SEARCH · Search PubMed

Results for “CASEIN”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,459 records · Page 81Linked to original sources

PubMed1990

[Physiologic requirements for casein protein and wheat gluten in 4-month-old rats].

Sources of casein protein and wheat gluten were analysed for the content of proteins, fats, saccharides, water and amino acids. The chemical score of the amino acids and the ratio of essential and non-essential amino acids (E/N) were determined. In rats (males) at the age of 120 days, given the diets for 14 days, the optimal and maintenance physiological daily rations were determined from the changes of body nitrogen, body water and weight dependent on the protein intake, using the method of increasing casein protein and wheat gluten content from 0 to 40 per cent in the diet. In 120-134-day-old rats, the optimal daily dose was 1.75 g of casein protein (7.5 per cent of all proteins in the diet) and 2.46 g of wheat gluten protein (10 per cent of all proteins in the diet). As to the maintenance rations determined from the weight changes, body nitrogen and body water in dependence on the protein intake, in these rats the successive daily rations were 1216 mg, 1214 mg and 1302 mg for the casein protein, and 1731 mg, 1760 mg and 1861 mg for the wheal gluten protein.

Age Factors↗

PubMed1990

Promotion of colonic microadenoma growth in mice and rats fed cooked sugar or cooked casein and fat.

We studied the effect of cooked food components on the promotion of microadenoma growth in the colons of mice and rats. CF1 mice and Fisher 344 rats were initiated with azoxymethane, with 152 mice receiving four weekly i.p. injections of 5 mg/kg, 59 rats receiving a single injection of 20 mg/kg, and 24 rats receiving 30 mg/kg. A week after the last injection, the animals were randomly assigned to one of eight diets with identical ingredients, but the three components, sucrose, casein, and beef tallow, either uncooked or cooked. Control animals were given diets with uncooked ingredients. Experimental animals were fed diets in which one, two, or three of the components were cooked in an oven at 180 degrees C until golden brown before they were added to the diet. After 100 days on the diets, the colons were fixed, stained with methylene blue, and scored for microadenomas. The mice and the rats fed cooked sucrose, or casein and beef tallow cooked together, had three to five times more large microadenomas than did the controls (P ranging from 0.02 to 0.0001). No significant increase was observed with the five other cooked diets. Two rats fed the casein and beef tallow cooked together had adenocarcinomas. Thus, a diet containing 20% of cooked sucrose, or 40% of casein and beef tallow cooked together, promotes the growth of colonic microadenomas in initiated mice and rats, and would appear to contain promoters for colon cancer.

Adenoma↗

PubMed1989

[Isolation and characterization of casein kinases I and II from rabbit liver. Analysis of their effects on protein biosynthesis in the cell].

Two cAMP-independent protein kinases isolated from rabbit liver extracts phosphorylate casein far more effectively than histones. The first protein kinase consists of one polypeptide chain (Mr = 37,000), utilizes exclusively ATP and is not inhibited in the presence of low heparin and RNA concentrations. The second protein kinase consists of three subunits (Mr = 42,000, 40,000 and 25,000 Da), utilizes both ATP and GTP and is inhibited by low heparin and RNA concentrations. The latter enzyme has Mr approximately 140,000 Da and possesses a polyanion-binding activity. These characteristics allow to relate the above enzymes to casein kinases I and II, respectively. Injection of casein kinase I into frog oocytes results in the inhibition of the rate of amino acid incorporations into the soluble and detergent extractable proteins. Casein kinase II has no effect on the amino acid incorporation into the recipient oocytes.

Animals↗

PubMed1989

Synergistic phosphorylation of rabbit muscle glycogen synthase by cyclic AMP-dependent protein kinase and casein kinase I. Implications for hormonal regulation of glycogen synthase.

The phosphorylation of rabbit skeletal muscle glycogen synthase by casein kinase I is markedly enhanced if the enzyme has previously been phosphorylated by cAMP-dependent protein kinase. The presence of phosphate in the primary cAMP-dependent protein kinase sites, sites 1a, 1b, and 2 (serine 7), increases the activity of casein kinase I toward residues in the vicinity of these sites. This synergistic phosphorylation correlates with potent inactivation of the glycogen synthase. Analysis of the NH2 terminus of the enzyme subunit indicated that phosphorylation at serine 7 caused serine 10 to become a preferred casein kinase I site and that phosphoserine can be an important recognition determinant for casein kinase I. This finding can also explain how epinephrine stimulation of skeletal muscle provokes significant increases in the phosphorylation state of serine residues, in particular serine 10, not recognized by cAMP-dependent protein kinase.

