis (CE, and Kjeldahl and BSA protein assays were used to investigate the unknown mechanism of action of induced cellulase activity during hydrolysis of casein-treated biomass. Adsorption of casein to biomass was observed with all of the analytical techniques used and varied depending on the pretreatment techniques of biomass. FT-IR analysis of amides I and II suggested that the substructure of protein from casein or skim milk were deformed at the time of contact with biomass. With no additive, the majority of one of the cellulase mono-component, 97.1 ± 1.1, was adsorbed to CS within 24 h, this adsorption was irreversible and increased by 2% after 72 h. However, biomass treatment with skim-milk and casein reduced the adsorption to 32.9% ± 6.0 and 82.8% ± 6.0, respectively.

Analysis of Casein Biopolymers Adsorption to Lignocellulosic Biomass as a Potential Cellulase Stabilizer

Science.gov (United States)

Eckard, Anahita Dehkhoda; Muthukumarappan, Kasiviswanathan; Gibbons, William

2012-01-01

Although lignocellulosic materials have a good potential to substitute current feedstocks used for ethanol production, conversion of these materials to fermentable sugars is still not economical through enzymatic hydrolysis. High cost of cellulase has prompted research to explore techniques that can prevent from enzyme deactivation. Colloidal proteins of casein can form monolayers on hydrophobic surfaces that alleviate the de-activation of protein of interest. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FT-IR), capillary electrophoresis (CE), and Kjeldahl and BSA protein assays were used to investigate the unknown mechanism of action of induced cellulase activity during hydrolysis of casein-treated biomass. Adsorption of casein to biomass was observed with all of the analytical techniques used and varied depending on the pretreatment techniques of biomass. FT-IR analysis of amides I and II suggested that the substructure of protein from casein or skim milk were deformed at the time of contact with biomass. With no additive, the majority of one of the cellulase mono-component, 97.1 ± 1.1, was adsorbed to CS within 24 h, this adsorption was irreversible and increased by 2% after 72 h. However, biomass treatment with skim-milk and casein reduced the adsorption to 32.9% ± 6.0 and 82.8% ± 6.0, respectively. PMID:23118515

FAM83H and casein kinase I regulate the organization of the keratin cytoskeleton and formation of desmosomes.

Science.gov (United States)

Kuga, Takahisa; Sasaki, Mitsuho; Mikami, Toshinari; Miake, Yasuo; Adachi, Jun; Shimizu, Maiko; Saito, Youhei; Koura, Minako; Takeda, Yasunori; Matsuda, Junichiro; Tomonaga, Takeshi; Nakayama, Yuji

2016-05-25

FAM83H is essential for the formation of dental enamel because a mutation in the FAM83H gene causes amelogenesis imperfecta (AI). We previously reported that the overexpression of FAM83H often occurs and disorganizes the keratin cytoskeleton in colorectal cancer cells. We herein show that FAM83H regulates the organization of the keratin cytoskeleton and maintains the formation of desmosomes in ameloblastoma cells. FAM83H is expressed and localized on keratin filaments in human ameloblastoma cell lines and in mouse ameloblasts and epidermal germinative cells in vivo. FAM83H shows preferential localization to keratin filaments around the nucleus that often extend to cell-cell junctions. Alterations in the function of FAM83H by its overexpression, knockdown, or an AI-causing truncated mutant prevent the proper organization of the keratin cytoskeleton in ameloblastoma cells. Furthermore, the AI-causing mutant prevents desmosomal proteins from being localized to cell-cell junctions. The effects of the AI-causing mutant depend on its binding to and possible inhibition of casein kinase I (CK-1). The suppression of CK-1 by its inhibitor, D4476, disorganizes the keratin cytoskeleton. Our results suggest that AI caused by the FAM83H mutation is mediated by the disorganization of the keratin cytoskeleton and subsequent disruption of desmosomes in ameloblasts.

Stability of the Human Hsp90-p50Cdc37 Chaperone Complex against Nucleotides and Hsp90 Inhibitors, and the Influence of Phosphorylation by Casein Kinase 2

Directory of Open Access Journals (Sweden)

Sanne H. Olesen

2015-01-01

Full Text Available The molecular chaperone Hsp90 is regulated by co-chaperones such as p50Cdc37, which recruits a wide selection of client protein kinases. Targeted disruption of the Hsp90-p50Cdc37 complex by protein–protein interaction (PPI inhibitors has emerged as an alternative strategy to treat diseases characterized by aberrant Hsp90 activity. Using isothermal microcalorimetry, ELISA and GST-pull down assays we evaluated reported Hsp90 inhibitors and nucleotides for their ability to inhibit formation of the human Hsp90β-p50Cdc37 complex, reconstituted in vitro from full-length proteins. Hsp90 inhibitors, including the proposed PPI inhibitors gedunin and H2-gamendazole, did not affect the interaction of Hsp90 with p50Cdc37 in vitro. Phosphorylation of Hsp90 and p50Cdc37 by casein kinase 2 (CK2 did not alter the thermodynamic signature of complex formation. However, the phosphorylated complex was vulnerable to disruption by ADP (IC50 = 32 µM, while ATP, AMPPNP and Hsp90 inhibitors remained largely ineffective. The differential inhibitory activity of ADP suggests that phosphorylation by CK2 primes the complex for dissociation in response to a drop in ATP/ADP levels. The approach applied herein provides robust assays for a comprehensive biochemical evaluation of potential effectors of the Hsp90-p50Cdc37 complex, such as phosphorylation by a kinase or the interaction with small molecule ligands.

A casein-kinase-2-related protein kinase is tightly associated with the large T antigen of simian virus 40

DEFF Research Database (Denmark)

Götz, C; Koenig, M G; Issinger, O G

1995-01-01

by the addition of protein kinase CK2 suggest that at least one of the T-antigen-associated protein kinases is CK2 or a protein-kinase-CK2-related enzyme. The association of recombinant CK2 with T antigen was strongly confirmed by in vitro binding studies. Experiments with temperature-sensitive SV40-transformed......The simian virus 40 (SV40) large T antigen is a multifunctional protein involved in SV40 cell transformation and lytic virus infection. Some of its activities are regulated by interaction with cellular proteins and/or by phosphorylation of T antigen by various protein kinases. In this study, we...... show that immuno-purified T antigen from SV40-transformed cells and from baculovirus-infected insect cells is tightly associated with a protein kinase that phosphorylates T antigen in vitro. In the presence of heparin or a peptide resembling a protein kinase CK2 recognition site, the phosphorylation...

and K-casein genes in Egyptian sheep breeds

African Journals Online (AJOL)

Objective: Casein genetic polymorphisms are important and well known due to their effects on quantitative traits and technological properties of milk manufacturing. The casein fraction of ruminant milk proteins consists of four caseins, namely 8s1-, 8s2-, β-and K-casein. At the DNA level, polymerase chain reaction (PCR) ...

Iron binding to caseins in the presence of orthophosphate.

Science.gov (United States)

Mittal, V A; Ellis, A; Ye, A; Edwards, P J B; Das, S; Singh, H

2016-01-01

As adding >5mM ferric chloride to sodium caseinate solutions results in protein precipitation, the effects of orthophosphate (0-64 mM) addition to sodium caseinate solution (2% w/v protein) on iron-induced aggregation of the caseins were studied at pH 6.8. Up to 20mM ferric chloride could be added to sodium caseinate solution containing 32 mM orthophosphate without any protein precipitation. The addition of iron to sodium caseinate solution containing orthophosphate reduced the diffusible phosphorus content in a concentration-dependent manner. Added iron appeared to interact simultaneously with phosphoserine on the caseins and inorganic phosphorus. The relative sizes of the casein aggregates were governed by the concentration of orthophosphate and the aggregates consisted of all casein fractions, even at the lowest level of ferric chloride addition (5mM). It is hypothesised that the addition of iron to caseins in the presence of orthophosphate results in the formation of colloidal structures involving casein-iron-orthophosphate interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

The study of zinc ions binding to casein.

Science.gov (United States)

Pomastowski, P; Sprynskyy, M; Buszewski, B

2014-08-01

The presented research was focused on physicochemical study of casein properties and the kinetics of zinc ions binding to the protein. Moreover, a fast and simple method of casein extraction from cow's milk has been proposed. Casein isoforms, zeta potential (ζ) and particle size of the separated caseins were characterized with the use of capillary electrophoresis, zeta potential analysis and field flow fractionation (FFF) technique, respectively. The kinetics of the metal-binding process was investigated in batch adsorption experiments. Intraparticle diffusion model, first-order and zero-order kinetic models were applied to test the kinetic experimental data. Analysis of changes in infrared bands registered for casein before and after zinc binding was also performed. The obtained results showed that the kinetic process of zinc binding to casein is not homogeneous but is expressed with an initial rapid stage with about 70% of zinc ions immobilized by casein and with a much slower second step. Maximum amount of bound zinc in the experimental conditions was 30.04mgZn/g casein. Copyright © 2014 Elsevier B.V. All rights reserved.

Casein micelle structure: a concise review

Directory of Open Access Journals (Sweden)

Chanokphat Phadungath

2005-01-01

Full Text Available Milk is a complex biological fluid with high amount of proteins, lipid and minerals. The function of milk is to supply nutrients such as essential amino acids required for the growth of the newborn. In addition, due to the importance of casein and casein micelles for the functional behavior of dairy products, the nature and structure of casein micelles have been studied extensively. However, the exact structure of casein micelles is still under debate. Various models for casein micelle structure have been proposed. Most of the proposedmodels fall into three general categories, which are: coat-core, subunit (sub-micelles, and internal structure models. The coat-core models, proposed by Waugh and Nobel in 1965, Payens in 1966, Parry and Carroll in 1969, and Paquin and co-workers in 1987, describe the micelle as an aggregate of caseins with outer layer differing in composition form the interior, and the structure of the inner part is not accurately identified. The sub-micelle models, proposed by Morr in 1967, Slattery and Evard in 1973, Schmidt in 1980, Walstra in1984, and Ono and Obata in 1989, is considered to be composed of roughly spherical uniform subunits. The last models, the internal structure models, which were proposed by Rose in 1969, Garnier and Ribadeau- Dumas in 1970, Holt in 1992, and Horne in 1998, specify the mode of aggregation of the different caseins.

Effect of calcium chelators on physical changes in casein micelles in concentrated micellar casein solutions

NARCIS (Netherlands)

Kort, de E.J.P.; Minor, M.; Snoeren, T.H.M.; Hooijdonk, van A.C.M.; Linden, van der E.

2011-01-01

The effect of calcium chelators on physical changes of casein micelles in concentrated micellar casein solutions was investigated by measuring calcium-ion activity, viscosity and turbidity, and performing ultracentrifugation. The highest viscosities were measured on addition of sodium

Characteristic aroma components of rennet casein.

Science.gov (United States)

Karagül-Yüceer, Yonca; Vlahovich, Katrina N; Drake, MaryAnne; Cadwallader, Keith R

2003-11-05

Rennet casein, produced by enzymatic (rennet) precipitation of casein from pasteurized skim milk, is used in both industrial (technical) and food applications. The flavor of rennet casein powder is an important quality parameter; however, the product often contains an odor described as like that of animal/wet dog. Two commercial rennet casein powders were evaluated to determine the compounds responsible for the typical odor. Aroma extracts were prepared by high-vacuum distillation of direct solvent (ether) extracts and analyzed by gas chromatography-olfactometry (GCO), aroma extract dilution analysis (AEDA), and GC-mass spectrometry (MS). Odorants detected by GCO were typical of those previously reported in skim milk powders and consisted mainly of short-chain volatile acids, phenolic compounds, lactones, and furanones. Results of AEDA indicated o-aminoacetophenone to be a potent odorant; however, sensory descriptive sensory analysis of model aroma systems revealed that the typical odor of rennet casein was principally caused by hexanoic acid, indole, guaiacol, and p-cresol.

Identification of a secreted casein kinase 1 in Leishmania donovani: effect of protein over expression on parasite growth and virulence.

Directory of Open Access Journals (Sweden)

Mary Dan-Goor

Full Text Available Casein kinase 1 (CK1 plays an important role in eukaryotic signaling pathways, and their substrates include key regulatory proteins involved in cell differentiation, proliferation and chromosome segregation. The Leishmania genome encodes six potential CK1 isoforms, of which five have orthologs in other trypanosomatidae. Leishmania donovani CK1 isoform 4 (Ldck1.4, orthologous to LmjF27.1780 is unique to Leishmania and contains a putative secretion signal peptide. The full-length gene and three shorter constructs were cloned and expressed in E. coli as His-tag proteins. Only the full-length 62.3 kDa protein showed protein kinase activity indicating that the N-terminal and C-terminal domains are essential for protein activity. LdCK1.4-FLAG was stably over expressed in L. donovani, and shown by immunofluorescence to be localized primarily in the cytosol. Western blotting using anti-FLAG and anti-CK1.4 antibodies showed that this CK1 isoform is expressed and secreted by promastigotes. Over expression of LdCK1.4 had a significant effect on promastigote growth in culture with these parasites growing to higher cell densities than the control parasites (wild-type or Ld:luciferase, P<0.001. Analysis by flow cytometry showed a higher percentage, ∼4-5-fold, of virulent metacyclic promastigotes on day 3 among the LdCK1.4 parasites. Finally, parasites over expressing LdCK1.4 gave significantly higher infections of mouse peritoneal macrophages compared to wild-type parasites, 28.6% versus 6.3%, respectively (p = 0.0005. These results suggest that LdCK1.4 plays an important role in parasite survival and virulence. Further studies are needed to validate CK1.4 as a therapeutic target in Leishmania.

Some rheological properties of sodium caseinate-starch gels.

Science.gov (United States)

Bertolini, Andrea C; Creamer, Lawrence K; Eppink, Mieke; Boland, Mike

2005-03-23

The influence of sodium caseinate on the thermal and rheological properties of starch gels at different concentrations and from different botanical sources was evaluated. In sodium caseinate-starch gels, for all starches with the exception of potato starch, the sodium caseinate promoted an increase in the storage modulus and in the viscosity of the composite gel when compared with starch gels. The addition of sodium caseinate resulted in an increase in the onset temperature, the gelatinization temperature, and the end temperature, and there was a significant interaction between starch and sodium caseinate for the onset temperature, the peak temperature, and the end temperature. Microscopy results suggested that sodium caseinate promoted an increase in the homogeneity in the matrix of cereal starch gels.

21 CFR 520.1157 - Iodinated casein tablets.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iodinated casein tablets. 520.1157 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1157 Iodinated casein tablets. (a) Specifications. Each 1-gram tablet contains 25 milligrams of iodinated casein. (b) Sponsor...

κ-Casein-deficient mice fail to lactate

Science.gov (United States)

Shekar, P. Chandra; Goel, Sandeep; Rani, S. Deepa Selvi; Sarathi, D. Partha; Alex, Jomini Liza; Singh, Shashi; Kumar, Satish

2006-01-01

Acquisition of milk production capabilities by an ancestor of mammals is at the root of mammalian evolution. Milk casein micelles are a primary source of amino acids and calcium phosphate to neonates. To understand the role of κ-casein in lactation, we have created and characterized a null mouse strain (Csnk−/−) lacking this gene. The mutant κ-casein allele did not affect the expression of other milk proteins in Csnk−/− females. However, these females did not suckle their pups and failed to lactate because of destabilization of the micelles in the lumina of the mammary gland. Thus, κ-casein is essential for lactation and, consequently, for the successful completion of the process of reproduction in mammals. In view of the extreme structural conservation of the casein locus, as well as the phenotype of Csnk−/− females, we propose that the organization of a functional κ-casein gene would have been one of the critical events in the evolution of mammals. Further, κ-casein variants are known to affect the industrial properties of milk in dairy animals. Given the expenses and the time scale of such experiments in livestock species, it is desirable to model the intended genetic modifications in mice first. The mouse strain that we have created would be a useful model to study the effect of κ-casein variants on the properties of milk and/or milk products. PMID:16698927

Membrane skeletal proteins and their integral membrane protein anchors are targets for tyrosine and threonine kinases in Euglena.

Science.gov (United States)

Fazio, M J; Da Silva, A C; Rosiere, T K; Bouck, G B

1995-01-01

Proteins of the membrane skeleton of Euglena gracilis were extensively phosphorylated in vivo and in vitro after incubation with [32P]-orthophosphate or gamma-[32P] ATP. Endogenous protein threonine/serine activity phosphorylated the major membrane skeletal proteins (articulins) and the putative integral membrane protein (IP39) anchor for articulins. The latter was also the major target for endogenous protein tyrosine kinase activity. A cytoplasmic domain of IP39 was specifically phosphorylated, and removal of this domain with papain eliminated the radiolabeled phosphoamino acids and eliminated or radically shifted the PI of the multiple isoforms of IP39. In gel kinase assays IP39 autophosphorylated and a 25 kDa protein which does not autophosphorylate was identified as a threonine/serine (casein) kinase. Plasma membranes from the membrane skeletal protein complex contained threonine/serine (casein) kinase activity, and cross-linking experiments suggested that IP39 was the likely source for this membrane activity. pH optima, cation requirements and heparin sensitivity of the detergent solubilized membrane activity were determined. Together these results suggest that protein kinases may be important modulators of protein assembly and function of the membrane skeleton of these protistan cells.

Subcellular localization of casein kinase I

DEFF Research Database (Denmark)

Grankowski, N; Issinger, O G

1990-01-01

An anti-yeast CKI antiserum was shown to cross-react with CKI isolated from Krebs II mouse ascites tumour cells. The mammalian CKI showed virtually the same molecular mass (app. 45 kDa) as the yeast enzyme. By immunofluorescence it could be shown that CKI is preferably located in the nucleolus....

Obesity-Linked Phosphorylation of SIRT1 by Casein Kinase 2 Inhibits Its Nuclear Localization and Promotes Fatty Liver.

Science.gov (United States)

Choi, Sung E; Kwon, Sanghoon; Seok, Sunmi; Xiao, Zhen; Lee, Kwan-Woo; Kang, Yup; Li, Xiaoling; Shinoda, Kosaku; Kajimura, Shingo; Kemper, Byron; Kemper, Jongsook Kim

2017-08-01

Sirtuin1 (SIRT1) deacetylase delays and improves many obesity-related diseases, including nonalcoholic fatty liver disease (NAFLD) and diabetes, and has received great attention as a drug target. SIRT1 function is aberrantly low in obesity, so understanding the underlying mechanisms is important for drug development. Here, we show that obesity-linked phosphorylation of SIRT1 inhibits its function and promotes pathological symptoms of NAFLD. In proteomic analysis, Ser-164 was identified as a major serine phosphorylation site in SIRT1 in obese, but not lean, mice, and this phosphorylation was catalyzed by casein kinase 2 (CK2), the levels of which were dramatically elevated in obesity. Mechanistically, phosphorylation of SIRT1 at Ser-164 substantially inhibited its nuclear localization and modestly affected its deacetylase activity. Adenovirus-mediated liver-specific expression of SIRT1 or a phosphor-defective S164A-SIRT1 mutant promoted fatty acid oxidation and ameliorated liver steatosis and glucose intolerance in diet-induced obese mice, but these beneficial effects were not observed in mice expressing a phosphor-mimic S164D-SIRT1 mutant. Remarkably, phosphorylated S164-SIRT1 and CK2 levels were also highly elevated in liver samples of NAFLD patients and correlated with disease severity. Thus, inhibition of phosphorylation of SIRT1 by CK2 may serve as a new therapeutic approach for treatment of NAFLD and other obesity-related diseases. Copyright © 2017 American Society for Microbiology.

A sensitive radioimmunoassay for a component of mouse casein

International Nuclear Information System (INIS)

Enami, Jumpei; Nandi, S.; California Univ. Berkeley

1977-01-01

Mouse casein (m.w. 22,000 daltons) has been purified by employing Sephadex G-100 and DEAE-cellulose column chromatographies. A sensitive radioimmunoassay method has been developed by using [ 125 I]-labelled casein and antiserum elicited in rabbits after injection of glutaraldehyde-treated casein. The assay method is capable of detecting as little as 0.1 ng of casein. The use of the present radioimmunoassay method in detecting casein production in cultured mouse mammary explants has also been demonstrated

The inhibitor of cyclin-dependent kinases, olomoucine II, exhibits potent antiviral properties

Czech Academy of Sciences Publication Activity Database

Holčáková, J.; Tomašec, P.; Burget, J. J.; Wang, E. C. Y.; Wilkinson, G. W. G.; Hrstka, R.; Kryštof, Vladimír; Strnad, Miroslav; Vojtešek, B.

2010-01-01

Roč. 20, č. 3 (2010), s. 133-142 ISSN 0956-3202 R&D Projects: GA ČR GA301/08/1649 Institutional research plan: CEZ:AV0Z50380511 Keywords : Cyclin-dependent Kinase * Olomoucine II * vaccinia Subject RIV: EE - Microbiology, Virology

Importance of intrinsic properties of dense caseinate dispersions for structure formation.

Science.gov (United States)

Manski, Julita M; van Riemsdijk, Lieke E; van der Goot, Atze J; Boom, Remko M

2007-11-01

Rheological measurements of dense calcium caseinate and sodium caseinate dispersions (> or =15%) provided insight into the factors determining shear-induced structure formation in caseinates. Calcium caseinate at a sufficiently high concentration (30%) was shown to form highly anisotropic structures during shearing and concurrent enzymatic cross-linking. In contrast, sodium caseinate formed isotropic structures using similar processing conditions. The main difference between the two types of caseinates is the counterion present, and as a consequence, the size of structural elements and their interactions. The rheological behavior of calcium caseinate and sodium caseinate reflected these differences, yielding non-monotonic and shear thinning flow behavior for calcium caseinate whereas sodium caseinate behaved only slightly shear thinning. It appears that the intrinsic properties of the dense caseinate dispersions, which are reflected in their rheological behavior, affect the structure formation that was found after applying shear. Therefore, rheological measurements are useful to obtain an indication of the structure formation potential of caseinate dispersions.

Differential Roles of the Glycogen-Binding Domains of β Subunits in Regulation of the Snf1 Kinase Complex▿

Science.gov (United States)

Mangat, Simmanjeet; Chandrashekarappa, Dakshayini; McCartney, Rhonda R.; Elbing, Karin; Schmidt, Martin C.

2010-01-01

Members of the AMP-activated protein kinase family, including the Snf1 kinase of Saccharomyces cerevisiae, are activated under conditions of nutrient stress. AMP-activated protein kinases are heterotrimeric complexes composed of a catalytic α subunit and regulatory β and γ subunits. In this study, the role of the β subunits in the regulation of Snf1 activity was examined. Yeasts express three isoforms of the AMP-activated protein kinase consisting of Snf1 (α), Snf4 (γ), and one of three alternative β subunits, either Sip1, Sip2, or Gal83. The Gal83 isoform of the Snf1 complex is the most abundant and was analyzed in the greatest detail. All three β subunits contain a conserved domain referred to as the glycogen-binding domain. The deletion of this domain from Gal83 results in a deregulation of the Snf1 kinase, as judged by a constitutive activity independent of glucose availability. In contrast, the deletion of this homologous domain from the Sip1 and Sip2 subunits had little effect on Snf1 kinase regulation. Therefore, the different Snf1 kinase isoforms are regulated through distinct mechanisms, which may contribute to their specialized roles in different stress response pathways. In addition, the β subunits are subjected to phosphorylation. The responsible kinases were identified as being Snf1 and casein kinase II. The significance of the phosphorylation is unclear since the deletion of the region containing the phosphorylation sites in Gal83 had little effect on the regulation of Snf1 in response to glucose limitation. PMID:19897735

Differential roles of the glycogen-binding domains of beta subunits in regulation of the Snf1 kinase complex.

Science.gov (United States)

Mangat, Simmanjeet; Chandrashekarappa, Dakshayini; McCartney, Rhonda R; Elbing, Karin; Schmidt, Martin C

2010-01-01

Members of the AMP-activated protein kinase family, including the Snf1 kinase of Saccharomyces cerevisiae, are activated under conditions of nutrient stress. AMP-activated protein kinases are heterotrimeric complexes composed of a catalytic alpha subunit and regulatory beta and gamma subunits. In this study, the role of the beta subunits in the regulation of Snf1 activity was examined. Yeasts express three isoforms of the AMP-activated protein kinase consisting of Snf1 (alpha), Snf4 (gamma), and one of three alternative beta subunits, either Sip1, Sip2, or Gal83. The Gal83 isoform of the Snf1 complex is the most abundant and was analyzed in the greatest detail. All three beta subunits contain a conserved domain referred to as the glycogen-binding domain. The deletion of this domain from Gal83 results in a deregulation of the Snf1 kinase, as judged by a constitutive activity independent of glucose availability. In contrast, the deletion of this homologous domain from the Sip1 and Sip2 subunits had little effect on Snf1 kinase regulation. Therefore, the different Snf1 kinase isoforms are regulated through distinct mechanisms, which may contribute to their specialized roles in different stress response pathways. In addition, the beta subunits are subjected to phosphorylation. The responsible kinases were identified as being Snf1 and casein kinase II. The significance of the phosphorylation is unclear since the deletion of the region containing the phosphorylation sites in Gal83 had little effect on the regulation of Snf1 in response to glucose limitation.

Structure-rheology relations in sodium caseinate containing systems

NARCIS (Netherlands)

Ruis, H.G.M.

2007-01-01

The general aim of the work described in this thesis was to investigate structure-rheologyrelations for dairy related products, focusing on model systems containing sodium caseinate. The acid inducedgelationof sodium caseinate, of sodium caseinate stabilized emulsions, and the effect of shear on the

BIOLOGICAL VALUE OF GOAT MILK CASEIN

OpenAIRE

Samir Ahmed Salem; Elsayed Ibrahim Elagamy; Fatma Salama; Nagwa Hussein Abosoliman

2009-01-01

The effect of feeding of goat and cow milk caseins on the body weight gain, body organs, erythrocytic & leukocytic counts and their parameters, plasma lipid profile, liver enzyme activities, renal function and plasma proteins of rats over a period of 45 days was studied. Feeding of goat or cow milk caseins had no significant effect on the parameters studied (P≤0.05) between rats fed either milk. However, rats fed on goat milk casein showed a significant increase in high density lipoproteins...

RAMA casein zymography: Time-saving and highly sensitive casein zymography for MMP7 and trypsin.

Science.gov (United States)

Yasumitsu, Hidetaro; Ozeki, Yasuhiro; Kanaly, Robert A

2016-11-01

To detect metalloproteinase-7 (MMP7), zymography is conducted using a casein substrate and conventional CBB stain. It has disadvantages because it is time consuming and has low sensitivity. Previously, a sensitive method to detect MMP7 up to 30 pg was reported, however it required special substrates and complicated handlings. RAMA casein zymography described herein is rapid, sensitive, and reproducible. By applying high-sensitivity staining with low substrate conditions, the staining process is completed within 1 h and sensitivity was increased 100-fold. The method can detect 10 pg MMP7 by using commercially available casein without complicated handlings. Moreover, it increases detection sensitivity for trypsin. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Threonine phosphorylation of rat liver glycogen synthase

International Nuclear Information System (INIS)

Arino, J.; Arro, M.; Guinovart, J.J.

1985-01-01

32 P-labeled glycogen synthase specifically immunoprecipitated from 32 P-phosphate incubated rat hepatocytes contains, in addition to [ 32 P] phosphoserine, significant levels of [ 32 P] phosphothreonine. When the 32 P-immunoprecipitate was cleaved with CNBr, the [ 32 P] phosphothreonine was recovered in the large CNBr fragment (CB-2, Mapp 28 Kd). Homogeneous rat liver glycogen synthase was phosphorylated by all the protein kinases able to phosphorylate CB-2 in vitro. After analysis of the immunoprecipitated enzyme for phosphoaminoacids, it was observed that only casein kinase II was able to phosphorylate on threonine and 32 P-phosphate was only found in CB-2. These results demonstrate that rat liver glycogen synthase is phosphorylated at threonine site(s) contained in CB-2 and strongly indicate that casein kinase II may play a role in the ''in vivo'' phosphorylation of liver glycogen synthase. This is the first protein kinase reported to phosphorylate threonine residues in liver glycogen synthase

COMPARATIVE STUDY ON MILK CASEIN ASSAY METHODS

Directory of Open Access Journals (Sweden)

RODICA CĂPRIłĂ

2008-05-01

Full Text Available Casein, the main milk protein was determined by different assay methods: the gravimetric method, the method based on the neutralization of the NaOH excess used for the casein precipitate solving and the method based on the titration of the acetic acid used for the casein precipitation. The last method is the simplest one, with the fewer steps, and also with the lowest error degree. The results of the experiment revealed that the percentage of casein from the whole milk protein represents between 72.6–81.3% in experiment 1, between 73.6–81.3% in experiment 2 and between 74.3–81% in experiment 3.

NCBI nr-aa BLAST: CBRC-PCAP-01-0533 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PCAP-01-0533 ref|NP_570096.2| protein kinase C and casein kinase substrate in neurons...ein kinase C and casein kinase substrate in neurons 2 [Rattus norvegicus] gb|EDM15628.1| protein kinase C an...d casein kinase substrate in neurons 2, isoform CRA_a [Rattus norvegicus] gb|EDM1...5629.1| protein kinase C and casein kinase substrate in neurons 2, isoform CRA_a [Rattus norvegicus] gb|EDM1...5631.1| protein kinase C and casein kinase substrate in neurons 2, isoform CRA_a [Rattus norvegicus] NP_570096.2 1e-176 87% ...

NCBI nr-aa BLAST: CBRC-MMUR-01-0237 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-MMUR-01-0237 ref|NP_570096.2| protein kinase C and casein kinase substrate in neurons...ein kinase C and casein kinase substrate in neurons 2 [Rattus norvegicus] gb|EDM15628.1| protein kinase C an...d casein kinase substrate in neurons 2, isoform CRA_a [Rattus norvegicus] gb|EDM1...5629.1| protein kinase C and casein kinase substrate in neurons 2, isoform CRA_a [Rattus norvegicus] gb|EDM1...5631.1| protein kinase C and casein kinase substrate in neurons 2, isoform CRA_a [Rattus norvegicus] NP_570096.2 0.0 85% ...

Stability of casein micelles in milk

Science.gov (United States)

Tuinier, R.; de Kruif, C. G.

2002-07-01

Casein micelles in milk are proteinaceous colloidal particles and are essential for the production of flocculated and gelled products such as yogurt, cheese, and ice-cream. The colloidal stability of casein micelles is described here by a calculation of the pair potential, containing the essential contributions of brush repulsion, electrostatic repulsion, and van der Waals attraction. The parameters required are taken from the literature. The results are expressed by the second osmotic virial coefficient and are quite consistent with experimental findings. It appears that the stability is mainly attributable to a steric layer of κ-casein, which can be described as a salted polyelectrolyte brush.

Importance of intrinsic properties of dense caseinate dispersions for structure formation

NARCIS (Netherlands)

Manski, J.M.; Riemsdijk, van L.E.; Goot, van der A.J.; Boom, R.M.

2007-01-01

Rheological measurements of dense calcium caseinate and sodium caseinate dispersions (15%) provided insight into the factors determining shear-induced structure formation in caseinates. Calcium caseinate at a sufficiently high concentration (30%) was shown to form highly anisotropic structures

The comparison of nuclear ubiquitous casein and cyclin-dependent kinases substrate (NUCKS) with Ki67 proliferation marker expression in common skin tumors.

Science.gov (United States)

Zduniak, Krzysztof; Agrawal, Siddarth; Symonowicz, Krzysztof; Jurczyszyn, Kamil; Ziółkowski, Piotr

2014-03-01

Nuclear ubiquitous casein and cyclin-dependent kinases substrate (NUCKS) is a chromosomal protein of unknown function. Its amino acid composition and structure of its DNA binding domain resemble those of high mobility group A (HMGA) proteins which are associated with various malignancies. Since changes in expression of HMGA are considered as a marker of tumor progression, it is possible that similar changes in expression of NUCKS could be a useful tool in diagnosis of malignant skin tumors. To investigate this assumption we used specific antibodies against NUCKS for immunohistochemistry of squamous (SCC) and basal cell carcinoma (BCC) as well as keratoacanthoma (KA). We found high expression of NUCKS in nuclei of SCC and BCC cells which exceeded expression of the well-known proliferation marker Ki67. Expression of NUCKS in benign KA was much below that of malignant tumors. With the present study and based on our previous experience we would like to suggest the NUCKS protein as a novel proliferation marker for immunohistochemical evaluation of formalin-fixed and paraffin-embedded skin tumor specimens. We would like to emphasize that NUCKS abundance in malignant skin tumors is higher than that of the well-known proliferation marker Ki67, thus allowing more precise assessment of tumor proliferation potential.

Long-term stability of sodium caseinate-stabilized nanoemulsions.

Science.gov (United States)

Yerramilli, Manispuritha; Ghosh, Supratim

2017-01-01

Oil-in-water (5 wt%) nanoemulsions were prepared with different concentration (2.5-10 wt%) of sodium caseinate as a sole emulsifier and their long-term storage stability was investigated for 6 months. Previous studies associated with sodium caseinate looked only into nanoemulsion formation; hence the challenges with long-term stability were not addressed. All nanoemulsions displayed an average droplet size sodium caseinate-stabilized nanoemulsions.

Antimicrobial activity and mechanism of the human milk-sourced peptide Casein201

International Nuclear Information System (INIS)

Zhang, Fan; Cui, Xianwei; Fu, Yanrong; Zhang, Jun; Zhou, Yahui; Sun, Yazhou; Wang, Xing; Li, Yun; Liu, Qianqi; Chen, Ting

2017-01-01

Introduction: Casein201 is one of the human milk sourced peptides that differed significantly in preterm and full-term mothers. This study is designed to demonstrate the biological characteristics, antibacterial activity and mechanisms of Casein201 against common pathogens in neonatal infection. Methodology: The analysis of biological characteristics was done by bioinformatics. Disk diffusion method and flow cytometry were used to detect the antimicrobial activity of Casein201. Killing kinetics of Casein201 was measured using microplate reader. The antimicrobial mechanism of Casein201 was studied by electron microscopy and electrophoresis. Results: Bioinformatics analysis indicates that Casein201 derived from β-casein and showed significant sequence overlap. Antibacterial assays showed Casein201 inhibited the growth of S taphylococcus aureus and Y ersinia enterocolitica. Ultrastructural analyses revealed that the antibacterial activity of Casein201 is through cytoplasmic structures disintegration and bacterial cell envelope alterations but not combination with DNA. Conclusion: We conclude the antimicrobial activity and mechanism of Casein201. Our data demonstrate that Casein201 has potential therapeutic value for the prevention and treatment of pathogens in neonatal infection.

21 CFR 558.295 - Iodinated casein.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iodinated casein. 558.295 Section 558.295 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... in Animal Feeds § 558.295 Iodinated casein. (a) Approvals. See 017762 in § 510.600(c) of this chapter...

ISOLATION, MOLECULAR AND BIOCHEMICAL CHARACTERIZATION OF GOAT MILK CASEIN AND ITS FRACTIONS

Directory of Open Access Journals (Sweden)

Samir Ahmed Salem

2009-06-01

Full Text Available The SDS-PAGE electrophoretic pattern of goats´ milk has a unique pattern compared to those of cow and human milk. β-casein is the major fraction and comprises 70.2% of total goat-milk caseins, while αs- is a minor fraction (29.85 %. This pattern is similar to that of human casein but different to that of cow casein. Purified casein fractions of goat milk showed different electrophoretic migration compared to those of bovine milk. The corresponding Mr(s of goat αs- and β-casein were estimated at 30.2 for αs and 26.6 & 23.9 for β1 and β2 versus 32.6 and 26.6 for bovine αs- and β-casein, respectively. The amino acid composition of goat-milk whole casein appeared to be similar to those of cow, sheep and camel caseins. Meanwhile, goat casein has the satisfactory balance of essential amino acids equal to or exceeding the FAO/ WHO/ UNU requirements for each amino acid. Goat αs-casein was characterized by the presence of higher contents of both acidic and basic amino acids than β-casein. Peptide mapping profiles of goat, cow and human caseins were completely different. This means that each protein has its own unique peptide mapping.

Apical-to-basolateral transepithelial transport of cow's milk caseins by intestinal Caco-2 cell monolayers: MS-based quantitation of cellularly degraded α- and β-casein fragments.

Science.gov (United States)

Sakurai, Nao; Nishio, Shunsuke; Akiyama, Yuka; Miyata, Shinji; Oshima, Kenzi; Nadano, Daita; Matsuda, Tsukasa

2018-02-27

Casein is the major milk protein to nourish infants but, in certain population, it causes cow's milk allergy, indicating the uptake of antigenic casein and their peptides through the intestinal epithelium. Using human intestinal Caco-2 cell monolayers, the apical-to-basal transepithelial transport of casein was investigated. Confocal microscopy using component-specific antibodies showed that αs1-casein antigens became detectable as punctate signals at the apical-side cytoplasm and reached to the cytoplasm at a tight-junction level within a few hours. Such intracellular casein signals were more remarkable than those of the other antigens, β-lactoglobulin and ovalbumin, colocalized in part with an early endosome marker protein, EEA1, and decreased in the presence of cytochalasin D or sodium azide and also at lowered temperature at 4 °C. LC-MS analysis of the protein fraction in the basal-side medium identified the αs1-casein fragment including the N-terminal region and the αs2-casein fragment containing the central part of polypeptide at 100∼1000 fmol per well levels. Moreover, β-casein C-terminal overlapping peptides were identified in the peptide fraction below 10 kDa of the basal medium. These results suggest that caseins are partially degraded by cellular proteases and/or peptidases and immunologically active casein fragments are transported to basal side of the cell monolayers.

NCBI nr-aa BLAST: CBRC-PVAM-01-1589 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PVAM-01-1589 ref|NP_057307.2| protein kinase C and casein kinase substrate in neurons... 3 [Homo sapiens] ref|XP_001110379.1| PREDICTED: similar to protein kinase C and casein kinase substrate in neurons...asein kinase substrate in neurons 3 isoform 2 [Macaca mulatta] ref|XP_001166571.1...| PREDICTED: protein kinase C and casein kinase substrate in neurons 3 isoform 1 [Pan troglodytes] ref|XP_00...1166605.1| PREDICTED: protein kinase C and casein kinase substrate in neurons 3 isoform 2 [Pan troglodytes

NCBI nr-aa BLAST: CBRC-MDOM-05-0155 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-MDOM-05-0155 ref|NP_057307.2| protein kinase C and casein kinase substrate in neurons... 3 [Homo sapiens] ref|XP_001110379.1| PREDICTED: similar to protein kinase C and casein kinase substrate in neurons...asein kinase substrate in neurons 3 isoform 2 [Macaca mulatta] ref|XP_001166571.1...| PREDICTED: protein kinase C and casein kinase substrate in neurons 3 isoform 1 [Pan troglodytes] ref|XP_00...1166605.1| PREDICTED: protein kinase C and casein kinase substrate in neurons 3 isoform 2 [Pan troglodytes

NCBI nr-aa BLAST: CBRC-MEUG-01-0587 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-MEUG-01-0587 ref|NP_057307.2| protein kinase C and casein kinase substrate in neurons... 3 [Homo sapiens] ref|XP_001110379.1| PREDICTED: similar to protein kinase C and casein kinase substrate in neurons...asein kinase substrate in neurons 3 isoform 2 [Macaca mulatta] ref|XP_001166571.1...| PREDICTED: protein kinase C and casein kinase substrate in neurons 3 isoform 1 [Pan troglodytes] ref|XP_00...1166605.1| PREDICTED: protein kinase C and casein kinase substrate in neurons 3 isoform 2 [Pan troglodytes

NCBI nr-aa BLAST: CBRC-PCAP-01-1696 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PCAP-01-1696 ref|NP_057307.2| protein kinase C and casein kinase substrate in neurons... 3 [Homo sapiens] ref|XP_001110379.1| PREDICTED: similar to protein kinase C and casein kinase substrate in neurons...asein kinase substrate in neurons 3 isoform 2 [Macaca mulatta] ref|XP_001166571.1...| PREDICTED: protein kinase C and casein kinase substrate in neurons 3 isoform 1 [Pan troglodytes] ref|XP_00...1166605.1| PREDICTED: protein kinase C and casein kinase substrate in neurons 3 isoform 2 [Pan troglodytes

Structure-rheology relations in sodium caseinate containing systems

OpenAIRE

Ruis, H.G.M.

2007-01-01

The general aim of the work described in this thesis was to investigate structure-rheologyrelations for dairy related products, focusing on model systems containing sodium caseinate. The acid inducedgelationof sodium caseinate, of sodium caseinate stabilized emulsions, and the effect of shear on the structure formation was characterized. Special attention was given to the sol-gel transition point, which was defined by a frequency independent loss tangent. It was shown that the sol-gel transit...

Virtual screening filters for the design of type II p38 MAP kinase inhibitors: a fragment based library generation approach.

Science.gov (United States)

Badrinarayan, Preethi; Sastry, G Narahari

2012-04-01

In this work, we introduce the development and application of a three-step scoring and filtering procedure for the design of type II p38 MAP kinase leads using allosteric fragments extracted from virtual screening hits. The design of the virtual screening filters is based on a thorough evaluation of docking methods, DFG-loop conformation, binding interactions and chemotype specificity of the 138 p38 MAP kinase inhibitors from Protein Data Bank bound to DFG-in and DFG-out conformations using Glide, GOLD and CDOCKER. A 40 ns molecular dynamics simulation with the apo, type I with DFG-in and type II with DFG-out forms was carried out to delineate the effects of structural variations on inhibitor binding. The designed docking-score and sub-structure filters were first tested on a dataset of 249 potent p38 MAP kinase inhibitors from seven diverse series and 18,842 kinase inhibitors from PDB, to gauge their capacity to discriminate between kinase and non-kinase inhibitors and likewise to selectively filter-in target-specific inhibitors. The designed filters were then applied in the virtual screening of a database of ten million (10⁷) compounds resulting in the identification of 100 hits. Based on their binding modes, 98 allosteric fragments were extracted from the hits and a fragment library was generated. New type II p38 MAP kinase leads were designed by tailoring the existing type I ATP site binders with allosteric fragments using a common urea linker. Target specific virtual screening filters can thus be easily developed for other kinases based on this strategy to retrieve target selective compounds. Copyright © 2012 Elsevier Inc. All rights reserved.

Isolation and Molecular Characterization of Local Goat Milk Casein for Nutraceutical Value

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Azhar Mohd Akmal

2017-01-01

Full Text Available Bioactive peptide from casein play a very important role in biological functionalities such as antioxidant and antimicrobial activities. Casein is the main protein that derived from goat milk which consists of alpha (α, beta (β and kappa (κ casein. Dietary protein such as casein from animal can provide rich source of bioactive peptide. However, the macromolecular protein such as cow milk can cause allergic response to certain individuals. On the other hand, goat milk have been known for its hypoallergenic and therapeutic properties in human nutrition and health. The purpose of this study is to extract casein from local breed goat milk and identify the molecular characterization of casein for nutraceutical value. The casein was successfully extracted using extraction method. Extraction is a common technique used to separate a desired substance when it is mixed with other components. The average percentage of casein obtained was 24.25%. Then, the casein was analysed by running it in the SDS-Page. The major fraction is β-casein and the minor is α-casein that can be seen between 20kDa and 30kDa respectively. There is no contaminated protein appear in the purified α-amylase. The result obtained in this study indicates that isolated casein from Malaysian goat milk was pure and can be used as bioactive peptide for nutraceutical value.