Amino Acid Sequence↗

PubMedDate not supplied

[Casein kinase type II during lens fiber differentiation in amphibians].

cAMP-independent protein kinase activity of casein type was found in Rana temporaria eye lens. The highest activity was observed in "cortex" lens fibres, and decreased two-fold in lens epithelium. Minimum activity was found in lens "nucleus" fibres. Thus, protein kinase activity is characteristic of metabolically active differentiating lens cells. Enzyme fraction showed almost complete binding to the immobilized RNA. The enzyme was inhibited by heparine, phosphorylated casein (but not histones). It could use either ATP or GTP as a source of phosphate, and caused modification of serine and threonine residues in casein molecule. The protein kinase from lens epithelium and cortex was purified 6,000-7,000-fold and was identified as a type II casein kinase.

Amphibians↗

PubMed1989

Sequence of caprine alpha s1-casein and characterization of those of its genetic variants which are synthesized at a high level, alpha s1-CnA, B and C.

The sequence of caprine alpha s1-casein (199 residues) was established. The peptide chain has the same length as, and shows a 88% degree of identity with, its bovine counterpart. With the ovine alpha s1-casein, the sequence of which was deduced from that of its mRNA, the degree of identity is 97%, counting as one difference a deletion of eight residues in the ovine protein. The differences between the three genetic variants associated with a high alpha s1-casein content in milk are simple substitutions. Variant alpha s1-CnA differs from variant alpha s1-CnB by two substitutions, 16 Leu (A)----Pro (B) and 77 Gln (A)----Glu (B), the latter inducing the appearance of a phosphate group on 75 Ser. Variant alpha s1-CnC differs from alpha s1-CnB by three substitutions, 8 His (B)----Ile (C), 100 Arg (B)----Lys (C) and 195 Thr (B)----Ala (C). The original type of caprine alpha s1-casein could be another hypothetical genetic variant, having the same electrophoretic mobility as alpha s1-CnB.

Amino Acid Sequence↗

PubMed1989

[Phosphorylation of components of high molecular weight aminoacyl-tRNA-synthetase complex from the rabbit liver by associated casein kinase type I].

The aminoacyl-tRNA synthetase complex from rabbit liver possesses an endogenous protein kinase activity. The associated protein kinase in the complex was defined as casein kinase I. Using FPLC, a fraction of the supramolecular complex with a high level of metabolic activity was isolated; this preparation was found to be enriched in the casein kinase activity. Incubation of this fraction with [gamma-32P] ATP leads to the intensive incorporation of labeled phosphate into 12 polypeptides of the complex, i.e., glutamyl-, isoleucyl-, leucyl-, methionyl-, lysyl-, arginyl- and aspartyl-tRNA synthetases. An addition of free homologous casein kinase I does not change the spectrum or level of phosphorylation of the complex substrates. The homologous casein kinase II phosphorylates polypeptides with Mr of 65, 43 and 20 kDa in the complex.

Amino Acyl-tRNA Synthetases↗

PubMed1986

[Effect of aspirin and nordihydroguaiaretic acid on the secretion of milk caseins by the mammary epithelial cell].

Phospholipase A2 and arachidonic acid mimic the stimulatory effect of prolactin on casein exocytosis. We suggest that prolactin by activating phospholipase A2, induces a release of arachidonic acid which is metabolized by a cyclooxygenase pathway leading to prostaglandins, prostacyclins and thromboxanes, a lipoxygenase pathway leading to hydroperoxides and leukotrienes and an epoxygenase pathway. The effects of prolactin and of the major products of arachidonic acid metabolism were studied by incubating mammary gland fragments of lactating rabbit and by measuring neosynthesized caseins and prostaglandins F (PGF2 alpha) in the incubation medium. Aspirin (10(-3) M) which strongly decreases PGF2 alpha synthesis did not modify exocytosis or prolactin stimulation of exocytosis. However, in some cases where prolactin did not stimulate exocytosis, aspirin could restore this stimulation. Nor-dihydroguaiaretic acid (10 microM), an inhibitor of lipoxygenases, increased PGF2 alpha synthesis in the presence of prolactin. In parallel, this inhibitor increased casein exocytosis but inhibited prolactin stimulation. These results are consistent with the action of arachidonic acid metabolites in the regulation of casein exocytosis. We suggest a dual control by the metabolites of the lipoxygenase and the cyclooxygenase pathways.