Effects of gamma-irradiation on some properties of bovine casein micelles

International Nuclear Information System (INIS)

Saito, Zenichi

1974-01-01

Sedimentation studies and electron microscopic observations revealed that an association between casein micelles dispersed in water or milk serum was not induced significantly by gamma-irradiation of exposure up to 3 x 10 6 R, whereas a release of nonprotein nitrogen was observed to a certain extent. It was concluded from the results of turbidi-metry and gel filtration using 3 size groups of casein micelles, namely large, medium and small, that an irradiation-induced polymerization or association occurred within individual casein micelles, and strengthend the micelle structure. Thus the irradiated casein micelles resisted, more or less, to the solubilizing effect of NaCl, EDTA, pyrophosphate and urea. Stabilities of casein micelles for ethanol and for acidification to an isoelectric point were decreased and increased, respectively, after irradiation. Gamma irradiation also caused the decrease of glycomacropeptide released from casein micelles by the action of rennin, and this resulted in the delay of rennin-coagulation of casein. There were no essential differences among the 3 size groups of casein micelles concerning the above described tendencies. (auth.)

Formation of free-standing sterilized edible-films from irradiated caseinates

International Nuclear Information System (INIS)

Brault, D.; D'Aprano, G.; Lacroix, M.

1998-01-01

γ-irradiation was used to produce free-standing sterilized edible films based on milk protein, namely sodium-caseinate and calcium-caseinate. The nature of the counter-ion as well as the protein and glycerol concentrations were examined. Irradiation of solution based on calcium-caseinate produced more crosslinks than solution based on sodium-caseinate. As a consequence, films based on calcium-caseinate showed a better mechanical strength. Glycerol was found to play a double role in enhancing the formation of crosslinks within caseinate chains, accounting for the increase of the puncture strength, and acting as a plasticizer, being responsible for the improved film extensibility and viscoelasticity. Moreover, the effect of the irradiation on the mechanical properties were strongly dependent on the glycerol/protein ratio, i.e. the formulation of the films. Films of high quality and a satisfactory mechanical behaviour were generated at glycerol/protein ratios of 0.5 and 0.67

Regulation of Xenopus laevis DNA topoisomerase I activity by phosphorylation in vitro

International Nuclear Information System (INIS)

Kaiserman, H.B.; Ingebritsen, T.S.; Benbow, R.M.

1988-01-01

DNA topoisomerase I has been purified to electrophoretic homogeneity from ovaries of the frog Xenopus laevis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the most purified fraction revealed a single major band at 110 kDa and less abundant minor bands centered at 62 kDa. Incubation of the most purified fraction with immobilized calf intestinal alkaline phosphatase abolished all DNA topoisomerase enzymatic activity in a time-dependent reaction. Treatment of the dephosphorylated X. laevis DNA topoisomerase I with a X. laevis casein kinase type II activity and ATP restored DNA topoisomerase activity to a level higher than that observed in the most purified fraction. In vitro labeling experiments which employed the most purified DNA topoisomerase I fraction, [γ- 32 P]ATP, and the casein kinase type II enzyme showed that both the 110- and 62-kDa bands became phosphorylated in approximately molar proportions. Phosphoamino acid analysis showed that only serine residues became phosphorylated. Phosphorylation was accompanied by an increase in DNA topoisomerase activity in vitro. Dephosphorylation of DNA topoisomerase I appears to block formation of the initial enzyme-substrate complex on the basis of the failure of the dephosphorylated enzyme to nick DNA in the presence of camptothecin. The authors conclude that X. laevis DNA topoisomerase I is partially phosphorylated as isolated and that this phosphorylation is essential for expression of enzymatic activity in vitro. On the basis of the ability of the casein kinase type II activity to reactivate dephosphorylated DNA topoisomerase I, they speculate that this kinase may contribute to the physiological regulation of DNA topoisomerase I activity

Characterization of casein and alpha lactalbumin of African elephant (Loxodonta africana) milk.

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Madende, M; Osthoff, G; Patterton, H-G; Patterton, H E; Martin, P; Opperman, D J

2015-12-01

The current research reports partial characterization of the caseins and α-lactalbumin (α-LA) of the African elephant with proposed unique structure-function properties. Extensive research has been carried out to understand the structure of the casein micelles. Crystallographic structure elucidation of caseins and casein micelles is not possible. Consequently, several models have been developed in an effort to describe the casein micelle, specifically of cow milk. Here we report the characterization of African elephant milk caseins. The κ-caseins and β-caseins were investigated, and their relative ratio was found to be approximately 1:8.5, whereas α-caseins were not detected. The gene sequence of β-casein in the NCBI database was revisited, and a different sequence in the N-terminal region is proposed. Amino acid sequence alignment and hydropathy plots showed that the κ-casein of African elephant milk is similar to that of other mammals, whereas the β-casein is similar to the human protein, and displayed a section of unique AA composition and additional hydrophilic regions compared with bovine caseins. Elephant milk is destabilized by 62% alcohol, and it is speculated that the β-casein characteristics may allow maintenance of the colloidal nature of the casein micelle, a role that was previously only associated with κ-casein. The oligosaccharide content of milk was reported to be low in dairy animals but high in some other species such as humans and elephants. In the milk of the African elephant, lactose and oligosaccharides both occur at high levels. These levels are typically related to the content of α-LA in the mammary gland and thus point to a specialized carbohydrate synthesis, where the whey protein α-LA plays a role. We report the characterization of African elephant α-LA. Homology modeling of the α-LA showed that it is structurally similar to crystal structures of other mammalian species, which in turn may be an indication that its functional

Protein kinase that phosphorylates light-harvesting complex is autophosphorylated and is associated with photosystem II

International Nuclear Information System (INIS)

Coughlan, S.J.; Hind, G.

1987-01-01

Thylakoid membranes were phosphorylated with [γ- 32 P]ATP and extracted with octyl glucoside and cholate. Among the radiolabeled phosphoproteins in the extract was a previously characterized protein kinase of 64-kDa apparent mass. The ability of this enzyme to undergo autophosphorylation in situ was used to monitor its distribution in the membrane. Fractionation studies showed that the kinase is confined to granal regions of the thylakoid, where it appears to be associated with the light-harvesting chlorophyll-protein complex of photosystem II. The kinetics of kinase autophosphorylation were investigated both in situ and in extracted, purified enzyme. In the membrane, autophosphorylation saturated within 20-30 min and was reversed with a half-time of 7-8 min upon removal of ATP or oxidative inactivation of the kinase; the accompanying dephosphorylation of light-harvesting complex was slower and kinetically complex. Fluoride (10 mM) inhibited these dephosphorylations. Autophosphorylation of the isolated kinase was independent of enzyme concentration, indicative of an intramolecular mechanism. A maximum of one serine residue per mole of kinase was esterified. Autophosphorylation was more rapid in the presence of histone IIIs, an exogenous substrate. Dephosphorylation of the isolated enzyme was not observed

Casein Glycomacropeptide Hydrolysates Exert Cytoprotective Effect against Cellular Oxidative Stress by Up-Regulating HO-1 Expression in HepG2 Cells

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Tiange Li

2017-01-01

Full Text Available Oxidative stress is considered as an important mediator in the progression of metabolic disorders. The objective of this study was to investigate the potential hepatoprotective effects and mechanisms of bovine casein glycomacropeptide hydrolysates (GHP on hydrogen peroxide (H2O2-induced oxidative damage in HepG2 cells. Results showed that GHP significantly blocked H2O2-induced intracellular reactive oxygen species (ROS generation and cell viability reduction in a dose-dependent manner. Further, GHP concentration-dependently induced heme oxygenase-1 (HO-1 expression and increased nuclear factor-erythroid 2-related factor 2 (Nrf2 nuclear translocation. Moreover, pretreatment of GHP increased the activation of p38 mitogen-activated protein kinase (p38 MAPK and extracellular signal-regulated protein kinase 1/2 (ERK1/2, which were shown to contribute to Nrf2-mediated HO-1 expression. Taken together, GHP protected HepG2 cells from oxidative stress by activation of Nrf2 and HO-1 via p38 MAPK and ERK1/2 signaling pathways. Our findings indicate that bovine casein glycomacropeptide hydrolysates might be a potential ingredient in the treatment of oxidative stress-related disorders and further studies are needed to investigate the protective effects in vivo.

Short communication: Effect of casein haplotype on angiotensin-converting enzyme inhibitory and antioxidant capacities of milk casein from Italian Holstein cows before and following in vitro digestion with gastrointestinal enzymes.

Science.gov (United States)

Perna, Annamaria; Simonetti, Amalia; Gambacorta, Emilio

2016-09-01

The aim of this work was to investigate the effect of casein haplotype (αS1, β, and κ) on antioxidative and angiotensin-converting enzyme (ACE) inhibitory capacities of milk casein from Italian Holstein cows before and following in vitro digestion with gastrointestinal enzymes. The antioxidant capacity was measured using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power assays, whereas ACE inhibition was determined by ACE-inhibitory assay. The ACE-inhibitory and antioxidant capacities of milk casein increased during in vitro gastrointestinal digestion. Casein haplotype significantly influenced the antioxidative and ACE-inhibitory capacities of digested casein. In particular, BB-A(2)A(1)-AA casein and BB-A(1)A(1)-AA casein showed the highest ACE-inhibitory capacity, BB-A(2)A(2)-AA casein showed the highest antioxidant capacity, whereas BB-A(2)A(2)-BB casein showed the lowest biological capacity. To date, few studies have been done on the effect of casein haplotype on biological capacity of milk casein, thus the present study sets the basis for a new knowledge that could lead to the production of milk with better nutraceutical properties. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI

Science.gov (United States)

Greenberg, David M.; Schmidt, Carl L. A.

1924-01-01

1. The deposition of casein on a platinum anode which takes place on the passage of a direct current through solutions of alkali caseinates was quantitatively studied, and it was found that: (a) the amount of casein which is deposited is directly proportional to the current, i.e. it obeys Faraday's law; (b) the amount of casein deposited is inversely proportional (within the limits studied) to the amount of alkali which is combined with the casein. 2. A method of determining the transport numbers of proteins insoluble at their isoelectric point has been developed. 3. A titration method for determining the amount of alkali in a casein solution is given. 4. Data from the results of transference experiments on sodium caseinate, potassium caseinate, cesium caseinate, and rubidium caseinate solutions are given. It is shown that the data are best explained on the assumption that in these solutions the carriers of the current are alkali metal cations and casein anions. 5. On the basis of our transference results an explanation is given of the results which were obtained by Robertson and by Haas in their migration experiments. PMID:19872135

Rheological behavior of high-concentration sodium caseinate dispersions.

Science.gov (United States)

Loveday, Simon M; Rao, M Anandha; Creamer, Lawrence K; Singh, Harjinder

2010-03-01

Apparent viscosity and frequency sweep (G', G'') data for sodium caseinate dispersions with concentrations of approximately 18% to 40% w/w were obtained at 20 degrees C; colloidal glass behavior was exhibited by dispersions with concentration >or=23% w/w. The high concentrations were obtained by mixing frozen powdered buffer with sodium caseinate in boiling liquid nitrogen, and allowing the mixtures to thaw and hydrate at 4 degrees C. The low-temperature G'-G'' crossover seen in temperature scans between 60 and 5 degrees C was thought to indicate gelation. Temperature scans from 5 to 90 degrees C revealed gradual decrease in G' followed by plateau values. In contrast, G'' decreased gradually and did not reach plateau values. Increase in hydrophobicity of the sodium caseinate or a decrease in the effective volume fraction of its aggregates may have contributed to these phenomena. The gelation and end of softening temperatures of the dispersions increased with the concentration of sodium caseinate. From an Eldridge-Ferry plot, the enthalpy of softening was estimated to be 29.6 kJ mol(-1). The results of this study should be useful for creating new products with high concentrations of sodium caseinate.

Serine Protease Zymography: Low-Cost, Rapid, and Highly Sensitive RAMA Casein Zymography.

Science.gov (United States)

Yasumitsu, Hidetaro

2017-01-01

To detect serine protease activity by zymography, casein and CBB stain have been used as a substrate and a detection procedure, respectively. Casein zymography has been using substrate concentration at 1 mg/mL and employing conventional CBB stain. Although ordinary casein zymography provides reproducible results, it has several disadvantages including time-consuming and relative low sensitivity. Improved casein zymography, RAMA casein zymography, is rapid and highly sensitive. RAMA casein zymography completes the detection process within 1 h after incubation and increases the sensitivity at least by tenfold. In addition to serine protease, the method also detects metalloprotease 7 (MMP7, Matrilysin) with high sensitivity.

The evolution of milk casein genes from tooth genes before the origin of mammals.

Science.gov (United States)

Kawasaki, Kazuhiko; Lafont, Anne-Gaelle; Sire, Jean-Yves

2011-07-01

Caseins are among cardinal proteins that evolved in the lineage leading to mammals. In milk, caseins and calcium phosphate (CaP) form a huge complex called casein micelle. By forming the micelle, milk maintains high CaP concentrations, which help altricial mammalian neonates to grow bone and teeth. Two types of caseins are known. Ca-sensitive caseins (α(s)- and β-caseins) bind Ca but precipitate at high Ca concentrations, whereas Ca-insensitive casein (κ-casein) does not usually interact with Ca but instead stabilizes the micelle. Thus, it is thought that these two types of caseins are both necessary for stable micelle formation. Both types of caseins show high substitution rates, which make it difficult to elucidate the evolution of caseins. Yet, recent studies have revealed that all casein genes belong to the secretory calcium-binding phosphoprotein (SCPP) gene family that arose by gene duplication. In the present study, we investigated exon-intron structures and phylogenetic distributions of casein and other SCPP genes, particularly the odontogenic ameloblast-associated (ODAM) gene, the SCPP-Pro-Gln-rich 1 (SCPPPQ1) gene, and the follicular dendritic cell secreted peptide (FDCSP) gene. The results suggest that contemporary Ca-sensitive casein genes arose from a putative common ancestor, which we refer to as CSN1/2. The six putative exons comprising CSN1/2 are all found in SCPPPQ1, although ODAM also shares four of these exons. By contrast, the five exons of the Ca-insensitive casein gene are all reminiscent of FDCSP. The phylogenetic distribution of these genes suggests that both SCPPPQ1 and FDCSP arose from ODAM. We thus argue that all casein genes evolved from ODAM via two different pathways; Ca-sensitive casein genes likely originated directly from SCPPPQ1, whereas the Ca-insensitive casein genes directly differentiated from FDCSP. Further, expression of ODAM, SCPPPQ1, and FDCSP was detected in dental tissues, supporting the idea that both types of caseins

Contribution to Casein Determination by UV Spectrophotometry

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Stefanescu Raluca

2017-12-01

Full Text Available In the present paper, the interaction between copper ions and proteins is presented, in order to elaborate a simple and rapid spectrophotometric assay of casein in milk. Under alkaline conditions, copper ions form the biuret complex with the proteins, which can be used in protein determination. Although very specific, the biuret method is less sensitive. Using insoluble copper phosphate, casein is able to extract copper ions, with which it forms the biuret complex, while either the complex or copper ions could be determined in the ultraviolet range. Indeed, an increased absorbance of biuret complex at 215 nm was found. Nevertheless, copper ions can be determined in UV as well, their concentration being proportional to that of casein. When used tetraglycine instead casein, mass spectrometric measurements at pH higher than 11 revealed the formation of complexes with many copper ions bound to each peptide bond-containing molecule. Nevertheless, on diluting the biuret solution the complex may dissociate leading to very complex UV spectra that should be further studied.

Formation of fibrous materials from dense caseinate dispersions

NARCIS (Netherlands)

Manski, J.M.; Goot, van der A.J.; Boom, R.M.

2007-01-01

Application of shear and cross-linking enzyme transglutaminase (Tgase) induced fibrous hierarchical structures in dense (30% w/w) calcium caseinate (Ca-caseinate) dispersions. Using Tgase was essential for the anisotropic structure formation. The fibrous materials showed anisotropy on both micro-

Casein Kinase 2 Is a Novel Regulator of the Human Organic Anion Transporting Polypeptide 1A2 (OATP1A2) Trafficking.

Science.gov (United States)

Chan, Ting; Cheung, Florence Shin Gee; Zheng, Jian; Lu, Xiaoxi; Zhu, Ling; Grewal, Thomas; Murray, Michael; Zhou, Fanfan

2016-01-04

Human organic anion transporting polypeptides (OATPs) mediate the influx of many important drugs into cells. Casein kinase 2 (CK2) is a critical protein kinase that phosphorylates >300 protein substrates and is dysregulated in a number of disease states. Among the CK2 substrates are several transporters, although whether this includes human OATPs has not been evaluated. The current study was undertaken to evaluate the regulation of human OATP1A2 by CK2. HEK-239T cells in which OATP1A2 was overexpressed were treated with CK2 specific inhibitors or transfected with CK2 specific siRNA, and the activity, expression, and subcellular trafficking of OATP1A2 was evaluated. CK2 inhibition decreased the uptake of the prototypic OATP1A2 substrate estrone-3-sulfate (E3S). Kinetic studies revealed that this was due to a decrease in the maximum velocity (Vmax) of E3S uptake, while the Michaelis constant was unchanged. The cell surface expression, but not the total cellular expression of OATP1A2, was impaired by CK2 inhibition and knockdown of the catalytic α-subunits of CK2. CK2 inhibition decreased the internalization of OATP1A2 via a clathrin-dependent pathway, decreased OATP1A2 recycling, and likely impaired OATP1A2 targeting to the cell surface. Consistent with these findings, CK2 inhibition also disrupted the colocalization of OATP1A2 and Rab GTPase (Rab)4-, Rab8-, and Rab9-positive endosomal and secretory vesicles. Taken together, CK2 has emerged as a novel regulator of the subcellular trafficking and stability of OATP1A2. Because OATP1A2 transports many molecules of physiological and pharmacological importance, the present data may inform drug selection in patients with diseases in which CK2 and OATP1A2 are dysregulated.

Gluten-free and casein-free diets in the therapy of autism.

Science.gov (United States)

Lange, Klaus W; Hauser, Joachim; Reissmann, Andreas

2015-11-01

The purpose of this study is to discuss the role of gluten-free and casein-free diets in the treatment of autism. In a recent UK survey, more than 80% of parents of children with autism spectrum disorder reported some kind of dietary intervention for their child (gluten-free and casein-free diet in 29%). When asked about the effects of the gluten-free and casein-free diet, 20-29% of the parents reported significant improvements on the autism spectrum disorder core dimensions. The findings of this study suggest additional effects of a gluten-free and casein-free diet on comorbid problems of autism such as gastrointestinal symptoms, concentration, and attention. The findings of another recent investigation suggested that age and certain urine compounds may predict the response of autism symptoms to a gluten-free and casein-free diet. Although these results need to be replicated, they highlight the importance of patient subgroup analysis. Intervention trials evaluating the effects of a gluten-free and casein-free diet on autistic symptoms have so far been contradictory and inconclusive. Most investigations assessing the efficacy of a gluten-free and casein-free diet in the treatment of autism are seriously flawed. The evidence to support the therapeutic value of this diet is limited and weak. A gluten-free and casein-free diet should only be administered if an allergy or intolerance to nutritional gluten or casein is diagnosed.

Genetic variations of β- and K-casein genes in Egyptian sheep breeds

African Journals Online (AJOL)

SARAH

2013-04-25

Apr 25, 2013 ... ABSTRACT. Objective: Casein genetic polymorphisms are important and well known due to their effects on quantitative traits and technological properties of milk manufacturing. The casein fraction of ruminant milk proteins consists of four caseins, namely αs1-, αs2-, β-and K-casein. At the DNA level, ...

Milk lacking α-casein leads to permanent reduction in body size in mice.

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Andreas F Kolb

Full Text Available The major physiological function of milk is the transport of amino acids, carbohydrates, lipids and minerals to mammalian offspring. Caseins, the major milk proteins, are secreted in the form of a micelle consisting of protein and calcium-phosphate.We have analysed the role of the milk protein α-casein by inactivating the corresponding gene in mice. Absence of α-casein protein significantly curtails secretion of other milk proteins and calcium-phosphate, suggesting a role for α-casein in the establishment of casein micelles. In contrast, secretion of albumin, which is not synthesized in the mammary epithelium, into milk is not reduced. The absence of α-casein also significantly inhibits transcription of the other casein genes. α-Casein deficiency severely delays pup growth during lactation and results in a life-long body size reduction compared to control animals, but has only transient effects on physical and behavioural development of the pups. The data support a critical role for α-casein in casein micelle assembly. The results also confirm lactation as a critical window of metabolic programming and suggest milk protein concentration as a decisive factor in determining adult body weight.

Milk Lacking α-Casein Leads to Permanent Reduction in Body Size in Mice

Science.gov (United States)

Kolb, Andreas F.; Huber, Reinhard C.; Lillico, Simon G.; Carlisle, Ailsa; Robinson, Claire J.; Neil, Claire; Petrie, Linda; Sorensen, Dorte B.; Olsson, I. Anna S.; Whitelaw, C. Bruce A.

2011-01-01

The major physiological function of milk is the transport of amino acids, carbohydrates, lipids and minerals to mammalian offspring. Caseins, the major milk proteins, are secreted in the form of a micelle consisting of protein and calcium-phosphate. We have analysed the role of the milk protein α-casein by inactivating the corresponding gene in mice. Absence of α-casein protein significantly curtails secretion of other milk proteins and calcium-phosphate, suggesting a role for α-casein in the establishment of casein micelles. In contrast, secretion of albumin, which is not synthesized in the mammary epithelium, into milk is not reduced. The absence of α-casein also significantly inhibits transcription of the other casein genes. α-Casein deficiency severely delays pup growth during lactation and results in a life-long body size reduction compared to control animals, but has only transient effects on physical and behavioural development of the pups. The data support a critical role for α-casein in casein micelle assembly. The results also confirm lactation as a critical window of metabolic programming and suggest milk protein concentration as a decisive factor in determining adult body weight. PMID:21789179

Application of a decanter centrifuge for casein fractionation on pilot scale

NARCIS (Netherlands)

Schubert, Thomas; Meric, Asutay; Boom, Remko; Hinrichs, Jörg; Atamer, Zeynep

2018-01-01

Individual casein fractions are of growing interest because of their multifunctional applications. The fractions of caseins (α_S-, β- & κ-) possess a wide range of bio- and techno-functional properties. Although various isolation and purification methods to obtain casein fractions

hermal decomposition of irradiated casein molecules

International Nuclear Information System (INIS)

Ali, M.A.; Elsayed, A.A.

1998-01-01

NON-Isothermal studies were carried out using the derivatograph where thermogravimetry (TG) and differential thermogravimetry (DTG) measurements were used to obtain the activation energies of the first and second reactions for casein (glyco-phospho-protein) decomposition before and after exposure to 1 Gy γ-rays and up to 40 x 1 04 μg Gy fast neutrons. 25C f was used as a source of fast neutrons, associated with γ-rays. 137 Cs source was used as pure γ-source. The activation energies for the first and second reactions for casein decomposition were found to be smaller at 400 μGy than that at lower and higher fast neutron doses. However, no change in activation energies was observed after γ-irradiation. it is concluded from the present study that destruction of casein molecules by low level fast neutron doses may lead to changes of shelf storage period of milk

Lactoferrin binding to transglutaminase cross-linked casein micelles

NARCIS (Netherlands)

Anema, S.G.; de Kruif, C.G.|info:eu-repo/dai/nl/073609609

2012-01-01

Casein micelles in skim milk were either untreated (untreated milk) or were cross-linked using transglutaminase (TGA-milk). Added lactoferrin (LF) bound to the casein micelles and followed Langmuir adsorption isotherms. The adsorption level was the same in both milks and decreased the micellar zeta

Quantification of Melanoidin Concentration in Sugar-Casein Systems

NARCIS (Netherlands)

Brands, C.M.J.; Wedzicha, B.L.; Boekel, van M.A.J.S.

2002-01-01

Melanoidins are the final, brown, high molecular weight products of the Maillard reaction. The aim of the present study was to determine the average molar extinction coefficients of melanoidins formed in heated glucose-casein and fructose-casein systems. The value of the extinction coefficient can

Horseradish peroxidase-catalyzed cross-linking of feruloylated arabinoxylans with β-casein

NARCIS (Netherlands)

Boeriu, C.G.; Oudgenoeg, G.; Spekking, W.T.J.; Berendsen, L.B.J.M.; Vancon, L.; Boumans, H.; Gruppen, H.; Berkel, W.J.H. van; Laane, C.; Voragen, A.G.J.

2004-01-01

Heterologous conjugates of wheat arabinoxylan and β-casein were prepared via enzymatic cross-linking, using sequential addition of the arabinoxylan to a mixture of β-casein, peroxidase, and hydrogen peroxide. The maximal formation of adducts between the β-casein and the feruloylated arabinoxylan was

Rapid method for measuring protease activity in milk using radiolabeled casein

International Nuclear Information System (INIS)

Christen, G.L.

1987-01-01

A rapid means to detect the presence of protease activity in raw milk could be useful in predicting keeping ability of products made from that milk. A 30-min assay has been developed and compared with three other methods of detecting protease. Casein, [methyl- 14 C]-methylated-alpha was purchased from a radioisotope supplier. Concentrations of substrate from 2 to 20 nCi gave counts per minute, which increased linearly when counted with the Charm analyzer. There was not a significant difference in counting times of 10, 20, or 30 min. A mixture of sodium acetate and acetic acid precipitated nonhydrolyzed substrate with an efficiency of 97%. Comparison of the [ 14 C] casein assay, a casein fluorescein isothiocyanate assay, trinitrobenzenesulfonic acid procedure, and the Hull procedure using protease from psychrotrophic bacteria revealed that the [ 14 C] casein and casein fluorescein isothiocyanate methods were roughly equivalent and that the radiometric procedure was 10 times more sensitive than the trinitrobenzenesulfonic acid assay. The radiometric procedure was approximately 10(4) times more sensitive than the Hull procedure. The [ 14 C] casein and casein fluorescein isothiocyanate methods were similar in time required, about 30 min, while the trinitrobenzenesulfonic acid assay and Hull method required about 1 h plus reagent preparation time. The [ 14 C] casein procedure was most expensive per test; the other three were cheaper and similar to each other in cost

Biliary lipid composition and gallstone formation in rabbits fed on soy protein, cholesterol, casein and modified casein.

OpenAIRE

Ozben, T

1989-01-01

In four experimental groups, rabbits were fed on diets containing soy beans, soy beans plus cholesterol (1%, w/w), casein and modified casein for 8 weeks. Biliary lipid levels, lithogenic-index values and the rate of gallstone formation were determined. The highest mean relative concentrations (mol%) of cholesterol and phospholipid were found in the soy bean + cholesterol group, and the highest mean relative bile acid concentration was in the soy bean group. The lowest mean relative cholester...

Aroma barrier properties of sodium caseinate-based films.

Science.gov (United States)

Fabra, Maria José; Hambleton, Alicia; Talens, Pau; Debeaufort, Fréderic; Chiralt, Amparo; Voilley, Andrée

2008-05-01

The mass transport of six different aroma compounds (ethyl acetate, ethyl butyrate, ethyl hexanoate, 2-hexanone, 1-hexanol, and cis-3-hexenol) through sodium caseinate-based films with different oleic acid (OA)/beeswax (BW) ratio has been studied. OA is less efficient than BW in reducing aroma permeability, which can be attributed to its greater polarity. Control film (without lipid) and films prepared with 0:100 OA/BW ratio show the lowest permeability. OA involves a decrease in aroma barrier properties of the sodium caseinate-based films due to its plasticization ability. Preferential sorption and diffusion occurs through OA instead of caseinate matrix and/or BW. The efficiency of sodium caseinate-based films to retain or limit aroma compound transfers depend on the affinity of the volatile compound to the films, which relates physicochemical interaction between volatile compound and film. Specific interactions (aroma compound-hydrocolloid and aroma compound-lipid) induce structural changes during mass transfer.

Cryo-transmission electron tomography of native casein micelles from bovine milk

Science.gov (United States)

Trejo, R.; Dokland, T.; Jurat-Fuentes, J.; Harte, F.

2013-01-01

Caseins are the principal protein components in milk and an important ingredient in the food industry. In liquid milk, caseins are found as micelles of casein proteins and colloidal calcium nanoclusters. Casein micelles were isolated from raw skim milk by size exclusion chromatography and suspended in milk protein-free serum produced by ultrafiltration (molecular weight cut-off of 3 kDa) of raw skim milk. The micelles were imaged by cryo-electron microscopy and subjected to tomographic reconstruction methods to visualize the 3-dimensional and internal organization of native casein micelles. This provided new insights into the internal architecture of the casein micelle that had not been apparent from prior cryo-transmission electron microscopy studies. This analysis demonstrated the presence of water-filled cavities (~20 to 30 nm in diameter), channels (diameter greater than ~5 nm), and several hundred high-density nanoclusters (6 to 12 nm in diameter) within the interior of the micelles. No spherical protein submicellar structures were observed. PMID:22118067

Influence of succinylation on physicochemical property of yak casein micelles.

Science.gov (United States)

Yang, Min; Yang, Jitao; Zhang, Yuan; Zhang, Weibing

2016-01-01

Succinylation is a chemical-modification method that affects the physicochemical characteristics and functional properties of proteins. This study assessed the influence of succinylation on the physicochemical properties of yak casein micelles. The results revealed that surface hydrophobicity indices decreased with succinylation. Additionally, denaturation temperature and denaturation enthalpy decreased with increasing succinylation level, except at 82%. The buffering properties of yak casein micelles were affected by succinylation. It was found that chemical modification contributed to a slight shift of the buffering peak towards a lower pH value and a markedly increase of the maximum buffering values of yak casein micelles at pH 4.5-6.0 and pH casein micellar hydration and whiteness values. The findings obtained from this study will provide the basic information on the physicochemical properties of native and succinylated yak casein micelles. Copyright © 2015 Elsevier Ltd. All rights reserved.

Casein mediated green synthesis and decoration of reduced graphene oxide

Science.gov (United States)

Maddinedi, Sireesh Babu; Mandal, Badal Kumar; Vankayala, Raviraj; Kalluru, Poliraju; Tammina, Sai Kumar; Kiran Kumar, H. A.

This research is mainly focusing on one-step biosynthesis of graphene from graphene oxide and its stabilization using naturally occurring milk protein, casein. The synthesis of casein reduced graphene oxide (CRGO) was completed within 7 h under reflux at 90 °C with the formation of few layered fine graphene nanosheets. UV-Vis, XRD, XPS analysis data revealed the reduction process of the graphene oxide. Results of FT-IR, HPLC and TEM analysis have shown that the ensuing material consists of graphene decorated with casein molecules. Aspartic acid and glutamic acid residue present in casein molecules are responsible for the reduction of graphene oxide.

Characterization of casein and poly-l-arginine multilayer films

Science.gov (United States)

Szyk-Warszyńska, Lilianna; Kilan, Katarzyna; Socha, Robert P.

2014-06-01

Thin films containing casein appear to be a promising material for coatings used in the medical area to promote biomineralization. alfa- and beta-casein and poly-L-arginine multilayer films were formed by the layer-by layer technique and their thickness and mass were analyzed by ellipsometry and quartz crystal microbalance with dissipation monitoring (QCM-D). We investigated the effect of the type of casein used for the film formation and of the polyethyleneimine anchoring layer on the thickness and mass of adsorbed films. The analysis of the mass of films during their post-treatment with the solutions of various ionic strength and pH provided the information concerning films stability, while the XPS elemental analysis confirmed binding of calcium ions by the casein embedded in the multilayers.

Sodium caseinate stabilized zein colloidal particles.

Science.gov (United States)

Patel, Ashok R; Bouwens, Elisabeth C M; Velikov, Krassimir P

2010-12-08

The present work deals with the preparation and stabilization of zein colloidal particles using sodium caseinate as electrosteric stabilizer. Colloidal particles with well-defined size range (120-150 nm) and negative surface potential (-29 to -47 mV) were obtained using a simple antisolvent precipitation method. Due to the presence of caseinate, the stabilized colloidal particles showed a shift of isoelectric point (IEP) from 6.0 to around pH 5.0 and thus prevent the aggregation of zein near its native IEP (pH 6.2). The particles also showed good stability to varying ionic strength (15 mM-1.5 M NaCl). Furthermore, stabilized particles retained the property of redispersibility after drying. In vitro protein hydrolysis study confirmed that the presence of caseinate did not alter the digestibility of zein. Such colloidal particles could potentially serve as all-natural delivery systems for bioactive molecules in food, pharmaceutical, and agricultural formulations.

Amino acid composition of casein isolated from the milks of different species

Energy Technology Data Exchange (ETDEWEB)

Lauer, B H; Baker, B E

1977-01-01

Casein was isolated from the milks of the following species: cow, horse, pig, reindeer, caribou, moose, harp seal, musk-ox, polar bear, dall sheep, and fin whale. The caseins were subjected to acid hydrolysis, the resultant amino acids were converted to their n-butyl-N-trifluoroacetyl esters, and the amino acid composition of the caseins was determined by gas chromatographic analysis of these esters. Notable among the results was the close similarity, with respect to amino acid composition, of reindeer and caribou caseins. The results of the amino acid analyses of the other caseins are presented and discussed.

Mechanism of Ca²⁺/calmodulin-dependent kinase II regulation of AMPA receptor gating

DEFF Research Database (Denmark)

Kristensen, Anders Skov; Jenkins, Meagan A; Banke, Tue G

2011-01-01

The function, trafficking and synaptic signaling of AMPA receptors are tightly regulated by phosphorylation. Ca(2+)/calmodulin-dependent kinase II (CaMKII) phosphorylates the GluA1 AMPA receptor subunit at Ser831 to increase single-channel conductance. We show that CaMKII increases the conductanc...

Slit and Netrin-1 guide cranial motor axon pathfinding via Rho-kinase, myosin light chain kinase and myosin II

Directory of Open Access Journals (Sweden)

Drescher Uwe

2010-06-01

Full Text Available Abstract Background In the developing hindbrain, cranial motor axon guidance depends on diffusible repellent factors produced by the floor plate. Our previous studies have suggested that candidate molecules for mediating this effect are Slits, Netrin-1 and Semaphorin3A (Sema3A. It is unknown to what extent these factors contribute to floor plate-derived chemorepulsion of motor axons, and the downstream signalling pathways are largely unclear. Results In this study, we have used a combination of in vitro and in vivo approaches to identify the components of floor plate chemorepulsion and their downstream signalling pathways. Using in vitro motor axon deflection assays, we demonstrate that Slits and Netrin-1, but not Sema3A, contribute to floor plate repulsion. We also find that the axon pathways of dorsally projecting branchiomotor neurons are disrupted in Netrin-1 mutant mice and in chick embryos expressing dominant-negative Unc5a receptors, indicating an in vivo role for Netrin-1. We further demonstrate that Slit and Netrin-1 signalling are mediated by Rho-kinase (ROCK and myosin light chain kinase (MLCK, which regulate myosin II activity, controlling actin retrograde flow in the growth cone. We show that MLCK, ROCK and myosin II are required for Slit and Netrin-1-mediated growth cone collapse of cranial motor axons. Inhibition of these molecules in explant cultures, or genetic manipulation of RhoA or myosin II function in vivo causes characteristic cranial motor axon pathfinding errors, including the inability to exit the midline, and loss of turning towards exit points. Conclusions Our findings suggest that both Slits and Netrin-1 contribute to floor plate-derived chemorepulsion of cranial motor axons. They further indicate that RhoA/ROCK, MLCK and myosin II are components of Slit and Netrin-1 signalling pathways, and suggest that these pathways are of key importance in cranial motor axon navigation.

Inhibition of hydroxyapatite growth by casein, a potential salivary phosphoprotein homologue.

Science.gov (United States)

Romero, Maria J R H; Nakashima, Syozi; Nikaido, Toru; Ichinose, Shizuko; Sadr, Alireza; Tagami, Junji

2015-08-01

Salivary phosphoproteins are essential in tooth mineral regulation but are often overlooked in vitro. This study aimed to evaluate the effect of casein, as a salivary phosphoprotein homologue, on the deposition and growth of hydroxyapatite (HA) on tooth surfaces. Hydroxyapatite growth was quantified using seeded crystal systems. Artificial saliva (AS) containing HA powder and 0, 10, 20, 50, or 100 μg ml(-1) of casein, or 100 μg ml(-1) of dephosphorylated casein (Dcasein), was incubated for 0-8 h at 37°C, pH 7.2. Calcium concentrations were measured using atomic absorption spectroscopy (AAS). Surface precipitation of HA on bovine enamel and dentine blocks, incubated in similar conditions for 7 d, was examined using field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) with selected area electron diffraction (SAED). Casein adsorption was assessed using modified Lowry assays and zeta-potential measurements. The AAS results revealed a concentration-dependent inhibition of calcium consumption. Hydroxyapatite precipitation occurred when no casein was present, whereas precipitation of HA was apparently completely inhibited in casein-containing groups. Adsorption data demonstrated increasingly negative zeta-potential with increased casein concentration and an affinity constant similar to proline-rich proteins with Langmuir modelling. Casein inhibited the deposition and growth of HA primarily through the binding of esterized phosphate to HA active sites, indicating its potential as a mineral-regulating salivary phosphoprotein homologue in vitro. © 2015 Eur J Oral Sci.

Digestibility of transglutaminase cross-linked caseinate versus native caseinate in an in vitro multicompartmental model simulating young child and adult gastrointestinal conditions

NARCIS (Netherlands)

Havenaar, R.; Jong, A. de; Koenen, M.E.; Bilsen, J. van; Janssen, A.M.; Labij, E.; Westerbeek, H.J.M.

2013-01-01

Aim of this study was to investigate the digestion of transglutaminase cross-linked caseinate (XLC) versus native caseinate (NC) in solution and in cheese spread under digestive conditions for adults and children mimicked in a gastrointestinal model. Samples were collected for gel electrophoresis

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor.

Science.gov (United States)

Ojeda, Norma B; Royals, Thomas P; Alexander, Barbara T

2013-04-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg(-1)·min(-1)) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats.

A global, myosin light chain kinase-dependent increase in myosin II contractility accompanies the metaphase-anaphase transition in sea urchin eggs.

Science.gov (United States)

Lucero, Amy; Stack, Christianna; Bresnick, Anne R; Shuster, Charles B

2006-09-01

Myosin II is the force-generating motor for cytokinesis, and although it is accepted that myosin contractility is greatest at the cell equator, the temporal and spatial cues that direct equatorial contractility are not known. Dividing sea urchin eggs were placed under compression to study myosin II-based contractile dynamics, and cells manipulated in this manner underwent an abrupt, global increase in cortical contractility concomitant with the metaphase-anaphase transition, followed by a brief relaxation and the onset of furrowing. Prefurrow cortical contractility both preceded and was independent of astral microtubule elongation, suggesting that the initial activation of myosin II preceded cleavage plane specification. The initial rise in contractility required myosin light chain kinase but not Rho-kinase, but both signaling pathways were required for successful cytokinesis. Last, mobilization of intracellular calcium during metaphase induced a contractile response, suggesting that calcium transients may be partially responsible for the timing of this initial contractile event. Together, these findings suggest that myosin II-based contractility is initiated at the metaphase-anaphase transition by Ca2+-dependent myosin light chain kinase (MLCK) activity and is maintained through cytokinesis by both MLCK- and Rho-dependent signaling. Moreover, the signals that initiate myosin II contractility respond to specific cell cycle transitions independently of the microtubule-dependent cleavage stimulus.

A Global, Myosin Light Chain Kinase-dependent Increase in Myosin II Contractility Accompanies the Metaphase–Anaphase Transition in Sea Urchin Eggs

Science.gov (United States)

Lucero, Amy; Stack, Christianna; Bresnick, Anne R.

2006-01-01

Myosin II is the force-generating motor for cytokinesis, and although it is accepted that myosin contractility is greatest at the cell equator, the temporal and spatial cues that direct equatorial contractility are not known. Dividing sea urchin eggs were placed under compression to study myosin II-based contractile dynamics, and cells manipulated in this manner underwent an abrupt, global increase in cortical contractility concomitant with the metaphase–anaphase transition, followed by a brief relaxation and the onset of furrowing. Prefurrow cortical contractility both preceded and was independent of astral microtubule elongation, suggesting that the initial activation of myosin II preceded cleavage plane specification. The initial rise in contractility required myosin light chain kinase but not Rho-kinase, but both signaling pathways were required for successful cytokinesis. Last, mobilization of intracellular calcium during metaphase induced a contractile response, suggesting that calcium transients may be partially responsible for the timing of this initial contractile event. Together, these findings suggest that myosin II-based contractility is initiated at the metaphase–anaphase transition by Ca2+-dependent myosin light chain kinase (MLCK) activity and is maintained through cytokinesis by both MLCK- and Rho-dependent signaling. Moreover, the signals that initiate myosin II contractility respond to specific cell cycle transitions independently of the microtubule-dependent cleavage stimulus. PMID:16837551

Structural investigations of sodium caseinate micelles in complex environments

International Nuclear Information System (INIS)

Huck Iriart, C.; Herrera, M.L.; Candal, R.; Oliveira, C.L.P.; Torriani, I.

2012-01-01

Full text: The most frequent destabilization mechanisms in Sodium Caseinate (NaCas) emulsions are creaming and flocculation. Coarse or fine emulsions with low protein con- tent destabilize mainly by creaming. If migration mechanism is suppressed, flocculation may become the main mechanism of destabilization. Small Angle X-Ray Scattering (SAXS) technique was applied to investigate sodium caseinate micelles structure in different environments. As many natural products, Sodium Caseinate samples have large polydisperse size distribution. The experimental data was analyzed using advanced modeling approaches. The Form Factor for the Caseinate micelle subunits was described by an ellipsoidal core shell model and the structure factor was split into two contributions, one corresponding to the particle-particle interactions and another one for the long range correlation of the subunits in the supramolecular structure. For the first term the hard sphere structure factor using the Percus-Yevick approximation for closure relation was used and for the second term a fractal model was applied. Three concentrations of sodium Caseinate (2, 5 and 7.5 %wt.) were measured in pure water, sugar solutions (20 %wt.) and in three different lipid phase emulsions containing 10 %wt. sunflower seed, olive and fish oils. Data analysis provided an average casein subunit radius of 4 nm, an average distance between the subunits of around 20nm and a fractal dimension value of around 3 for all samples. As indicated by the values of the correlation lengths for the set of studied samples, the casein aggregation is strongly affected by simple sugar additions and it is enhanced by emulsion droplets hydrophobic interaction. As will be presented, these nanoscale structural results provided by scattering experiments is consistent with macroscopic results obtained from several techniques, providing a new understanding of NaCas emulsions. (author)

Structural investigations of sodium caseinate micelles in complex environments

Energy Technology Data Exchange (ETDEWEB)

Huck Iriart, C.; Herrera, M.L.; Candal, R. [Universidad de Buenos Aires, Buenos Aires (Argentina); Oliveira, C.L.P. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil); Torriani, I. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)

2012-07-01

Full text: The most frequent destabilization mechanisms in Sodium Caseinate (NaCas) emulsions are creaming and flocculation. Coarse or fine emulsions with low protein con- tent destabilize mainly by creaming. If migration mechanism is suppressed, flocculation may become the main mechanism of destabilization. Small Angle X-Ray Scattering (SAXS) technique was applied to investigate sodium caseinate micelles structure in different environments. As many natural products, Sodium Caseinate samples have large polydisperse size distribution. The experimental data was analyzed using advanced modeling approaches. The Form Factor for the Caseinate micelle subunits was described by an ellipsoidal core shell model and the structure factor was split into two contributions, one corresponding to the particle-particle interactions and another one for the long range correlation of the subunits in the supramolecular structure. For the first term the hard sphere structure factor using the Percus-Yevick approximation for closure relation was used and for the second term a fractal model was applied. Three concentrations of sodium Caseinate (2, 5 and 7.5 %wt.) were measured in pure water, sugar solutions (20 %wt.) and in three different lipid phase emulsions containing 10 %wt. sunflower seed, olive and fish oils. Data analysis provided an average casein subunit radius of 4 nm, an average distance between the subunits of around 20nm and a fractal dimension value of around 3 for all samples. As indicated by the values of the correlation lengths for the set of studied samples, the casein aggregation is strongly affected by simple sugar additions and it is enhanced by emulsion droplets hydrophobic interaction. As will be presented, these nanoscale structural results provided by scattering experiments is consistent with macroscopic results obtained from several techniques, providing a new understanding of NaCas emulsions. (author)

Binding of vitamin A by casein micelles in commercial skim milk

Science.gov (United States)

Mohan, M. S.; Jurat-Fuentes, J. L.; Harte, F.

2015-01-01

Recent studies have shown that reassembled micelles formed by caseinates and purified casein fractions (αs- and β-casein) bind to hydrophobic compounds, including curcumin, docosahexaenoic acid, and vitamin D. However, limited research has been done on the binding of hydrophobic compounds by unmodified casein micelles in skim milk. In the present study, we investigated the ability of casein micelles in commercial skim milk to associate with vitamin A (retinyl palmitate), a fat-soluble vitamin commonly used to fortify milk. Milk protein fractions from different commercially available skim milk samples subjected to different processing treatments, including pasteurized, ultrapasteurized, organic pasteurized, and organic ultrapasteurized milks, were separated by fast protein liquid chromatography. The fractions within each peak were combined and freeze-dried. Sodium dodecyl sulfate-PAGE with silver staining was used to identify the proteins present in each of the fractions. The skim milk samples and fractions were extracted for retinyl palmitate and quantified against a standard using normal phase-HPLC. Retinyl palmitate was found to associate with the fraction of skim milk containing caseins, whereas the other proteins (BSA, β-lactoglobulin, α-lactalbumin) did not show any binding. The retinyl palmitate content in the various samples ranged from 1.59 to 2.48 μg of retinyl palmitate per mL of milk. The casein fractions contained between 14 and 40% of total retinyl palmitate in the various milks tested. The variation in the retention of vitamin A by caseins was probably explained by differences in the processing of different milk samples, including thermal treatment, the form of vitamin A emulsion used for fortification, and the point of fortification during processing. Unmodified casein micelles have a strong intrinsic affinity toward the binding of vitamin A used to fortify commercially available skim milks. PMID:23261375

Cloning and sequencing of the gene for human β-casein

International Nuclear Information System (INIS)

Loennerdal, B.; Bergstroem, S.; Andersson, Y.; Hialmarsson, K.; Sundgyist, A.; Hernell, O.

1990-01-01

Human β-casein is a major protein in human milk. This protein is part of the casein micelle and has been suggested to have several physiological functions in the newborn. Since there is limited information on βcasein and the factors that affect its concentration in human milk, the authors have isolated and sequenced the gene for this protein. A human mammary gland cDNA library (Clontech) in gt 11 was screened by plaque hy-hybridization using a 42-mer synthetic 32 p-labelled oligo-nucleotide. Positive clones were identified and isolated, DNA was prepared and the gene isolated by cleavage with EcoR1. Following subcloning (PUC18), restriction mapping and Southern blotting, DNA for sequencing was prepared. The gene was sequenced by the dideoxy method. Human β-casein has 212 amino acids and the amino acid sequence deducted from the nucleotide sequence is to 91% identical to the published sequence for human β-casein show a high degree of conservation at the leader peptide and the highly phosphorylated sequences, but also deletions and divergence at several positions. These results provide insight into the structure of the human β-casein gene and will facilitate studies on factors affecting its expression

Topography of Protein Kinase C βII in Benign and Malignant Melanocytic Lesions.

Science.gov (United States)

Krasagakis, Konstanin; Tsentelierou, Eleftheria; Chlouverakis, Gregory; Stathopoulos, Efstathios N

2017-09-01

Protein kinase C βII promotes melanogenesis and affects proliferation of melanocytic cells but is frequently absent or decreased in melanoma cells in vitro. To investigate PKC-βII expression and spatial distribution within a lesion in various benign and malignant melanocytic proliferations. Expression of PKC-βII was semiquantitatively assessed in the various existing compartments (intraepidermal [not nested], junctional [nested], and dermal) of benign (n = 43) and malignant (n = 28) melanocytic lesions by immunohistochemistry. Melanocytes in the basal layer of normal skin or in lentigo simplex stained strongly for PKC-βII. Common nevi lacked completely PKC-βII. All other lesions expressed variably PKC-βII, with cutaneous melanoma metastases displaying the lowest rate of positivity (14%). In the topographical analysis within a lesion, PKC-βII expression was largely retained in the intraepidermal and junctional part of all other lesions (dysplastic nevus, lentigo maligna, and melanoma). Reduced expression of PKC-βII was found in the dermal component of benign and malignant lesions ( P = .041 vs intraepidermal). PKC-βII expression in the various compartments did not differ significantly between benign and malignant lesions. The current study revealed a significant correlation between PKC-βII expression and spatial localization of melanocytes, with the lowest expression found in the dermal compartment and the highest in the epidermal compartment.

Kappa-casein gene polymorphism in Holstein and Iranian native ...

African Journals Online (AJOL)

Caseins amount to nearly 80% of the protein output in cow milk. Caseins are biologically important proteins and they are also a raw material for the cheese ... BB genotype could be a good factor for increase of fat and protein content of milk.

Structural characterization of casein micelles: shape changes during film formation

International Nuclear Information System (INIS)

Gebhardt, R; Kulozik, U; Vendrely, C

2011-01-01

The objective of this study was to determine the effect of size-fractionation by centrifugation on the film structure of casein micelles. Fractionated casein micelles in solution were asymmetrically distributed with a small distribution width as measured by dynamic light scattering. Films prepared from the size-fractionated samples showed a smooth surface in optical microscopy images and a homogeneous microstructure in atomic force micrographs. The nano- and microstructure of casein films was probed by micro-beam grazing incidence small angle x-ray scattering (μGISAXS). Compared to the solution measurements, the sizes determined in the film were larger and broadly distributed. The measured GISAXS patterns clearly deviate from those simulated for a sphere and suggest a deformation of the casein micelles in the film. (paper)

Alginate/sodium caseinate aqueous-core capsules: a pH-responsive matrix.

Science.gov (United States)

Ben Messaoud, Ghazi; Sánchez-González, Laura; Jacquot, Adrien; Probst, Laurent; Desobry, Stéphane

2015-02-15

Alginate capsules have several applications. Their functionality depends considerably on their permeability, chemical and mechanical stability. Consequently, the creation of composite system by addition of further components is expected to control mechanical and release properties of alginate capsules. Alginate and alginate-sodium caseinate composite liquid-core capsules were prepared by a simple extrusion. The influence of the preparation pH and sodium caseinate concentration on capsules physico-chemical properties was investigated. Results showed that sodium caseinate influenced significantly capsules properties. As regards to the membrane mechanical stability, composite capsules prepared at pH below the isoelectric point of sodium caseinate exhibited the highest surface Young's modulus, increasing with protein content, explained by potential electrostatic interactions between sodium caseinate amino-groups and alginate carboxylic group. The kinetic of cochineal red A release changed significantly for composite capsules and showed a pH-responsive release. Sodium caseinate-dye mixture studied by absorbance and fluorescence spectroscopy confirmed complex formation at pH 2 by electrostatic interactions between sodium caseinate tryptophan residues and cochineal red sulfonate-groups. Consequently, the release mechanism was explained by membrane adsorption process. This global approach is useful to control release mechanism from macro and micro-capsules by incorporating guest molecules which can interact with the entrapped molecule under specific conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

Casein Aggregates Built Step-by-Step on Charged Polyelectrolyte Film Surfaces Are Calcium Phosphate-cemented*

Science.gov (United States)

Nagy, Krisztina; Pilbat, Ana-Maria; Groma, Géza; Szalontai, Balázs; Cuisinier, Frédéric J. G.

2010-01-01

The possible mechanism of casein aggregation and micelle buildup was studied in a new approach by letting α-casein adsorb from low concentration (0.1 mg·ml−1) solutions onto the charged surfaces of polyelectrolyte films. It was found that α-casein could adsorb onto both positively and negatively charged surfaces. However, only when its negative phosphoseryl clusters remained free, i.e. when it adsorbed onto a negative surface, could calcium phosphate (CaP) nanoclusters bind to the casein molecules. Once the CaP clusters were in place, step-by-step building of multilayered casein architectures became possible. The presence of CaP was essential; neither Ca2+ nor phosphate could alone facilitate casein aggregation. Thus, it seems that CaP is the organizing motive in the casein micelle formation. Atomic force microscopy revealed that even a single adsorbed casein layer was composed of very small (in the range of tens of nanometers) spherical forms. The stiffness of the adsorbed casein layer largely increased in the presence of CaP. On this basis, we can imagine that casein micelles emerge according to the following scheme. The amphipathic casein monomers aggregate into oligomers via hydrophobic interactions even in the absence of CaP. Full scale, CaP-carrying micelles could materialize by interlocking these casein oligomers with CaP nanoclusters. Such a mechanism would not contradict former experimental results and could offer a synthesis between the submicelle and the block copolymer models of casein micelles. PMID:20921229

Caseoperoxidase, mixed β-casein-SDS-hemin-imidazole complex: a nano artificial enzyme.

Science.gov (United States)

Moosavi-Movahedi, Zainab; Gharibi, Hussein; Hadi-Alijanvand, Hamid; Akbarzadeh, Mohammad; Esmaili, Mansoore; Atri, Maliheh S; Sefidbakht, Yahya; Bohlooli, Mousa; Nazari, Khodadad; Javadian, Soheila; Hong, Jun; Saboury, Ali A; Sheibani, Nader; Moosavi-Movahedi, Ali A

2015-01-01

A novel peroxidase-like artificial enzyme, named "caseoperoxidase", was biomimetically designed using a nano artificial amino acid apo-protein hydrophobic pocket. This four-component nano artificial enzyme containing heme-imidazole-β-casein-SDS exhibited high activity growth and k(cat) performance toward the native horseradish peroxidase demonstrated by the steady state kinetics using UV-vis spectrophotometry. The hydrophobicity and secondary structure of the caseoperoxidase were studied by ANS fluorescence and circular dichroism spectroscopy. Camel β-casein (Cβ-casein) was selected as an appropriate apo-protein for the heme active site because of its innate flexibility and exalted hydrophobicity. This selection was confirmed by homology modeling method. Heme docking into the newly obtained Cβ-casein structure indicated one heme was mainly incorporated with Cβ-casein. The presence of a main electrostatic site for the active site in the Cβ-casein was also confirmed by experimental methods through Wyman binding potential and isothermal titration calorimetry. The existence of Cβ-casein protein in this biocatalyst lowered the suicide inactivation and provided a suitable protective role for the heme active-site. Additional experiments confirmed the retention of caseoperoxidase structure and function as an artificial enzyme.

Creatine Kinase Activity in Patients with Diabetes Mellitus Type I and Type II

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Adlija Jevrić-Čaušević

2006-08-01

Full Text Available Diabetes mellitus can be looked upon as an array of diseases, all of which exhibit common symptoms. While pathogenesis of IDDM (insulin dependant diabetes mellitus is well understood, the same is not true for diabetes mellitus type II. In the latter case, relative contribution of the two factors (insulin resistance or decreased insulin secretion varies individually, being highly increased in peripheral tissues and strictly dependant on insulin for glucose uptake. Moreover, in patients with diabetes mellitus type II, disbalance at the level of regulation of glucose metabolism as well as lipid metabolism has been noted in skeletal muscles. It is normal to assume that in this type of diabetes, these changes are reflected at the level of total activity of enzyme creatine kinase. This experimental work was performed on a group of 80 regular patients of Sarajevo General Hospital. Forty of those patients were classified as patients with diabetes type I and forty as patients with diabetes type II. Each group of patients was carefully chosen and constituted of equal number of males and females. The same was applied for adequate controls. Concentration of glucose was determined for each patient with GOD method, while activity of creatine kinase was determined with CK-NAC activated kit. Statistical analysis of the results was performed with SPSS software for Windows. Obtained results point out highly expressed differences in enzyme activity between two populations examined. Changes in enzyme activity are more expressed in patients with diabetes type II. Positive correlation between concentration of glucose and serum activity of the enzyme is seen in both categories of diabetic patients which is not the case for the patients in control group. At the same time, correlation between age and type of diabetes does exist . This is not followed at the level of enzyme activity or concentration of glucose.

Thermal decomposition of irradiated casein molecules

Energy Technology Data Exchange (ETDEWEB)

Aly, M A; Elsayed, A A [Biophysics Dept., Faculty of Science, Cairo University, Giza (Egypt)

1997-12-31

Non-isothermal studies were carried out using the derivatograph where thermogravimetry (TG), and differential thermogravimetry (DTG) measurements were used to obtain the activation energies of the first and second reactions for casein decomposition before and after exposure to gamma rays and fast neutrons. Cf- 252 was used as a source of fast neutrons associated with gamma rays. TG and DTG patterns were also recorded for casein samples before and after irradiation with 1 Gy gamma-rays of 0.662 MeV from Cs - 137. However, no change in a activation energies were observed after exposure to gamma-irradiation. On the other hand, the activation energies for first and second reactions were found to be smaller at 0.4 m Gy than that at lower and higher neutron doses. However, no change in activation energies was observed after {gamma} irradiation. It is concluded from the present study that destruction of casein molecules by low level fast neutron doses may lead to changes of shelf storage period milk. 3 figs., 1 tab.

Effect of microfluidization on casein micelle size of bovine milk

Science.gov (United States)

Sinaga, H.; Deeth, H.; Bhandari, B.

2018-02-01

The properties of milk are likely to be dependent on the casein micelle size, and various processing technologies produce particular change in the average size of casein micelles. The main objective of this study was to manipulate casein micelle size by subjecting milk to microfluidizer. The experiment was performed as a complete block randomised design with three replications. The sample was passed through the microfluidizer at the set pressure of 83, 97, 112 and 126 MPa for one, two, three, four, five and six cycles, except for the 112 MPa. The results showed that microfluidized milk has smaller size by 3% with pressure up to 126 MPa. However, at each pressure, no further reduction was observed after increasing the passed up to 6 cycles. Although the average casein micelle size was similar, elevating pressure resulted in narrower size distribution. In contrast, increasing the number of cycles had little effect on casein micelle distribution. The finding from this study can be applied for future work to characterize the fundamental and functional properties of the treated milk.

The bioactive effects of casein proteins on enteroendocrine cell health, proliferation and incretin hormone secretion.

Science.gov (United States)

Gillespie, Anna L; Green, Brian D

2016-11-15

Previous studies suggest that casein exerts various anti-diabetic effects. However, it is not known which casein proteins are bioactive, nor their effects on enteroendocrine cells. This study evaluated the effects of intact whole casein, intact individual proteins (alpha, beta and kappa casein) and hydrolysates on an enteroendocrine cell line. High content analysis accurately monitored changes in cell health and intracellular glucagon-like peptide-1 (GLP-1) content. Cheese ripening duration and GLP-1 secretory responses were also considered. Beta casein significantly stimulated enteroendocrine cell proliferation and all caseins were potent GLP-1 secretagogues (except kappa casein). Interestingly the GLP-1 secretory activity was almost always lost or significantly reduced upon hydrolysis with proteolytic enzymes. Only pepsin-derived beta casein hydrolysates had significantly increased potency compared with the intact protein, but this was diminished with prolonged hydrolysis. In conclusion casein proteins are not detrimental to enteroendocrine cells, and alpha and beta casein are particularly beneficial stimulating proliferation and GLP-1 secretion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Conditioned taste aversion and Ca/calmodulin-dependent kinase II in the parabrachial nucleus of rats

Czech Academy of Sciences Publication Activity Database

Křivánek, Jiří

2001-01-01

Roč. 76, č. 1 (2001), s. 46-56 ISSN 1074-7427 R&D Projects: GA AV ČR IAA7011706 Institutional research plan: CEZ:AV0Z5011922 Keywords : calcium/calmodulin-dependent kinase II * conditioned taste aversion * parabrachial nucleus of rat Subject RIV: FH - Neurology Impact factor: 1.830, year: 2001

Switch control pocket inhibitors of p38-MAP kinase. Durable type II inhibitors that do not require binding into the canonical ATP hinge region.

Science.gov (United States)

Ahn, Yu Mi; Clare, Michael; Ensinger, Carol L; Hood, Molly M; Lord, John W; Lu, Wei-Ping; Miller, David F; Patt, William C; Smith, Bryan D; Vogeti, Lakshminarayana; Kaufman, Michael D; Petillo, Peter A; Wise, Scott C; Abendroth, Jan; Chun, Lawrence; Clark, Robin; Feese, Michael; Kim, Hidong; Stewart, Lance; Flynn, Daniel L

2010-10-01

Switch control pocket inhibitors of p38-alpha kinase are described. Durable type II inhibitors were designed which bind to arginines (Arg67 or Arg70) that function as key residues for mediating phospho-threonine 180 dependant conformational fluxing of p38-alpha from an inactive type II state to an active type I state. Binding to Arg70 in particular led to potent inhibitors, exemplified by DP-802, which also exhibited high kinase selectivity. Binding to Arg70 obviated the requirement for binding into the ATP Hinge region. X-ray crystallography revealed that DP-802 and analogs induce an enhanced type II conformation upon binding to either the unphosphorylated or the doubly phosphorylated form of p38-alpha kinase. Copyright © 2010 Elsevier Ltd. All rights reserved.

Chemical synthesis and structure elucidation of bovine κ-casein (1-44)

International Nuclear Information System (INIS)

Bansal, Paramjit S.; Grieve, Paul A.; Marschke, Ronald J.; Daly, Norelle L.; McGhie, Emily; Craik, David J.; Alewood, Paul F.

2006-01-01

The caseins (α s1 , α s2 , β, and κ) are phosphoproteins present in bovine milk that have been studied for over a century and whose structures remain obscure. Here we describe the chemical synthesis and structure elucidation of the N-terminal segment (1-44) of bovine κ-casein, the protein which maintains the micellar structure of the caseins. κ-Casein (1-44) was synthesised by highly optimised Boc solid-phase peptide chemistry and characterised by mass spectrometry. Structure elucidation was carried out by circular dichroism and nuclear magnetic resonance spectroscopy. CD analysis demonstrated that the segment was ill defined in aqueous medium but in 30% trifluoroethanol it exhibited considerable helical structure. Further, NMR analysis showed the presence of a helical segment containing 26 residues which extends from Pro 8 to Arg 34 . This is First report which demonstrates extensive secondary structure within the casein class of proteins

Casein kinase 1-Like 3 is required for abscisic acid regulation of ...

African Journals Online (AJOL)

Jane

2011-10-10

Oct 10, 2011 ... root growth compared with ckl3 plants under different ABA concentration treatment. Also, compared with wild-type plants, the expressions of the ABA and abiotic stress-responsive ... CK1 isoforms show that the interaction between CK1 and ..... kinase I, in root development and plant hormone sensitivity.

Depletion interaction of casein micelles and an exocellular polysaccharide

Science.gov (United States)

Tuinier, R.; Ten Grotenhuis, E.; Holt, C.; Timmins, P. A.; de Kruif, C. G.

1999-07-01

Casein micelles become mutually attractive when an exocellular polysaccharide produced by Lactococcus lactis subsp. cremoris NIZO B40 (hereafter called EPS) is added to skim milk. The attraction can be explained as a depletion interaction between the casein micelles induced by the nonadsorbing EPS. We used three scattering techniques (small-angle neutron scattering, turbidity measurements, and dynamic light scattering) to measure the attraction. In order to connect the theory of depletion interaction with experiment, we calculated structure factors of hard spheres interacting by a depletion pair potential. Theoretical predictions and all the experiments showed that casein micelles became more attractive upon increasing the EPS concentration.

Calmodulin kinase II interacts with the dopamine transporter C terminus to regulate amphetamine-induced reverse transport

DEFF Research Database (Denmark)

Fog, Jacob U; Khoshbouei, Habibeh; Holy, Marion

2006-01-01

Efflux of dopamine through the dopamine transporter (DAT) is critical for the psychostimulatory properties of amphetamines, but the underlying mechanism is unclear. Here we show that Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) plays a key role in this efflux. CaMKIIalpha bound to the d...

The increasing of enamel calcium level after casein phosphopeptideamorphous calcium phosphate covering

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Widyasri Prananingrum

2012-06-01

Full Text Available Background: Caries process is characterized by the presence of demineralization. Demineralization is caused by organic acids as a result of carbohydrate substrate fermentation. Remineralization is a natural repair process for non-cavitated lesions. Remineralization occurs if there are Ca2+ and PO43- ions in sufficient quantities. Casein-amorphous calcium phosphate phosphopeptide (CPP-ACP is a paste material containing milk protein (casein, that actually contains minerals, such as calcium and phosphate. The casein ability to stabilize calcium phosphate and enhance mineral solubility and bioavailability confers upon CPP potential to be biological delivery vehicles for calcium and phosphate. Purpose: The aim of this study was to determine the calcium levels in tooth enamel after being covered with CPP-ACP 2 times a day for 3, 14 and 28 days. Methods: Sample were bovine incisors of 3 year old cows divided into 4 groups, namely group I as control group, group II, III and IV as treatment groups covered with CPP-ACP 2 times a day. All of those teeth were then immersed in artificial saliva. Group II was immersed for 3 days, while group III was immersed for 14 days, and group IV was immersed for 28 days. One drop of CPP-ACP was used to cover the entire labial surface of teeth. The measurement of the calcium levels was then conducted by using titration method. All data were analyzed by One- Way ANOVA test with 5% degree of confidence. Results: The results showed significant difference of the calcium levels in tooth enamel of those groups after covered with CPP-ACP 2 times a day for 3, 14 and 28 days (p = 0.001. There is also significant difference of the calcium levels in tooth enamel of those treatment groups and the control group (p = 0.001. Conclusion: The calcium levels of tooth enamel are increased after covered with CPP-ACP 2 times a day for 3, 14 and 28 days.Latar belakang: Proses terjadinya karies gigi ditandai oleh adanya demineralisasi

The presence of the casein kinase II phosphorylation sites of Vpu enhances the CD4+ T cell loss caused by the simian-human immunodeficiency virus SHIVKU-lbMC33 in pig-tailed macaques

International Nuclear Information System (INIS)

Singh, Dinesh K.; Griffin, Darcy M.; Pacyniak, Erik; Jackson, Mollie; Werle, Michael J.; Wisdom, Bo; Sun, Francis; Hout, David R.; Pinson, David M.; Gunderson, Robert S.; Powers, Michael F.; Wong, Scott W.; Stephens, Edward B.

2003-01-01

reversion of the glycine residues in the vpu sequences isolated from this macaque. These results contrast with those from four macaques inoculated with the parental pathogenic SHIV KU-1bMC33 , all of which developed severe CD4 + T cell loss within 1 month after inoculation. Taken together, these results indicate that casein kinase II phosphorylation sites of Vpu contributes to the pathogenicity of the SHIV KU-1bMC33 and suggest that the SHIV KU-1bMC33 /pig-tailed macaque model will be useful in analyzing amino acids/domains of Vpu that contribute to the pathogenesis of HIV-1

Lipopolysaccharide inhibits colonic biotin uptake via interference with membrane expression of its transporter: a role for a casein kinase 2-mediated pathway.

Science.gov (United States)

Lakhan, Ram; Said, Hamid M

2017-04-01

Biotin (vitamin B7), an essential micronutrient for normal cellular functions, is obtained from both dietary sources as well as gut microbiota. Absorption of biotin in both the small and large intestine is via a carrier-mediated process that involves the sodium-dependent multivitamin transporter (SMVT). Although different physiological and molecular aspects of intestinal biotin uptake have been delineated, nothing is known about the effect of LPS on the process. We addressed this issue using in vitro (human colonic epithelial NCM460 cells) and in vivo (mice) models of LPS exposure. Treating NCM460 cells with LPS was found to lead to a significant inhibition in carrier-mediated biotin uptake. Similarly, administration of LPS to mice led to a significant inhibition in biotin uptake by native colonic tissue. Although no changes in total cellular SMVT protein and mRNA levels were observed, LPS caused a decrease in the fraction of SMVT expressed at the cell surface. A role for casein kinase 2 (CK2) (whose activity was also inhibited by LPS) in mediating the endotoxin effects on biotin uptake and on membrane expression of SMVT was suggested by findings that specific inhibitors of CK2, as well as mutating the putative CK2 phosphorylation site (Thr 78 Ala) in the SMVT protein, led to inhibition in biotin uptake and membrane expression of SMVT. This study shows for the first time that LPS inhibits colonic biotin uptake via decreasing membrane expression of its transporter and that these effects likely involve a CK2-mediated pathway.

Identification and analysis of a novel protein-tyrosine kinase from bovine thymus

International Nuclear Information System (INIS)

Zioncheck, T.F.; Harrison, M.L.; Geahlen, R.L.

1986-01-01

A cytosolic protein-tyrosine kinase has been identified and purified to near homogeneity from calf thymus by using the phosphorylation of the tyrosine-containing peptide angiotensin I as an assay. Specific peptide phosphorylating activity was enhanced by carrying out the assay at high ionic strength (2M NaCl). The inclusion of NaCl at this concentration acts to stimulate endogenous protein-tyrosine kinase activity while simultaneously inhibiting other endogenous kinases. The purification procedure involved extraction of the enzyme from calf-thymus and sequential chromatography on columns of DEAE-cellulose, heparin-agarose, casein-sepharose, butylagarose, and Sephadex G-75. Analysis of the most highly purified preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single Coomassie blue-stained band of 41 KDa. This molecular weight was consistent with results obtained from gel filtration, indicating that the enzyme exists as a monomer. The enzyme has also been found to catalyze an autophosphorylation reaction. Incubation of the enzyme with Mn 2+ and [γ- 32 P]ATP led to its modification on a tyrosine residue. Phosphopeptide mapping experiments indicated that the 41 KDa kinase was distinct from p56, the major membrane-associated protein-tyrosine kinase in T lymphocytes

Stromal serine protein kinase activity in spinach chloroplasts

International Nuclear Information System (INIS)

Cortez, N.; Lucero, H.A.; Vallejos, R.H.

1987-01-01

At least twelve 32 P-labeled stromal proteins were detected by electrophoresis under denaturing conditions when intact chloroplasts were incubated with 32 Pi, in the light but only three were detected in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) or in the dark. Incubation of isolated stroma with [gamma- 32 P]ATP resulted in the preferential phosphorylation of one of them, a 70-kDa polypeptide, in serine residues. Thylakoid membranes in the dark promoted the phosphorylation of two additional stromal polypeptides of 55 and 40 kDa. Illumination during the phosphorylation of stroma in the presence of thylakoids stimulated severalfold the labeling of the 40-kDa polypeptide but not when DCMU was added. The protein kinase activity present in isolated stroma phosphorylated exogenous substrates like histone III, phosvitin, histone II, and casein with specific activities of 3, 1.8, 0.7, and 0.2 pmol X mg-1 X min-1. Histone III polypeptides were phosphorylated differently by stroma and by thylakoids in the dark. Moreover, histone III phosphorylated by thylakoids in the dark yielded a pattern of phosphopeptides after V8 protease treatment that was different from the pattern obtained when histone III was phosphorylated by stroma

Quantitative determination of casein genetic variants in goat milk: Application in Girgentana dairy goat breed.

Science.gov (United States)

Montalbano, Maria; Segreto, Roberta; Di Gerlando, Rosalia; Mastrangelo, Salvatore; Sardina, Maria Teresa

2016-02-01

The study was conducted to develop a high-performance liquid chromatographic (HPLC) method to quantify casein genetic variants (αs2-, β-, and κ-casein) in milk of homozygous individuals of Girgentana goat breed. For calibration experiments, pure genetic variants were extracted from individual milk samples of animals with known genotypes. The described HPLC approach was precise, accurate and highly suitable for quantification of goat casein genetic variants of homozygous individuals. The amount of each casein per allele was: αs2-casein A = 2.9 ± 0.8 g/L and F = 1.8 ± 0.4 g/L; β-casein C = 3.0 ± 0.8 g/L and C1 = 2.0 ± 0.7 g/L and κ-casein A = 1.6 ± 0.3 g/L and B = 1.1 ± 0.2 g/L. A good correlation was found between the quantities of αs2-casein genetic variants A and F, and β-casein C and C1 with other previously described method. The main important result was obtained for κ-casein because, till now, no data were available on quantification of single genetic variants for this protein. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antiproliferative activity of olomoucine II, a novel 2,6,9-trisubstituted purine cyclin-dependent kinase inhibitor

Czech Academy of Sciences Publication Activity Database

Kryštof, Vladimír; McNae, I. W.; Walkinshaw, M. D.; Fischer, P.M.; Müller, P.; Vojtešek, B.; Orság, Martin; Havlíček, Libor; Strnad, Miroslav

2005-01-01

Roč. 62, č. 15 (2005), s. 1763-1771 ISSN 1420-682X R&D Projects: GA ČR GP204/03/D231 Institutional research plan: CEZ:AV0Z50380511 Keywords : olomoucine II * roscovitine * cyclin-dependent kinase inhibitor Subject RIV: CE - Biochemistry Impact factor: 4.582, year: 2005

Purification and characterization of a thylakoid protein kinase

International Nuclear Information System (INIS)

Coughlan, S.J.; Hind, G.

1986-01-01

Control of state transitions in the thylakoid by reversible phosphorylation of the light-harvesting chlorophyll a/b protein complex of photosystem II (LHC-II) is modulated by a kinase. The kinase catalyzing this phosphorylation is associated with the thylakoid membrane, and is regulated by the redox state of the plastoquinone pool. The isolation and partial purification from spinach thylakoids of two protein kinases (CPK1, CPK2) of apparent molecular masses 25 kDa and 38 kDa has been reported. Neither enzyme utilizes isolated LHC-II as a substrate. The partial purification of a third protein kinase (LHCK) which can utilize both lysine-rich histones (IIIs and Vs) and isolated LHC-II as substrate has now been purified to homogeneity and characterized by SDS-polyacrylamide gel electrophoresis as a 64 kDa peptide. From a comparison of the two isolation procedures we have concluded that CPK1 is indeed a protein kinase, but has a lower specific activity than that of LHCK. 8 refs., 4 figs

Ablation of phosphoinositide-3-kinase class II alpha suppresses hepatoma cell proliferation

Energy Technology Data Exchange (ETDEWEB)

Ng, Stanley K.L. [Singapore Immunology Network A-STAR (Singapore); Neo, Soek-Ying, E-mail: neo_soek_ying@sics.a-star.edu.sg [Singapore Immunology Network A-STAR (Singapore); Yap, Yann-Wan [Singapore Immunology Network A-STAR (Singapore); Karuturi, R. Krishna Murthy; Loh, Evelyn S.L. [Genome Institute of Singapore A-STAR (Singapore); Liau, Kui-Hin [Department of General Surgery, Tan Tock Seng Hospital (Singapore); Ren, Ee-Chee, E-mail: ren_ee_chee@immunol.a-star.edu.sg [Singapore Immunology Network A-STAR (Singapore); Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore (Singapore)

2009-09-18

Cancer such as hepatocellular carcinoma (HCC) is characterized by complex perturbations in multiple signaling pathways, including the phosphoinositide-3-kinase (PI3K/AKT) pathways. Herein we investigated the role of PI3K catalytic isoforms, particularly class II isoforms in HCC proliferation. Among the siRNAs tested against the eight known catalytic PI3K isoforms, specific ablation of class II PI3K alpha (PIK3C2{alpha}) was the most effective in impairing cell growth and this was accompanied by concomitant decrease in PIK3C2{alpha} mRNA and protein levels. Colony formation ability of cells deficient for PIK3C2{alpha} was markedly reduced and growth arrest was associated with increased caspase 3 levels. A small but significant difference in gene dosage and expression levels was detected between tumor and non-tumor tissues in a cohort of 19 HCC patients. Taken together, these data suggest for the first time that in addition to class I PI3Ks in cancer, class II PIK3C2{alpha} can modulate HCC cell growth.

Nutritional evaluation of caseins and whey proteins and their hydrolysates from Protamex*

Science.gov (United States)

Sindayikengera, Séverin; Xia, Wen-shui

2006-01-01

Whey protein concentrate (WPC 80) and sodium caseinate were hydrolyzed by Protamex to 5%, 10%, 15%, and 20% degree of hydrolysis (DH). WPC 80, sodium caseinate and their hydrolysates were then analyzed, compared and evaluated for their nutritional qualities. Their chemical composition, protein solubility, amino acid composition, essential amino acid index (EAA index), biological value (BV), nutritional index (NI), chemical score, enzymic protein efficiency ratio (E-PER) and in vitro protein digestibility (IVPD) were determined. The results indicated that the enzymatic hydrolysis of WPC 80 and sodium caseinate by Protamex improved the solubility and IVPD of their hydrolysates. WPC 80, sodium caseinate and their hydrolysates were high-quality proteins and had a surplus of essential amino acids compared with the FAO/WHO/UNU (1985) reference standard. The nutritive value of WPC 80 and its hydrolysates was superior to that of sodium caseinate and its hydrolysates as indicated by some nutritional parameters such as the amino acid composition, chemical score, EAA index and predicted BV. However, the E-PER was lower for the WPC hydrolysates as compared to unhydrolyzed WPC 80 but sodium caseinate and its hydrolysates did not differ significantly. The nutritional qualities of WPC 80, sodium caseinate and their hydrolysates were good and make them appropriate for food formulations or as nutritional supplements. PMID:16421963

Dual Inhibition of Topoisomerase II and Tyrosine Kinases by the Novel Bis-Fluoroquinolone Chalcone-Like Derivative HMNE3 in Human Pancreatic Cancer Cells.

Directory of Open Access Journals (Sweden)

Yong-Chao Ma

Full Text Available Both tyrosine kinase and topoisomerase II (TopII are important anticancer targets, and their respective inhibitors are widely used in cancer therapy. However, some combinations of anticancer drugs could exhibit mutually antagonistic actions and drug resistance, which further limit their therapeutic efficacy. Here, we report that HMNE3, a novel bis-fluoroquinolone chalcone-like derivative that targets both tyrosine kinase and TopII, induces tumor cell proliferation and growth inhibition. The viabilities of 6 different cancer cell lines treated with a range of HMNE3 doses were detected using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Cellular apoptosis was determined using Hoechst 33258 fluorescence staining and the terminal deoxynucleotidyl transferase (TdT dUTP nick-end labeling (TUNEL assay. The expression of activated Caspase-3 was examined by immunocytochemistry. The tyrosine kinase activity was measured with a human receptor tyrosine kinase (RTK detection kit using a horseradish peroxidase (HRP-conjugated phosphotyrosine (pY20 antibody as the substrate. The topoisomerase II activity was measured using agarose gel electrophoresis with the DNA plasmid pBR322 as the substrate. The expression levels of the P53, Bax, Bcl-2, Caspase-3, -8, -9, p-cSrc, c-Src and topoisomerase II proteins were detected by western blot analysis. The proliferation of five of the six cancer cell lines was significantly inhibited by HMNE3 at 0.312 to 10 μmol/L in a time- and dose-dependent manner. Treatment of the Capan-1 and Panc-1 cells with 1.6 to 3.2 μM HMNE3 for 48 h significantly increased the percentage of apoptotic cells (P<0.05, and this effect was accompanied by a decrease in tyrosine kinase activity. HMNE3 potentially inhibited tyrosine kinase activity in vitro with an IC50 value of 0.64±0.34 μmol/L in Capan-1 cells and 3.1±0.86 μmol/L in Panc-1 cells. The activity of c-Src was significantly inhibited by HMNE3 in a dose

Including α s1 casein gene information in genomic evaluations of French dairy goats.

Science.gov (United States)

Carillier-Jacquin, Céline; Larroque, Hélène; Robert-Granié, Christèle

2016-08-04

Genomic best linear unbiased prediction methods assume that all markers explain the same fraction of the genetic variance and do not account effectively for genes with major effects such as the α s1 casein polymorphism in dairy goats. In this study, we investigated methods to include the available α s1 casein genotype effect in genomic evaluations of French dairy goats. First, the α s1 casein genotype was included as a fixed effect in genomic evaluation models based only on bucks that were genotyped at the α s1 casein locus. Less than 1 % of the females with phenotypes were genotyped at the α s1 casein gene. Thus, to incorporate these female phenotypes in the genomic evaluation, two methods that allowed for this large number of missing α s1 casein genotypes were investigated. Probabilities for each possible α s1 casein genotype were first estimated for each female of unknown genotype based on iterative peeling equations. The second method is based on a multiallelic gene content approach. For each model tested, we used three datasets each divided into a training and a validation set: (1) two-breed population (Alpine + Saanen), (2) Alpine population, and (3) Saanen population. The α s1 casein genotype had a significant effect on milk yield, fat content and protein content. Including an α s1 casein effect in genetic and genomic evaluations based only on male known α s1 casein genotypes improved accuracies (from 6 to 27 %). In genomic evaluations based on all female phenotypes, the gene content approach performed better than the other tested methods but the improvement in accuracy was only slightly better (from 1 to 14 %) than that of a genomic model without the α s1 casein effect. Including the α s1 casein effect in a genomic evaluation model for French dairy goats is possible and useful to improve accuracy. Difficulties in predicting the genotypes for ungenotyped animals limited the improvement in accuracy of the obtained estimated breeding values.

Interactions between tea catechins and casein micelles and their impact on renneting functionality.

Science.gov (United States)

Haratifar, Sanaz; Corredig, Milena

2014-01-15

Many studies have shown that tea catechins bind to milk proteins. This research focused on the association of tea polyphenols with casein micelles, and the consequences of the interactions on the renneting behaviour of skim milk. It was hypothesized that epigallocatechin-gallate (EGCG), the main catechin present in green tea, forms complexes with the casein micelles and that the association modifies the processing functionality of casein micelles. The binding of EGCG to casein micelles was quantified using HPLC. The formation of catechin-casein micelles complexes affected the rennet induced gelation of milk, and the effect was concentration dependent. Both the primary as well as the secondary stage of gelation were affected. These experiments clearly identify the need for a better understanding of the effect of tea polyphenols on the processing functionality of casein micelles, before milk products can be used as an appropriate platform for delivery of bioactive compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Addition of sodium caseinate to skim milk increases nonsedimentable casein and causes significant changes in rennet-induced gelation, heat stability, and ethanol stability.

Science.gov (United States)

Lin, Yingchen; Kelly, Alan L; O'Mahony, James A; Guinee, Timothy P

2017-02-01

The protein content of skim milk was increased from 3.3 to 4.1% (wt/wt) by the addition of a blend of skim milk powder and sodium caseinate (NaCas), in which the weight ratio of skim milk powder to NaCas was varied from 0.8:0.0 to 0.0:0.8. Addition of NaCas increased the levels of nonsedimentable casein (from ∼6 to 18% of total casein) and calcium (from ∼36 to 43% of total calcium) and reduced the turbidity of the fortified milk, to a degree depending on level of NaCas added. Rennet gelation was adversely affected by the addition of NaCas at 0.2% (wt/wt) and completely inhibited at NaCas ≥0.4% (wt/wt). Rennet-induced hydrolysis was not affected by added NaCas. The proportion of total casein that was nonsedimentable on centrifugation (3,000 × g, 1 h, 25°C) of the rennet-treated milk after incubation for 1 h at 31°C increased significantly on addition of NaCas at ≥0.4% (wt/wt). Heat stability in the pH range 6.7 to 7.2 and ethanol stability at pH 6.4 were enhanced by the addition of NaCas. It is suggested that the negative effect of NaCas on rennet gelation is due to the increase in nonsedimentable casein, which upon hydrolysis by chymosin forms into small nonsedimentable particles that physically come between, and impede the aggregation of, rennet-altered para-casein micelles, and thereby inhibit the development of a gel network. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Investigation of eco-friendly casein fibre production methods

Science.gov (United States)

Bier, M. C.; Kohn, S.; Stierand, A.; Grimmelsmann, N.; Homburg, S. V.; Rattenholl, A.; Ehrmann, A.

2017-10-01

The growing environmentally awareness of the consumers leads to a lot of new products in the textile industry. Either a sustainably produced textile or one which is created by reuse of a waste product is preferred. One possibility to create fibers from waste is using waste milk for casein fiber production. Opposite to several other biopolymers, however, spinning fibers from casein causes diverse problems. This article gives an overview of the investigations on how to produce fibres from the milk protein casein in a sustainable way, i.e. without formaldehyde or other polluting ingredients. Mechanical properties as well as water-resistance were investigated for chemical and physical modifications of the base composition. In this way, the positive influence of paraffin oil and wax as well as aggregation at high temperatures could be proven, while temperature treatment resulted in a higher E-modulus.

Influence of shear during enzymatic gelation of caseinate-water and caseinate-water-fat systems

NARCIS (Netherlands)

Manski, J.M.; Goot, van der A.J.; Boom, R.M.

2007-01-01

Solidification, emulsification and application of shear were combined to induce diversity and heterogeneity in the micro- and macrostructure of concentrated caseinate-based food matrices containing a dispersed fat phase. The products were evaluated with selected parameters from small-scale and

Fractionation of milk proteins on pilot scale with particular focus on β-casein

NARCIS (Netherlands)

Thienel, Katharina J.F.; Holder, Aline; Schubert, Thomas; Boom, Remko M.; Hinrichs, Jörg; Atamer, Zeynep

2018-01-01

The aim of this study was to increase the yield and purity of casein fractions at pilot scale and determine the main process parameters influencing the isolation of β-casein, such as cold extraction time, separation speed. The fractions were obtained from micellar casein by means of selective

Electrochemical Sensing of Casein Based on the Interaction between Its Phosphate Groups and a Ruthenium(III) Complex.

Science.gov (United States)

Inaba, Iku; Kuramitz, Hideki; Sugawara, Kazuharu

2016-01-01

A reaction to casein, along with β-lactoglobulin, is a main cause of milk allergies, and also is a useful indicator of protein in allergic analyses. In the present study, a simple casein sensor was developed based on the interaction between a phosphate group of casein and electroactive [Ru(NH3)6](3+). We evaluated the voltammetric behavior of a casein-[Ru(NH3)6](3+) complex using a glassy carbon electrode. When the ruthenium(III) complex was combined with the phosphate groups of casein, the structure of the casein was changed. Since the hydrophobicity of casein was increased due to the binding, the casein was adsorbed onto the electrode. Furthermore, we modified an electrode with a ruthenium(III) ions/collagen film. When the sensor was applied to the detection of the casein contained in milk, the values coincided with those indicated by the manufacturer. Accordingly, this electrode could be a powerful sensor for the determination of casein in several foods.

H- ras deletion protects against angiotensin II-induced arterial hypertension and cardiac remodeling through protein kinase G-Iβ pathway activation.

Science.gov (United States)

Martín-Sánchez, Paloma; Luengo, Alicia; Griera, Mercedes; Orea, María Jesús; López-Olañeta, Marina; Chiloeches, Antonio; Lara-Pezzi, Enrique; de Frutos, Sergio; Rodríguez-Puyol, Manuel; Calleros, Laura; Rodríguez-Puyol, Diego

2018-02-01

Ras proteins regulate cell survival, growth, differentiation, blood pressure, and fibrosis in some organs. We have demonstrated that H- ras gene deletion produces mice hypotension via a soluble guanylate cyclase-protein kinase G (PKG)-dependent mechanism. In this study, we analyzed the consequences of H- ras deletion on cardiac remodeling induced by continuous angiotensin II (AngII) infusion and the molecular mechanisms implied. Left ventricular posterior wall thickness and mass and cardiomyocyte cross-sectional area were similar between AngII-treated H-Ras knockout (H -ras -/- ) and control wild-type (H -ras +/+ ) mice, as were extracellular matrix protein expression. Increased cardiac PKG-Iβ protein expression in H -ras -/- mice suggests the involvement of this protein in heart protection. Ex vivo experiments on cardiac explants could support this mechanism, as PKG blockade blunted protection against AngII-induced cardiac hypertrophy and fibrosis markers in H -ras -/- mice. Genetic modulation studies in cardiomyocytes and cardiac and embryonic fibroblasts revealed that the lack of H-Ras down-regulates the B-RAF/MEK/ERK pathway, which induces the glycogen synthase kinase-3β-dependent activation of the transcription factor, cAMP response element-binding protein, which is responsible for PKG-Iβ overexpression in H -ras -/- mouse embryonic fibroblasts. This study demonstrates that H- ras deletion protects against AngII-induced cardiac remodeling, possibly via a mechanism in which PKG-Iβ overexpression could play a partial role, and points to H-Ras and/or downstream proteins as potential therapeutic targets in cardiovascular disease.-Martín-Sánchez, P., Luengo, A., Griera, M., Orea, M. J., López-Olañeta, M., Chiloeches, A., Lara-Pezzi, E., de Frutos, S., Rodríguez-Puyol, M., Calleros, L., Rodríguez-Puyol, D. H- ras deletion protects against angiotensin II-induced arterial hypertension and cardiac remodeling through protein kinase G-Iβ pathway activation.

Modulation of type II TGF-β receptor degradation by integrin-linked kinase.

Science.gov (United States)

Vi, Linda; Boo, Stellar; Sayedyahossein, Samar; Singh, Randeep K; McLean, Sarah; Di Guglielmo, Gianni M; Dagnino, Lina

2015-03-01

Cutaneous responses to injury, infection, and tumor formation involve the activation of resident dermal fibroblasts and subsequent transition to myofibroblasts. The key for induction of myofibroblast differentiation is the activation of transforming growth factor-β (TGF-β) receptors and stimulation of integrins and their associated proteins, including integrin-linked kinase (ILK). Cross-talk processes between TGF-β and ILK are crucial for myofibroblast formation, as ILK-deficient dermal fibroblasts exhibit impaired responses to TGF-β receptor stimulation. We now show that ILK associates with type II TGF-β receptors (TβRII) in ligand- and receptor kinase activity-independent manners. In cells with targeted Ilk gene inactivation, cellular levels of TβRII are decreased, through mechanisms that involve enhanced ubiquitination and proteasomal degradation. Partitioning of TGF-β receptors into membrane has been linked to proteasome-dependent receptor degradation. We found that interfering with membrane raft formation in ILK-deficient cells restored TβRII levels and signaling. These observations support a model whereby ILK functions in fibroblasts to direct TβRII away from degradative pathways during their differentiation into myofibroblasts.

Inflammatory Signaling by NOD-RIPK2 Is Inhibited by Clinically Relevant Type II Kinase Inhibitors.

Science.gov (United States)

Canning, Peter; Ruan, Qui; Schwerd, Tobias; Hrdinka, Matous; Maki, Jenny L; Saleh, Danish; Suebsuwong, Chalada; Ray, Soumya; Brennan, Paul E; Cuny, Gregory D; Uhlig, Holm H; Gyrd-Hansen, Mads; Degterev, Alexei; Bullock, Alex N

2015-09-17

RIPK2 mediates pro-inflammatory signaling from the bacterial sensors NOD1 and NOD2, and is an emerging therapeutic target in autoimmune and inflammatory diseases. We observed that cellular RIPK2 can be potently inhibited by type II inhibitors that displace the kinase activation segment, whereas ATP-competitive type I inhibition was only poorly effective. The most potent RIPK2 inhibitors were the US Food and Drug Administration-approved drugs ponatinib and regorafenib. Their mechanism of action was independent of NOD2 interaction and involved loss of downstream kinase activation as evidenced by lack of RIPK2 autophosphorylation. Notably, these molecules also blocked RIPK2 ubiquitination and, consequently, inflammatory nuclear factor κB signaling. In monocytes, the inhibitors selectively blocked NOD-dependent tumor necrosis factor production without affecting lipopolysaccharide-dependent pathways. We also determined the first crystal structure of RIPK2 bound to ponatinib, and identified an allosteric site for inhibitor development. These results highlight the potential for type II inhibitors to treat indications of RIPK2 activation as well as inflammation-associated cancers. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Role of integrin-linked kinase in vascular smooth muscle cells: Regulation by statins and angiotensin II

International Nuclear Information System (INIS)

Friedrich, Erik B.; Clever, Yvonne P.; Wassmann, Sven; Werner, Nikos; Boehm, Michael; Nickenig, Georg

2006-01-01

Our goal was to characterize the role of integrin-linked kinase (ILK) in vascular smooth muscle cells (VSMC), which play a crucial role in atherogenesis. Transfection of VSMC with wild-type and dominant-negative ILK cDNA constructs revealed that ILK mediates migration and proliferation of VSMC but has no effect on VSMC survival. The pro-atherogenic mediator angiotensin II increases ILK protein expression and kinase activity while statin treatment down-regulates ILK in VSMC. Functionally, ILK is necessary for angiotensin II-mediated VSMC migration and proliferation. In VSMC transduced with dominant-negative ILK, statins mediate an additive inhibition of VSMC migration and proliferation, while transfection with wild-type ILK is sufficient to overcome the inhibitory effects of statin treatment on VSMC migration and proliferation. In vivo, ILK is expressed in VSMC of aortic sections from wild-type mice where it is down-regulated following statin treatment and up-regulated following induction of atherosclerosis in apoE-/- mice. These data identify ILK as a novel target in VSMC for anti-atherosclerotic therapy

Salt-modulated structure formation in a dense calcium caseinate system

NARCIS (Netherlands)

Grabowska, K.J.; Goot, van der A.J.; Boom, R.M.

2012-01-01

A 30 wt% calcium caseinate dispersion can be transformed in an anisotropic and fibrous structure by applying well-defined flow and enzymatic gelation. The formation of an anisotropic structure is thought to be due to the micellar structure of the caseinate and the mild adhesion between the micelles

The cystic fibrosis transmembrane recruiter the alter ego of CFTR as a multi-kinase anchor.

Science.gov (United States)

Mehta, Anil

2007-11-01

This review focuses on a newly discovered interaction between protein kinases involved in cellular energetics, a process that may be disturbed in cystic fibrosis for unknown reasons. I propose a new model where kinase-mediated cellular transmission of energy provides mechanistic insight to a latent role of the cystic fibrosis transmembrane conductance regulator (CFTR). I suggest that CFTR acts as a multi-kinase recruiter to the apical epithelial membrane. My group finds that, in the cytosol, two protein kinases involved in cell energy homeostasis, nucleoside diphosphate kinase (NDPK) and AMP-activated kinase (AMPK), bind one another. Preliminary data suggest that both can also bind CFTR (function unclear). The disrupted role of this CFTR-kinase complex as 'membrane transmitter to the cell' is proposed as an alternative paradigm to the conventional ion transport mediated and CFTR/chloride-centric view of cystic fibrosis pathogenesis. Chloride remains important, but instead, chloride-induced control of the phosphohistidine content of one kinase component (NDPK, via a multi-kinase complex that also includes a third kinase, CK2; formerly casein kinase 2). I suggest that this complex provides the necessary near-equilibrium conditions needed for efficient transmission of phosphate energy to proteins controlling cellular energetics. Crucially, a new role for CFTR as a kinase controller is proposed with ionic concentration acting as a signal. The model posits a regulatory control relay for energy sensing involving a cascade of protein kinases bound to CFTR.

Transglutaminase-treated conjugation of sodium caseinate and corn fiber gum hydrolysate: Interfacial and dilatational properties.

Science.gov (United States)

Liu, Yan; Selig, Michael J; Yadav, Madhav P; Yin, Lijun; Abbaspourrad, Alireza

2018-05-01

This study compliments previous work where peroxidase was successfully used to crosslink corn fiber gum (CFG) with bovine serum albumin and improve CFG's emulsifying properties. Herein, an alternative type of enzyme, transglutaminase, was used to prepare conjugates of CFG and sodium caseinate. Additionally, the CFG was partially hydrolyzed by sulfuric acid and its crosslinking pattern with caseinate was evaluated. The interfacial crosslinking degree between caseinate and CFG increased after hydrolysis according to high performance size exclusion chromatography. The equilibrium interfacial tension of CFG hydrolysate-caseinate conjugate was lower than that of CFG-caseinate conjugate as the rearrangement rate of the CFG hydrolysate-caseinate conjugate was higher. The dilatational modulus of CFG hydrolysate decreased from that of CFG. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sodium butyrate-mediated differentiation of colorectal cancer cells: regulation of PKC-betaII by PI3-kinase

Czech Academy of Sciences Publication Activity Database

Turečková, Jolana; Vojtěchová, Martina; Kučerová, Dana; Velek, Jiří; Tuháčková, Zdena

2005-01-01

Roč. 15, č. 2 (2005), s. 329-335 ISSN 1107-3756 R&D Projects: GA ČR(CZ) GP301/02/D159; GA AV ČR(CZ) KSK5020115 Keywords : phosphatidylinositol 3-kinase * PKCbetaII * adenocarcinoma Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.090, year: 2005

NCBI nr-aa BLAST: CBRC-TTRU-01-0672 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TTRU-01-0672 ref|NP_001039933.1| protein kinase C and casein kinase substrate in neurons... 2 [Bos taurus] gb|AAI14746.1| Protein kinase C and casein kinase substrate in neurons 2 [Bos taurus] NP_001039933.1 1e-178 74% ...

Synergistic effect of casein glycomacropeptide on sodium caseinate foaming properties.

Science.gov (United States)

Morales, R; Martinez, M J; Pilosof, A M R

2017-11-01

Several strategies to improve the interfacial properties and foaming properties of proteins may be developed; among them, the use of mixtures of biopolymers that exhibit synergistic interactions. The aim of the present work was to evaluate the effect of casein glycomacropeptide (CMP) on foaming and surface properties of sodium caseinate (NaCas) and to establish the role of protein interactions in the aqueous phase. To this end particles size, interfacial and foaming properties of CMP, NaCas and NaCas-CMP mixtures at pH 5.5 and 7 were determined. At both pH, the interaction between CMP and NaCas induced a decrease in the aggregation state of NaCas. Single CMP foams showed the highest and NaCas the lowest foam overrun (FO) and the mixture exhibited intermediate values. CMP foam quickly drained. The drainage profile of mixed foams was closer to NaCas foams; at pH 5.5, mixed foams drained even slower than NaCas foam, exhibiting a synergistic performance. Additionally, a strong synergism was observed on the collapse of mixed foams at pH 5.5. Finally, a model to explain the synergistic effect observed on foaming properties in CMP-NaCas mixtures has been proposed; the reduced aggregation state of NaCas in the presence of CMP, made it more efficient for foam stabilization. Copyright © 2017 Elsevier B.V. All rights reserved.

Calcium/calmodulin-dependent protein kinase II activity regulates the proliferative potential of growth plate chondrocytes.

Science.gov (United States)

Li, Yuwei; Ahrens, Molly J; Wu, Amy; Liu, Jennifer; Dudley, Andrew T

2011-01-01

For tissues that develop throughout embryogenesis and into postnatal life, the generation of differentiated cells to promote tissue growth is at odds with the requirement to maintain the stem cell/progenitor cell population to preserve future growth potential. In the growth plate cartilage, this balance is achieved in part by establishing a proliferative phase that amplifies the number of progenitor cells prior to terminal differentiation into hypertrophic chondrocytes. Here, we show that endogenous calcium/calmodulin-dependent protein kinase II (CamkII, also known as Camk2) activity is upregulated prior to hypertrophy and that loss of CamkII function substantially blocks the transition from proliferation to hypertrophy. Wnt signaling and Pthrp-induced phosphatase activity negatively regulate CamkII activity. Release of this repression results in activation of multiple effector pathways, including Runx2- and β-catenin-dependent pathways. We present an integrated model for the regulation of proliferation potential by CamkII activity that has important implications for studies of growth control and adult progenitor/stem cell populations.

Irradiation effect on α- and β-caseins of milk and Queso Blanco cheese determined by capillary electrophoresis

International Nuclear Information System (INIS)

Ham, J.S.; Jeong, S.G.; Lee, S.G.; Han, G.S.; Chae, H.S.; Yoo, Y.M.; Kim, D.H.; Lee, W.K.; Jo, C.

2009-01-01

Milk and Queso Blanco cheese were exposed to irradiation with doses of 1, 2, 3, 5, and 10 kGy to investigate the irradiation effect on α- and β-casein using a capillary electrophoresis. α S1 -Casein to total protein ratio in raw milk was decreased from 19.63% to 8.64% by 10 kGy of gamma irradiation. The ratio of α S1 - to α S0 -casein was also decreased from 1.38 to 0.53, which showed α S1 -casein is more susceptible to gamma irradiation than α S0 -casein. Similarly, α S1 -casein to total protein ratio in Queso Blanco cheese was decreased from 17.48% to 7.82% and the ratio of α S1 - to α S0 -casein was decreased from 1.16 to 0.43 by 10 kGy of gamma irradiation. Dose-dependent reduction of β A1 -casein was also found. β A1 -Casein to total protein ratios in raw milk and Queso Blanco cheese were decreased from 22.00% to 14.16% and from 21.96% to 13.89% after 10 kGy, respectively. The ratios of β A1 - to β A2 -casein were from 1.10 to 0.64 and 0.93 to 0.57 in milk and Queso Blanco cheese, respectively. However, α S0 -, β B -, and β A3 -casein increased by irradiation at 10 kGy. The results suggest that α S1 -casein and β A1 -casein were more susceptible to gamma irradiation, and may be related to the reduction of milk allergenicity caused by gamma irradiation

LY294002 inhibits glucocorticoid-induced COX-2 gene expression in cardiomyocytes through a phosphatidylinositol 3 kinase-independent mechanism

International Nuclear Information System (INIS)

Sun Haipeng; Xu Beibei; Sheveleva, Elena; Chen, Qin M.

2008-01-01

Glucocorticoids induce COX-2 expression in rat cardiomyocytes. While investigating whether phosphatidylinositol 3 kinase (PI3K) plays a role in corticosterone (CT)-induced COX-2, we found that LY294002 (LY29) but not wortmannin (WM) attenuates CT from inducing COX-2 gene expression. Expression of a dominant-negative mutant of p85 subunit of PI3K failed to inhibit CT from inducing COX-2 expression. CT did not activate PI3K/AKT signaling pathway whereas LY29 and WM decreased the activity of PI3K. LY303511 (LY30), a structural analogue and a negative control for PI3K inhibitory activity of LY29, also suppressed COX-2 induction. These data suggest PI3K-independent mechanisms in regulating CT-induced COX-2 expression. LY29 and LY30 do not inhibit glucocorticoid receptor transactivity. Both compounds have been reported to inhibit Casein Kinase 2 activity and modulate potassium and calcium levels independent of PI3K, while LY29 has been reported to inhibit mammalian Target of Rapamycin (mTOR), and DNA-dependent Protein Kinase (DNA-PK). Inhibitor of Casein Kinase 2 (CK2), mTOR or DNA-PK failed to prevent CT from inducing COX-2 expression. Tetraethylammonium (TEA), a potassium channel blocker, and nimodipine, a calcium channel blocker, both attenuated CT from inducing COX-2 gene expression. CT was found to increase intracellular Ca 2+ concentration, which can be inhibited by LY29, TEA or nimodipine. These data suggest a possible role of calcium instead of PI3K in CT-induced COX-2 expression in cardiomyocytes

Fractionation and identification of novel antioxidant peptides from buffalo and bovine casein hydrolysates.

Science.gov (United States)

Shazly, Ahmed Behdal; He, Zhiyong; El-Aziz, Mahmoud Abd; Zeng, Maomao; Zhang, Shuang; Qin, Fang; Chen, Jie

2017-10-01

Buffalo and bovine caseins were hydrolysed by alcalase and trypsin to produce novel antioxidant peptides. The casein hydrolysates were purified using ultrafiltration (UF) and further characterized by RP-HPLC. The fractions produced higher antioxidant activities were identified for their peptides using LC MS/MS. All UF-VI (MWcasein (UF-VI with 54.84-fold purification) showed higher antioxidant activity than that obtained by trypsin. Trypsin hydrolysate contained high amount of hydrophobic amino acids while alcalase hydrolysate consisted mainly of Ser, Arg, Ala and Leu. The antioxidant peptides identified by LC MS/MS were RELEE, MEDNKQ and TVA, EQL in buffalo casein hydrolysates produced by trypsin and alcalase, respectively. Mechanism and reaction pathways of selected antioxidant peptides with ABTS were proposed. Conclusively, buffalo casein provided antioxidant peptides similar to bovine, suggesting that buffalo casein is a novel source of antioxidant. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protective role of ascorbic acid in the decontamination of cow milk casein by gamma-irradiation.

Science.gov (United States)

Kouass Sahbani, Saloua; Klarskov, Klaus; Aloui, Amine; Kouass, Salah; Landoulsi, Ahmed

2013-06-01

The aim of this work was to investigate the protective role of ascorbic acid on irradiation-induced modification of casein. Casein stock solutions were irradiated with increasing doses 2-10 kGy using (60)Co Gamma rays at a dose rate D• = 136.73 Gy/min at room temperature. The total viable microorganism content of cow milk casein was evaluated by Plate Count Agar (PCA) incubation for 48 h at 37°C. Sodium dodecylsulfate gel electrophoresis (SDS-PAGE) and Matrix-Assisted Laser Desorption-Ionization Time-of-Flight mass spectrometry (MALDI-TOF-MS) analysis were used to evaluate the effect of gamma irradiation on casein integrity. Gamma irradiation reduced the bacterial contamination of casein solutions at a lower irradiation dose when performed in the presence of ascorbic acid. The irradiation treatment of casein in the absence of ascorbic acid with a dose of 4 kGy could reduce 99% of the original amount of bacterial colonies. However, in the presence of ascorbic acid the irradiation treatment of casein with a dose lower than 2 kGy could reduce 99% of the original amount of bacterial colonies which suggested that the irradiation dose lower than 2 kGy achieved almost the entire decontamination result. SDS-PAGE and MALDI-TOF-MS analysis showed that ascorbic acid protected cow milk casein from degradation and subsequent aggregation probably by scavenging oxygen and protein radicals produced by the irradiation. It is demonstrated that the combination of gamma irradiation and ascorbic acid produce additive effects, providing acceptable hygienic quality of cow milk casein and protects caseins against Reactive Oxygen Species (ROS) generated, during the irradiation process.

Preferential localization of Lactococcus lactis cells entrapped in a caseinate/alginate phase separated system.

Science.gov (United States)

Léonard, Lucie; Gharsallaoui, Adem; Ouaali, Fahima; Degraeve, Pascal; Waché, Yves; Saurel, Rémi; Oulahal, Nadia

2013-09-01

This study aimed to entrap bioprotective lactic acid bacteria in a sodium caseinate/sodium alginate aqueous two-phase system. Phase diagram at pH=7 showed that sodium alginate and sodium caseinate were not miscible when their concentrations exceeded 1% (w/w) and 6% (w/w), respectively. The stability of the caseinate/alginate two-phase system was also checked at pH values of 6.0 and 5.5. Lactococcus lactis subsp. lactis LAB3 cells were added in a 4% (w/w) caseinate/1.5% (w/w) alginate two-phase system at pH=7. Fluorescence microscopy allowed to observe that the caseinate-rich phase formed droplets dispersed in a continuous alginate-rich phase. The distribution of bacteria in such a system was observed by epifluorescence microscopy: Lc. lactis LAB3 cells stained with Live/Dead(®) Baclight kit™ were located exclusively in the protein phase. Since zeta-potential measurements indicated that alginate, caseinate and bacterial cells all had an overall negative charge at pH 7, the preferential adhesion of LAB cells was assumed to be driven by hydrophobic effect or by depletion phenomena in such biopolymeric systems. Moreover, LAB cells viability was significantly higher in the ternary mixture obtained in the presence of both caseinate and alginate than in single alginate solution. Caseinate/alginate phase separated systems appeared thus well suited for Lc. lactis LAB3 cells entrapment. Copyright © 2013 Elsevier B.V. All rights reserved.

Physicochemical characterization of native and modified sodium caseinate- Vitamin A complexes.

Science.gov (United States)

Gupta, Chitra; Arora, Sumit; Syama, M A; Sharma, Apurva

2018-04-01

Native and modified sodium caseinate- Vitamin A complexes {Sodium caseinate- Vit A complex by stirring (NaCas-VA ST), succinylated sodium caseinate- Vit A complex by stirring (SNaCas-VA ST), reassembled sodium caseinate- Vit A complex (RNaCas-VA) and reassembled succinylated sodium caseinate- Vit A complex (RSNaCas-VA)} were prepared and characterized for their physicochemical characteristics e.g. particle size, zeta potential, turbidity analysis and tryptophan intensities which confirmed structural modification of both native (NaCas-VA ST) and modified (SNaCas-VA ST, RNaCas-VA and RSNaCas- VA) proteins upon complex formation with vitamin A. Binding of vitamin A to milk protein reduced the turbidity caused by vitamin A, however, the particle size and zeta potential of milk protein increased after complexation. Microstructure details of NaCas (spray dried) showed uniform spherical structure, however, other milk proteins and milk protein- Vit A complexes (freeze dried) showed broken glass and flaky structures. Tiny particles were observed on the surface of reassembled protein and reassembled protein- Vit A complexes. Binding of vitamin A to milk protein did not have an influence on the electrophoretic mobility and elution profile (RP-HPLC). Copyright © 2018 Elsevier Ltd. All rights reserved.

Skim Milk, Whey, and Casein Increase Body Weight and Whey and Casein Increase the Plasma C-Peptide Concentration in Overweight Adolescents12

DEFF Research Database (Denmark)

Arnberg, Karina; Mølgaard, Christian; Michaelsen, Kim Fleischer

2012-01-01

insulin, and insulin secretion estimated as the plasma C-peptide concentration in overweight adolescents. Overweight adolescents (n = 203) aged 12–15 y with a BMI of 25.4 ± 2.3 kg/m2 (mean ± SD) were randomized to 1 L/d of skim milk, whey, casein, or water for 12 wk. All milk drinks contained 35 g protein....... Outcomes were BMI-for-age Z-scores (BAZs), waist circumference, plasma insulin, homeostatic model assessment, and plasma C-peptide. We found no change in BAZ in the pretest control and water groups, whereas it was greater at 12 wk in the skim milk, whey, and casein groups compared with baseline...... and with the water and pretest control groups. The plasma C-peptide concentration increased from baseline to wk 12 in the whey and casein groups and increments were greater than in the pretest control (P

PFG-NMR self-diffusion in casein dispersions: effect of probe size and protein aggregate size

NARCIS (Netherlands)

Salami, S.; Rondeau, C.; Duynhoven, van J.P.M.; Mariette, F.

2013-01-01

The self-diffusion coefficients of different molecular weight PEGs (Polyethylene glycol) and casein particles were measured, using a pulsed-gradient nuclear magnetic resonance technique (PFG-NMR), in native phosphocaseinate (NPC) and sodium caseinate (SC) dispersions where caseins are not structured

The decontamination of industrial casein and milk powder by irradiation

Energy Technology Data Exchange (ETDEWEB)

Zegota, H. [Institute of Applied Radiation Chemistry, Technical University, Wroblewskiego 15, 93-590 Lodz (Poland)], E-mail: ahzegota@mitr.p.lodz.pl; Malolepszy, B. [Fleur Comp. Ltd., Artyleryjska 6, 91-072 Lodz (Poland)

2008-09-15

The efficacy of gamma radiation decontamination of industrial casein, a milk protein utilized as a component of many food and non-food products has been studied. Low-fat milk powder was also included with a purpose to study the microflora survival in protein-rich materials. Microbial analysis of the samples prior to irradiation showed that the initial total viable count was higher than 6.0 log cfu g{sup -1} in both casein and milk powders. The contamination of casein with moulds and yeasts was found to be equal to 3.56 log cfu g{sup -1}. The counts of coliforms have not exceeded the value of 2.48 log cfu g{sup -1}. Radiation processing of casein and milk powder has substantially reduced the microbial population of all samples. The dose of 5 kGy was sufficient to reduce the total microflora and coliforms counts to the level permitted for food products. Survivals of microorganisms were analyzed by the generalized exponential equation, SF=exp[-D/D{sub o}){sup {alpha}}]. Values of an exponent, {alpha}, standing for the dispersion parameter, were equal to 0.65 and 0.70 for microorganisms contaminating casein and milk powders, respectively. The numerical value of the dispersion parameter {alpha}<1 indicates the concave dependence of a logarithm of surviving fraction versus radiation dose. No difference in microflora survival in irradiated samples tested immediately and in samples stored for 1-month after irradiation has been noticed.

The decontamination of industrial casein and milk powder by irradiation

International Nuclear Information System (INIS)

Zegota, H.; Malolepszy, B.

2008-01-01

The efficacy of gamma radiation decontamination of industrial casein, a milk protein utilized as a component of many food and non-food products has been studied. Low-fat milk powder was also included with a purpose to study the microflora survival in protein-rich materials. Microbial analysis of the samples prior to irradiation showed that the initial total viable count was higher than 6.0 log cfu g -1 in both casein and milk powders. The contamination of casein with moulds and yeasts was found to be equal to 3.56 log cfu g -1 . The counts of coliforms have not exceeded the value of 2.48 log cfu g -1 . Radiation processing of casein and milk powder has substantially reduced the microbial population of all samples. The dose of 5 kGy was sufficient to reduce the total microflora and coliforms counts to the level permitted for food products. Survivals of microorganisms were analyzed by the generalized exponential equation, SF=exp[-D/D o ) α ]. Values of an exponent, α, standing for the dispersion parameter, were equal to 0.65 and 0.70 for microorganisms contaminating casein and milk powders, respectively. The numerical value of the dispersion parameter α<1 indicates the concave dependence of a logarithm of surviving fraction versus radiation dose. No difference in microflora survival in irradiated samples tested immediately and in samples stored for 1-month after irradiation has been noticed

The membrane-associated form of α(s1-casein interacts with cholesterol-rich detergent-resistant microdomains.

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Annabelle Le Parc

Full Text Available Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that α(s1-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of α(s1-casein in rat mammary epithelial cells. Using metabolic labelling we show that α(s1-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of α(s1-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of α(s1-casein. These experiments reveal that the insolubility of α(s1-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of α(s1-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells.

The Membrane-Associated Form of αs1-Casein Interacts with Cholesterol-Rich Detergent-Resistant Microdomains

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Le Parc, Annabelle; Honvo Houéto, Edith; Pigat, Natascha; Chat, Sophie; Leonil, Joëlle; Chanat, Eric

2014-01-01

Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that αs1-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of αs1-casein in rat mammary epithelial cells. Using metabolic labelling we show that αs1-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of αs1-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of αs1-casein. These experiments reveal that the insolubility of αs1-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of αs1-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells. PMID:25549363

The membrane-associated form of α(s1)-casein interacts with cholesterol-rich detergent-resistant microdomains.

Science.gov (United States)

Le Parc, Annabelle; Honvo Houéto, Edith; Pigat, Natascha; Chat, Sophie; Leonil, Joëlle; Chanat, Eric

2014-01-01

Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that α(s1)-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of α(s1)-casein in rat mammary epithelial cells. Using metabolic labelling we show that α(s1)-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of α(s1)-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of α(s1)-casein. These experiments reveal that the insolubility of α(s1)-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of α(s1)-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells.

Irradiation effect on {alpha}- and {beta}-caseins of milk and Queso Blanco cheese determined by capillary electrophoresis

Energy Technology Data Exchange (ETDEWEB)

Ham, J.S.; Jeong, S.G.; Lee, S.G.; Han, G.S.; Chae, H.S.; Yoo, Y.M.; Kim, D.H. [Animal Food Processing Division, National Institute of Animal Science, Suwon 441-706 (Korea, Republic of); Lee, W.K. [College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Jo, C. [Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)], E-mail: cheorun@cnu.ac.kr

2009-02-15

Milk and Queso Blanco cheese were exposed to irradiation with doses of 1, 2, 3, 5, and 10 kGy to investigate the irradiation effect on {alpha}- and {beta}-casein using a capillary electrophoresis. {alpha}{sub S1}-Casein to total protein ratio in raw milk was decreased from 19.63% to 8.64% by 10 kGy of gamma irradiation. The ratio of {alpha}{sub S1}- to {alpha}{sub S0}-casein was also decreased from 1.38 to 0.53, which showed {alpha}{sub S1}-casein is more susceptible to gamma irradiation than {alpha}{sub S0}-casein. Similarly, {alpha}{sub S1}-casein to total protein ratio in Queso Blanco cheese was decreased from 17.48% to 7.82% and the ratio of {alpha}{sub S1}- to {alpha}{sub S0}-casein was decreased from 1.16 to 0.43 by 10 kGy of gamma irradiation. Dose-dependent reduction of {beta}{sub A1}-casein was also found. {beta}{sub A1}-Casein to total protein ratios in raw milk and Queso Blanco cheese were decreased from 22.00% to 14.16% and from 21.96% to 13.89% after 10 kGy, respectively. The ratios of {beta}{sub A1}- to {beta}{sub A2}-casein were from 1.10 to 0.64 and 0.93 to 0.57 in milk and Queso Blanco cheese, respectively. However, {alpha}{sub S0}-, {beta}{sub B}-, and {beta}{sub A3}-casein increased by irradiation at 10 kGy. The results suggest that {alpha}{sub S1}-casein and {beta}{sub A1}-casein were more susceptible to gamma irradiation, and may be related to the reduction of milk allergenicity caused by gamma irradiation.

Mediator kinase module and human tumorigenesis.

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Clark, Alison D; Oldenbroek, Marieke; Boyer, Thomas G

2015-01-01

Mediator is a conserved multi-subunit signal processor through which regulatory informatiosn conveyed by gene-specific transcription factors is transduced to RNA Polymerase II (Pol II). In humans, MED13, MED12, CDK8 and Cyclin C (CycC) comprise a four-subunit "kinase" module that exists in variable association with a 26-subunit Mediator core. Genetic and biochemical studies have established the Mediator kinase module as a major ingress of developmental and oncogenic signaling through Mediator, and much of its function in signal-dependent gene regulation derives from its resident CDK8 kinase activity. For example, CDK8-targeted substrate phosphorylation impacts transcription factor half-life, Pol II activity and chromatin chemistry and functional status. Recent structural and biochemical studies have revealed a precise network of physical and functional subunit interactions required for proper kinase module activity. Accordingly, pathologic change in this activity through altered expression or mutation of constituent kinase module subunits can have profound consequences for altered signaling and tumor formation. Herein, we review the structural organization, biological function and oncogenic potential of the Mediator kinase module. We focus principally on tumor-associated alterations in kinase module subunits for which mechanistic relationships as opposed to strictly correlative associations are established. These considerations point to an emerging picture of the Mediator kinase module as an oncogenic unit, one in which pathogenic activation/deactivation through component change drives tumor formation through perturbation of signal-dependent gene regulation. It follows that therapeutic strategies to combat CDK8-driven tumors will involve targeted modulation of CDK8 activity or pharmacologic manipulation of dysregulated CDK8-dependent signaling pathways.

54Mn absorption and excretion in rats fed soy protein and casein diets

International Nuclear Information System (INIS)

Lee, D.Y.; Johnson, P.E.

1989-01-01

Rats were fed diets containing either soy protein or casein and different levels of manganese, methionine, phytic acid, or arginine for 7 days and then fed test meals labeled with 2 microCi of 54Mn after an overnight fast. Retention of 54Mn in each rat was measured every other day for 21 days using a whole-body counter. Liver manganese was higher (P less than 0.0001) in soy protein-fed rats (8.8 micrograms/g) than in casein-fed rats (5.2 micrograms/g); manganese superoxide dismutase activity also was higher in soy protein-fed rats than in casein-fed rats (P less than 0.01). There was a significant interaction between manganese and protein which affected manganese absorption and biologic half-life of 54Mn. In a second experiment, rats fed soy protein-test meals retained more 54Mn (P less than 0.001) than casein-fed rats. Liver manganese (8.3 micrograms/g) in the soy protein group was also higher than that (5.7 micrograms/g) in the casein group (P less than 0.0001), but manganese superoxide dismutase activity was unaffected by protein. Supplementation with methionine increased 54Mn retention from both soy and casein diets (P less than 0.06); activity of manganese superoxide dismutase increased (P less than 0.05) but liver manganese did not change. The addition of arginine to casein diets had little effect on manganese bioavailability. Phytic acid affected neither manganese absorption nor biologic half-life in two experiments, but it depressed liver manganese in one experiment. These results suggest that neither arginine nor phytic acid was the component in soy protein which made manganese more available from soy protein diets than casein diets

Cloning, expression, and mapping of allergenic determinants of alphaS1-casein, a major cow's milk allergen.

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Schulmeister, Ulrike; Hochwallner, Heidrun; Swoboda, Ines; Focke-Tejkl, Margarete; Geller, Beate; Nystrand, Mats; Härlin, Annika; Thalhamer, Josef; Scheiblhofer, Sandra; Keller, Walter; Niggemann, Bodo; Quirce, Santiago; Ebner, Christoph; Mari, Adriano; Pauli, Gabrielle; Herz, Udo; Valenta, Rudolf; Spitzauer, Susanne

2009-06-01

Milk is one of the first components introduced into human diet. It also represents one of the first allergen sources, which induces IgE-mediated allergies in childhood ranging from gastrointestinal, skin, and respiratory manifestations to severe life-threatening manifestations, such as anaphylaxis. Here we isolated a cDNA coding for a major cow's milk allergen, alphaS1-casein, from a bovine mammary gland cDNA library with allergic patients' IgE Abs. Recombinant alphaS1-casein was expressed in Escherichia coli, purified, and characterized by circular dichroism as a folded protein. IgE epitopes of alphaS1-casein were determined with recombinant fragments and synthetic peptides spanning the alphaS1-casein sequence using microarrayed components and sera from 66 cow's milk-sensitized patients. The allergenic activity of ralphaS1-casein and the alphaS1-casein-derived peptides was determined using rat basophil leukemia cells transfected with human FcepsilonRI, which had been loaded with the patients' serum IgE. Our results demonstrate that ralphaS1-casein as well as alphaS1-casein-derived peptides exhibit IgE reactivity, but mainly the intact ralphaS1-casein induced strong basophil degranulation. These results suggest that primarily intact alphaS1-casein or larger IgE-reactive portions thereof are responsible for IgE-mediated symptoms of food allergy. Recombinant alphaS1-casein as well as alphaS1-casein-derived peptides may be used in clinical studies to further explore pathomechanisms of food allergy as well as for the development of new diagnostic and therapeutic strategies for milk allergy.

Is there a feeding strategy to increase milk casein content?

Directory of Open Access Journals (Sweden)

A. Formigoni

2010-04-01

Full Text Available Because more than 60% of milk produced in Italy is transformed into cheese, milk economical value strongly depends on cheese yield. Among the factors that influence cheese yield, milk casein and fat content plays a major role: when milk is converted into Grana Padano and Parmigiano reggiano, three grams of seasoned cheese are produced from one gram of milk casein.....

Phosphorylation of eukaryotic aminoacyl-tRNA synthetases

International Nuclear Information System (INIS)

Pendergast, A.M.

1986-01-01

The phosphorylation of the highly purified aminoacyl-tRNA synthetase complex from rabbit reticulocytes was examined. The synthetase complex contained, in addition to eight aminoacyl-tRNA synthetases, three unidentified proteins and was free of endogenous protein kinase activity. Incubation of the complex with casein kinase I in the presence of ATP resulted in the phosphorylation of four synthetases, the glutamyl-, isoleucyl-, methionyl-, and lysyl-tRNA synthetases. Phosphorylation by casein kinase I altered binding to tRNA-Sepharose such that the phosphorylated complex eluted at 190 mM NaCl instead of the 275 mM salt observed for the nonphosphorylated form. Phosphorylation by casein kinase I resulted in a significant inhibition of aminoacylation with the four synthetases; the activities of the nonphosphorylated synthetases were unchanged. One of the unidentified proteins in the complex (M/sub r/ 37,000) was also an excellent substrate for casein kinase I. A comparison of the properties and two-dimensional phosphopeptide pattern of this protein with that of casein kinase I suggest that the 37,000 dalton protein in the synthetase complex is an inactive form of casein kinase I. Two other protein kinases were shown to phosphorylate aminoacyl-tRNA synthetases in the complex. The phosphorylation of threonyl-tRNA synthetase was also investigated. Five aminoacyl-tRNA synthetases in the high molecular weight complex were shown to be phosphorylated in rabbit reticulocytes following labeling with ( 32 P)orthophosphate

Magnetic bead and gold nanoparticle probes based immunoassay for β-casein detection in bovine milk samples.

Science.gov (United States)

Li, Y S; Meng, X Y; Zhou, Y; Zhang, Y Y; Meng, X M; Yang, L; Hu, P; Lu, S Y; Ren, H L; Liu, Z S; Wang, X R

2015-04-15

In this work, a double-probe based immunoassay was developed for rapid and sensitive determination of β-casein in bovine milk samples. In the method, magnetic beads (MBs), employed as supports for the immobilization of anti-β-casein polyclonal antibody (PAb), were used as the capture probe. Colloidal gold nanoparticles (AuNPs), employed as a bridge for loading anti-β-casein monoclonal antibody (McAb) and horseradish peroxidase (HRP), were used as the amplification probe. The presence of β-casein causes the sandwich structures of MBs-PAb-β-casein-McAb-AuNPs through the interaction between β-casein and the anti-β-casein antibodies. The HRP, used as an enzymatic-amplified tracer, can catalytically oxidize the substrate 3,3',5,5'-tetramethylbenzidine (TMB), generating optical signals that are proportional to the quantity of β-casein. The linear range of the immunoassay was from 6.5 to 1520ngmL(-1). The limit of detection (LOD) was 4.8ngmL(-1) which was 700 times lower than that of MBs-antibody-HRP based immunoassay and 6-7 times lower than that from the microplate-antibody-HRP based assay. The recoveries of β-casein from bovine milk samples were from 95.0% to 104.3% that had a good correlation coefficient (R(2)=0.9956) with those obtained by an official standard Kjeldahl method. For higher sensitivity, simple sample pretreatment and shorter time requirement of the antigen-antibody reaction, the developed immunoassay demonstrated the viability for detection of β-casein in bovine milk samples. Copyright © 2014. Published by Elsevier B.V.

Differential effects of Rho-kinase inhibitor and angiotensin II type-1 receptor antagonist on the vascular function in hypertensive rats induced by chronic l-NAME treatment

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Bainian Chen

2012-10-01

Full Text Available Little attention has been paid to the effect of Rho-kinase inhibitor on the vascular dysfunction of nitric oxide-deficient hypertension. We aimed to investigate whether the Rho-kinase inhibitor fasudil showed beneficial effect on the vascular dysfunction of the NG-nitro-l-arginine methyl ester (l-NAME treated rat, as well as to compare the differential effects of fasudil and angiotensin II receptor antagonist valsartan on vascular function. In the present study, both valsartan and fasudil exerted antihypertensive action on the l-NAME-treated rats, while only valsartan attenuated the cardiac hypertrophy. Treatment with valsartan showed improvement on vascular reactivity to norepinephrine, KCl and CaCl2, whereas fasudil therapy showed little effect on vasoconstriction. Endothelium-dependent vasodilation to acetylcholine was reduced in the NO-deficient group but was normalized by the fasudil therapy. The increased expression of RhoA and Rho-kinase (ROCK in the vasculature was corrected well to normal level by either valsartan or fasudil administration, which seemed to be at least partially responsible for the beneficial effect of the drug infusion. These findings suggest that the angiotensin II receptor antagonist interferes more with the contractile response than Rho-kinase inhibitor, whereas inhibition of Rho-kinase activity exhibits a better improvement on vasorelaxation than blockade of angiotensin II receptor.

Spectrofluoremetric and molecular docking study on the interaction of bisdemethoxycurcumin with bovine β-casein nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Mehranfar, Fahimeh [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Bordbar, Abdol-Khalegh, E-mail: bordbar@chem.ui.ac.ir [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Keyhanfar, Mehrnaz; Behbahani, Mandana [Faculty of Advanced Sciences and Technologies, Department of Biotechnology, University of Isfahan, Isfahan, 81746-73441 (Iran, Islamic Republic of)

2013-11-15

The interaction of bisdemethoxycurcumin (BDMC), as one of the main active component of turmeric (Curcuma longa L.), with bovine β-casein nanoparticle, as an efficient drug carrier system, was investigated using steady-state fluorescence spectroscopy and molecular docking calculations. Results of fluorescence quenching experiments, Forster energy transfer measurements and molecular docking calculations suggested that BDMC bind to the hydrophobic core of β-casein via formation of 3 hydrogen bonds and several vander Waals contacts that represented the encapsulation of BDMC in β-casein micelle nanoparticles. The binding parameters including number of substantive binding sites and the binding constants were evaluated by fluorescence quenching method. Additionally, the cytotoxicity of free BDMC and BDMC-β-casein complex in human breast cancer cell line MCF7 was evaluated in vitro. The study revealed the higher cytotoxic effects of encapsulated BDMC on MCF7 cells compared to equal dose of free BDMC. -- Highlights: • BDMC binds to the hydrophobic core of β-casein. • The effective encapsulation of BDMC in β-casein micelle nanoparticles was shown. • Enhanced cytotoxicity was observed for encapsulated BDMC in β-casein nanoparticles.

Spectrofluoremetric and molecular docking study on the interaction of bisdemethoxycurcumin with bovine β-casein nanoparticles

International Nuclear Information System (INIS)

Mehranfar, Fahimeh; Bordbar, Abdol-Khalegh; Keyhanfar, Mehrnaz; Behbahani, Mandana

2013-01-01

The interaction of bisdemethoxycurcumin (BDMC), as one of the main active component of turmeric (Curcuma longa L.), with bovine β-casein nanoparticle, as an efficient drug carrier system, was investigated using steady-state fluorescence spectroscopy and molecular docking calculations. Results of fluorescence quenching experiments, Forster energy transfer measurements and molecular docking calculations suggested that BDMC bind to the hydrophobic core of β-casein via formation of 3 hydrogen bonds and several vander Waals contacts that represented the encapsulation of BDMC in β-casein micelle nanoparticles. The binding parameters including number of substantive binding sites and the binding constants were evaluated by fluorescence quenching method. Additionally, the cytotoxicity of free BDMC and BDMC-β-casein complex in human breast cancer cell line MCF7 was evaluated in vitro. The study revealed the higher cytotoxic effects of encapsulated BDMC on MCF7 cells compared to equal dose of free BDMC. -- Highlights: • BDMC binds to the hydrophobic core of β-casein. • The effective encapsulation of BDMC in β-casein micelle nanoparticles was shown. • Enhanced cytotoxicity was observed for encapsulated BDMC in β-casein nanoparticles

Cloning and characterization of PAK5, a novel member of mammalian p21-activated kinase-II subfamily that is predominantly expressed in brain

DEFF Research Database (Denmark)

Pandey, A.; Dan, I.; Kristiansen, T.Z.

2002-01-01

cloned a novel human PAK family kinase that has been designated as PAK5. PAK5 contains a CDC42/Rac1 interactive binding (CRIB) motif at the N-terminus and a Ste20-like kinase domain at the C-terminus. PAK5 is structurally most related to PAK4 and PAK6 to make up the PAK-II subfamily. We have shown...

Inhibitory effects of KN-93, an inhibitor of Ca2+ calmodulin-dependent protein kinase II, on light-regulated root gravitropism in maize

Science.gov (United States)

Feldman, L. J.; Hidaka, H.

1993-01-01

Light is essential for root gravitropism in Zea mays L., cultivar Merit. It is hypothesized that calcium mediates this light-regulated response. KN-93, an inhibitor of calcium/calmodulin kinase II (CaMK II), inhibits light-regulated root gravitropism but does not affect light perception. We hypothesize that CaMK II, or a homologue, operates late in the light/gravity signal transduction chain. Here we provide evidence suggesting a possible physiological involvement of CaMK II in root gravitropism in plants.

Short communication: Tryptic β-casein hydrolysate modulates enteric nervous system development in primary culture.

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Cossais, F; Clawin-Rädecker, I; Lorenzen, P C; Klempt, M

2017-05-01

The intestinal tract of the newborn is particularly sensitive to gastrointestinal disorders, such as infantile diarrhea or necrotizing colitis. Perinatal development of the gut also encompasses the maturation of the enteric nervous system (ENS), a main regulator of intestinal motility and barrier functions. It was recently shown that ENS maturation can be enhanced by nutritional factors to improve intestinal maturation. Bioactivity of milk proteins is often latent, requiring the release of bioactive peptides from inactive native proteins. Several casein-derived hydrolysates presenting immunomodulatory properties have been described recently. Furthermore, accumulating data indicate that milk-derived hydrolysate can enhance gut maturation and enrichment of milk formula with such hydrolysates has recently been proposed. However, the capability of milk-derived bioactive hydrolysate to target ENS maturation has not been analyzed so far. We, therefore, investigated the potential of a recently described tryptic β-casein hydrolysate to modulate ENS growth parameters in an in vitro model of rat primary culture of ENS. Rat primary cultures of ENS were incubated with a bioactive tryptic β-casein hydrolysate and compared with untreated controls or to cultures treated with native β-casein or a Prolyve β-casein hydrolysate (Lyven, Colombelles, France). Differentiation of enteric neurons and enteric glial cells, and establishment of enteric neural network were analyzed using immunohistochemistry and quantitative PCR. Effect of tryptic β-casein hydrolysate on bone morphogenetic proteins (BMP)/Smad pathway, an essential regulator of ENS development, was further assessed using quantitative PCR and immunochemistry. Tryptic β-casein hydrolysate stimulated neurite outgrowth and simultaneously modulated the formation of enteric ganglia-like structures, whereas native β-casein or Prolyve β-casein hydrolysate did not. Additionally, treatment with tryptic bioactive β-casein

The Effect of Milk Constituents and Crowding Agents on Amyloid Fibril Formation by κ-Casein.

Science.gov (United States)

Liu, Jihua; Dehle, Francis C; Liu, Yanqin; Bahraminejad, Elmira; Ecroyd, Heath; Thorn, David C; Carver, John A

2016-02-17

When not incorporated into the casein micelle, κ-casein, a major milk protein, rapidly forms amyloid fibrils at physiological pH and temperature. In this study, the effects of milk components (calcium, lactose, lipids, and heparan sulfate) and crowding agents on reduced and carboxymethylated (RCM) κ-casein fibril formation was investigated using far-UV circular dichroism spectroscopy, thioflavin T binding assays, and transmission electron microscopy. Longer-chain phosphatidylcholine lipids, which form the lining of milk ducts and milk fat globules, enhanced RCM κ-casein fibril formation irrespective of whether the lipids were in a monomeric or micellar state, whereas shorter-chain phospholipids and triglycerides had little effect. Heparan sulfate, a component of the milk fat globule membrane and catalyst of amyloid deposition in extracellular tissue, had little effect on the kinetics of RCM κ-casein fibril formation. Major nutritional components such as calcium and lactose also had no significant effect. Macromolecular crowding enhances protein-protein interactions, but in contrast to other fibril-forming species, the extent of RCM κ-casein fibril formation was reduced by the presence of a variety of crowding agents. These data are consistent with a mechanism of κ-casein fibril formation in which the rate-determining step is dissociation from the oligomer to give the highly amyloidogenic monomer. We conclude that the interaction of κ-casein with membrane-associated phospholipids along its secretory pathway may contribute to the development of amyloid deposits in mammary tissue. However, the formation of spherical oligomers such as casein micelles is favored over amyloid fibrils in the crowded environment of milk, within which the occurrence of amyloid fibrils is low.

Improvement of ACE inhibitory activity of casein hydrolysate by Maillard reaction with xylose.

Science.gov (United States)

Hong, Xu; Meng, Jun; Lu, Rong-Rong

2015-01-01

The Maillard reaction is widely used to improve the functional properties or biological activities of food. The purpose of this study was to investigate the effect of the Maillard reaction on angiotensin I converting enzyme (ACE) inhibitory activity in a casein hydrolysate-xylose system. Two-step hydrolysis was used to prepare casein ACE inhibitory peptides. Maillard reaction products (MRPs) were prepared by heating hydrolyzed casein with xylose at pH 8.0, 110 °C for up to 16 h. The results showed that the content of free amino group decreased (P Maillard reaction (P reaction in the MRPs. The study shows that the Maillard reaction under appropriate conditions can improve the ACE inhibitory activity of casein hydrolysate effectively. © 2014 Society of Chemical Industry.

The 'retro-design' concept for novel kinase inhibitors.

Science.gov (United States)

Müller, Gerhard; Sennhenn, Peter C; Woodcock, Timothy; Neumann, Lars

2010-07-01

Protein kinases are among the most attractive therapeutic targets for a broad range of diseases. This feature review highlights and classifies the main design principles employed to generate active and selective kinase inhibitors. In particular, emphasis is focused on a fragment-based lead-generation approach, which constitutes a novel design method for developing type II kinase inhibitors with distinct binding kinetic attributes. This 'retro-design' strategy relies on a customized fragment library, and contrasts the traditional approach used in the design of type II inhibitors.

Hydrolyzed Casein Reduces Diet-Induced Obesity in Male C57BL/6J Mice

DEFF Research Database (Denmark)

Lillefosse, Haldis H.; Tastesen, Hanne Sørup; Du, Zhen-Yu

2013-01-01

used a factorial ANOVA design to investigate the effects of protein form (intact vs. hydrolyzed casein) and protein level (16 vs. 32 energy percent protein) on body mass gain and adiposity in obesity-prone male C57BL/6J mice fed Western diets with 35 energy percent fat. Mice fed the hydrolyzed casein......The digestion rate of dietary protein is a regulating factor for postprandial metabolism both in humans and animal models. However, few data exist about the habitual consumption of proteins with different digestion rates with regard to the development of body mass and diet-induced obesity. Here, we...... diets had higher spontaneous locomotor activity than mice fed intact casein. During the light phase, mice fed hydrolyzed casein tended (P = 0.08) to have a lower respiratory exchange ratio, indicating lower utilization of carbohydrates as energy substrate relative to those fed intact casein. In further...

Enhanced pattern resolution, swelling-behaviour and biocompatibility of bioimprinted casein microdevices

Directory of Open Access Journals (Sweden)

Azadeh Hashemi

2017-11-01

Full Text Available This work introduces casein microstructures with surface features as a biodegradable biomedical platform technology for enhancing tissue-engineering applications. An optimized fabrication process is presented to reduce the hydrophobicity of intermediate polydimethylsiloxane (PDMS molds and to transfer high-resolution regular and biomimetic features onto the surface of casein devices. Four different cross-linking reagents, glutaraldehyde, formaldehyde, citric acid and transglutaminase (TG were investigated to increase the degradation time of casein and their influence on swelling and biocompatibility of the films was studied. TG was found to be the only cross-linker to effectively increase the degradation time and show reduced film swelling after immersion into media, while remaining compatible with cell-culture. The maximum expansion of the films cross-linked via TG was 33% after 24 hours of immersion in cell-culture media. C2C12 cells were successfully cultured on the patterned films for up to 72 hours. The patterned biodegradable casein substrates presented here have promising applications in stem-cell engineering, regenerative medicine, and implantable devices.

Enhanced pattern resolution, swelling-behaviour and biocompatibility of bioimprinted casein microdevices

Science.gov (United States)

Hashemi, Azadeh; de Decker, Fanny; Orcheston-Findlay, Louise; Ali, M. Azam; Alkaisi, Maan M.; Nock, Volker

2017-11-01

This work introduces casein microstructures with surface features as a biodegradable biomedical platform technology for enhancing tissue-engineering applications. An optimized fabrication process is presented to reduce the hydrophobicity of intermediate polydimethylsiloxane (PDMS) molds and to transfer high-resolution regular and biomimetic features onto the surface of casein devices. Four different cross-linking reagents, glutaraldehyde, formaldehyde, citric acid and transglutaminase (TG) were investigated to increase the degradation time of casein and their influence on swelling and biocompatibility of the films was studied. TG was found to be the only cross-linker to effectively increase the degradation time and show reduced film swelling after immersion into media, while remaining compatible with cell-culture. The maximum expansion of the films cross-linked via TG was 33% after 24 hours of immersion in cell-culture media. C2C12 cells were successfully cultured on the patterned films for up to 72 hours. The patterned biodegradable casein substrates presented here have promising applications in stem-cell engineering, regenerative medicine, and implantable devices.

Thymol nanoencapsulated by sodium caseinate: physical and antilisterial properties.

Science.gov (United States)

Pan, Kang; Chen, Huaiqiong; Davidson, P Michael; Zhong, Qixin

2014-02-19

In this work, thymol was encapsulated in sodium caseinate using high shear homogenization. The transparent dispersion at neutral pH was stable for 30 days at room temperature as determined by dynamic light scattering and atomic force microscopy, which agreed with high ζ potential of nanoparticles. The slightly decreased particle dimension during storage indicates the absence of Ostwald ripening. When molecular binding was studied by fluorescence spectroscopy, thymol was observed to bind with tyrosine and possibly other amino acid residues away from tryptophan of caseins. At pH 4.6 (isoelectric point of caseins), the stabilization of thymol nanoparticles against aggregation was enabled by soluble soybean polysaccharide, resulting from the combined electrostatic and steric repulsions. The encapsulated thymol showed the significantly improved antilisterial activity in milk with different fat levels when compared to thymol crystals, resulting from the quicker mixing and increased solubility in the milk serum. The transparent thymol nanodispersions have promising applications to improve microbiological safety and quality of foods.

Polymerization of calcium caseinates solutions induced by gamma irradiation

International Nuclear Information System (INIS)

Lacroix, M.; Jobin, M.; Mezgheni, E.; Srour, M.; Boileau, S.

1998-01-01

Solutions of calcium caseinate (5%) combined with propylene glycol (PG) or triethylene glycol(TEG) (0, 2.5% and 5%) and used for the development of edible films and coatings, were irradiated at doses between 0 to 128 kGy. Solutions were chromatographed through toyopearl HW 55F resin to observe the effect of irradiation on cross-link reactions. In unirradiated calcium caseinate solutions, two peaks could be observed (fractions 30 and 37) while samples irradiated at 64 kGy and 128 kGy showed one shifted peak at fraction 32 and 29 respectively. No effect of the plasticizers was observed. According to proteins standards of knowed molecular weights, the molecular weight of calcium caseinate increased approximately 10 times when irradiated at 128 kGy and 5 times when irradiated at 64 kGy. The physico-chemical properties of bio-films prepared with the irradiated solutions, demonstrated that tensile strength at break increased with increase of irradiation dose. A maximum dose was obtained at 16 kGy

Whey or Casein Hydrolysate with Carbohydrate for Metabolism and Performance in Cycling.

Science.gov (United States)

Oosthuyse, T; Carstens, M; Millen, A M E

2015-07-01

The protein type most suitable for ingestion during endurance exercise is undefined. This study compared co-ingestion of either 15 g/h whey or casein hydrolysate with 63 g/h fructose: maltodextrin (0.8:1) on exogenous carbohydrate oxidation, exercise metabolism and performance. 2 h postprandial, 8 male cyclists ingested either: carbohydrate-only, carbohydrate-whey hydrolysate, carbohydrate-casein hydrolysate or placebo-water in a crossover, double-blind design during 2 h of exercise at 60%W max followed by a 16-km time trial. Data were evaluated by magnitude-based inferential statistics. Exogenous carbohydrate oxidation, measured from (13)CO2 breath enrichment, was not substantially influenced by co-ingestion of either protein hydrolysate. However, only co-ingestion of carbohydrate-casein hydrolysate substantially decreased (98% very likely decrease) total carbohydrate oxidation (mean±SD, 242±44; 258±47; 277±33 g for carbohydrate-casein, carbohydrate-whey and carbohydrate-only, respectively) and substantially increased (93% likely increase) total fat oxidation (92±14; 83±27; 73±19 g) compared with carbohydrate-only. Furthermore, only carbohydrate-casein hydrolysate ingestion resulted in a faster time trial (-3.6%; 90% CI: ±3.2%) compared with placebo-water (95% likely benefit). However, neither protein hydrolysate enhanced time trial performance when compared with carbohydrate-only. Under the conditions of this study, ingesting carbohydrate-casein, but not carbohydrate-whey hydrolysate, favourably alters metabolism during prolonged moderate-strenuous cycling without substantially altering cycling performance compared with carbohydrate-only. © Georg Thieme Verlag KG Stuttgart · New York.

Examination of rheological properties of aqueous solutions of sodium caseinate

OpenAIRE

Jolanta Gawałek; Piotr Wesołowski

2012-01-01

Application of sodium caseinate as a functional additive in manufacturing processes requires production of its concentrated aqueous solutions which, in industrial conditions, presents a number of difficulties. In order to develop an effective and optimal industrial process of mixing – manufacturing a concentrated solution of sodium caseinate, it is essential to know rheological properties in a definite range of concentrations changing in the course of the dissolving process. The materia...

Interfacial composition and stability of emulsions made with mixtures of commercial sodium caseinate and whey protein concentrate.

Science.gov (United States)

Ye, Aiqian

2008-10-15

The interfacial composition and the stability of oil-in-water emulsion droplets (30% soya oil, pH 7.0) made with mixtures of sodium caseinate and whey protein concentrate (WPC) (1:1 by protein weight) at various total protein concentrations were examined. The average volume-surface diameter (d32) and the total surface protein concentration of emulsion droplets were similar to those of emulsions made with both sodium caseinate alone and WPC alone. Whey proteins were adsorbed in preference to caseins at low protein concentrations (caseins were adsorbed in preference to whey proteins at high protein concentrations. The creaming stability of the emulsions decreased markedly as the total protein concentration of the system was increased above 2% (sodium caseinate >1%). This was attributed to depletion flocculation caused by the sodium caseinate in these emulsions. Whey proteins did not retard this instability in the emulsions made with mixtures of sodium caseinate and WPC. Copyright © 2008 Elsevier Ltd. All rights reserved.

Effects of dietary casein and soy protein on metabolism of radiolabelled low density apolipoprotein B in rabbits

International Nuclear Information System (INIS)

Samman, S.; Khosla, P.; Carroll, K.K.

1989-01-01

Rabbits fed semipurified diets containing casein have elevated plasma cholesterol levels compared to those fed soy protein. As part of continuing studies on the mechanism of casein-induced hypercholesterolemia, two groups of six rabbits were fed these diets for 14 to 16 weeks. Animals fed the casein diet were found to have significantly higher plasma concentrations of protein, cholesterol, triacylglycerol, phospholipid and apolipoprotein B (apo B) associated with low density lipoprotein (LDL) than those fed the soy protein diet. Kinetic studies showed that the fractional catabolic rate of LDL-apo B was significantly lower in animals fed casein than in those fed soy protein regardless of whether the tracer LDL was obtained from donors fed casein or soy protein. The production rate of LDL-apo B was higher in casein-fed animals but this was not statistically significant. These results show that the efficiency of removal of LDL is significantly reduced in animals fed casein compared to those fed soy protein, and that the source of LDL did not affect the efficiency of its subsequent removal. The accumulation of LDL in casein-fed animals is consistent with down-regulation of the LDL receptor

Brain Region-Specific Effects of cGMP-Dependent Kinase II Knockout on AMPA Receptor Trafficking and Animal Behavior

Science.gov (United States)

Kim, Seonil; Pick, Joseph E.; Abera, Sinedu; Khatri, Latika; Ferreira, Danielle D. P.; Sathler, Matheus F.; Morison, Sage L.; Hofmann, Franz; Ziff, Edward B.

2016-01-01

Phosphorylation of GluA1, a subunit of AMPA receptors (AMPARs), is critical for AMPAR synaptic trafficking and control of synaptic transmission. cGMP-dependent protein kinase II (cGKII) mediates this phosphorylation, and cGKII knockout (KO) affects GluA1 phosphorylation and alters animal behavior. Notably, GluA1 phosphorylation in the KO…

The pressure-induced, lactose-dependent changes in the composition and size of casein micelles.

Science.gov (United States)

Wang, Pengjie; Jin, Shaoming; Guo, Huiyuan; Zhao, Liang; Ren, Fazheng

2015-04-15

The effects of lactose on the changes in the composition and size of casein micelles induced by high-pressure treatment and the related mechanism of action were investigated. Dispersions of ultracentrifuged casein micelle pellets with 0-10% (w/v) lactose were subjected to high pressure (400 MPa) at 20 °C for 40 min. The results indicated that the level of non-sedimentable caseins was positively related to the amount of lactose added prior to pressure treatment, and negatively correlated to the size. A mechanism for the pressure-induced, lactose-dependent changes in the casein micelles is proposed. Lactose inhibits the hydrophobic interactions between the micellar fragments during or after pressure release, through the hydrophilic layer formed by their hydrogen bonds around the micellar fragments. In addition, lactose does not favour the association between calcium and the casein aggregates after pressure release. Due to these two functions, lactose inhibited the formation of larger micelles after pressure treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stimulation of muscle protein synthesis by whey and caseinate ingestion after resistance exercise in elderly individuals

DEFF Research Database (Denmark)

Dideriksen, K J; Reitelseder, S; Petersen, S G

2011-01-01

Sarcopenia is a well-known phenomenon in elderly individuals and resistance exercise together with sufficient amino acid (AA) availability has proved to be a counteractive implement. However, the source of AA and supplement timing require further investigation. The objective was to compare muscle...... protein synthesis (MPS) to intakes of whey and caseinate after heavy resistance exercise in healthy elderly individuals, and, furthermore, to compare the timing effect of caseinate intake. Twenty-four elderly men and women (mean ± SEM; 68 ± 1 years) were randomized to one of four groups: caseinate intake...... and caseinate feeding immediately after heavy resistance exercise in elderly individuals, and MPS is similar with caseinate ingestion before and after exercise....

Heteroaggregation of lipid droplets coated with sodium caseinate and lactoferrin.

Science.gov (United States)

de Figueiredo Furtado, Guilherme; Michelon, Mariano; de Oliveira, Davi Rocha Bernardes; da Cunha, Rosiane Lopes

2016-11-01

Formation and characterization of droplet heteroaggregates were investigated by mixing two emulsions previously stabilized by proteins oppositely charged. Emulsions were composed of 5vol.% of sunflower oil and 95vol.% of sodium caseinate or lactoferrin aqueous dispersions. They were produced using ultrasound with fixed power (300W) and sonication time (6min). Different volume ratios (0-100%) of sodium caseinate-stabilized emulsion (droplet diameter around 1.75μm) to lactoferrin-stabilized emulsion (droplet diameter around 1.55μm) were mixed under conditions that both proteins showed opposite charges (pH7). Influence of ionic strength (0-400mM NaCl) on the heteroaggregates stability was also evaluated. Creaming stability, zeta potential, microstructure, mean particle diameter and rheological properties of the heteroaggregates were measured. These properties depended on the volume ratio (0-100%) of sodium caseinate to lactoferrin-stabilized emulsion (C:L) and the ionic strength. In the absence of salt, different zeta potential values were obtained, rheological properties (viscosity and elastic moduli) were improved and the largest heteroaggregates were formed at higher content of lactoferrin-stabilized emulsion (60-80%). The system containing 40 and 60vol.% of sodium caseinate and lactoferrin stabilized emulsion, respectively, presented good stability against phase separation besides showing enhanced rheological and size properties due to extensive droplets aggregation. Phase separation was observed only in the absence of sodium caseinate, demonstrating the higher susceptibility of lactoferrin to NaCl. The heteroaggregates produced may be useful functional agents for texture modification and controlled release since different rheological properties and sizes can be achieved depending on protein concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

The association of low-molecular-weight hydrophobic compounds with native casein micelles in bovine milk.

Science.gov (United States)

Cheema, M; Mohan, M S; Campagna, S R; Jurat-Fuentes, J L; Harte, F M

2015-08-01

The agreed biological function of the casein micelles in milk is to carry minerals (calcium, magnesium, and phosphorus) from mother to young along with amino acids for growth and development. Recently, native and modified casein micelles were used as encapsulating and delivery agents for various hydrophobic low-molecular-weight probes. The ability of modified casein micelles to bind certain probes may derive from the binding affinity of native casein micelles. Hence, a study with milk from single cows was conducted to further elucidate the association of hydrophobic molecules into native casein micelles and further understand their biological function. Hydrophobic and hydrophilic extraction followed by ultraperformance liquid chromatography-high resolution mass spectrometry analysis were performed over protein fractions obtained from size exclusion fractionation of raw skim milk. Hydrophobic compounds, including phosphatidylcholine, lyso-phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin, showed strong association exclusively to casein micelles as compared with whey proteins, whereas hydrophilic compounds did not display any preference for their association among milk proteins. Further analysis using liquid chromatography-tandem mass spectrometry detected 42 compounds associated solely with the casein-micelles fraction. Mass fragments in tandem mass spectrometry identified 4 of these compounds as phosphatidylcholine with fatty acid composition of 16:0/18:1, 14:0/16:0, 16:0/16:0, and 18:1/18:0. These results support that transporting low-molecular-weight hydrophobic molecules is also a biological function of the casein micelles in milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Optimization of β-casein stabilized nanoemulsions using experimental mixture design.

Science.gov (United States)

Maher, Patrick G; Fenelon, Mark A; Zhou, Yankun; Kamrul Haque, Md; Roos, Yrjö H

2011-10-01

The objective of this study was to determine the effect of changing viscosity and glass transition temperature in the continuous phase of nanoemulsion systems on subsequent stability. Formulations comprising of β-casein (2.5%, 5%, 7.5%, and 10% w/w), lactose (0% to 20% w/w), and trehalose (0% to 20% w/w) were generated from Design of Experiments (DOE) software and tested for glass transition temperature and onset of ice-melting temperature in maximally freeze-concentrated state (T(g) ' & T(m) '), and viscosity (μ). Increasing β-casein content resulted in significant (P mixture design was used to predict the optimum levels of lactose and trehalose required to attain the minimum and maximum T(g) ' and viscosity in solution at fixed protein contents. These mixtures were used to form the continuous phase of β-casein stabilized nanoemulsions (10% w/w sunflower oil) prepared by microfluidization at 70 MPa. Nanoemulsions were analyzed for T(g) ' & T(m) ', as well as viscosity, mean particle size, and stability. Increasing levels of β-casein (2.5% to 10% w/w) resulted in a significant (P mixture DOE was successfully used to predict glass transition and rheological properties for development of a continuous phase for use in nanoemulsions. © 2011 Institute of Food Technologists®

Phase behavior, rheological characteristics and microstructure of sodium caseinate-Persian gum system.

Science.gov (United States)

Sadeghi, Farzad; Kadkhodaee, Rassoul; Emadzadeh, Bahareh; Phillips, Glyn O

2018-01-01

In this study, the phase behavior of sodium caseinate-Persian gum mixtures was investigated. The effect of thermodynamic incompatibility on phase distribution of sodium caseinate fractions as well as the flow behavior and microstructure of the biopolymer mixtures were also studied. The phase diagram clearly demonstrated the dominant effect of Persian gum on the incompatibility of the two biopolymers. SDS-PAGE electrophoresis indicated no selective fractionation of sodium caseinate subunits between equilibrium phases upon de-mixing. The microstructure of mixtures significantly changed depending on their position within the phase diagram. Fitting viscometric data to Cross and Bingham models revealed that the apparent viscosity, relaxation time and shear thinning behavior of the mixtures is greatly influenced by the volume ratio and concentration of the equilibrium phases. There is a strong dependence of the flow behavior of sodium caseinate-Persian gum mixtures on the composition of the equilibrium phases and the corresponding microstructure of the system. Copyright © 2017. Published by Elsevier Ltd.

Characterization of phosphorylation sites in the cytoplasmic domain of the 300 kDa mannose-6-phosphate receptor

DEFF Research Database (Denmark)

Rosorius, O; Mieskes, G; Issinger, O G

1993-01-01

The human 300 kDa mannose-6-phosphate receptor (MPR 300) is phosphorylated in vivo at serine residues of its cytoplasmic domain. Two-dimensional separation can resolve tryptic phosphopeptides into four major species. To identify the kinases involved in MPR 300 phosphorylation and the phosphorylat......The human 300 kDa mannose-6-phosphate receptor (MPR 300) is phosphorylated in vivo at serine residues of its cytoplasmic domain. Two-dimensional separation can resolve tryptic phosphopeptides into four major species. To identify the kinases involved in MPR 300 phosphorylation...... and the phosphorylation sites the entire coding sequence of the cytoplasmic tail was expressed in Escherichia coli. The isolated cytoplasmic domain was used as a substrate for four purified serine/threonine kinases [casein kinase II (CK II), protein kinase A (PKA), protein kinase C and Ca2+/calmodulin kinase]. All...... kinases phosphorylate the cytoplasmic tail exclusively on serine residues. Inhibition studies using synthetic peptides, partial sequencing of isolated tryptic phosphopeptides and co-migration with tryptic phosphopeptides from MPR 300 labelled in vivo showed that (i) PKA phosphorylates the cytoplasmic MPR...

Antiproliferative activity of tea catechins associated with casein micelles, using HT29 colon cancer cells.

Science.gov (United States)

Haratifar, S; Meckling, K A; Corredig, M

2014-02-01

Numerous studies have shown that green tea polyphenols display anticancer activities in many organ sites by using different experimental models in rodents and in cultured cell lines in vitro. The present study tested the ability of casein micelles to deliver biologically active concentrations of polyphenols to HT-29 colon cancer cells. Epigallocatechin gallate (EGCG), the major catechin found in green tea, was used as the model molecule, as it has been shown to have antiproliferative activity on colon cancer cells. In the present work, we hypothesized that due to the binding of caseins with EGCG, casein micelles may be an ideal platform for the delivery of this bioactive molecule and that the binding would not affect the bioaccessibility of EGCG. The cytotoxicity and proliferation behavior of HT-29 colon cancer cells when exposed to free EGCG was compared with that of nanoencapsulated EGCG in casein micelles of skim milk. Epigallocatechin gallate-casein complexes were able to decrease the proliferation of HT-29 cancer cells, demonstrating that bioavailability may not be reduced by the nanoencapsulation. As casein micelles may act as protective carriers for EGCG in foods, it was concluded that nanoencapsulation of tea catechins in casein micelles may not diminish their antiproliferative activity on colon cancer cells compared with free tea catechins. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Categorization of rheological scaling models for particle gels applied to casein gels

NARCIS (Netherlands)

Mellema, M.; Opheusden, van J.H.J.; Vliet, van T.

2002-01-01

Rennet-induced casein gels made from skim milk were studied rheologically. A scaling model or framework for describing the rheological behavior of gels is discussed and used for classification of the structure of casein gels. There are two main parameters in the model that describe the number of

High pressure homogenization to improve the stability of casein - hydroxypropyl cellulose aqueous systems.

Science.gov (United States)

Ye, Ran; Harte, Federico

2014-03-01

The effect of high pressure homogenization on the improvement of the stability hydroxypropyl cellulose (HPC) and micellar casein was investigated. HPC with two molecular weights (80 and 1150 kDa) and micellar casein were mixed in water to a concentration leading to phase separation (0.45% w/v HPC and 3% w/v casein) and immediately subjected to high pressure homogenization ranging from 0 to 300 MPa, in 100 MPa increments. The various dispersions were evaluated for stability, particle size, turbidity, protein content, and viscosity over a period of two weeks and Scanning Transmission Electron Microscopy (STEM) at the end of the storage period. The stability of casein-HPC complexes was enhanced with the increasing homogenization pressure, especially for the complex containing high molecular weight HPC. The apparent particle size of complexes was reduced from ~200nm to ~130nm when using 300 MPa, corresponding to the sharp decrease of absorbance when compared to the non-homogenized controls. High pressure homogenization reduced the viscosity of HPC-casein complexes regardless of the molecular weight of HPC and STEM imagines revealed aggregates consistent with nano-scale protein polysaccharide interactions.

Phase behavior of casein micelles/exocellular polysaccharide mixtures: Experiment and theory

Science.gov (United States)

Tuinier, R.; de Kruif, C. G.

1999-05-01

Dispersions of casein micelles and an exocellular polysaccharide (EPS), obtained from Lactococcus lactis subsp. cremoris NIZO B40 EPS, show a phase separation. The phase separation is of the colloidal gas-liquid type. We have determined a phase diagram that describes the separation of skim milk with EPS into a casein-micelle rich phase and an EPS rich phase. We compare the phase diagram with those calculated from theories developed by Vrij, and by Lekkerkerker and co-workers, showing that the experimental phase boundary can be predicted quite well. From dynamic light scattering measurements of the self-diffusion of the casein micelles in the presence of EPS the spinodal could be located and it corresponds with the experimental phase boundary.

Casein addition to a whey-based formula has limited effects on gut function in preterm pigs

DEFF Research Database (Denmark)

Thymann, T.; Støy, Ann Cathrine Findal; Bering, S. B.

2012-01-01

Preterm infants are susceptible to necrotizing enterocolitis (NEC). Using preterm pigs, we determined whether a whey–casein-based formula would be superior to a formula based on whey protein alone. Twenty cesarean-derived preterm pigs (92% gestation) were given total parenteral nutrition for 36 h...... followed by 30 h of enteral feeding with whey [protein fraction of milk formula based on whey (WHEY); n = 11] or casein and/or whey [protein fraction of milk formula based on a combination of casein and whey (CASEIN); n = 9]-based formulas. Sugar absorptive function was investigated at 6 and 30 h after...... studied in gut contents. Severity of NEC lesions was similar between diet groups but galactose absorption was markedly higher in CASEIN than in WHEY (P

Search for phosphopeptides in the feces of axenic rats fed radioactive ovine casein

International Nuclear Information System (INIS)

Pelissier, J.P.; Dubos, F.; Daburon, F.

1981-01-01

Radioactive ovine casein was obtained by injecting 100 μCi of 14 C-Ser into the jugular vein of an ewe. The milk collected 17 and 24 h after this injection contained 12% of the radioactivity injected in protein form. The seryl residues were specificially labelled. This casein was used as the only protein source fed to axenic rats; 0.30% of the tracer ingested was found in the feces of those rats. Since phosphoserine represented 25% of the total casein seryl residues, the phosphopeptides may not be selectively unabsorbable [fr

Behaviour of casein micelles at conditions comparable to those in ice cream

NARCIS (Netherlands)

Jonkman, M.J.

2000-01-01

The physical properties of ice cream are mainly determined by the processing and the ingredients. Milk (powder) is one of the ingredients and ice cream thus contains casein, the major milk protein. A large proportion of casein in ice cream is present in the plasma phase of ice cream. Since

IL-6 stabilizes Twist and enhances tumor cell motility in head and neck cancer cells through activation of casein kinase 2.

Directory of Open Access Journals (Sweden)

Ying-Wen Su

Full Text Available BACKGROUND: Squamous cell carcinoma of the head and neck (SCCHN is the seventh most common cancer worldwide. Unfortunately, the survival of patients with SCCHN has not improved in the last 40 years, and thus new targets for therapy are needed. Recently, elevations in serum level of interleukin 6 (IL-6 and expression of Twist in tumor samples were found to be associated with poor clinical outcomes in multiple types of cancer, including SCCHN. Although Twist has been proposed as a master regulator of epithelial-mesenchymal transition and metastasis in cancers, the mechanisms by which Twist levels are regulated post-translationally are not completely understood. Tumor progression is characterized by the involvement of cytokines and growth factors and Twist induction has been connected with a number of these signaling pathways including IL-6. Since many of the effects of IL-6 are mediated through activation of protein phosphorylation cascades, this implies that Twist expression must be under a tight control at the post-translational level in order to respond in a timely manner to external stimuli. METHODOLOGY/PRINCIPAL FINDINGS: Our data show that IL-6 increases Twist expression via a transcription-independent mechanism in many SCCHN cell lines. Further investigation revealed that IL-6 stabilizes Twist in SCCHN cell lines through casein kinase 2 (CK2 phosphorylation of Twist residues S18 and S20, and that this phosphorylation inhibits degradation of Twist. Twist phosphorylation not only increases its stability but also enhances cell motility. Thus, post-translational modulation of Twist contributes to its tumor-promoting properties. CONCLUSIONS/SIGNIFICANCE: Our study shows Twist expression can be regulated at the post-translational level through phosphorylation by CK2, which increases Twist stability in response to IL-6 stimulation. Our findings not only provide novel mechanistic insights into post-translational regulation of Twist but also suggest

Use of sunlight to partially detoxify groundnut (peanut) cake flour and casein contaminated with aflatoxin B1.

Science.gov (United States)

Shantha, T; Murthy, V S

1981-03-01

Sunlight destroyed 83 and 50% of the toxin added to casein and groundnut cake flour, respectively. Equilibrium dialysis revealed that both casein and groundnut protein bind aflatoxin but the toxin bound to casein appeared more photo-labile than that bound to groundnut protein.

Optimizing the taste-masked formulation of acetaminophen using sodium caseinate and lecithin by experimental design.

Science.gov (United States)

Hoang Thi, Thanh Huong; Lemdani, Mohamed; Flament, Marie-Pierre

2013-09-10

In a previous study of ours, the association of sodium caseinate and lecithin was demonstrated to be promising for masking the bitterness of acetaminophen via drug encapsulation. The encapsulating mechanisms were suggested to be based on the segregation of multicomponent droplets occurring during spray-drying. The spray-dried particles delayed the drug release within the mouth during the early time upon administration and hence masked the bitterness. Indeed, taste-masking is achieved if, within the frame of 1-2 min, drug substance is either not released or the released amount is below the human threshold for identifying its bad taste. The aim of this work was (i) to evaluate the effect of various processing and formulation parameters on the taste-masking efficiency and (ii) to determine the optimal formulation for optimal taste-masking effect. Four investigated input variables included inlet temperature (X1), spray flow (X2), sodium caseinate amount (X3) and lecithin amount (X4). The percentage of drug release amount during the first 2 min was considered as the response variable (Y). A 2(4)-full factorial design was applied and allowed screening for the most influential variables i.e. sodium caseinate amount and lecithin amount. Optimizing these two variables was therefore conducted by a simplex approach. The SEM and DSC results of spray-dried powder prepared under optimal conditions showed that drug seemed to be well encapsulated. The drug release during the first 2 min significantly decreased, 7-fold less than the unmasked drug particles. Therefore, the optimal formulation that performed the best taste-masking effect was successfully achieved. Copyright © 2013 Elsevier B.V. All rights reserved.

On studying protein phosphorylation patterns using bottom-up LC-MS/MS: the case of human alpha-casein

DEFF Research Database (Denmark)

Kjeldsen, Frank; Savitski, Mikhail M; Nielsen, Michael L

2007-01-01

-LC-MS/MS. The occupancy rates of phosphosites in proteins may differ by orders of magnitude, and thus the occupancy rate must be reported for each occupied phosphosite. To highlight potential pitfalls in quantifying the occupancy rates, alpha(s1)-casein from human milk was selected as a model molecule representing...... moderately phosphorylated proteins. For this purpose, human milk from one Caucasian woman in the eighth month of lactation was used. The phosphorylation level of caseins is believed to have major implications for the formation of micelles that are involved in delivering valuable calcium phosphate and other...... minerals to the new-born. Human alpha(s1)-casein has been reported to be much less phosphorylated than ruminant caseins, which may indicate a different function of caseins in humans. Revealing the phosphorylation pattern in human casein can thus shed light on its function. The current study found...

2,5-hexanedione (HD) treatment alters calmodulin, Ca2+/calmodulin-dependent protein kinase II, and protein kinase C in rats' nerve tissues

International Nuclear Information System (INIS)

Wang Qingshan; Hou Liyan; Zhang Cuili; Zhao Xiulan; Yu Sufang; Xie, Ke-Qin

2008-01-01

Calcium-dependent mechanisms, particularly those mediated by Ca 2+ /calmodulin (CaM)-dependent protein kinase II (CaMKII), have been implicated in neurotoxicant-induced neuropathy. However, it is unknown whether similar mechanisms exist in 2,5-hexanedione (HD)-induced neuropathy. For that, we investigated the changes of CaM, CaMKII, protein kinase C (PKC) and polymerization ratios (PRs) of NF-L, NF-M and NF-H in cerebral cortex (CC, including total cortex and some gray), spinal cord (SC) and sciatic nerve (SN) of rats treated with HD at a dosage of 1.75 or 3.50 mmol/kg for 8 weeks (five times per week). The results showed that CaM contents in CC, SC and SN were significantly increased, which indicated elevation of Ca 2+ concentrations in nerve tissues. CaMKII contents and activities were also increased in CC and were positively correlated with gait abnormality, but it could not be found in SC and SN. The increases of PKC contents and activities were also observed in SN and were positively correlated with gait abnormality. Except for that of NF-M in CC, the PRs of NF-L, NF-M and NF-H were also elevated in nerve tissues, which was consistent with the activation of protein kinases. The results suggested that CaMKII might be partly (in CC but not in SC and SN) involved in HD-induced neuropathy. CaMKII and PKC might mediate the HD neurotoxicity by altering the NF phosphorylation status and PRs

Type II cGMP‑dependent protein kinase inhibits the migration, invasion and proliferation of several types of human cancer cells.

Science.gov (United States)

Wu, Min; Wu, Yan; Qian, Hai; Tao, Yan; Pang, Ji; Wang, Ying; Chen, Yongchang

2017-10-01

Previous studies have indicated that type II cyclic guanosine monophosphate (cGMP)‑dependent protein kinase (PKG II) could inhibit the proliferation and migration of gastric cancer cells. However, the effects of PKG II on the biological functions of other types of cancer cells remain to be elucidated. Therefore, the aim of the present study was to investigate the effects of PKG II on cancer cells derived from various types of human tissues, including A549 lung, HepG2 hepatic, OS‑RC‑2 renal, SW480 colon cancer cells and U251 glioma cells. Cancer cells were infected with adenoviral constructs coding PKG II (Ad‑PKG II) to up‑regulate PKG II expression, and treated with 8‑(4‑chlorophenylthio) (8‑pCPT)‑cGMP to activate the kinase. A Cell Counting kit 8 assay was used to detect cell proliferation. Cell migration was measured using a Transwell assay, whereas a terminal deoxynucleotidyl transferase 2'‑deoxyuridine, 5'‑triphosphate nick‑end labeling assay was used to detect cell apoptosis. A pull‑down assay was used to investigate the activation of Ras‑related C3 botulinum toxin substrate (Rac) 1 and western blotting was used to detect the expression of proteins of interest. The present results demonstrated that EGF (100 ng/ml, 24 h) promoted the proliferation and migration of cancer cells, and it suppressed their apoptosis. In addition, treatment with EGF enhanced the activation of Rac1, and up‑regulated the protein expression of proliferating cell nuclear antigen, matrix metalloproteinase (MMP)2, MMP7 and B‑cell lymphoma (Bcl)‑2, whereas it down‑regulated the expression of Bcl‑2‑associated X protein. Transfection of cancer cells with Ad‑PKG II, and PKG II activation with 8‑pCPT‑cGMP, was identified to counteract the effects triggered by EGF. The present results suggested that PKG II may exert inhibitory effects on the proliferation and migration of various types of cancer cells.

Effect of casein and inulin addition on physico-chemical characteristics of low fat camel dairy cream.

Science.gov (United States)

Ziaeifar, Leila; Labbafi Mazrae Shahi, Mohsen; Salami, Maryam; Askari, Gholam R

2018-05-21

The effect of the addition of the camel casein fraction on some physico-chemical properties of low fat camel milk cream was studied. Oil-in-water emulsions, 25, 30, and 35 (w/w) fat, were prepared using inulin, camel skim milk, milk fat and variable percentages of casein (1, 2, and 3% w/w). The droplet size, ζ-potential, surface protein concentration, viscosity and surface tension of low fat dairy creams was measured. Cream containing 2% (w/w) casein had better stability. The modifications in physico-chemical properties appeared to be driven by changes in particle size distribution caused by droplet aggregation. The cream containing 2% casein leads to a gradual decrease in droplet size, as the particle size decreased, apparent viscosity increased. When casein concentration increased, ζ-potential decreased due to combination of c terminal (negative charge) with the surface of fat particles but steric repulsion improved textural properties. Cream with 30% fat and 2% casein had the best result. Copyright © 2018 Elsevier B.V. All rights reserved.

Nano-preparation of Andrographis paniculata extract by casein micelle for antidiabetic agent

Science.gov (United States)

Arbianti, Rita; Dewi, Veronica; Imansari, Farisa; Hermansyah, Heri; Sahlan, Muhamad

2017-02-01

Side effects caused by oral medications for person with diabetic are the background of the development of alternative treatments by traditional medicine, herbs. Andrographis paniculata (AP) is one of the herbs that is potent to be anti-diabetic agent. The active compound of AP, andrographolide have been examined to have anti-diabetic activity as α-glucosidase enzyme inhibitor. This research aims to encapsulate sambiloto's extract with casein micelle and produce nanoparticles which have anti-diabetic activity as α-glucosidase inhibitor. Extract of AP is encapsulated by casein micelle and made into nano size using sonicator. The dominant active compounds in AP extract coated by casein are andrographolide, neoandrographolide, 14-deoxy-11,12didehydroandrographolide with encapsulation efficiency of 68.83%, 89.15% and 81.69%, the average diameter of the particles is about 120.57 nm and its loading capacity is 28.85%. AP's extract has antidiabetic activity as α-glucosidase inhibitor with percent inhibition of 95%. The morphology of nanoencapsulated AP's extract analyzed by FE-SEM, were similar with casein micelle.

Analysis of bovine milk caseins on organic monolithic columns: an integrated capillary liquid chromatography-high resolution mass spectrometry approach for the study of time-dependent casein degradation.

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Pierri, Giuseppe; Kotoni, Dorina; Simone, Patrizia; Villani, Claudio; Pepe, Giacomo; Campiglia, Pietro; Dugo, Paola; Gasparrini, Francesco

2013-10-25

Casein proteins constitute approximately 80% of the proteins present in bovine milk and account for many of its nutritional and technological properties. The analysis of the casein fraction in commercially available pasteurized milk and the study of its time-dependent degradation is of considerable interest in the agro-food industry. Here we present new analytical methods for the study of caseins in fresh and expired bovine milk, based on the use of lab-made capillary organic monolithic columns. An integrated capillary high performance liquid chromatography and high-resolution mass spectrometry (Cap-LC-HRMS) approach was developed, exploiting the excellent resolution, permeability and biocompatibility of organic monoliths, which is easily adaptable to the analysis of intact proteins. The resolution obtained on the lab-made Protein-Cap-RP-Lauryl-γ-Monolithic column (270 mm × 0.250 mm length × internal diameter, L × I.D.) in the analysis of commercial standard caseins (αS-CN, β-CN and κ-CN) through Cap-HPLC-UV was compared to the one observe using two packed capillary C4 columns, the ACE C4 (3 μm, 150 mm × 0.300 mm, L × I.D.) and the Jupiter C4 column (5 μm, 150 mm × 0.300 mm, L × I.D.). Thanks to the higher resolution observed, the monolithic capillary column was chosen for the successive degradation studies of casein fractions extracted from bovine milk 1-4 weeks after expiry date. The comparison of the UV chromatographic profiles of skim, semi-skim and whole milk showed a major stability of whole milk towards time-dependent degradation of caseins, which was further sustained by high-resolution analysis on a 50-cm long monolithic column using a 120-min time gradient. Contemporarily, the exact monoisotopic and average molecular masses of intact αS-CN and β-CN protein standards were obtained through high resolution mass spectrometry and used for casein identification in Cap-LC-HRMS analysis. Finally, the proteolytic degradation of β-CN in skim milk

Antioxidant activity of camel milk casein before and after in vitro simulated enzymatic digestion

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Zeineb Jrad

2014-11-01

Full Text Available The effect of a successive in vitro hydrolysis by pepsin and pancreatin on the free radical scavenging activity of camel milk casein was investigated in order to assess the effect of gastro-intestinal digestion. Hydrolysis of camel casein was controlled by reversed-phase high performance liquid chromatography. Anti-oxidant activity was measured by the 2,2’-azino-bis-(3-ethylbensothiazoline-6- sulfonic acid (ABTS method. The Trolox equivalent antioxidant capacity (TEAC values of camel casein and its hydrolysate were 1.6±0.12 μmol TE/mg protein and 0.25 μmol TE/μmol eq. NH2, respectively. After digestion, the scavenging activity of the casein peptides was more efficient than those reported in the literature regarding digestive hydrolysates of camel milk, colostrum and whey proteins.

Preparation, characterisation and antioxidant activities of rutin-loaded zein-sodium caseinate nanoparticles.

Science.gov (United States)

Zhang, Shuangling; Han, Yue

2018-01-01

Novel rutin-loaded zein-sodium caseinate nanoparticles (ZP) with antioxidant activity in aqueous medium were investigated. The results showed that the sodium caseinate concentrations, dosages of rutin and ethanol volume fractions significantly affected the zein nanoparticles' characteristics. Concerning the antioxidant properties, the highest values of rutin loaded ZP obtained using 2, 2-diphenyl-1-picrylhydrazyl scavenging and 2 and 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) decolourisation assays were 52.7% and 71.2%, respectively, and the total antioxidant capacity was 0.40 nmol g-1. The results suggest that zein-sodium caseinate nanoparticles can be used as a new nano carrier system for rutin or other water insoluble active ingredients.

Conformational transition of κ-casein in micellar environment: Insight from the tryptophan fluorescence

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Mishra, Smruti; Meher, Geetanjali; Chakraborty, Hirak

2017-11-01

Intrinsically disordered proteins (IDPs) are under intense analysis due to their structural flexibility and importance in biological functions. Minuscule modulation in the microenvironment induces significant conformational changes in IDPs, and these non-native conformations of the IDPs often induce aggregation and cause cell death. Changes in the membrane composition often change the microenvironment, which promote conformational change and aggregation of IDPs. κ-Casein, an important milk protein, belongs to the class of IDPs containing net negative charges. In this present work, we have studied the interaction of κ-casein with cetyltrimethyl ammonium bromide (CTAB), a positively charged surfactant, utilizing various steady state fluorescence, time-resolved fluorescence and circular dichroism spectroscopy. Our results clearly indicate that κ-casein undergoes at least two conformational transitions in presence of various concentrations of CTAB. The intrinsically disordered κ-casein assumes a partially folded conformation at lower concentration of CTAB, which adopts an unstructured conformation at higher concentration of CTAB. The partially folded conformation of κ-casein at a lower CTAB concentration might be induced by the favorable electrostatic interaction between the positively charged surfactant headgroup and net negative charges of the protein, whereas surfactant nature of CTAB is being pronounced at higher concentration of CTAB.

Production of the antimicrobial peptides Caseicin A and B by Bacillus isolates growing on sodium caseinate.

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Kent, R M; Guinane, C M; O'Connor, P M; Fitzgerald, G F; Hill, C; Stanton, C; Ross, R P

2012-08-01

The aim of this study was to identify Bacillus isolates capable of degrading sodium caseinate and subsequently to generate bioactive peptides with antimicrobial activity. Sodium caseinate (2.5% w/v) was inoculated separately with 16 Bacillus isolates and allowed to ferment overnight. Protein breakdown in the fermentates was analysed using gel permeation-HPLC (GP-HPLC) and screened for peptides (casein. This study highlights the potential to exploit Bacillus sp. or the enzymes they produce for the generation of bioactive antimicrobial peptides from bovine casein. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows' milk.

Science.gov (United States)

Jianqin, Sun; Leiming, Xu; Lu, Xia; Yelland, Gregory W; Ni, Jiayi; Clarke, Andrew J

2016-04-02

Cows' milk generally contains two types of β-casein, A1 and A2 types. Digestion of A1 type can yield the peptide β-casomorphin-7, which is implicated in adverse gastrointestinal effects of milk consumption, some of which resemble those in lactose intolerance. This study aimed to compare the effects of milk containing A1 β-casein with those of milk containing only A2 β-casein on inflammation, symptoms of post-dairy digestive discomfort (PD3), and cognitive processing in subjects with self-reported lactose intolerance. Forty-five Han Chinese subjects participated in this double-blind, randomized, 2 × 2 crossover trial and consumed milk containing both β-casein types or milk containing only A2 β-casein. Each treatment period was 14 days with a 14-day washout period at baseline and between treatment periods. Outcomes included PD3, gastrointestinal function (measured by smart pill), Subtle Cognitive Impairment Test (SCIT), serum/fecal laboratory biomarkers, and adverse events. Compared with milk containing only A2 β-casein, the consumption of milk containing both β-casein types was associated with significantly greater PD3 symptoms; higher concentrations of inflammation-related biomarkers and β-casomorphin-7; longer gastrointestinal transit times and lower levels of short-chain fatty acids; and increased response time and error rate on the SCIT. Consumption of milk containing both β-casein types was associated with worsening of PD3 symptoms relative to baseline in lactose tolerant and lactose intolerant subjects. Consumption of milk containing only A2 β-casein did not aggravate PD3 symptoms relative to baseline (i.e., after washout of dairy products) in lactose tolerant and intolerant subjects. Consumption of milk containing A1 β-casein was associated with increased gastrointestinal inflammation, worsening of PD3 symptoms, delayed transit, and decreased cognitive processing speed and accuracy. Because elimination of A1 β-casein attenuated these effects

Sodium Caseinate-Carrageenan Biopolymeric Nanocomplexes as a Carrier of Vitamin D: Study of Complex Formation, Particles Size and Encapsulation Efficiency

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Maryam Khoshmanzar

2014-04-01

Full Text Available The protein-polysaccharide complex-based nanocapsule is one type of polymeric nanocarrier which can be potentially useful for encapsulation of hydrophobic nutraceuticals. In this research, caseinate-carrageenan complex was used for encapsulation of vitamin D. The complex formation between caseinate and carrageenan was carried out by lowering the pH under isoelectric point of protein. The Fourier transform infrared spectroscopy (FTIR and differential scanning colorimetry (DSC confirmed complex formation between carrageenan, caseinate and vitamin D. The particle size of 1% caseinate particles was in the range of 150-300 nanometer and by addition of vitamin D the particle size increased to 450-750 nanometer. Moreover, carrageenan of all concentrations (at constant concentration of caseinate (1% and pH4.9 resulted in lower particle size below 100 nanometer. The stability of caseinate and its complex formation with carrageenan showed that encapsulation was achieved at 45% efficiency and also vitamin D stability (during 5 days storage was higher in nanocomplex compared to pure caseinate particles (60-63% compared to 53%. The complex formation between caseinate and carrageenan was carried out by pH decreasing under isoelectric point of protein. The FTIR and DSC confirmed complex formation between carrageenan, caseinate and vitamin D. The particle size of caseinate 1% particles were in the range of 150 -300 nanometer and with adding vitamin D, particle size increased to 450-750 nanometer. Moreover, adding carrageenan at all used concentration (at constant concentration of caseinate (1% and pH4.9 resulted in reduced particle size to less than 100 nanometer and vitamin D stability (during 5 days storage was higher (60-63% in nanocomplex compared to pure caseinate particles (53%.The protein-polysaccharide complex based nanocapsule is one type of the polymeric nanocarriers which can potentially be used for encapsulation of hydrophobic nutraceuticals. In

Grafting C8-C16 alkyl groups altered the self-assembly and curcumin –loading properties of sodium caseinate in water

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Yaqiong Zhang

2018-02-01

Full Text Available The data presented here are related to the research article entitled “Synthesis and characterization of alkylated caseinate, and its structure-curcumin loading property relationship in water” (Zhang et al., 2018 [1]. This data article reports the detailed spectra information for 1H NMR, 13C NMR and UPLC-Q-TOF MS of the N-succinimidyl fatty acid esters with various alkyl chain lengths (Cn-NHSs, n = 8, 12, 14 and 16. 1H NMR, 13C NMR and UPLC-Q-TOF MS spectra for C16-NHS are shown as an example. Then the stacked 1H NMR spectra of the obtained alkylated caseinates (Cn-caseinates, n = 8, 12, 14 and 16 are provided. The surface hydrophobicity index (S0 of Cn-caseinates with different substitution degrees (SD of alkyl groups is shown. Additionally, Visual appearances for the formed aqueous dispersions of curcumin-loaded native caseinate (NaCas and Cn-caseinates self-assemblies are shown. X-ray diffraction patterns of curcumin, C16-caseinate, its physical mixture and curcumin-loaded C16-caseinate self-assemblies are examined. The re-dispersibility and short-term storage stability of the curcumin-loaded NaCas and C16-caseinate self-assemblies are also studied. Keywords: Caseinate, Alkylated caseinate, Self-assembly, Curcumin-loading property

Molecular cloning and expression of bovine kappa-casein in Escherichia coli

International Nuclear Information System (INIS)

Kang, Y.C.; Richardson, T.

1988-01-01

A cDNA library was constructed using poly(A) + RNA from bovine mammary gland. This cDNA library of 6000 clones was screened employing colony hybridization using 32 P-labelled oligonucleotide probes and restriction endonuclease mapping. The cDNA from the selected plasmid, pKR76, was sequenced using the dideoxy-chain termination method. The cDNA insert of pKR76 carries the full-length sequence, which codes for mature kappa-casein protein. The amino acid sequence deduced from the cDNA sequence fits the published amino acid sequence with three exceptions; the reported pyroglutamic acid at position 1, tyrosine at position 35, and aspartic acid at position 81 are, respectively, a glutamine, a histidine, and an asparagine in the clone containing pKR76. The MspI-, NlaIV-cleaved fragment (630 base pair) from the kappa-casein cDNA insert has been subcloned into expression vectors pUC18 and pKK233-2, which contain a lac promoter and a trc promoter, respectively. Escherichia coli cells carrying the recombinant expression plasmids were shown to produce kappa-casein protein having the expected mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and being recognized by specific antibodies raised against natural bovine kappa-casein

Improved sugar beet pectin-stabilized emulsions through complexation with sodium caseinate.

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Li, Xiangyang; Fang, Yapeng; Phillips, Glyn O; Al-Assaf, Saphwan

2013-02-13

The study investigates the complexes formed between sodium caseinate (SC) and sugar beet pectin (SBP) and to harness them to stabilize SBP emulsions. We find that both hydrophobic and electrostatic interactions are involved in the complexation. In SC/SBP mixed solution, soluble SC/SBP complexes first form on acidification and then aggregate into insoluble complexes, which disassociate into soluble polymers upon further decreasing pH. The critical pH's for the formation of soluble and insoluble complexes and disappearance of insoluble complexes are designated as pH(c), pH(φ), and pH(d), respectively. These critical pH values define four regions in the phase diagram of complexation, and SC/SBP emulsions were prepared in these regions. The results show that the stability of SBP-stabilized emulsion is greatly improved at low SC/SBP ratios and acidic pH's. This enhancement can be attributed to an increase in the amount of adsorbed SBP as a result of cooperative adsorption to sodium caseinate. Using a low ratio of SC/SBP ensured that all caseinate molecules are completely covered by adsorbed SBP chains, which eliminates possible instability induced by thermal aggregation of caseinate molecules resulting from stress acceleration at elevated temperatures. A mechanistic model for the behavior is proposed.

Divergence at the casein haplotypes in dairy and meat goat breeds.

Science.gov (United States)

Küpper, Julia; Chessa, Stefania; Rignanese, Daniela; Caroli, Anna; Erhardt, Georg

2010-02-01

Casein genes have been proved to have an influence on milk properties, and are in addition appropriate for phylogeny studies. A large number of casein polymorphisms exist in goats, making their analysis quite complex. The four casein loci were analyzed by molecular techniques for genetic polymorphism detection in the two dairy goat breeds Bunte Deutsche Edelziege (BDE; n=96), Weisse Deutsche Edelziege (WDE; n=91), and the meat goat breed Buren (n=75). Of the 35 analyzed alleles, 18 were found in BDE, and 17 in Buren goats and WDE. In addition, a new allele was identified at the CSN1S1 locus in the BDE, showing a frequency of 0.05. This variant, named CSN1S1*A', is characterized by a t-->c transversion in intron 9. Linkage disequilibrium was found at the casein haplotype in all three breeds. A total of 30 haplotypes showed frequencies higher than 0.01. In the Buren breed only one haplotype showed a frequency higher than 0.1. The ancestral haplotype B-A-A-B (in the order: CSN1S1-CSN2-CSN1S2-CSN3) occurred in all three breeds, showing a very high frequency (>0.8) in the Buren.

Oncogenic Receptor Tyrosine Kinases Directly Phosphorylate Focal Adhesion Kinase (FAK) as a Resistance Mechanism to FAK-Kinase Inhibitors.

Science.gov (United States)

Marlowe, Timothy A; Lenzo, Felicia L; Figel, Sheila A; Grapes, Abigail T; Cance, William G

2016-12-01

Focal adhesion kinase (FAK) is a major drug target in cancer and current inhibitors targeted to the ATP-binding pocket of the kinase domain have entered clinical trials. However, preliminary results have shown limited single-agent efficacy in patients. Despite these unfavorable data, the molecular mechanisms that drive intrinsic and acquired resistance to FAK-kinase inhibitors are largely unknown. We have demonstrated that receptor tyrosine kinases (RTK) can directly bypass FAK-kinase inhibition in cancer cells through phosphorylation of FAK's critical tyrosine 397 (Y397). We also showed that HER2 forms a direct protein-protein interaction with the FAK-FERM-F1 lobe, promoting direct phosphorylation of Y397. In addition, FAK-kinase inhibition induced two forms of compensatory RTK reprogramming: (i) the rapid phosphorylation and activation of RTK signaling pathways in RTK High cells and (ii) the long-term acquisition of RTKs novel to the parental cell line in RTK Low cells. Finally, HER2 +: cancer cells displayed resistance to FAK-kinase inhibition in 3D growth assays using a HER2 isogenic system and HER2 + cancer cell lines. Our data indicate a novel drug resistance mechanism to FAK-kinase inhibitors whereby HER2 and other RTKs can rescue and maintain FAK activation (pY397) even in the presence of FAK-kinase inhibition. These data may have important ramifications for existing clinical trials of FAK inhibitors and suggest that individual tumor stratification by RTK expression would be important to predict patient response to FAK-kinase inhibitors. Mol Cancer Ther; 15(12); 3028-39. ©2016 AACR. ©2016 American Association for Cancer Research.

Formation of stable nanoparticles via electrostatic complexation between sodium caseinate and gum arabic.

Science.gov (United States)

Ye, Aiqian; Flanagan, John; Singh, Harjinder

2006-06-05

The formation of electrostatic complexes between sodium caseinate and gum arabic (GA) was studied as a function of pH (2.0-7.0), using slow acidification in situ with glucono-delta-lactone (GDL) or titration with HCl. The colloidal behavior of the complexes under specific conditions was investigated using absorbance measurements (at 515 or 810 nm) and dynamic light scattering (DLS). In contrast to the sudden increase in absorbance and subsequent precipitation of sodium caseinate solutions at pH sodium caseinate and GA increased to a level that was dependent on GA concentration at pH 5.4 (pH(c)). The absorbance values remained constant with further decreases in pH until a sudden increase in absorbance was observed (at pH(phi)). The pH(phi) was also dependent upon the GA concentration. Dynamic light scattering (DLS) data showed that the sizes of the particles formed by the complexation of sodium caseinate and GA between pH(c) and pH(phi) were between 100 and 150 nm and these nanoparticles were visualized using negative staining transmission electron microscopy (TEM). Below pH(phi), the nanoparticles associated to form larger particles, causing phase separation. zeta-Potential measurements of the nanoparticles and chemical analysis after phase separation showed that phase separation was a consequence of charge neutralization. The formation of complexes between sodium caseinate and GA was inhibited at high ionic strength (>50 mM NaCl). It is postulated that the structure of the nanoparticles comprises an aggregated caseinate core, protected from further aggregation by steric repulsion of one, or more, electrostatically attached GA molecules. Copyright 2005 Wiley Periodicals, Inc.

Trichostatin A inhibits beta-casein expression in mammary epithelial cells

International Nuclear Information System (INIS)

Pujuguet, Philippe; Radisky, Derek; Levy, Dinah; Lacza, Charlemagne; Bissell, Mina J.

2002-01-01

Many aspects of cellular behavior are affected by information derived from association of the extracellular matrix (ECM) and with cell membrane receptors. When cultured in the presence of laminin-containing ECM and prolactin (Prl), normal mammary epithelial cells express the milk protein beta-casein. Previously, we defined the minimal ECM- and Prl-responsive enhancer element BCE-1 from the upstream region of the beta-casein gene. We also found that BCE-1 was only active when stably integrated into chromatin, and that trichostatin A (TSA), a reagent that leads to alterations in chromatin structure, was able to activate the integrated enhancer element. We now show that endogenous b-casein gene, which is controlled by a genetic assembly that is highly similar to that of BCE-1 and which is also activated by incubation in ECM and Prl, is instead inhibited by TSA. We provide evidence that the differing response of b-casein and BCE-1 to TSA is neither due to an unusual effect of TSA on mammary epithelial cells, nor to secondary consequences from the expression of a separate gene, nor to a particular property of the BCE-1 construct. As a component of this investigation, we also showed that ECM could mediate rapid histone deacetylation in mammary epithelial cells. These results are discussed in combination with previous work showing that TSA mediates the differentiation of many types of cancer cells but inhibits differentiation of some nonmalignant cell types

Intraileal casein infusion increases plasma concentrations of amino acids in humans: A randomized cross over trial.

Science.gov (United States)

Ripken, Dina; van Avesaat, Mark; Troost, Freddy J; Masclee, Ad A; Witkamp, Renger F; Hendriks, Henk F

2017-02-01

Activation of the ileal brake by casein induces satiety signals and reduces energy intake. However, adverse effects of intraileal casein administration have not been studied before. These adverse effects may include impaired amino acid digestion, absorption and immune activation. To investigate the effects of intraileal infusion of native casein on plasma amino acid appearance, immune activation and gastrointestinal (GI) symptoms. A randomized single-blind cross over study was performed in 13 healthy subjects (6 male; mean age 26 ± 2.9 years; mean body mass index 22.8 ± 0.4 kg/m -2 ), who were intubated with a naso-ileal feeding catheter. Thirty minutes after intake of a standardized breakfast, participants received an ileal infusion, containing either control (C) consisting of saline, a low-dose (17.2 kcal) casein (LP) or a high-dose (51.7 kcal) of casein (HP) over a period of 90 min. Blood samples were collected for analysis of amino acids (AAs), C-reactive protein (CRP), pro-inflammatory cytokines and oxylipins at regular intervals. Furthermore, GI symptom questionnaires were collected before, during and after ileal infusion. None of the subjects reported any GI symptoms before, during or after ileal infusion of C, LP and HP. Plasma concentrations of all AAs analyzed were significantly increased after infusion of HP as compared to C (p casein, respectively. Ileal casein infusion did not affect plasma concentrations of CRP, IL-6, IL-8, IL-1β and TNF-α. Infusion of HP resulted in a decreased concentration of 11,12-dihydroxyeicosatrienoic acid whereas none of the other oxylipins analyzed were affected. A single intraileal infusion of native casein results in a concentration and time dependent increase of AAs in plasma, suggesting an effective digestion and absorption of AAs present in casein. Also, ileal infusion did not result in immune activation nor in GI symptoms. CLINICALTRIALS.GOV: NCT01509469. Copyright © 2016 The Authors. Published by Elsevier

Effect of sodium azide addition and aging storage on casein micelle size

Science.gov (United States)

Sinaga, H.; Deeth, H.; Bhandari, B.

2018-02-01

Casein micelles affected most of milk properties, therefore the use sodium azide as milk preservation is not expected to alter milk properties during storage, including the casein micelle size. The aim of this study was to analyse casein micelle size after the addition of sodium azide during storage. The experiment was performed as a complete block randomised design with three replications. The addition of 0.02-0.10% Na-azide do not lead to any noticeable differences in average casein size at the same day and show similar trend after 14 day-storage. At concentration of 0.02% sodium azide (Na-azide), the size of pasteurised milk did not change up to 12 days, while the size of raw skim milk slightly increased by ageing time at day 5. The treated concentration did not affect the size distribution, except for milk with 0.02% Na-azide which had narrower distribution compared to other treated and control milk. The finding from this study suggests that the role of Na-azide in this experiments during storage at 4°C is only for preventing the microbial growth.

Coacervates of lactotransferrin and β- or κ-casein: structure determined using SAXS.

Science.gov (United States)

de Kruif, C G Kees; Pedersen, JanSkov; Huppertz, Thom; Anema, Skelte G

2013-08-20

Lactotransferrin (LF) is a large globular protein in milk with immune-regulatory and bactericidal properties. At pH 6.5, LF (M = 78 kDa) carries a net (calculated) charge of +21. β-Casein (BCN) and κ-casein (KCN) are part of the casein micelle complex in milk. Both BCN and KCN are amphiphillic proteins with a molar mass of 24 and 19 kDa and carry net charges of -14 and -4, respectively. Both BCN and KCN form soap-like micelles, with 40 and 65 monomers, respectively. The net negative charges are located in the corona of the micelles. On mixing LF with the caseins, coacervates are formed. We analyzed the structure of these coarcervates using SAXS. It was found that LF binds to the corona of the micellar structures, at the charge neutrality point. BCN/LF and KCN/LF ratios at the charge neutrality point were found to be ~1.2 and ~5, respectively. We think that the findings are relevant for the protection mechanism of globular proteins in bodily fluids where unstructured proteins are abundant (saliva). The complexes will prevent docking of enzymes on specific charged groups on the globular protein.

Casein infusion rate influences feed intake differently depending on metabolizable protein balance in dairy cows: A multilevel meta-analysis.

Science.gov (United States)

Martineau, R; Ouellet, D R; Kebreab, E; Lapierre, H

2016-04-01

The effects of casein infusion have been investigated extensively in ruminant species. Its effect on responses in dry matter intake (DMI) has been reviewed and indicated no significant effect. The literature reviewed in the current meta-analysis is more extensive and limited to dairy cows fed ad libitum. A total of 51 studies were included in the meta-analysis and data were fitted to a multilevel model adjusting for the correlated nature of some studies. The effect size was the mean difference calculated by subtracting the means for the control from the casein-infused group. Overall, casein infusion [average of 333 g of dry matter (DM)/d; range: 91 to 1,092 g of DM/d] tended to increase responses in DMI by 0.18 kg/d (n=48 studies; 3 outliers). However, an interaction was observed between the casein infusion rate (IR) and the initial metabolizable protein (MP) balance [i.e., supply minus requirements (NRC, 2001)]. When control cows were in negative MP balance (n=27 studies), responses in DMI averaged 0.28 kg/d at mean MP balance (-264 g/d) and casein IR (336 g/d), and a 100g/d increment in the casein IR from its mean increased further responses by 0.14 kg/d (MP balance being constant), compared with cows not infused with casein. In contrast, when control cows were in positive MP balance (n=22 studies; 2 outliers), responses in DMI averaged -0.20 kg/d at mean casein IR (339 g/d), and a 100g/d increment in the casein IR from its mean further decreased responses by 0.33 kg/d, compared with cows not infused with casein. Responses in milk true protein yield at mean casein IR were greater (109 vs. 65 g/d) for cows in negative vs. positive MP balance, respectively, and the influence of the casein IR on responses was significant only for cows in negative MP balance. A 100g/d increment in the casein IR from its mean increased further responses in milk true protein yield by 25 g/d, compared with cows not infused with casein. Responses in blood urea concentration increased in

Order of 17 july 1991 on treatment by ionizing radiation of casein and casein products for human consumption

International Nuclear Information System (INIS)

1991-01-01

This Order authorizes and fixes the conditions for the sale and marketing of casein (one of the chief constituents of milk which forms the basis of cheese), which is treated by ionizing radiation, for human consumption. The absorbed radiation dose must not exceed 6 kGy [fr

Fused deposition modelling of sodium caseinate dispersions

NARCIS (Netherlands)

Schutyser, M.A.I.; Houlder, S.; Wit, de Martin; Buijsse, C.A.P.; Alting, A.C.

2018-01-01

Only recently, researchers have started experimenting with 3D printing of foods. The aim of this study was to investigate 3D printed objects from sodium caseinate dispersions, exhibiting reversible gelation behaviour. Gelation and dispensing behaviour were explored and structures of different

Factors affecting antioxidant activity of soybean meal and caseine protein hydrolysates

International Nuclear Information System (INIS)

Korczak, J.

1998-01-01

Antioxidative activity of protein hydrolysates was dependent on the raw material, condition of hydrolysis and lipid substrate used in model systems. Soybean meal hydrolysate was more active in lard and in linoleic acid emulsion than caseine hydrolysate, whereas caseine was more active in vegetable oils. Antioxidant activity of evaluated protein hydrolysates in all lipid systems, with or without oxidation catalysts, suggests them as natural food additives for lipid stabilization, thus for improvement of its nutritional value and sensory properties

Grafting C8-C16 alkyl groups altered the self-assembly and curcumin -loading properties of sodium caseinate in water.

Science.gov (United States)

Zhang, Yaqiong; Yang, Puyu; Yao, Fangyi; Liu, Jie; Yu, Liangli Lucy

2018-02-01

The data presented here are related to the research article entitled "Synthesis and characterization of alkylated caseinate, and its structure-curcumin loading property relationship in water" (Zhang et al., 2018) [1]. This data article reports the detailed spectra information for 1 H NMR, 13 C NMR and UPLC-Q-TOF MS of the N-succinimidyl fatty acid esters with various alkyl chain lengths (Cn-NHSs, n = 8, 12, 14 and 16). 1 H NMR, 13 C NMR and UPLC-Q-TOF MS spectra for C16-NHS are shown as an example. Then the stacked 1 H NMR spectra of the obtained alkylated caseinates (Cn-caseinates, n = 8, 12, 14 and 16) are provided. The surface hydrophobicity index (S 0 ) of Cn-caseinates with different substitution degrees (SD) of alkyl groups is shown. Additionally, Visual appearances for the formed aqueous dispersions of curcumin-loaded native caseinate (NaCas) and Cn-caseinates self-assemblies are shown. X-ray diffraction patterns of curcumin, C16-caseinate, its physical mixture and curcumin-loaded C16-caseinate self-assemblies are examined. The re-dispersibility and short-term storage stability of the curcumin-loaded NaCas and C16-caseinate self-assemblies are also studied.

Toxicity and biodistribution of orally administered casein nanoparticles.

Science.gov (United States)

Gil, Ana Gloria; Irache, Juan Manuel; Peñuelas, Iván; González Navarro, Carlos Javier; López de Cerain, Adela

2017-08-01

In the last years, casein nanoparticles have been proposed as carriers for the oral delivery of biologically active compounds. However, till now, no information about their possible specific hazards in vivo was available. The aim of this work was to assess the safety of casein nanoparticles when administered orally to animals through a 90 days dose-repeated toxicity study (OECD guideline 408), that was performed in Wistar rats under GLP conditions. After 90 days, no evidences of significant alterations in animals treated daily with 50, 150 or 500 mg/kg bw of nanoparticles were found. This safety agrees well with the fact that nanoparticles were not absorbed and remained within the gut as observed by radiolabelling in the biodistribution study. After 28 days, there was a generalized hyperchloremia in males and females treated with the highest dose of 500 mg/kg bw, that was coupled with hypernatremia in the females. These effects were related to the presence of mannitol which was used as excipient in the formulation of casein nanoparticles. According to these results, the No Observed Adverse Effect Level (NOAEL) could be established in 150 mg/kg bw/day and the Lowest Observed Effect Level (LOEL) could be established in 500 mg/kg bw/day. Copyright © 2017. Published by Elsevier Ltd.

Partial contribution of Rho-kinase inhibition to the bioactivity of Ganoderma lingzhi and its isolated compounds: insights on discovery of natural Rho-kinase inhibitors.

Science.gov (United States)

Amen, Yhiya; Zhu, Qinchang; Tran, Hai-Bang; Afifi, Mohamed S; Halim, Ahmed F; Ashour, Ahmed; Shimizu, Kuniyoshi

2017-04-01

Recent studies identified Rho-kinase enzymes (ROCK-I and ROCK-II) as important targets that are involved in a variety of diseases. Synthetic Rho-kinase inhibitors have emerged as potential therapeutic agents to treat disorders such as hypertension, stroke, cancer, diabetes, glaucoma, etc. Our study is the first to screen the total ethanol extract of the medicinal mushroom Ganoderma lingzhi with thirty-five compounds for Rho-kinase inhibitory activity. Moreover, a molecular binding experiment was designed to investigate the binding affinity of the compounds at the active sites of Rho-kinase enzymes. The structure-activity relationship analysis was investigated. Our results suggest that the traditional uses of G. lingzhi might be in part due to the ROCK-I and ROCK-II inhibitory potential of this mushroom. Structure-activity relationship studies revealed some interesting features of the lanostane triterpenes that potentiate their Rho-kinase inhibition. These findings would be helpful for further studies on the design of Rho-kinase inhibitors from natural sources and open the door for contributions from other researchers for optimizing the development of natural Rho-kinase inhibitors.

Gluten and casein supplementation does not increase symptoms in children with autism spectrum disorder.

Science.gov (United States)

Pusponegoro, Hardiono D; Ismael, Sofyan; Firmansyah, Agus; Sastroasmoro, Sudigdo; Vandenplas, Yvan

2015-11-01

A gluten- and casein-free diet is often given to children with autism spectrum disorder (ASD). We aimed to determine the effect of gluten and casein supplementation on maladaptive behaviour, gastrointestinal symptom severity and intestinal fatty acids binding protein (I-FABP) excretion in children with ASD. A randomised, controlled, double-blind trial was performed on 74 children with ASD with severe maladaptive behaviour and increased urinary I-FABP. Subjects were randomised to receive gluten-casein or a placebo for seven days. We evaluated maladaptive behaviour before and after supplementation, using I-FABP excretion, the approach withdrawal problem composite subtest of the Pervasive Developmental Disorder Behavior Inventory and the Gastrointestinal Symptom Severity Index. The mean approach withdrawal problem composite score was significantly higher before supplementation than after, both in the placebo and in the gluten-casein group. However, the mean difference was not significant and may have been caused by additional therapy. There was no significant difference in gastrointestinal symptoms and urinary I-FABP excretion. Administrating gluten-casein to children with ASD for one week did not increase maladaptive behaviour, gastrointestinal symptom severity or urinary I-FABP excretion. The effect of prolonged administration or other mechanisms of enterocyte damage in ASD should be explored. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Plasmin digest of κ-casein as a source of antibacterial peptides.

Science.gov (United States)

Sedaghati, Marjaneh; Ezzatpanah, Hamid; Boojar, Masoud Mashhadi Akbar; Ebrahimi, Maryam Tajabadi; Aminafshar, Mehdi

2014-05-01

This study investigated the antibacterial properties of plasmin, the plasmin hydrolysis of bovine κ-casein and the fractions (named κC1, κC2, κC3, κC4, and κC5) liberated from it using RP-HPLC. The target bacteria were Escherichia coli, Staphylococcus aureus (pathogenic), Lactobacillus casei and Lactobacillus acidophilus (probiotic). Three peptides (kC1, kC3, and kC4) were found to have antibacterial activity, with κC3 peptide being the most active. The plasmin digest of bovine κ-casein proved to be stronger than any of its fractions in terms of antibacterial potential. Measurement of the minimum inhibitory concentration (MIC) showed that Gram-positive bacteria are generally more sensitive to antibacterial activity than Gram-negative bacteria. The MIC of nisin, as a bacteriocin peptide, was also measured. The three antibacterial peptides were identified using LC-Mass. The molecular mass of kC1, kC3, and kC4 corresponded to the f(17-21), f(22-24), and f(1-3) of bovine κ-casein, respectively. It was also found that the positive charge and hydrophobicity of a peptide are not key factors in antibacterial activity. On the whole, the present study demonstrated that the plasmin digest of κ-casein has a high antibacterial potential and can be considered as a natural antibacterial agent in the food chain.

Evaluation of Structure, Chaperone-Like Activity and Allergenicity of Reduced Glycated Adduct of Bovine β-casein.

Science.gov (United States)

Yousefi, Reza; Ferdowsi, Leila; Tavaf, Zohreh; Sadeghian, Tanaz; Tamaddon, Ali M; Moghtaderi, Mozhgan; Pourpak, Zahra

2017-01-01

Milk has a potent reducing environment with an important quantity of sugar levels. In the current study β-casein was glycated in the presence of D-glucose and sodium cyanoborohydride as a reducing agent. Then, the reduced glucitol adduct of β-casein was used for the structural and functional analyses using different spectroscopic techniques. The results of fluorescence and far ultraviolet circular dichroism assessments suggest important structural alteration upon non-enzymatic glycation of β-casein. In addition, the chaperone activity, micellization properties and antioxidant activity of this protein were altered upon glucose modification. Also, as a result of reduced glycation, the allergenicity profile of this protein remained largely unchanged. Additional to its energetic and nutritional values, β-casein has important functional properties. The native structure of this protein is important to perform accurately its biological functions. Non-enzymatic glycation under reducing state was capable to alter both structural and functional aspects of β-casein. Due to effective reducing environment and significant quantity of reducing sugar of human milk, similar structural and functional alterations are most likely to occur upon reducing glycation of β-casein in vivo. Also, these changes might be even intensified during chronic hyperglycemia in diabetic mothers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Influence of dispersed particles on small and large deformation properties of concentrated caseinate composites

NARCIS (Netherlands)

Manski, J.M.; Kretzers, I.M.J.; Brenk, van S.; Goot, van der A.J.; Boom, R.M.

2007-01-01

Concentrated sodium caseinate composites (30% w/w in water), which contained either dispersed palm fat or glass spheres varying in size and surface properties were prepared in a Brabender Do-Corder kneader. The influence of the dispersed phase on the structural properties of the sodium caseinate

The increasing of enamel calcium level after casein phosphopeptideamorphous calcium phosphate covering

OpenAIRE

Widyasri Prananingrum; Puguh Bayu Prabowo

2012-01-01

Background: Caries process is characterized by the presence of demineralization. Demineralization is caused by organic acids as a result of carbohydrate substrate fermentation. Remineralization is a natural repair process for non-cavitated lesions. Remineralization occurs if there are Ca2+ and PO43- ions in sufficient quantities. Casein-amorphous calcium phosphate phosphopeptide (CPP-ACP) is a paste material containing milk protein (casein), that actually contains minerals, such as calcium an...

Effects of hydrolysis on solid-state relaxation and stickiness behavior of sodium caseinate-lactose powders.

Science.gov (United States)

Mounsey, J S; Hogan, S A; Murray, B A; O'Callaghan, D J

2012-05-01

Hydrolyzed or nonhydrolyzed sodium caseinate-lactose dispersions were spray dried, at a protein: lactose ratio of 0.5, to examine the effects of protein hydrolysis on relaxation behavior and stickiness of model powders. Sodium caseinate (NC) used included a nonhydrolyzed control (DH 0) and 2 hydrolyzed variants (DH 8.3 and DH 15), where DH = degree of hydrolysis (%). Prior to spray drying, apparent viscosities of liquid feeds (at 70°C) at a shear rate of 20/s were 37.6, 3.14, and 3.19 mPa·s, respectively, for DH 0, DH 8, and DH 15 dispersions. Powders containing hydrolyzed casein were more susceptible to sticking than those containing intact NC. The former had also lower bulk densities and powder particle sizes. Scanning electron microscopy showed that hydrolyzed powders had thinner particle walls and were more friable than powders containing intact NC. Secondary structure of caseinates, determined by Fourier transform infrared spectroscopy, was affected by the relative humidity of storage and the presence of lactose as co-solvent rather than its physical state. Glass transition temperatures and lactose crystallization temperatures, determined by differential scanning calorimetry were not affected by caseinate hydrolysis, although the effects of protein hydrolysis on glass-rubber transitions (T(gr)) could be determined by thermo-mechanical analysis. Powders containing hydrolyzed NC had lower T(gr) values (~30°C) following storage at a higher subcrystallization relative humidity (33%) compared with powder with nonhydrolyzed NC (T(gr) value of ~40°C), an effect that reflects more extensive plasticization of powder matrices by moisture. Results support that sodium caseinate-lactose interactions were weak but that relaxation behavior, as determined by the susceptibility of powder to sticking, was affected by hydrolysis of sodium caseinate. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Mapping of Epitopes Occurring in Bovine α(s1)-Casein Variants by Peptide Microarray Immunoassay.

Science.gov (United States)

Lisson, Maria; Erhardt, Georg

2016-01-01

Immunoglobulin E epitope mapping of milk proteins reveals important information about their immunologic properties. Genetic variants of αS1-casein, one of the major allergens in bovine milk, are until now not considered when discussing the allergenic potential. Here we describe the complete procedure to assess the allergenicity of αS1-casein variants B and C, which are frequent in most breeds, starting from milk with identification and purification of casein variants by isoelectric focusing (IEF) and anion-exchange chromatography, followed by in vitro gastrointestinal digestion of the casein variants, identification of the resulting peptides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), in silico analysis of the variant-specific peptides as allergenic epitopes, and determination of their IgE-binding properties by microarray immunoassay with cow's milk allergic human sera.

Casein - whey protein interactions in heated milk

NARCIS (Netherlands)

Vasbinder, Astrid Jolanda

2002-01-01

Heating of milk is an essential step in the processing of various dairy products, like for example yoghurt. A major consequence of the heat treatment is the denaturation of whey proteins, which either associate with the casein micelle or form soluble whey protein aggregates. By combination of

Measurement by radioimmunoassay of casein content in rabbit mammary gland during pregnancy and after prolactin stimulation in organ culture

International Nuclear Information System (INIS)

Jahn, G.; Dusanter-Fourt, I.; Kelly, P.A.; Houdebine, L.M.; Djiane, J.

1987-01-01

A specific homologous radioimmunoassay was developed to measure rabbit β-casein in rabbit mammary gland with a sensitivity of 0.5 ng/ml protein. It was used to measure casein concentration during pregnancy and in organ culture of mammary gland explants. Casein was detectable in virgin mammary glands, showed a small increase during the first half of pregnancy, increased more than 20-fold between Days 21 and 27, and diminished somewhat on the first days of lactation. After 24 hr of culture, mammary gland explants had no detectable casein, but the addition of increasing concentrations of prolactin to a culture medium which contained insulin (5 μg/ml) and cortisol (0.5 μg/ml) induced a regular increase in the casein content of the tissue. Casein started to increase when 10 ng/ml of prolactin was present and maximal values were achieved for 100 ng/ml of the hormone

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion related to a notification from the International Organisation of Vine and Wine (OIV) on casein/caseinate/milk products to be used in the manufacture of wine as clarification processing aids pursuant to Article 6

DEFF Research Database (Denmark)

Tetens, Inge

of the fining agents regarding their content of milk proteins other than casein, the lack of standardisation of the wine manufacturing process, and that no new clinical data have been provided in the present application, the Panel concludes that wines fined with casein/caseinate/milk products may trigger......Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion related to a notification from the International Organisation of Vine and Wine on casein/caseinate/milk products to be used in the manufacture...... refers to new analytical methods developed for the detection of milk allergens in the fining agent and the detection of casein in wine. There were no changes in the wine manufacturing process and no new clinical studies were provided. Taking into account the information provided on the characterisation...

Yak milk casein as potential precursor of angiotensin I-converting enzyme inhibitory peptides based on in silico proteolysis.

Science.gov (United States)

Lin, Kai; Zhang, Lan-Wei; Han, Xue; Xin, Liang; Meng, Zhao-Xu; Gong, Pi-Min; Cheng, Da-You

2018-07-15

Yak milk casein was selected as a potential precursor of bioactive peptides based on in silico analysis. Most notable among these are the angiotensin I-converting enzyme (ACE) inhibitory peptides. First, yak milk casein has high homology with cow milk casein by homologous analysis. The potential of yak milk casein for the releasing bioactive peptides was evaluated by determining the frequency of occurrence of fragments with a given activity. Through the BIOPEP database analysis, there are many bioactive peptides in yak milk casein sequences. Then, an in silico proteolysis using single or combined enzymes to obtained ACE inhibitory peptides was investigated. Cytotoxicity analysis using the online toxic prediction tool ToxinPred revealed that all in silico proteolysis derived ACE inhibitory peptides are non-cytotoxic. Overall, the present study highlights a in silico proteolysis approach to assist the yak milk casein releasing ACE inhibitory peptides and provides a guidance for the actual hydrolysis of proteins for the production of bioactive peptides. Copyright © 2018 Elsevier Ltd. All rights reserved.

Molecular mechanisms involved in casein gene expression and secretion in mouse mammary epithelial cells

International Nuclear Information System (INIS)

Lee, E.Y.H.P.; Lee, W.H.; Parry, G.; Bissell, M.J.

1985-01-01

Mouse mammary epithelial cells (MMEC) secrete a group of milk-specific proteins including various caseins and whey proteins. Dissociated mammary epithelial cells maintain expression of most of their differentiated functions only if cells are plated on a suitable substratum. Casein production and section, cell morphology, and production of α-lactalbumin have been used as markers to assess the degree of differentiation of mammary cells in culture. The general consensus is that cells express their differentiated properties at high levels and for longer periods of time on such substrata. In this paper, the authors demonstrate that modulation of the expression of caseins by floating collagen gels is manifested at several regulatory points

Incorporation of 32P-Na2HPO4 into caseins and lipoprotein complexes of milk from a lactating buffalo

International Nuclear Information System (INIS)

Ahuja, S.P.; Jassal, S.S.

1979-01-01

32 P-phosphate was given intravenously to a lactating buffalo to study the utilization of blood inorganic-phosphate by the mammary gland. The distribution of radioactivity in the mammary-cell-plasma membrane (MCPM), milk-fat-globule membrane (MFGM), low density lipoproteins (LDLP) and caseins was studied. Maximum radioactivity was incorporated into casein. Among the caseins, α-casein complex had minimum radioactivity. Radioactivity from γ-casein complex appeared to be incorporated into β-casein. On intravenous injection the peak specific activity of 32 P appeared at the same time in the MCPM and MFGM, but on prolonged infusion it appeared first in the MCPM and then in MFGM, indicating MFGM and MCPM to be of common origin. The peak specific activity of lipids from casein micelles appeared later than that in MCPM and MFGM. Autoradiography of MCPM and MFGM lipids showed that 32 P-phosphate was first incorporated into phosphatidyl choline (PC) and then into other phospholipids (PL). In LDLP, 32 P-phosphate was incorporated into PC alone even after 25 hr of injection. The role of PC in PL biosynthesis in mammary gland has been discussed. (author)

Nutritional evaluation of caseins and whey proteins and their hydrolysates from Protamex*

OpenAIRE

Sindayikengera, Séverin; Xia, Wen-shui

2006-01-01

Whey protein concentrate (WPC 80) and sodium caseinate were hydrolyzed by Protamex to 5%, 10%, 15%, and 20% degree of hydrolysis (DH). WPC 80, sodium caseinate and their hydrolysates were then analyzed, compared and evaluated for their nutritional qualities. Their chemical composition, protein solubility, amino acid composition, essential amino acid index (EAA index), biological value (BV), nutritional index (NI), chemical score, enzymic protein efficiency ratio (E-PER) and in vitro protein d...

Partial purification and characterization of a Ca(2+)-dependent protein kinase from pea nuclei

Science.gov (United States)

Li, H.; Dauwalder, M.; Roux, S. J.

1991-01-01

Almost all the Ca(2+)-dependent protein kinase activity in nuclei purified from etiolated pea (Pisum sativum, L.) plumules is present in a single enzyme that can be extracted from chromatin by 0.3 molar NaCl. This protein kinase can be further purified 80,000-fold by salt fractionation and high performance liquid chromatography, after which it has a high specific activity of about 100 picomoles per minute per microgram in the presence of Ca2+ and reaches half-maximal activation at about 3 x 10(-7) molar free Ca2+, without calmodulin. It is a monomer with a molecular weight near 90,000. It can efficiently use histone III-S, ribosomal S6 protein, and casein as artificial substrates, but it phosphorylates phosvitin only weakly. Its Ca(2+)-dependent kinase activity is half-maximally inhibited by 0.1 millimolar chlorpromazine, by 35 nanomolar K-252a and by 7 nanomolar staurosporine. It is insensitive to sphingosine, an inhibitor of protein kinase C, and to basic polypeptides that block other Ca(2+)-dependent protein kinases. It is not stimulated by exogenous phospholipids or fatty acids. In intact isolated pea nuclei it preferentially phosphorylates several chromatin-associated proteins, with the most phosphorylated protein band being near the same molecular weight (43,000) as a nuclear protein substrate whose phosphorylation has been reported to be stimulated by phytochrome in a calcium-dependent fashion.

Gastric Emptying and Gastrointestinal Transit Compared among Native and Hydrolyzed Whey and Casein Milk Proteins in an Aged Rat Model.

Science.gov (United States)

Dalziel, Julie E; Young, Wayne; McKenzie, Catherine M; Haggarty, Neill W; Roy, Nicole C

2017-12-13

Little is known about how milk proteins affect gastrointestinal (GI) transit, particularly for the elderly, in whom digestion has been observed to be slowed. We tested the hypothesis that GI transit is faster for whey than for casein and that this effect is accentuated with hydrolysates, similar to soy. Adult male rats (18 months old) were fed native whey or casein, hydrolyzed whey (WPH) or casein (CPH), hydrolyzed blend (HB; 60% whey:40% casein), or hydrolyzed soy for 14 days then treated with loperamide, prucalopride, or vehicle-control for 7 days. X-ray imaging tracked bead-transit for: gastric emptying (GE; 4 h), small intestine (SI) transit (9 h), and large intestine (LI) transit (12 h). GE for whey was 33 ± 12% faster than that for either casein or CPH. SI transit was decreased by 37 ± 9% for casein and 24 ± 6% for whey compared with hydrolyzed soy, and persisted for casein at 12 h. Although CPH and WPH did not alter transit compared with their respective intact counterparts, fecal output was increased by WPH. Slowed transit by casein was reversed by prucalopride (9-h), but not loperamide. However, rapid GE and slower SI transit for the HB compared with intact forms were inhibited by loperamide. The expected slower GI transit for casein relative to soy provided a comparative benchmark, and opioid receptor involvement was corroborated. Our findings provide new evidence that whey slowed SI transit compared with soy, independent of GE. Increased GI transit from stomach to colon for the HB compared with casein suggests that including hydrolyzed milk proteins in foods may benefit those with slowed intestinal transit.

Casein Hydrolysate with Glycemic Control Properties: Evidence from Cells, Animal Models, and Humans.

Science.gov (United States)

Drummond, Elaine; Flynn, Sarah; Whelan, Helena; Nongonierma, Alice B; Holton, Thérèse A; Robinson, Aisling; Egan, Thelma; Cagney, Gerard; Shields, Denis C; Gibney, Eileen R; Newsholme, Philip; Gaudel, Celine; Jacquier, Jean-Christophe; Noronha, Nessa; FitzGerald, Richard J; Brennan, Lorraine

2018-05-02

Evidence exists to support the role of dairy derived proteins whey and casein in glycemic management. The objective of the present study was to use a cell screening method to identify a suitable casein hydrolysate and to examine its ability to impact glycemia related parameters in an animal model and in humans. Following screening for the ability to stimulate insulin secretion in pancreatic beta cells, a casein hydrolysate was selected and further studied in the ob/ob mouse model. An acute postprandial study was performed in 62 overweight and obese adults. Acute and long-term supplementation with the casein hydrolysate in in vivo studies in mice revealed a glucose lowering effect and a lipid reducing effect of the hydrolysate (43% reduction in overall liver fat). The postprandial human study revealed a significant increase in insulin secretion ( p = 0.04) concomitant with a reduction in glucose ( p = 0.03). The area under the curve for the change in glucose decreased from 181.84 ± 14.6 to 153.87 ± 13.02 ( p = 0.009). Overall, the data supports further work on the hydrolysate to develop into a functional food product.

Complexation of sodium caseinate with gum tragacanth: Effect of various species and rheology of coacervates.

Science.gov (United States)

Ghorbani Gorji, Sara; Ghorbani Gorji, Elham; Mohammadifar, Mohammad Amin; Zargaraan, Azizollaah

2014-06-01

We investigated complex coacervation of sodium caseinate/Astragalus rahensis (A.r) as a function of pH with light scattering, spectrophotometry, and viscosity measurements. Interestingly, sodium caseinate/A.r displayed five structural transitions; pH 7.00 to pH ∼5.40: no interaction occurred, pH ∼5.40 to pH ∼4.80: initiation of the formation of primary soluble complexes, pH ∼4.80 to ∼4.30: formation of interpolymer complexes, pH ∼4.30 to ∼4.02: optimum coacervation and pH ∼4.02 to ∼2.50: suppression of coacervation. In addition, rheological properties of sodium caseinate/A.r coacervates were studied at various pH values. A much higher storage modulus (G') than loss modulus (G″) for all sodium caseinate/A.r coacervates suggests the formation of highly interconnected gel-like network structures with mainly elastic behaviour. Moreover, sodium caseinate/A.r coacervates at all pH values exhibited a shear thinning behaviour across the entire shear rate range investigated. Effects of different species of gum tragacanth on the interactions with sodium caseinate have been scarcely studied. Our study showed that systems containing various species (A.r, soluble fraction of A.r and Astragalus gossypinus (A.g)) had different critical pH values and particle sizes during complex coacervation, which could be due to different ratio of soluble to insoluble fractions and uronic acid content of various species. Copyright © 2014 Elsevier B.V. All rights reserved.

Relative efficacy of casein or soya protein combined with palm or safflower-seed oil on hyperuricaemia in rats.

Science.gov (United States)

Lo, Hui-Chen; Wang, Yao-Horng; Chiou, Hue-Ying; Lai, Shan-Hu; Yang, Yu

2010-07-01

Diets that ameliorate the adverse effects of uric acid (UA) on renal damage deserve attention. The effects of casein or soya protein combined with palm or safflower-seed oil on various serum parameters and renal histology were investigated on hyperuricaemic rats. Male Wistar rats administered with oxonic acid and UA to induce hyperuricaemia were fed with casein or soya protein plus palm- or safflower-seed oil-supplemented diets. Normal rats and hyperuricaemic rats with or without allopurinol treatment (150 mg/l in drinking water) were fed with casein plus maize oil-supplemented diets. After 8 weeks, allopurinol treatment and soya protein plus safflower-seed oil-supplemented diet significantly decreased serum UA in hyperuricaemic rats (one-way ANOVA; P soya protein and casein attenuated hyperuricaemia-induced decreases in serum albumin and insulin, respectively (two-way ANOVA; P soya protein significantly decreased renal NO and nitrotyrosine and palm oil significantly decreased renal nitrotyrosine, TNF-alpha and interferon-gamma and increased renal transforming growth factor-beta. Casein with safflower-seed oil significantly attenuated renal tubulointerstitial nephritis, crystals and fibrosis. Comparing casein v. soya protein combined with palm or safflower-seed oil, the results support that casein with safflower-seed oil may be effective in attenuating hyperuricaemia-associated renal damage, while soya protein with safflower-seed oil may be beneficial in lowering serum UA and TAG.

Structural changes induced by high-pressure processing in micellar casein and milk protein concentrates.

Science.gov (United States)

Cadesky, Lee; Walkling-Ribeiro, Markus; Kriner, Kyle T; Karwe, Mukund V; Moraru, Carmen I

2017-09-01

Reconstituted micellar casein concentrates and milk protein concentrates of 2.5 and 10% (wt/vol) protein concentration were subjected to high-pressure processing at pressures from 150 to 450 MPa, for 15 min, at ambient temperature. The structural changes induced in milk proteins by high-pressure processing were investigated using a range of physical, physicochemical, and chemical methods, including dynamic light scattering, rheology, mid-infrared spectroscopy, scanning electron microscopy, proteomics, and soluble mineral analyses. The experimental data clearly indicate pressure-induced changes of casein micelles, as well as denaturation of serum proteins. Calcium-binding α S1 - and α S2 -casein levels increased in the soluble phase after all pressure treatments. Pressurization up to 350 MPa also increased levels of soluble calcium and phosphorus, in all samples and concentrations, whereas treatment at 450 MPa reduced the levels of soluble Ca and P. Experimental data suggest dissociation of calcium phosphate and subsequent casein micelle destabilization as a result of pressure treatment. Treatment of 10% micellar casein concentrate and 10% milk protein concentrate samples at 450 MPa resulted in weak, physical gels, which featured aggregates of uniformly distributed, casein substructures of 15 to 20 nm in diameter. Serum proteins were significantly denatured by pressures above 250 MPa. These results provide information on pressure-induced changes in high-concentration protein systems, and may inform the development on new milk protein-based foods with novel textures and potentially high nutritional quality, of particular interest being the soft gel structures formed at high pressure levels. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Utilization in rats of 14C-L-lysine-labeled casein browned by amino-carbonyl reaction

International Nuclear Information System (INIS)

Mori, Bunpei; Nakatsuji, Hirotaka.

1977-01-01

The investigation was carried out in order to elucidate the reason for the reduction in nutritive value of browned protein, by using labeled casein as a model protein. Goat casein preparation in which lysine residues had been labeled with 14 C was browned by amino-carbonyl reaction with glucose at 37 0 C. Browned or non-browned casein was ingested by growing rats by spaced feeding. When the rats ingested the browned casein the experimental group, higher radioactivity was found in TCA-soluble fraction in the small intestine as compared with that in the control group, while radioactivity was scarecely found in feces for 22 hr. Along with absorption delay, considerably high radioactivity was found in urine. The recovery of radioactivity in expired air of rats fed the labeled casein (browned and non-browned) was measured. In the experimental group, expired 14 CO 2 came out slower than the control group. From these results, it is suggested that the main reason for the reduction in nutritive value by browning reaction may be the formation of a lysine derivative in a protein, which remains in the small intestinal lumen as an absorption-delayed material and is finally excreted in urine. (auth.)

Characterization of casein gene complex and genetic diversity analysis in Indian goats.

Science.gov (United States)

Rout, P K; Kumar, A; Mandal, A; Laloe, D; Singh, S K; Roy, R

2010-04-01

Milk protein polymorphism plays an important role in genetic diversity analysis, phylogenetic studies, establishing geographical diversity, conservation decision, and improving breeding goals. Milk protein polymorphism in Indian goat breeds has not been well studied; therefore, an investigation was carried out to analyze the genetic structure of the casein gene and milk protein diversity at six milk protein loci in nine Indian goat breeds/genetic groups from varied agro-climatic zones. Milk protein genotyping was carried out in 1098 individual milk samples by SDS-PAGE at alphaS1-CN (CSN1S1), beta-CN (CSN2), alphaS2-CN (CSN1S2), kappa-CN (CSN3), beta-LG, and alpha-LA loci. Indian goats exhibited alphaS1-casein A allele in higher frequency in the majority of breeds except Ganjam and local goats. The alphaS1-casein A allele frequencies varied from 0.45 to 0.77. A total of 16 casein haplotypes were observed in seven breeds and breed specific haplotypes were observed with respect to geographic region. The average number of alleles was lowest in Ganjam (1.66 +/- 0.81) and highest in Sirohi goats (2.50 +/- 1.05). Expected heterozygosity at six different loci demonstrated genetic diversity and breed fragmentation. Neighbor-Joining tree was built basing on Nei's distance. There was about 16.95% variability due to differences between breeds, indicating a strong subdivision. Principal component analysis was carried out to highlight the relationship among breeds. The variability among goat breeds was contributed by alphaS2-CN, beta-LG and alphaS1-CN. The Indian goats exhibited alphaS1-CN (CSN1S1) A allele in higher frequency in all the breeds indicating the higher casein yield in their milk.

Effect of polyoxyethylene sorbitan esters and sodium caseinate on physicochemical properties of palm-based functional lipid nanodispersions.

Science.gov (United States)

Cheong, Jean Ne; Mirhosseini, Hamed; Tan, Chin Ping

2010-06-01

The main objective of the present study was to investigate the effect of polyoxyethylene sorbitan esters and sodium caseinate on physicochemical properties of palm-based functional lipid nanodispersions prepared by the emulsification-evaporation technique. The results indicated that the average droplet size increased significantly (P sodium caseinate-stabilized nanodispersions containing carotenoids had the largest average droplet size (386 nm), thus indicating a greater emulsifying role for Polysorbate 20 compared with sodium caseinate.

A Preclinical Study of Casein Glycomacropeptide as a Dietary Intervention for Acute Mania

DEFF Research Database (Denmark)

Liebenberg, Nico; Jensen, Erik; Larsen, Erik Roj

2018-01-01

Background: Casein glycomacropeptide is a peptide that lacks phenylalanine, tyrosine, and tryptophan. This profile may enable it to deplete phenylalanine, tyrosine, and tryptophan, and subsequently the synthesis of dopamine and serotonin in the brain. Dopamine- and serotonin-depleting amino acid...... mixtures have shown promise as acute antimanic treatments. In this study, we explore the depleting effects on amino acids, dopamine and serotonin as well as its actions on manic-like and other behavior in rats. Methods: Casein glycomacropeptide and a selection of amino acid mixtures were administered...... orally at 2, 4, or 8 h or for 1 week chronically. Amino acid and monoamine levels were measured in plasma and brain and behavior was assessed in the amphetamine-hyperlocomotion, forced swim, prepulse inhibition, and elevated plus maze tests. Results: Casein glycomacropeptide induced a time...

Prior lactose glycation of caseinate via the Maillard reaction affects in vitro activities of the pepsin-trypsin digest toward intestinal epithelial cells.

Science.gov (United States)

Wang, X P; Zhao, X H

2017-07-01

The well-known Maillard reaction in milk occurs between lactose and milk proteins during thermal treatment, and its effects on milk nutrition and safety have been well studied. A lactose-glycated caseinate was prepared via this reaction and digested using 2 digestive proteases, pepsin and trypsin. The glycated caseinate digest was assessed for its in vitro activities on rat intestinal epithelial cells in terms of growth proliferation, anti-apoptotic effect, and differentiation induction using caseinate digest as reference, to verify potential effects of the Maillard reaction on these activities of caseinate digest to the cells. Two digests had proliferative and anti-apoptotic effects, and reached the highest effects at 0.02 g/L of digest concentration with treatment time of 24 h. In comparison with caseinate digest, glycated caseinate digest always showed weaker proliferative (5.3-14.2%) and anti-apoptotic (5.9-39.0%) effects, and was more toxic to the cells at 0.5 g/L of digest concentration with treatment time of 48 h. However, glycated caseinate digest at 2 incubation times of 4 to 7 d showed differentiation induction higher than caseinate digest, as it could confer the cells with increased activities in lactase (16.3-26.6%), sucrase (22.4-31.2%), and alkaline phosphatase (17.4-24.8%). Transmission electron microscopy observation results also confirmed higher differentiation induction of glycated caseinate digest. Amino acid loss and lactose glycation partially contributed to these decreased and enhanced activities of glycated caseinate digest, respectively. The Maillard reaction of caseinate and lactose is thus shown in this study to have effects on the activities of caseinate digest to intestinal epithelial cells. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Protein kinase activity associated with the corticosteroid binder IB

International Nuclear Information System (INIS)

Vujicic, M.; Djordjevic-Markovic, R.; Radic, O.; Krstic, M.; Kanazir, D.

1997-01-01

The physiological effects elicited by glucocorticoids are mediated via glucocorticoid receptors (GR). Analysis of specific glucocorticoid binding to radioactively labelled [ 3 H] triamcinolone acetonide in rat liver cytosol and analysis by ion exchange chromatography have revealed the presence of two distinct molecular species. The major form, designated as binder II appears to correspond to the well characterized glucocorticoid receptor by virtue of its size, charge, steroid binding characteristics and ability to bind to DNA.The second form, designated as corticosteroid binder IB, is a minor binding component in the liver. The binder IB differs from the binder II receptor by virtue of its lower molecular weight and its elution in the pre gradient of DEAE-Sephadex A-50 column which retains the un activated binder II receptor complexes. We examined the kinase activity of partially purified corticosteroid binder IB. Using (γ 3 2 P) ATP we detected kinase activity associated with the IB fraction from the rat liver. This kinase phosphorylate mixed histones and and dose not phosphorylate IB protein in vitro. The kinase activity is completely inhibited by the addition of Mg 2 + ions and is partially inhibited by the addition of Ca 2 +ions. (author)

Phosphorylation and mRNA splicing of collapsin response mediator protein-2 determine inhibition of rho-associated protein kinase (ROCK) II function in carcinoma cell migration and invasion

DEFF Research Database (Denmark)

Morgan-Fisher, Marie; Couchman, John R; Yoneda, Atsuko

2013-01-01

The Rho-associated protein kinases (ROCK I and II) are central regulators of important cellular processes such as migration and invasion downstream of the GTP-Rho. Recently, we reported collapsin response mediator protein (CRMP)-2 as an endogenous ROCK II inhibitor. To reveal how the CRMP-2-ROCK II......, the presented data show that CRMP-2-dependent regulation of ROCK II activity is mediated through interaction of the CRMP-2L N terminus with the ROCK II catalytic domain as well as by GSK3-dependent phosphorylation of CRMP-2....

Stimulation of muscle protein synthesis by whey and caseinate ingestion after resistance exercise in elderly individuals

DEFF Research Database (Denmark)

Dideriksen, K J; Reitelseder, S; Petersen, S G

2011-01-01

Sarcopenia is a well-known phenomenon in elderly individuals and resistance exercise together with sufficient amino acid (AA) availability has proved to be a counteractive implement. However, the source of AA and supplement timing require further investigation. The objective was to compare muscle...... protein synthesis (MPS) to intakes of whey and caseinate after heavy resistance exercise in healthy elderly individuals, and, furthermore, to compare the timing effect of caseinate intake. Twenty-four elderly men and women (mean ± SEM; 68 ± 1 years) were randomized to one of four groups: caseinate intake...

Milk β-casein as a vehicle for delivery of bis(indolyl)methane: Spectroscopy and molecular docking studies

Science.gov (United States)

Dezhampanah, Hamid; Esmaili, Masoomeh; Khorshidi, Alireza

2017-05-01

The interaction of bis(indolyl)methane with bovine milk β-casein was investigated using spectroscopy and molecular docking studies at different temperatures (25-37 °C). The circular dichroism and Fourier transform infrared spectroscopic data demonstrated that β-casein interacts with BIM molecule mainly via both the hydrophobic and hydrophilic interactions with a minor change in the secondary structure of β-casein. The fluorescence quenching measurements revealed that the presence of a single binding site on β-casein for BIM with the binding constant value of ∼104 M-1. The negative values of entropy and enthalpy changes confirm the predominate role of hydrogen binding and van der Waals interactions in the binding process. Fӧrster energy transfer measurement suggested that the distance between bound BIM and Trp residue is higher than the respective critical distance. Hence, the static quenching is more likely responsible for the fluorescence quenching rather than the mechanism of non-radiative. Docking study showed that BIM molecule forms three hydrogen bonds and several van der Waals contacts with β-casein.

Alpha-lactalbumin and casein-glycomacropeptide do not affect iron absorption from formula in healthy term infants

Science.gov (United States)

Iron absorption from infant formula is relatively low. Alpha-lactalbumin and casein-glycomacropeptide have been suggested to enhance mineral absorption. We therefore assessed the effect of alpha-lactalbumin and casein-glycomacropeptide on iron absorption from infant formula in healthy term infants. ...

Interactions of milk α- and β-casein with malvidin-3-O-glucoside and their effects on the stability of grape skin anthocyanin extracts.

Science.gov (United States)

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

2016-05-15

The interactions of α- and β-casein with malvidin-3-O-glucoside (MG), the major anthocyanin in grape skin anthocyanin extracts (GSAE), were examined at pH 6.3 by fluorescence, fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopy. The binding constant (KS), binding force and effects of the interactions on the caseins conformation and GSAE stability were investigated. The results showed that α- and β-casein bound with MG via hydrophilic (van der Waals forces or hydrogen bonding) and hydrophobic interactions, respectively. α-Casein had a slightly stronger binding affinity toward MG than β-casein, with respective KS values of 0.51×10(3)M(-1) and 0.46×10(3)M(-1) at 297K. The secondary structures of α- and β-casein were changed by MG binding, with a decrease in α-helix and an increase in turn for α-casein and no change in α-helix and a decrease in turn for β-casein. The casein-anthocyanin interaction appeared to have a positive effect on the thermal, oxidation and photo stability of GSAE. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lipoprotein(a) and dietary proteins: casein lowers lipoprotein(a) concentrations as compared with soy protein1-3

DEFF Research Database (Denmark)

Nilausen, Karin Johanne; Meinertz, H.

1999-01-01

Lipoprotein(a), plasma lipoproteins, dietary proteins, soy protein, casein, liquid-formula, coronary artery disease, men, Denmark......Lipoprotein(a), plasma lipoproteins, dietary proteins, soy protein, casein, liquid-formula, coronary artery disease, men, Denmark...

Simultaneously tracing the geographical origin and presence of bovine milk in Italian water buffalo Mozzarella cheese using MALDI-TOF data of casein signature peptides.

Science.gov (United States)

Caira, Simonetta; Pinto, Gabriella; Nicolai, Maria Adalgisa; Chianese, Lina; Addeo, Francesco

2016-08-01

Water buffalo (WB) casein (CN) and curd samples from indigenous Italian and international breeds were examined with the objective of identifying signature peptides that could function as an indicator to determine the origin of their milk products. CN in complex mixtures were digested with trypsin, and peptide fragments were subsequently identified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). The unique presence of a β-CN A variant and an internally deleted αs1-CN (f35-42) variant in international WB milk samples was ascertained by identifying signature tryptic peptides from either dephosphorylated or native CN. Four signature unphosphorylated peptides derived from β-CN A, i.e. (f49-68) Asn(68) (2223.6 Da), (f1-28) Ser(10) (3169.4 Da), (f1-29) Ser(10) (3297.4 Da) and (f33-48) Thr(41) (1982 Da) and two from αs1-CN (f35-42) deleted fragments, i.e. (f23-34) Met(31) (1415.7 Da) and (f43-58) Val(44) (1752.7 Da), were identified. Two signature casein phosphopeptides (CPPs), i.e. β-CN (f1-28) 4P (3489.1 Da) and β-CN (f33-48) 1P (2062.0 Da), were identified in the tryptic hydrolysate of native casein or curd and cheese samples using in-batch hydroxyapatite (HA) chromatography. All these fragments functioned as analytical surrogates of two αs1- and β-casein variants that specifically occur in the milk of international WB breeds. Furthermore, the bovine peptide β-CN (f1-28) 4P had a distinct and lower molecular mass compared with the WB counterpart and functioned as a species-specific marker for all breeds of WB. Advantages of this analytical approach are that (i) peptides are easier to separate than proteins, (ii) signature peptide probes originating from specific casein variants allow for the targeting of all international WB milk, curd and cheese samples and (iii) bovine and WB casein in mixtures can be simultaneously determined in protected designation of origin (PDO) "Mozzarella di Bufala Campana" cheese

Design of Simple Instrumentation System for the Quality Analysis of Milk (Casein Analysis

Directory of Open Access Journals (Sweden)

V. G. Sangam

2010-08-01

Full Text Available This paper describes the design of a simple instrumentation system for the analysis of casein concentration in the milk. Casein is one of the major constituent of milk and its concentration describes the quality of the milk. Normally casein is analyzed by conventional analytical methods or by using Spectrophotometric methods. Here an attempt has been made to develop a simple portable system using optical instrumentation technique. The objective of the developed system is the real time analysis of the casein concentration of the milk at the field. The system involves UV light source, UV filter, cuvette, photo detector, display unit, data Acquisition Card (DAC as peripheral with USB port. Appropriate program has been developed in visual studio 6 and turbo C. Repeated number of real time analysis was carried out for different samples of milk; the results obtained are in excellent agreement with the amount determined by standard conventional methods with an accuracy of ±1.5 %, and the response time is within 100 seconds. This system can be used in the field for the quality analysis of milk as an independent unit and can also be interfaced to PC with USB port. The system has good accuracy, less response time and low cost.

The usefulness of casein-specific IgE and IgG4 antibodies in cow's milk allergic children

Directory of Open Access Journals (Sweden)

Ito Komei

2012-01-01

Full Text Available Abstract Background Cow's milk allergy is one of the most common food allergies among younger children. We investigated IgE antibodies to milk, and IgE and IgG4 antibodies to casein, α-lactalbumin and β-lactoglobulin in cow's milk allergic (CMA and non-allergic (non-CMA children in order to study their clinical usefulness. Methods Eighty-three children with suspected milk allergy (median age: 3.5 years, range: 0.8-15.8 years were diagnosed as CMA (n = 61 or non-CMA (n = 22 based on an open milk challenge or convincing clinical history. Their serum concentrations of allergen-specific (s IgE and IgG4 antibodies were measured using ImmunoCAP®. For the sIgG4 analysis, 28 atopic and 31 non-atopic control children were additionally included (all non-milk sensitized. Results The CMA group had significantly higher levels of milk-, casein- and β-lactoglobulin-sIgE antibodies as compared to the non-CMA group. The casein test showed the best discriminating performance with a clinical decision point of 6.6 kUA/L corresponding to 100% specificity. All but one of the CMA children aged > 5 years had casein-sIgE levels > 6.6 kUA/L. The non-CMA group had significantly higher sIgG4 levels against all three milk allergens compared to the CMA group. This was most pronounced for casein-sIgG4 in non-CMA children without history of previous milk allergy. These children had significantly higher casein-sIgG4 levels compared to any other group, including the non-milk sensitized control children. Conclusions High levels of casein-sIgE antibodies are strongly associated with milk allergy in children and might be associated with prolonged allergy. Elevated casein-sIgG4 levels in milk-sensitized individuals on normal diet indicate a modified Th2 response. However, the protective role of IgG4 antibodies in milk allergy is unclear.

EFFECT OF ULTRA-HIGH PRESSURE HOMOGENIZATION ON THE INTERACTION BETWEEN BOVINE CASEIN MICELLES AND RITONAVIR

Science.gov (United States)

Corzo-Martínez, M.; Mohan, M.; Dunlap, J.; Harte, F.

2014-01-01

Purpose The aim of this work was to develop a milk-based powder formulation appropriate for pediatric delivery of ritonavir (RIT). Methods Ultra-high pressure homogenization (UHPH) at 0.1, 300 and 500 MPa was used to process a dispersion of pasteurized skim milk (SM) and ritonavir. Loading efficiency was determined by RP-HPLC-UV; characterization of RIT:SM systems was carried out by apparent average hydrodynamic diameter and rheological measurements as well as different analytical techniques including Trp fluorescence, UV spectroscopy, DSC, FTIR and SEM; and delivery capacity of casein micelles was determined by in vitro experiments promoting ritonavir release. Results Ritonavir interacted efficiently with milk proteins, especially, casein micelles, regardless of the processing pressure; however, results suggest that, at 0.1 MPa, ritonavir interacts with caseins at the micellar surface, whilst, at 300 and 500 MPa, ritonavir is integrated to the protein matrix during UHPH treatment. Likewise, in vitro experiments showed that ritonavir release from micellar casein systems is pH dependent; with a high retention of ritonavir during simulated gastric digestion and a rapid delivery under conditions simulating the small intestine environment. Conclusions Skim milk powder, especially, casein micelles are potentially suitable and efficient carrier systems to develop novel milk-based and low-ethanol powder formulations of ritonavir appropriate for pediatric applications. PMID:25270571

Post-exercise ingestion of a carbohydrate and casein hydrolysate ...

African Journals Online (AJOL)

casein hydrolysate) supplement on perceived muscle soreness and fatigue, in international level Sevens rugby players (n=23) during a pre-season training camp. Methods. A randomised, double-blind, placebo-controlled design was used. Players ...

Acceleration of selenium volatilization in seleniferous agricultural drainage sediments amended with methionine and casein

Energy Technology Data Exchange (ETDEWEB)

Banuelos, G.S. [USDA-ARS, Water Management Research Laboratory, Parlier, CA 93648 (United States)], E-mail: gbanuelos@fresno.ars.usda.gov; Lin, Z.-Q. [Department of Biological Sciences and Environmental Sciences Program, Southern Illinois University Edwardsville, Edwardsville, IL 62026-1651 (United States)

2007-12-15

Phytoremediation is potentially effective for managing excessive selenium (Se) in drainage sediment residing in the San Luis Drain in central California. This 2-year field study examined the feasibility of amending drainage sediment (containing 4.78 {mu}g Se g{sup -1}) with methionine and casein to enhance volatilization without or with vegetation of Sporobolus airoides. Results show that without organic amendments, rates of Se volatilization were less than 25 {mu}g m{sup -2} d{sup -1} in all plots. After amending the sediment with 71.4 mg methionine kg{sup -1} soil, Se volatilization rates were 434 {+-} 107 {mu}g m{sup -2} d{sup -1} in vegetated plots and 289 {+-} 117 {mu}g m{sup -2} d{sup -1} in irrigated bare plots. With the amendment of 572 mg casein kg{sup -1} soil, rates increased to 346 {+-} 103 {mu}g m{sup -2} d{sup -1} in irrigated bare plots and to 114 {+-} 55 {mu}g m{sup -2} d{sup -1} in vegetated plots. Both methionine and casein promoted biological remediation of Se via volatilization most effectively during the warmest months. - Amending drainage sediment with either methionine or casein promotes the volatilization of selenium.

Acceleration of selenium volatilization in seleniferous agricultural drainage sediments amended with methionine and casein

International Nuclear Information System (INIS)

Banuelos, G.S.; Lin, Z.-Q.

2007-01-01

Phytoremediation is potentially effective for managing excessive selenium (Se) in drainage sediment residing in the San Luis Drain in central California. This 2-year field study examined the feasibility of amending drainage sediment (containing 4.78 μg Se g -1 ) with methionine and casein to enhance volatilization without or with vegetation of Sporobolus airoides. Results show that without organic amendments, rates of Se volatilization were less than 25 μg m -2 d -1 in all plots. After amending the sediment with 71.4 mg methionine kg -1 soil, Se volatilization rates were 434 ± 107 μg m -2 d -1 in vegetated plots and 289 ± 117 μg m -2 d -1 in irrigated bare plots. With the amendment of 572 mg casein kg -1 soil, rates increased to 346 ± 103 μg m -2 d -1 in irrigated bare plots and to 114 ± 55 μg m -2 d -1 in vegetated plots. Both methionine and casein promoted biological remediation of Se via volatilization most effectively during the warmest months. - Amending drainage sediment with either methionine or casein promotes the volatilization of selenium

Small intestinal digestion of raw cornstarch in cattle consuming a soybean hull-based diet is improved by duodenal casein infusion.

Science.gov (United States)

Brake, D W; Titgemeyer, E C; Bailey, E A; Anderson, D E

2014-09-01

Six duodenally and ileally cannulated steers were used in 3 sequential studies to measure 1) basal nutrient flows from a soybean hull-based diet, 2) small intestinal digestibility of raw cornstarch continuously infused into the duodenum, and 3) responses of small intestinal starch digestion to duodenal infusion of 200 or 400 g/d casein. Our objective was to evaluate responses in small intestinal starch digestion in cattle over time and to measure responses in small intestinal starch digestion to increasing amounts of MP. On average, cattle consumed 3.7 kg/d DM, 68 g/d dietary N, and 70 g/d dietary starch. Starch flow to the duodenum was small (38 g/d), and N flow was 91 g/d. Small intestinal digestibility of duodenal N was 57%, and small intestinal digestion of duodenal starch flow was extensive (92%). Small intestinal starch digestibility was 34% when 1.5 kg/d raw cornstarch was continuously infused into the duodenum. Subsequently, cattle were placed in 1 of 2 replicated Latin squares that were balanced for carryover effects to determine response to casein infusions and time required for adaptation. Duodenal infusion of casein linearly increased (P ≤ 0.05) small intestinal starch digestibility, and small intestinal starch digestion adapted to infusion of casein in 6 d. Ethanol-soluble starch and unpolymerized glucose flowing to the ileum increased linearly (P ≤ 0.05) with increasing infusion of casein. Plasma cholecystokinin was not affected by casein infusion, but circulating levels of glucose were increased by casein supplementation (P ≤ 0.05). Responses in small intestinal starch digestion in cattle adapted to casein within 6 d, and increases in duodenal supply of casein up to 400 g/d increased small intestinal starch digestion in cattle.

Casein Fermentate of Lactobacillus animalis DPC6134 Contains a Range of Novel Propeptide Angiotensin-Converting Enzyme Inhibitors▿

Science.gov (United States)

Hayes, M.; Stanton, C.; Slattery, H.; O'Sullivan, O.; Hill, C.; Fitzgerald, G. F.; Ross, R. P.

2007-01-01

This work evaluated the angiotensin-converting-enzyme (ACE)-inhibitory activities of a bovine sodium caseinate fermentate generated using the proteolytic capabilities of the porcine small intestinal isolate Lactobacillus animalis DPC6134 (NCIMB deposit 41355). The crude 10-kDa L. animalis DPC6134 fermentate exhibited ACE-inhibitory activity of 85.51% (±15%) and had a 50% inhibitory concentration (IC50) of 0.8 mg protein/ml compared to captopril, which had an IC50 value of 0.005 mg/ml. Fractionation of the crude L. animalis DPC6134 fermentate by membrane filtration and reversed-phase high-performance liquid chromatography (HPLC) generated three bioactive fractions from a total of 72 fractions. Fractions 10, 19, and 43 displayed ACE-inhibitory activity percentages of 67.53 (±15), 83.71 (±19), and 42.36 (±11), respectively, where ACE inhibition was determined with 80 μl of the fractions with protein concentrations of 0.5 mg/ml. HPLC and mass spectrometry analysis identified 25 distinct peptide sequences derived from α-, β-, and κ-caseins. In silico predictions, based on the C-terminal tetrapeptide sequences, suggested that peptide NIPPLTQTPVVVPPFIQ, corresponding to β-casein f(73-89); peptide IGSENSEKTTMP, corresponding to αs1-casein f(201212); peptide SQSKVLPVPQ, corresponding to β-casein f(166-175); peptide MPFPKYPVEP, corresponding to β-casein f(124133); and peptide EPVLGPVRGPFP, corresponding to β-casein f(210-221), contained ACE-inhibitory activities. These peptides were chosen for chemical synthesis to confirm the ACE-inhibitory activity of the fractions. Chemically synthesized peptides displayed IC50 values in the range of 92 μM to 790 μM. Additionally, a simulated gastrointestinal digestion confirmed that the ACE-inhibitory 10-kDa L. animalis DPC6134 fermentation was resistant to a cocktail of digestive enzymes found in the gastrointestinal tract. PMID:17483275

Studies on the photophysical properties of 1,8-naphthalimide derivative and aggregation induced emission recognition for casein

Energy Technology Data Exchange (ETDEWEB)

Sun, Yang, E-mail: 66160692@qq.com [Department of Chemistry and Chemical Engineering, Xi' an University of Arts and Science, No. 168, Taibai South Road, Xi' an, Shaanxi 710065 (China); Liang, Xuhua; Fan, Jun [School of Chemical Engineering, Northwest University, No. 229, Taibai North Road, Xi' an, Shaanxi 710069 (China); Han, Quan, E-mail: xahanq@hotmail.com [Department of Chemistry and Chemical Engineering, Xi' an University of Arts and Science, No. 168, Taibai South Road, Xi' an, Shaanxi 710065 (China)

2013-09-15

A novel water-soluble 1,8-naphthalimide derivative 1, bearing two acetic carboxylic groups, exhibited fluorescent turn-on recognition for casein micelle based on the aggregation induced emission (AIE) character. The photophysical properties of 1 consisting of donor and acceptor units were investigated by the solvation effect. Changing from polar to non-polar solvent increased the solvent interaction; both the excitation and emission spectra were shifted to shorter wavelength and intensity decreased through taking advantage of twisted intramolecular charge transfer (TICT) and self-association fluorescence emission. Moreover, the red-shift and quenching in protic solvent were caused by the excited-state hydrogen bond strengthening effect. The density functional theory (DFT) and time dependent density functional theory (TDDFT) were used to obtain the most stable structure, electronic excitation energy, dipole moments and charge distribution. The AIE mechanism of 1 with casein micelle was due to 1 docked in the hydrophobic cavity between sub-micelles and bound with amino acid residues, resulting in the aggregation of 1 on the casein micelle surface and emission enhancement, based on which, a novel casein assay method was developed. The proposed method exhibited a good linear range from 0.1 to 10.5 μg mL{sup −1}, with the detection limit of 3.0 ng mL{sup −1}. Satisfactory reproducibility, reversibility and a short response time were realized. This method was applied for the determination of casein in milk powder samples, avoiding the interferences from other components and illegal additives in milk. -- Highlights: • A water-soluble 1,8-naphthalimide-based fluorescent probe 1 was synthesized. • Photophysical characterization of 1 was studied. • Aggregation induced emission enhancement of 1 with casein was investigated. • A novel casein quantification method was developed.

Studies on the photophysical properties of 1,8-naphthalimide derivative and aggregation induced emission recognition for casein

International Nuclear Information System (INIS)

Sun, Yang; Liang, Xuhua; Fan, Jun; Han, Quan

2013-01-01

A novel water-soluble 1,8-naphthalimide derivative 1, bearing two acetic carboxylic groups, exhibited fluorescent turn-on recognition for casein micelle based on the aggregation induced emission (AIE) character. The photophysical properties of 1 consisting of donor and acceptor units were investigated by the solvation effect. Changing from polar to non-polar solvent increased the solvent interaction; both the excitation and emission spectra were shifted to shorter wavelength and intensity decreased through taking advantage of twisted intramolecular charge transfer (TICT) and self-association fluorescence emission. Moreover, the red-shift and quenching in protic solvent were caused by the excited-state hydrogen bond strengthening effect. The density functional theory (DFT) and time dependent density functional theory (TDDFT) were used to obtain the most stable structure, electronic excitation energy, dipole moments and charge distribution. The AIE mechanism of 1 with casein micelle was due to 1 docked in the hydrophobic cavity between sub-micelles and bound with amino acid residues, resulting in the aggregation of 1 on the casein micelle surface and emission enhancement, based on which, a novel casein assay method was developed. The proposed method exhibited a good linear range from 0.1 to 10.5 μg mL −1 , with the detection limit of 3.0 ng mL −1 . Satisfactory reproducibility, reversibility and a short response time were realized. This method was applied for the determination of casein in milk powder samples, avoiding the interferences from other components and illegal additives in milk. -- Highlights: • A water-soluble 1,8-naphthalimide-based fluorescent probe 1 was synthesized. • Photophysical characterization of 1 was studied. • Aggregation induced emission enhancement of 1 with casein was investigated. • A novel casein quantification method was developed

Structural and shear characteristics of adsorbed sodium caseinate and monoglyceride mixed monolayers at the air-water interface.

Science.gov (United States)

Rodríguez Patino, Juan M; Cejudo Fernández, Marta; Carrera Sánchez, Cecilio; Rodríguez Niño, Ma Rosario

2007-09-01

The structural and shear characteristics of mixed monolayers formed by an adsorbed Na-caseinate film and a spread monoglyceride (monopalmitin or monoolein) on the previously adsorbed protein film have been analyzed. Measurements of the surface pressure (pi)-area (A) isotherm and surface shear viscosity (eta(s)) were obtained at 20 degrees C and at pH 7 in a modified Wilhelmy-type film balance. The structural and shear characteristics of the mixed films depend on the surface pressure and on the composition of the mixed film. At surface pressures lower than the equilibrium surface pressure of Na-caseinate (at picaseinate and monoglyceride coexist at the interface, with a structural polymorphism or a liquid expanded structure due to the presence of monopalmitin or monoolein in the mixture, respectively. At higher surface pressures, collapsed Na-caseinate residues may be displaced from the interface by monoglyceride molecules. For a Na-caseinate-monopalmitin mixed film the eta(s) value varies greatly with the surface pressure (or surface density) of the mixed monolayer at the interface. In general, the greater the surface pressure, the greater are the values of eta(s). However, the values of eta(s) for a Na-caseinate-monoolein mixed monolayer are very low and practically do not depend on the surface pressure. The collapsed Na-caseinate residues displaced from the interface by monoglyceride molecules at pi>pi(e)(CS) have important repercussions on the shear characteristics of the mixed films.

Impact of casein and egg white proteins on the structure of wheat gluten-based protein-rich food.

Science.gov (United States)

Wouters, Arno G B; Rombouts, Ine; Lagrain, Bert; Delcour, Jan A

2016-02-01

There is a growing interest in texturally and nutritionally satisfying vegetable alternatives to meat. Wheat gluten proteins have unique functional properties but a poor nutritional value in comparison to animal proteins. This study investigated the potential of egg white and bovine milk casein with well-balanced amino acid composition to increase the quality of wheat gluten-based protein-rich foods. Heating a wheat gluten (51.4 g)-water (100.0 mL) blend for 120 min at 100 °C increased its firmness less than heating a wheat gluten (33.0 g)-freeze-dried egg white (16.8 g)-water (100.0 mL) blend. In contrast, the addition of casein to the gluten-water blend negatively impacted firmness after heating. Firmness was correlated with loss of protein extractability in sodium dodecyl sulfate containing medium during heating, which was higher with egg white than with casein. Even more, heat-induced polymerization of the gluten-water blend with egg white but not with casein was greater than expected from the losses in extractability of gluten and egg white on their own. Structure formation was favored by mixing gluten with egg white but not with casein. These observations were linked to the intrinsic polymerization behavior of egg white and casein, but also to their interaction with gluten. Thus not all nutritionally suitable proteins can be used for enrichment of gluten-based protein-rich foods. © 2015 Society of Chemical Industry.

Calcium, vitamin D, casein and whey protein intakes and periodontitis among Danish adults

DEFF Research Database (Denmark)

Adegboye, Amanda Ra; Boucher, Barbara J; Kongstad, Johanne

2016-01-01

, smoking, sucrose intake, alcohol consumption, number of teeth, daily brushing, regular visits to the dentist and chronic illness, irrespective of vitamin D intake levels. Intake of vitamin D alone was not associated severe with periodontitis. CONCLUSIONS: Intakes of Ca, casein and whey protein were......OBJECTIVE: To investigate whether intakes of Ca, vitamin D, casein and whey are associated with periodontitis and to investigate the possibility of interactions between them. DESIGN: Cross-sectional study. An Internet-based, 267-item FFQ was used to assess dietary intake. Intakes of casein (32.0 g....../d), whey proteins (9.6 g/d) and vitamin D (5.8 μg/d) were classified as within v. above the 50th percentile. Ca intake was classified as within v. below age-specific recommendations. Severe periodontitis was defined as having ≥2 inter-proximal sites with clinical attachment loss ≥6 mm (not on the same...

Process efficiency of casein separation from milk using polymeric spiral-wound microfiltration membranes.

Science.gov (United States)

Mercier-Bouchard, D; Benoit, S; Doyen, A; Britten, M; Pouliot, Y

2017-11-01

Microfiltration is largely used to separate casein micelles from milk serum proteins (SP) to produce a casein-enriched retentate for cheese making and a permeate enriched in native SP. Skim milk microfiltration is typically performed with ceramic membranes and little information is available about the efficiency of spiral-wound (SW) membranes. We determined the effect of SW membrane pore size (0.1 and 0.2 µm) on milk protein separation in total recirculation mode with a transmembrane pressure gradient to evaluate the separation efficiency of milk proteins and energy consumption after repeated concentration and diafiltration (DF). Results obtained in total recirculation mode demonstrated that pore size diameter had no effect on the permeate flux, but a drastic loss of casein was observed in permeate for the 0.2-µm SW membrane. Concentration-DF experiments (concentration factor of 3.0× with 2 sequential DF) were performed with the optimal 0.1-µm SW membrane. We compared these results to previous data we generated with the 0.1-µm graded permeability (GP) membrane. Whereas casein rejection was similar for both membranes, SP rejection was higher for the 0.1-µm SW membrane (rejection coefficient of 0.75 to 0.79 for the 0.1-µm SW membrane versus 0.46 to 0.49 for the GP membrane). The 0.1-µm SW membrane consumed less energy (0.015-0.024 kWh/kg of permeate collected) than the GP membrane (0.077-0.143 kWh/kg of permeate collected). A techno-economic evaluation led us to conclude that the 0.1-µm SW membranes may represent a better option to concentrate casein for cheese milk; however, the GP membrane has greater permeability and its longer lifetime (about 10 yr) potentially makes it an interesting option. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Casein improves brachial and central aortic diastolic blood pressure in overweight adolescents: a randomised, controlled trial

DEFF Research Database (Denmark)

Arnberg, Karina; Larnkjær, Anni; Michaelsen, Kim F.

2013-01-01

of water, skimmed milk, whey or casein for 12 weeks. The milk-based test drinks contained 35 g protein/l. The effects were compared with the water group and a pretest control group consisting of thirty-two of the adolescents followed 12 weeks before the start of the intervention. Outcomes were brachial...... and central aortic BP, pulse wave velocity and augmentation index, serum C-reactive protein and blood lipids. Brachial and central aortic diastolic BP (DBP) decreased by 2·7% (P= 0·036) and 2·6% (P = 0·048), respectively, within the casein group and the changes were significantly different from those...... stiffness or blood lipid concentrations. A high intake of casein improves DBP in overweight adolescents. Thus, casein may be beneficial for younger overweight subjects in terms of reducing the longterm risk of CVD. In contrast, whey protein seems to increase BP compared with drinking water; however, water...

Casein Hydrolysates by Lactobacillus brevis and Lactococcus lactis Proteases: Peptide Profile Discriminates Strain-Dependent Enzyme Specificity.

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Bounouala, Fatima Zohra; Roudj, Salima; Karam, Nour-Eddine; Recio, Isidra; Miralles, Beatriz

2017-10-25

Casein from ovine and bovine milk were hydrolyzed with two extracellular protease preparations from Lactobacillus brevis and Lactococcus lactis. The hydrolysates were analyzed by HPLC-MS/MS for peptide identification. A strain-dependent peptide profile could be observed, regardless of the casein origin, and the specificity of these two proteases could be computationally ascribed. The cleavage pattern yielding phenylalanine, leucine, or tyrosine at C-terminal appeared both at L. lactis and Lb. brevis hydrolysates. However, the cleavage C-terminal to lysine was favored with Lb. brevis protease. The hydrolysates showed ACE-inhibitory activity with IC 50 in the 16-70 μg/mL range. Ovine casein hydrolysates yielded greater ACE-inhibitory activity. Previously described antihypertensive and opioid peptides were found in these ovine and bovine casein hydrolysates and prediction of the antihypertensive activity of the sequences based on quantitative structure and activity relationship (QSAR) was performed. This approach might represent a useful classification tool regarding health-related properties prior to further purification.

Humoral and cellular responses to casein in patients with food protein-induced enterocolitis to cow's milk.

Science.gov (United States)

Caubet, Jean Christoph; Bencharitiwong, Ramon; Ross, Andrew; Sampson, Hugh A; Berin, M Cecilia; Nowak-Węgrzyn, Anna

2017-02-01

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy manifesting within 1 to 4 hours of food ingestion with repetitive emesis and lethargy. We sought to characterize immune responses to casein in children with FPIES caused by cow's milk (CM). Total IgE and IgM, CM-specific IgG, and casein-specific IgE, IgG, IgG 4 , and IgM levels, as well as immunoglobulin free light chains, were measured in both patients with active and those with resolved CM-FPIES. Proliferating casein/T-effector cell counts were measured in children with CM-FPIES, children with IgE-mediated CM allergy, and those tolerating CM. Cytokine concentrations in the supernatants were quantified. Serum cytokine and tryptase levels were measured before and after a positive oral food challenge (OFC) result and compared with levels in those with a negative OFC result. We found low levels of CM and casein-specific IgG and casein-specific IgG 4 in patients with CM-FPIES versus those tolerating CM (P casein stimulation in children with CM-FPIES, results were similar to those in control subjects. Significantly lower secretion of IL-10 and higher secretion of IL-9 by casein-stimulated T cells were found in patients with CM-FPIES versus those with IgE-mediated CM allergy. Lower baseline serum levels of IL-10 and higher tryptase levels were found in active CM-FPIES versus resolved CM-FPIES. We found a significant increase in serum IL-10 and IL-8 levels after a positive OFC result. We confirm the paucity of humoral response in patients with CM-FPIES. IL-10 might play a key role in acquisition of tolerance in patients with CM-FPIES. Increased serum IL-8 levels in patients with active FPIES suggest neutrophil involvement. Elevated baseline serum tryptase levels in patients with active FPIES suggest low-grade intestinal mast cell activation or increased mast cell load. Copyright © 2016. Published by Elsevier Inc.

Incorporation of radiolabeled whey proteins into casein micelles by heat processing

International Nuclear Information System (INIS)

Noh, B.; Richardson, T.

1989-01-01

Skim milk was heated at .70, 95, and 140 degree C to simulate the processes of pasteurization, forewarming, and UHT sterilization, and the specific interactions between α-lactalbumin or β-lactoglobulin and the caseins studied using tracer amounts of added 14 C-labeled whey protein. Radioactivities of the whey and of the washed casein pellets from renneted skim milk were measured and the extent of the interaction estimated. Upon heating skim milk at 70 degree C for 45 s, less than 2% β-lactoglobulin and less than .3% α-lactalbumin were incorporated into the curd. Heating at 95 degree C for .5 to 20 min resulted in 58 to 85% of the β-lactoglobulin and 8 to 55% of the α-lactalbumin becoming associated with the curd. Heating at 140 degree C for 2 and 4 s caused 43 and 54% of the β-lactoglobulin and 9 and 12% of the α-lactalbumin, respectively, to be bound to the curd fraction. The radiolabeling technique is very sensitive and useful for tracing low levels of interaction between whey proteins and casein in heated milk systems

Effect of the coexistence of sodium caseinate and Tween 20 as stabilizers of food emulsions at acidic pH.

Science.gov (United States)

Perugini, Luisa; Cinelli, Giuseppe; Cofelice, Martina; Ceglie, Andrea; Lopez, Francesco; Cuomo, Francesca

2018-02-05

In the present investigation the properties of edible nanoemulsions were studied. Sodium caseinate represents a good candidate for food emulsion preparations thanks to its surface-active properties and because it is perceived as a natural product by consumers. Nevertheless, it is very sensitive to acidic pH close to its isoelectric point and, if used as emulsion stabilizer, this aspect can negatively affect the emulsion stability. In order to prevent this drawback, sodium caseinate was used in combination with a non-ionic surfactant (Tween 20) as emulsifier of oil/water nanoemulsions. For these reasons, nanoemulsions stabilized by Tween 20, sodium caseinate and by a blend of the two emulsifiers were studied and compared according to their response to pH variations. Nanoemulsions were characterized for size of the dispersed phase with variation of time and temperature, for their rheological properties, for surface charge as a function of pH and for protein fluorescence. Noticeably, it was ascertained that, at pH close to caseinate isoelectric point, emulsions stabilized with the blend of caseinate and Tween 20 were more stable, compared with emulsions stabilized only with sodium caseinate. Such behavior was explained according to the composition of the emulsifiers at the oil/water interface where, at acidic pH, the presence of Tween 20 ensured the steric stabilization thus improving the role of sodium caseinate as emulsion stabilizer. Copyright © 2018 Elsevier B.V. All rights reserved.

Binding analysis for interaction of diacetylcurcumin with β-casein nanoparticles by using fluorescence spectroscopy and molecular docking calculations

Science.gov (United States)

Mehranfar, Fahimeh; Bordbar, Abdol-Khalegh; Fani, Najme; Keyhanfar, Mehrnaz

2013-11-01

The interaction of diacetylcurcumin (DAC), as a novel synthetic derivative of curcumin, with bovine β-casein (an abundant milk protein that is highly amphiphilic and self assembles into stable micellar nanoparticles in aqueous solution) was investigated using fluorescence quenching experiments, Forster energy transfer measurements and molecular docking calculations. The fluorescence quenching measurements revealed the presence of a single binding site on β-casein for DAC with the binding constant value equals to (4.40 ± 0.03) × 104 M-1. Forster energy transfer measurements suggested that the distance between bound DAC and Trp143 residue is higher than the respective critical distance, hence, the static quenching is more likely responsible for fluorescence quenching other than the mechanism of non-radiative energy transfer. Our results from molecular docking calculations indicated that binding of DAC to β-casein predominantly occurred through hydrophobic contacts in the hydrophobic core of protein. Additionally, in vitro investigation of the cytotoxicity of free DAC and DAC-β-casein complex in human breast cancer cell line MCF7 revealed the higher cytotoxic effect of DAC-β-casein complex.

Immune activation by casein dietary antigens in bipolar disorder

NARCIS (Netherlands)

Severance, E.G.; Dupont, D.; Dickerson, F.B.; Stallings, C.R.; Origoni, A.E.; Krivogorsky, B.; Yang, S.; Haasnoot, W.; Yolken, R.H.

2010-01-01

Objectives: Inflammation and other immune processes are increasingly linked to psychiatric diseases. Antigenic triggers specific to bipolar disorder are not yet defined. We tested whether antibodies to bovine milk caseins were associated with bipolar disorder, and whether patients recognized

Identification and characterization of the donkey CSN1S2 I and II cDNAs

Directory of Open Access Journals (Sweden)

Davide Nicodemo

2010-04-01

Full Text Available The αs2 casein, encoded by the CSN1S2 gene, is one of the three Calcium sensitive caseins present in the milk of ruminants of zootechnical interest and in the milk of Equidae species (horse and donkey. In the present study, we cloned, sequenced and analysed two different donkey CSN1S2 cDNAs that we called CSN1S2 I and CSN1S2 II. The first, which spans over a fragment of 1016 nt, is constituted by 19 exons and encodes for a predicted protein (called αs2-I of 221 aminoacids; the second, of which we determined the entire sequence (16 exons, encodes for a predicted peptide (called αs2-II of 168 aminoacids. Alternative splicing and genetic markers are reported for both genes.

Influence of a reconstituted basement membrane and its components on casein gene expression and secretion in mouse mammary epithelial cells

International Nuclear Information System (INIS)

Li, M.L.; Aggeler, J.; Farson, D.A.; Hatier, C.; Hassell, J.; Bissell, M.J.

1987-01-01

When primary mouse mammary epithelial cells are cultured on plastic, they rapidly lose their ability to synthesize and secrete most milk proteins even in the presence of lactogenic hormones, whereas cells cultured on release type I collagen gels show greatly enhanced mRNA levels and secretion rates of β-casein and of some other milk proteins. The authors show here that culture on a reconstituted basement membrane from Engelbreth-Holm-Swarm tumor (EHS) allows > 90% of cells to produce high levels of β-casein. By comparison, 30-40% of cells on released type 1 gels and only 2-10% of cells on plastic express β-casein after 6 days in culture. Because only 40% of cells from late pregnant gland produced β-casein before culture, the EHS matrix can both induce and maintain an increased level of casein gene expression. Individual basal lamina components were also evaluated. Type IV collagen and fibronectin had little effect on morphology and β-casein mRNA levels. In contrast, both laminin and heparan sulfate proteoglycan increased β-casein mRNA levels. Profound morphological differences were evident between cells cultured on plastic and on EHS matrix, the latter cells forming ducts, ductules, and lumina and resembling secretory alveoli. These results emphasize the vital role of the extracellular matrix in receiving and integrating structural and functional signals that can direct specific gene expression in differentiated tissues

Skeletal effect of casein and whey protein intake during catch-up growth in young male Sprague-Dawley rats.

Science.gov (United States)

Masarwi, Majdi; Gabet, Yankel; Dolkart, Oleg; Brosh, Tamar; Shamir, Raanan; Phillip, Moshe; Gat-Yablonski, Galia

2016-07-01

The aim of the present study was to determine whether the type of protein ingested influences the efficiency of catch-up (CU) growth and bone quality in fast-growing male rats. Young male Sprague-Dawley rats were either fed ad libitum (controls) or subjected to 36 d of 40 % food restriction followed by 24 or 40 d of re-feeding with either standard rat chow or iso-energetic, iso-protein diets containing milk proteins - casein or whey. In terms of body weight, CU growth was incomplete in all study groups. Despite their similar food consumption, casein-re-fed rats had a significantly higher body weight and longer humerus than whey-re-fed rats in the long term. The height of the epiphyseal growth plate (EGP) in both casein and whey groups was greater than that of rats re-fed normal chow. Microcomputed tomography yielded significant differences in bone microstructure between the casein and whey groups, with the casein-re-fed animals having greater cortical thickness in both the short and long term in addition to a higher trabecular bone fraction in the short term, although this difference disappeared in the long term. Mechanical testing confirmed the greater bone strength in rats re-fed casein. Bone quality during CU growth significantly depends on the type of protein ingested. The higher EGP in the casein- and whey-re-fed rats suggests a better growth potential with milk-based diets. These results suggest that whey may lead to slower bone growth with reduced weight gain and, as such, may serve to circumvent long-term complications of CU growth.

Effects of composite casein and beta-lactoglobulin genotypes on renneting properties and composition of bovine milk by assuming an animal model

Directory of Open Access Journals (Sweden)

T. IKONEN

2008-12-01

Full Text Available The effects of kappa-beta-casein genotypes and b-lactoglobulin genotypes on the renneting properties and composition of milk were estimated for 174 and 155 milk samples of 59 Finnish Ayrshire and 55 Finnish Friesian cows, respectively. As well as the random additive genetic and permanent environmental effects of a cow, the model included the fixed effects for parity, lactation stage, season, kappa-beta-casein genotypes and b-lactoglobulin genotypes. Favourable renneting properties were associated with kappa-beta-casein genotypes ABA 1 A 2 , ABA 1 A 1 and AAA 1 A 2 in the Finnish Ayrshire, and with ABA 2 B, AAA 1 A 3 , AAA 2 A 3 , ABA 1 A 2 and ABA 2 A 2 in the Finnish Friesian. The favourable effect of these genotypes on curd firming time and on firmness of the curd was partly due to their association with a high kappa-casein concentration in the milk. The effect of the kappa-casein E allele on renneting properties was unfavourable compared with that of the kappa-casein B allele, and possibly with that of the A allele. The beta-lactoglobulin genotypes had no effect on renneting properties but they had a clear effect on the protein composition of milk. The beta-lactoglobulin AA genotype was associated with a high whey protein % and beta-lactoglobulin concentration and the BB genotype with a high casein % and casein number.;

Effect of solvent and temperature on the size distribution of casein micelles measured by dynamic light scattering.

Science.gov (United States)

Beliciu, C M; Moraru, C I

2009-05-01

The objectives of this study were to investigate the effect of the solvent on the accuracy of casein micelle particle size determination by dynamic light scattering (DLS) at different temperatures and to establish a clear protocol for these measurements. Dynamic light scattering analyses were performed at 6, 20, and 50 degrees C using a 90Plus Nanoparticle Size Analyzer (Brookhaven Instruments, Holtsville, NY). Raw and pasteurized skim milk were used as sources of casein micelles. Simulated milk ultrafiltrate, ultrafiltered water, and permeate obtained by ultrafiltration of skim milk using a 10-kDa cutoff membrane were used as solvents. The pH, ionic concentration, refractive index, and viscosity of all solvents were determined. The solvents were evaluated by DLS to ensure that they did not have a significant influence on the results of the particle size measurements. Experimental protocols were developed for accurate measurement of particle sizes in all solvents and experimental conditions. All measurements had good reproducibility, with coefficients of variation below 5%. Both the solvent and the temperature had a significant effect on the measured effective diameter of the casein micelles. When ultrafiltered permeate was used as a solvent, the particle size and polydispersity of casein micelles decreased as temperature increased. The effective diameter of casein micelles from raw skim milk diluted with ultrafiltered permeate was 176.4 +/- 5.3 nm at 6 degrees C, 177.4 +/- 1.9 nm at 20 degrees C, and 137.3 +/- 2.7 nm at 50 degrees C. This trend was justified by the increased strength of hydrophobic bonds with increasing temperature. Overall, the results of this study suggest that the most suitable solvent for the DLS analyses of casein micelles was casein-depleted ultrafiltered permeate. Dilution with water led to micelle dissociation, which significantly affected the DLS measurements, especially at 6 and 20 degrees C. Simulated milk ultrafiltrate seemed to give

The effect of casein, hydrolyzed casein and whey proteins on urinary and postprandial plasma metabolites in overweight and moderately obese human subjects

DEFF Research Database (Denmark)

Schmedes, Mette S; Bendtsen, Line Quist; Gomes, Sisse

2018-01-01

, hydrolyzed casein and whey proteins in overweight and moderately obese men and women by investigating select urinary and blood plasma metabolites. RESULTS: A total of 21 urinary and 23 plasma metabolites were identified by NMR spectroscopy. The postprandial plasma metabolites revealed a significant diet...

Water interactions with varying molecular states of bovine casein: 2H NMR relaxation studies

International Nuclear Information System (INIS)

Kumosinski, T.F.; Pessen, H.; Prestrelski, S.J.; Farrell, H.M. Jr.

1987-01-01

The caseins occur in milk as spherical colloidal complexes of protein and salts with an average diameter of 1200 A, the casein micelles. Removal of Ca2+ is thought to result in their dissociation into smaller protein complexes stabilized by hydrophobic interactions and called submicelles. Whether these submicelles actually occur within the micelles as discrete particles interconnected by calcium phosphate salt bridges has been the subject of much controversy. A variety of physical measurements have shown that casein micelles contain an inordinately high amount of trapped water (2 to 7 g H 2 O/g protein). With this in mind it was of interest to determine if NMR relaxation measurements could detect the presence of this trapped water within the micelles, and to evaluate whether it is a continuum with picosecond correlation times or is associated in part with discrete submicellar structures with nanosecond motions. For this purpose the variations in 2 H NMR longitudinal and transverse relaxation rates of water with protein concentration were determined for bovine casein at various temperatures, under both submicellar and micellar conditions. D 2 O was used instead of H 2 O to eliminate cross-relaxation effects. From the protein concentration dependence of the relaxation rates, the second virial coefficient of the protein was obtained by nonlinear regression analysis. Using either an isotropic tumbling or an intermediate asymmetry model, degrees of hydration, v, and correlation times, tau c, were calculated for the caseins; from the latter parameter the Stokes radius, r, was obtained. Next, estimates of molecular weights were obtained from r and the partial specific volume. Values were in the range of those published from other methodologies for the submicelles

Phase behaviour of oat β-glucan/sodium caseinate mixtures varying in molecular weight.

Science.gov (United States)

Agbenorhevi, Jacob K; Kontogiorgos, Vassilis; Kasapis, Stefan

2013-05-01

The isothermal phase behaviour at 5 °C of mixtures of sodium caseinate and oat β-glucan isolates varying in molecular weight (MW) was investigated by means of phase diagram construction, rheometry, fluorescence microscopy and electrophoresis. Phase diagrams indicated that the compatibility of the β-glucan/sodium caseinate system increases as β-glucan MW decreases. Images of mixtures taken at various biopolymer concentrations revealed phase separated domains. Results also revealed that at the state of thermodynamic equilibrium, lower MW samples yielded considerable viscosity in the mixture. At equivalent hydrodynamic volume of β-glucan in the mixtures, samples varying in molecular weight exhibited similar flow behaviour. A deviation dependent on the protein concentration was observed for the high MW sample in the concentrated regime due to the size of β-glucan aggregates formed. Results demonstrate that by controlling the structural features of β-glucan in mixtures with sodium caseinate, informed manipulation of rheological properties in these systems can be achieved. Copyright © 2012 Elsevier Ltd. All rights reserved.

Csk regulates angiotensin II-induced podocyte apoptosis.

Science.gov (United States)

Zhang, Lu; Ren, Zhilong; Yang, Qian; Ding, Guohua

2016-07-01

Increasing data have shown that angiotensin II (Ang II) perpetuates podocyte injury and promotes progression to end-stage kidney disease. The mechanism underlying Ang II-induced podocyte apoptosis has not been established. C-terminal Src kinase (Csk) is a cytoplasmic kinase that interacts with scaffolding proteins involved in cell growth, adhesion, and polarization, and the role of Csk in regulating cellular apoptosis has gradually attracted attention. This study evaluates the role of Csk in Ang II-induced podocyte apoptosis. In vivo, Wistar rats were randomly subjected to a normal saline or Ang II infusion. In vitro, we exposed differentiated mouse podocytes to Ang II. Ang II increased Csk expression and induced podocyte apoptosis, stimulated Csk translocation and binding to Caveolin-1, and stimulated decreased Fyn pY416, increased Fyn pY529, and nephrin dephosphorylation. Csk knockdown prevented Ang II-induced podocyte apoptosis, reduced Fyn kinase inactivation, and increased the interaction between nephrin and the activated form of Fyn, accompanied by a reduced interaction between Csk and Caveolin-1. These findings indicate that Ang II induces podocyte injury via a Csk-dependent pathway.

Impact of sodium caseinate concentration and location on magnesium release from multiple W/O/W emulsions.

Science.gov (United States)

Bonnet, Marie; Cansell, Maud; Placin, Frédéric; Anton, Marc; Leal-Calderon, Fernando

2010-06-15

Water-in-oil-in-water (W/O/W) double emulsions were prepared and the rate of release of magnesium ions from the internal to the external aqueous phase was followed. Sodium caseinate was used not only as a hydrophilic surface-active species but also as a chelating agent able to bind magnesium ions. The release occurred without film rupturing (no coalescence). The kinetics of the release process depended on the location (in only one or in both aqueous compartments) and on the concentration of sodium caseinate. The rate of release increased with the concentration of sodium caseinate in the external phase and decreased when sodium caseinate was present in the inner droplets. The experiments were interpreted within the frame of a mean-field model based on diffusion, integrating the effect of ion binding. The data could be adequately fitted by considering a time-dependent permeation coefficient of the magnesium ions across the oil phase. Our results suggested that ion permeability was influenced by the state of the protein interfacial layers which itself depended on the extent of magnesium binding.

Casein hydrolysate augments antimicrobial and antioxidative efficacy of cheddar whey based edible coating of retail-cut beefsteak

Science.gov (United States)

Hydrolysis of casein using chymotrypsin results in the formation of polypeptides (casein hydrolyzate, CH) with a hydrophobic aromatic amino acid on one end of the chain because the enzyme selectively cleaves the adjacent peptide-bond. Due to resonance of the aromatic micro-domain, thiols become redo...

Chaperone-like activity of β-casein and its effect on residual in vitro activity of horseradish peroxidase

DEFF Research Database (Denmark)

Sulewska, Anna Maria; Olsen, Karsten; Sørensen, Jens Christian

2014-01-01

, as similar experiment with bovine serum albumin resulted in residual activity of horseradish peroxidase that was significantly lower than without any addition. The effect of β-casein on HRP disappears when pH is below the isoelectric point of β-casein. It was also proven by light scattering studies that β...... proteins. Incubating HRP (0.1 mg mL-1) for 10 min at 72 °C resulted in residual activity of 59 ± 5%, while addition of 1 mg mL-1 β-casein resulted in increase in residual activity up to 85 ± 1%. Increased residual activity is not merely attributed to an effect of higher total protein concentration......-casein interacts with horseradish peroxidase when the temperature was increased from 25 to 70 °C whereas interactions seem to cease when temperature was lowered back to 25 °C. This study highlights how specific proteins can influence enzyme activity, which is of potential importance for various industries...

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol

International Nuclear Information System (INIS)

Miller, M.J.; Zhang, x.J.; Gu, x.A.; Clark, D.A.

1991-01-01

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of 51 Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in 51 Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal 51 Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol

Energy Technology Data Exchange (ETDEWEB)

Miller, M.J.; Zhang, x.J.; Gu, x.A.; Clark, D.A. (Department of Pediatrics, Louisiana State University School of Medicine, New Orleans (USA))

1991-07-01

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of {sup 51}Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in {sup 51}Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal {sup 51}Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol.

Subunit and whole molecule specificity of the anti-bovine casein immune response in recent onset psychosis and schizophrenia

NARCIS (Netherlands)

Severance, E.G.; Dickerson, F.B.; Halling, M.; Krivogorsky, B.; Haile, L.; Yang, S.; Stallings, C.R.; Origoni, A.E.; Bossis, I.; Xiao, J.; Dupont, D.; Haasnoot, W.; Yolken, R.H.

2010-01-01

Previous studies show increased antibody levels to bovine casein in some individuals with schizophrenia. The immunogenicity of specific domains of bovine casein varies among people with milk sensitivities and thus could vary among different neuropsychiatric disorders. Using ELISAs and

Effect of Fatty acids and beeswax addition on properties of sodium caseinate dispersions and films.

Science.gov (United States)

Fabra, M J; Jiménez, A; Atarés, L; Talens, P; Chiralt, A

2009-06-08

Edible films based on sodium caseinate and different saturated fatty acids, oleic acid, or beeswax were formulated. Film-forming emulsions were characterized in terms of particle size distribution, rheological behavior and surface tension. In order to evaluate the influence of lipids on sodium caseinate matrices, mechanical, optical, and water vapor barrier properties were studied, taking into account the effect of water content and film structure on such properties. Saturated fatty acids affected the film properties in a particular way due to the formation of bilayer structures which limited water vapor permeability, giving rise to nonflexible and more opaque films. Oleic acid and beeswax were less effective as water vapor barriers, although the former imparted more flexibility to the caseinate films and did not reduce the film transparency notably.

Study of chemically unfolded β-casein by means of small-angle neutron scattering

International Nuclear Information System (INIS)

Aschi, Adel; Gharbi, Abdelhafidh; Daoud, Mohamed; Douillard, Roger; Calmettes, Patrick

2007-01-01

β-casein is a flexible amphiphilic milk protein which forms an unfolded conformation in presence of very high denaturant concentrations. The structure of β-casein formed at the bulk was studied by small-angle neutron scattering (SANS). The value of the second virial coefficient of the protein solutions indicates that the interactions between the polypeptide chain and solvent are repulsive. The protein conformation is similar to an excluded volume chain. The corresponding values of the contour length, L, the statistical length, b and the apparent radius of the chain cross-section, R c are given

Comparison of angiotensin II (Ang II) effects in the internal anal sphincter (IAS) and lower esophageal sphincter smooth muscles.

Science.gov (United States)

Rattan, Satish; Fan, Ya-Ping; Puri, Rajinder N

2002-03-22

Studies were performed to compare the actions of Ang II in the internal anal sphincter (IAS) vs. lower esophageal sphincter (LES) smooth muscles in vitro, in opossum and rabbit. Studies also were carried out in isolated smooth muscle cells. In opossum, Ang II produced no discernible effects in the IAS, but did produce a concentration-dependent contraction in the LES. Conversely, in the rabbit, while Ang II caused a modest response in the LES, it caused a significant contraction in the IAS. The contractile responses of Ang II in the opossum LES were mostly resistant to different neurohumoral antagonists but were antagonized by AT1 antagonist losartan. AT2 antagonist PD 123,319, rather than inhibiting, prolonged the contractile action of Ang II. The contractile actions of Ang II in the opossum LES were not modified by the tyrosine kinase inhibitors (genistein and tyrphostin 1 x 10(-6) M) but were partially attenuated by the PKC inhibitor H-7 (1 x 10(-6) M), Ca2+ channel blocker nicardipine (1 x 10(-5) M), Rho kinase inhibitor HA-1077 (1 x 10(-7) M) or p(44/42) MAP kinase inhibitor PD 98059 (5 x 10(-5) M). The combination of HA-1077 and H-7 did not cause an additive attenuation of Ang II responses. Western blot analyses revealed the presence of both AT1 and AT2 receptors. We conclude that Ang lI-induced contraction of sphincteric smooth muscle occurs primarily by the activation of AT1 receptors at the smooth muscle cells and involves multiple pathways, influx of Ca2+, and PKC, Rho kinase and p(44/42) MAP kinase.

Oriented immobilization of His-tagged kinase RIO1 protein on redox active N-(IDA-like)-Cu(II) monolayer deposited on gold electrode—The base of electrochemical biosensor

International Nuclear Information System (INIS)

Mielecki, Marcin; Wojtasik, Justyn; Zborowska, Magdalena; Kurzątkowska, Katarzyna; Grzelak, Krystyna; Dehaen, Wim; Radecki, Jerzy; Radecka, Hanna

2013-01-01

Highlights: ► The redox active N-(IDA-like)-Cu(II) monolayer is suitable for oriented and stable immobilization of His-tagged kinase Rio1. ► Cu(II) deposited onto the electrode surface play double role: immobilization sites for His-tagged proteins and transduction centres tracking the protein–small molecule interactions. ► The base of biosensor response towards target compound is the change of Rio1 conformation lading to alternation of the permeability of counter ions to Cu(II) redox centres. -- Abstract: The fabrication of electrochemical biosensor consists of the following successive steps: formation of thiol derivative of iminodiacetic acid (IDA-like/N-heterocyclic donor) and N-acetylcysteamine (NAC) self-assembled monolayer on the Au electrode, complexation of Cu(II) by N(IDA-like) attached to the surface of the Au electrode and immobilization of kinase protein Rio1 through N(IDA-like)-Cu(II)-histidine-tag covalent bond formation. Each step of modification was controlled by cyclic voltammetry, electrochemical impedance spectrometry and atomic force microscopy. The interactions between rHis 6 -Rio1 attached to the surface of the electrode and tyrphostin inhibitor (2E)-N-Benzyl-2-cyano-3-(3,4-dihydroxyphenyl)-acrylamide (AG-490) and its analogue (2-cyano-N-(4-methoxyphenyl)-3-(pyridin-3-yl)prop-2-enamide) (CPE), present in aqueous solution were monitored with Osteryoung square wave voltammetry. The basis of the biosensor response was the change in the electrochemical properties of Cu(II) redox centres upon formation of the rHis 6 -Rio1-inhibitor complex. A linear responses with high reproducibility and stability were observed between 0.10 and 0.40 μM of AG-490 as well as of CPE. The interaction between rHis 6 -Rio1 and AG-490 was stronger than the interaction with its analogue CPE. Cu(II) redox current decrease of 37.9 ± 1.6% and 23.3 ± 1.0% were observed in the presence of 0.40 μM of AG-490 and CPE, respectively. The presented biosensor could be

Improvement of stability of oil-in-water emulsions containing caseinate-coated droplets by addition of sodium alginate.

Science.gov (United States)

Pallandre, S; Decker, E A; McClements, D J

2007-11-01

The potential of sodium alginate for improving the stability of emulsions containing caseinate-coated droplets was investigated. One wt% corn oil-in-water emulsions containing anionic caseinate-coated droplets (0.15 wt% sodium caseinate) and anionic sodium alginate (0 to 1 wt%) were prepared at pH 7. The pH of these emulsions was then adjusted to 3.5, so that the anionic alginate molecules adsorbed to the cationic caseinate-coated droplets. Extensive droplet aggregation occurred when there was insufficient alginate to completely saturate the droplet surfaces due to bridging flocculation, and when the nonadsorbed alginate concentration was high enough to induce depletion flocculation. Emulsions with relatively small particle sizes could be formed over a range of alginate concentrations (0.1 to 0.4 wt%). The influence of pHs (3 to 7) and sodium chloride (0 to 500 mM) on the properties of primary (0 wt% alginate) and secondary (0.15 wt% alginate) emulsions was studied. Alginate adsorbed to the droplet surfaces at pHs 3, 4, and 5, but not at pHs 6 and 7, due to electrostatic attraction between anionic groups on the alginate and cationic groups on the adsorbed caseinate. Secondary emulsions had better stability than primary emulsions at pH values near caseinate's isoelectric point (pHs 4 and 5). In addition, secondary emulsions were stable up to higher ionic strengths (< 300 mM) than primary emulsions (<50 mM). The controlled electrostatic deposition method utilized in this study could be used to extend the range of application of dairy protein emulsifiers in the food industry.

Modification of Casein by the Lipid Oxidation Product Malondialdehyde

NARCIS (Netherlands)

Adams, A.; Kimpe, de N.; Boekel, van T.

2008-01-01

The reaction of malondialdehyde with casein was studied in aqueous solution to evaluate the impact of this lipid oxidation product on food protein modification. By using multiresponse modeling, a kinetic model was developed for this reaction. The influence of temperature and pH on protein browning

Kinetic modelling of reactions in heated disaccharide-casein systems

NARCIS (Netherlands)

Brands, C.M.J.; Boekel, van M.A.J.S.

2003-01-01

The reactions occurring in disaccharide-casein reaction mixtures during heating at 120 degreesC and pH 6.8 were studied. The existence of two main degradation routes were established: (1) Isomerisation of the aldose sugars lactose and maltose in their ketose isomers lactulose and maltulose,

Exploiting the MDM2-CK1α Protein-Protein Interface to Develop Novel Biologics That Induce UBL-Kinase-Modification and Inhibit Cell Growth

Science.gov (United States)

Huart, Anne-Sophie; MacLaine, Nicola J.; Narayan, Vikram; Hupp, Ted R.

2012-01-01

Protein-protein interactions forming dominant signalling events are providing ever-growing platforms for the development of novel Biologic tools for controlling cell growth. Casein Kinase 1 α (CK1α) forms a genetic and physical interaction with the murine double minute chromosome 2 (MDM2) oncoprotein resulting in degradation of the p53 tumour suppressor. Pharmacological inhibition of CK1 increases p53 protein level and induces cell death, whilst small interfering RNA-mediated depletion of CK1α stabilizes p53 and induces growth arrest. We mapped the dominant protein-protein interface that stabilizes the MDM2 and CK1α complex in order to determine whether a peptide derived from the core CK1α-MDM2 interface form novel Biologics that can be used to probe the contribution of the CK1-MDM2 protein-protein interaction to p53 activation and cell viability. Overlapping peptides derived from CK1α were screened for dominant MDM2 binding sites using (i) ELISA with recombinant MDM2; (ii) cell lysate pull-down towards endogenous MDM2; (iii) MDM2-CK1α complex-based competition ELISA; and (iv) MDM2-mediated ubiquitination. One dominant peptide, peptide 35 was bioactive in all four assays and its transfection induced cell death/growth arrest in a p53-independent manner. Ectopic expression of flag-tagged peptide 35 induced a novel ubiquitin and NEDD8 modification of CK1α, providing one of the first examples whereby NEDDylation of a protein kinase can be induced. These data identify an MDM2 binding motif in CK1α which when isolated as a small peptide can (i) function as a dominant negative inhibitor of the CK1α-MDM2 interface, (ii) be used as a tool to study NEDDylation of CK1α, and (iii) reduce cell growth. Further, this approach provides a technological blueprint, complementing siRNA and chemical biology approaches, by exploiting protein-protein interactions in order to develop Biologics to manipulate novel types of signalling pathways such as cross-talk between

Exploiting the MDM2-CK1α protein-protein interface to develop novel biologics that induce UBL-kinase-modification and inhibit cell growth.

Directory of Open Access Journals (Sweden)

Anne-Sophie Huart

Full Text Available Protein-protein interactions forming dominant signalling events are providing ever-growing platforms for the development of novel Biologic tools for controlling cell growth. Casein Kinase 1 α (CK1α forms a genetic and physical interaction with the murine double minute chromosome 2 (MDM2 oncoprotein resulting in degradation of the p53 tumour suppressor. Pharmacological inhibition of CK1 increases p53 protein level and induces cell death, whilst small interfering RNA-mediated depletion of CK1α stabilizes p53 and induces growth arrest. We mapped the dominant protein-protein interface that stabilizes the MDM2 and CK1α complex in order to determine whether a peptide derived from the core CK1α-MDM2 interface form novel Biologics that can be used to probe the contribution of the CK1-MDM2 protein-protein interaction to p53 activation and cell viability. Overlapping peptides derived from CK1α were screened for dominant MDM2 binding sites using (i ELISA with recombinant MDM2; (ii cell lysate pull-down towards endogenous MDM2; (iii MDM2-CK1α complex-based competition ELISA; and (iv MDM2-mediated ubiquitination. One dominant peptide, peptide 35 was bioactive in all four assays and its transfection induced cell death/growth arrest in a p53-independent manner. Ectopic expression of flag-tagged peptide 35 induced a novel ubiquitin and NEDD8 modification of CK1α, providing one of the first examples whereby NEDDylation of a protein kinase can be induced. These data identify an MDM2 binding motif in CK1α which when isolated as a small peptide can (i function as a dominant negative inhibitor of the CK1α-MDM2 interface, (ii be used as a tool to study NEDDylation of CK1α, and (iii reduce cell growth. Further, this approach provides a technological blueprint, complementing siRNA and chemical biology approaches, by exploiting protein-protein interactions in order to develop Biologics to manipulate novel types of signalling pathways such as cross

A high-fat, high-protein diet attenuates the negative impact of casein-induced chronic inflammation on testicular steroidogenesis and sperm parameters in adult mice.

Science.gov (United States)

Zhao, Jing-Lu; Zhao, Yu-Yun; Zhu, Wei-Jie

2017-10-01

The interaction between obesity and chronic inflammation has been studied. Diet-induced obesity or chronic inflammation could reduce the testicular functions of males. However, the mechanism underlying the reproductive effects of fattening foods in males with or without chronic inflammation still needs further discussion. This study was aimed to investigate the effects of high-fat, high-protein diet on testicular steroidogenesis and sperm parameters in adult mice under physiological and chronic inflammatory conditions. Because casein can trigger a non-infectious systemic inflammatory response, we used casein injection to induce chronic inflammation in male adult Kunming mice. Twenty-four mice were randomly and equally divided into four groups: (i) normal diet+saline (Control); (ii) normal diet+casein (ND+CS); (iii) high-fat, high-protein diet+saline (HFPD+SI); (iv) high-fat, high-protein diet+casein (HFPD+CS). After 8weeks, there was a significant increase in body weight for groups HFPD+SI and HFPD+CS and a decrease in group ND+CS compared with the control. The serum levels of tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10) and lipid profiles were increased markedly in groups ND+CS, HFPD+SI and HFPD+CS compared with the control. A remarkable reduction of serum adiponectin level occurred in group HFPD+CS compared with group ND+CS. Sperm parameters (sperm count, viability and abnormality) were also adversely affected in groups ND+CS and HFPD+SI. Groups ND+CS and HFPD+SI showed severe pathological changes in testicular tissues. Semiquantitative RT-PCR, Western blot and immunohistochemical staining also showed significant reductions in both testicular mRNA and protein levels of steroidogenic acute regulatory (StAR) and cytochrome P450scc (CYP11A1) in groups HFPD+SI and HFPD+CS compared with the control, whereas testicular mRNA and protein levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) in groups HFPD+SI and HFPD+CS significantly increased. The m

Myosin light chain kinase phosphorylation in tracheal smooth muscle

International Nuclear Information System (INIS)

Stull, J.T.; Hsu, L.C.; Tansey, M.G.; Kamm, K.E.

1990-01-01

Purified myosin light chain kinase from smooth muscle is phosphorylated by cyclic AMP-dependent protein kinase, protein kinase C, and the multifunctional calmodulin-dependent protein kinase II. Because phosphorylation in a specific site (site A) by any one of these kinases desensitizes myosin light chain kinase to activation by Ca2+/calmodulin, kinase phosphorylation could play an important role in regulating smooth muscle contractility. This possibility was investigated in 32 P-labeled bovine tracheal smooth muscle. Treatment of tissues with carbachol, KCl, isoproterenol, or phorbol 12,13-dibutyrate increased the extent of kinase phosphorylation. Six primary phosphopeptides (A-F) of myosin light chain kinase were identified. Site A was phosphorylated to an appreciable extent only with carbachol or KCl, agents which contract tracheal smooth muscle. The extent of site A phosphorylation correlated to increases in the concentration of Ca2+/calmodulin required for activation. These results show that cyclic AMP-dependent protein kinase and protein kinase C do not affect smooth muscle contractility by phosphorylating site A in myosin light chain kinase. It is proposed that phosphorylation of myosin light chain kinase in site A in contracting tracheal smooth muscle may play a role in the reported desensitization of contractile elements to activation by Ca2+

Treatment of post-orthodontic white spot lesions with casein phosphopeptide-stabilised amorphous calcium phosphate

DEFF Research Database (Denmark)

Bröchner, Ann; Christensen, Carsten; Kristensen, Bjarne

2010-01-01

This study aims to investigate the effect of topical applications of 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on white spot lesions (WSL) detected after treatment with fixed orthodontic appliances. Sixty healthy adolescents with >/=1 clinically visible WSL at debonding were...... findings were largely reflected by the clinical scores. No side effects were reported. Topical treatment of white spot lesions after debonding of orthodontic appliances with a casein phosphopeptide-stabilised amorphous calcium phosphate agent resulted in significantly reduced fluorescence and a reduced...

Study of Thermal Properties, Turbidity, Effective Factors on Particle Size and Oscillatory Rheology of Pectin-Caseinate Biopolymer Nanocomplexes

Directory of Open Access Journals (Sweden)

Sajedeh Bahrani

2013-02-01

Full Text Available The biopolymer-based nanocomplexes are a group of nanocapsules that are used for encapsulation and control delivery of nutraceuticals. They are formed by binding of proteins and polysaccharides. In this study, complex formation between pectin and sodium caseinate was taken place by addition of pectin solutions(0.2, 0.45 and 0.7 % w/v into the caseinate solutions (0.5, 1 and 1.5 % w/v and adjusted their pH below isoelecteric point of sodium caseinate. The effect of various factors such as biopolymer concentration, salt concentration, temperature and time of ultrasound on the properties of pectin-casein nanocomplexes was investigated. Differential scanning calorimetry (DSC and particle size analyzer were used for study of complex formation and particle size determination, respectively. The results of DSC and turbidimetry showed complex formation between the pectin and casein at pH below 5 and the results of particle size showed formation of stable dispersion with a minimum size of 86 nm at pH 4.1, caseinate of 1 % w/v and pectin 0.45 % w/v concentration. The ultrasound for more than 1 min reduced particle size and addition of salt at high and low concentrations had different effects on the stability of the colloidal system. The lowering of temperature from 21 to 4°C resulted in smaller particle size of nanocomplexes. The oscillatory rheological results showed that with increasing pectin concentration, viscoelastic moduli were increased and loss moduli were higher than storage modulus.

Caseins from bovine colostrum and milk strongly bind piscidin-1, an antimicrobial peptide from fish.

Science.gov (United States)

Kütt, Mary-Liis; Stagsted, Jan

2014-09-01

A model system of bovine colostrum and piscidin, a fish-derived antimicrobial peptide, was developed to study potential interactions of antimicrobial peptides in colostrum. We did not detect any antimicrobial activity of colostrum using the radial plate diffusion assay; in fact colostrum completely abrogated activity of added piscidin. This could not be explained by degradation of piscidin by colostrum, which was less than ten percent. We found that colostrum even protected piscidin against degradation by added proteases. We further observed that colostrum and milk rapidly quenched the fluorescence of fluorescein-piscidin but not that of fluorescein. This effect was not seen with BSA and the specific quenching of fluorescein-piscidin by colostrum was saturably inhibited with unlabeled piscidin. Size exclusion chromatography indicated that fluorescein-piscidin bound to casein micelles with no apparent binding to IgG or whey proteins. Further, addition of pure caseins was able to quench fluorescence of fluorescein-piscidin and to inhibit the antimicrobial activity of piscidin. The interaction between caseins and piscidin could be dissociated by guanidine hydrochloride and recovered piscidin had antimicrobial activity against bacteria. Based on our results we propose that caseins could be carriers for antimicrobial peptides in colostrum and milk. Copyright © 2014 Elsevier B.V. All rights reserved.

Transglutaminase catalyzed cross-linking of sodium caseinate improves oxidative stability of flaxseed oil emulsion.

Science.gov (United States)

Ma, Hairan; Forssell, Pirkko; Kylli, Petri; Lampi, Anna-Maija; Buchert, Johanna; Boer, Harry; Partanen, Riitta

2012-06-20