Animals↗

PubMed1986

[Casein-like immunoreactivity in the male rat].

A substance presenting a beta-casein-like immunoreactivity (beta-cas-LI) was found in male serum and tissues. This beta-cas-LI was measured by a specific radioimmunoassay using a purified beta-casein and an anti beta-casein kindly supplied by L. M. Houdebine. Serial dilutions of serum or tissues samples showed a good parallelism to the standard curve. In male rat, beta-cas-Li was found in all sera and in some tissues = mammary gland, prostate and testis which contained respectively 6,200, 408 and 38 ng per organ. beta-cas-LI value in the serum was regulatable. Hypophysectomy and long-term castration strongly reduced basal levels. Insertion of testosterone silastic capsules (25 mg/capsule) was able to restore control values, while estradiol (E2) (4 mg/kg E2 valerianate) to castrated or intact rats increased serum beta-cas-LI above basal values. In conclusion, these results showed, for the first time, the presence in male rat serum and tissues of a beta-casein immunoreactive-like substance. Moreover, this beta-cas-LI seemed to be under pituitary and gonad regulation.

Animals↗

PubMed1985

Determination of physiological casein and wheat gluten protein requirements of adult rats aged 75-89 days.

Mounting doses of casein and wheat gluten protein (from 0% to 40% in the diet) were given to adult male rats aged 75-89 days for 14 days. The optimum physiological daily dose, determined from changes in body nitrogen, body water and body weight, was 2.76 g/d for casein protein (corresponding to a 10% casein protein diet) and 3.67 g/d for wheat gluten protein (corresponding to a 15% gluten protein diet). Determined from body weight changes, the daily maintaining dose of casein or wheat gluten protein was 1.054 and 1.511 mg/d respectively, from body nitrogen changes 970 and 1.514 mg/d and from body water changes 1.124 and 1.637 mg/d. Compared with newly weaned animals aged 35-49 days, the optimum physiological daily dietary protein doses for adult animals fall, while the maintaining doses rise.

Animals↗

PubMed1988

[Change in the level of casein mRNA in the mammary gland of rats and goats during lactation].

Cloned cDNAs for three distinct casein mRNAs (alpha s1-, beta- and chi) were used to determine the levels of individual mRNAs in total cell RNA preparations from both rat mammary glands in the course of natural lactation cycle and goat mammary glands at the most important lactation stages. Two maxima of active rat mRNA synthesis were shown to be closely associated with the particular developmental features of the progeny. A negative correlation between rat alpha s1-, and beta-casein mRNA levels was found. The length of goat casein mRNA was relatively increased at certain periods of the lactation cycle. The possible regulation mechanisms for the control of casein gene expression are discussed.

Animals↗

PubMed1987

[Type-II casein kinases: characteristics of their properties and possible physiological role].

A detailed characteristic of casein kinases of the second type based on the analysis of the literary data and own research is given. The main properties which allow to differ them from other protein kinases are described. The participation of casein kinases II in regulation of different cellular processes are shown: in carbohydrate and lipid metabolism, in transcription, translation and enzyme synthesis. The changes in the activity of the given casein kinases in the course of the cellular cycle and during some pathological states show that from the diagnostic point of view the measurements of the enzyme activity is a useful tool, especially in an early detection of uncontrolled cell proliferation. On the basis of the given data the casein kinases II have been concluded to play an important role in the control of organism normal development. The given proteins may be put in one line with well studied and physiologically important cAMP-dependent and Ca-dependent protein kinases.

Animals↗

PubMed1986

Casein kinase type II is involved in the inhibition by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole of specific RNA polymerase II transcription.

We have described a HeLa protein kinase whose activity is inhibited by the nucleotide analogue 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) at concentrations similar to those required to inhibit in vivo and in vitro specific transcription (Zandomeni, R., and Weinmann, R. (1984) J. Biol. Chem. 259, 14804-14822). We have now detected an analogous DRB-sensitive kinase from calf thymus and purified it to homogeneity. Based on the subunit composition of the enzyme and other common biochemical and chromatographic properties, we identified it as casein kinase II. The extent of DRB inhibition of the purified calf thymus enzyme is indistinguishable from that observed for inhibition of in vitro transcription with the HeLa cell extract. The DRB bromo- derivative, 5,6-dibromo-1-beta-D-ribofuranosylbenzimidazole is a more potent inhibitor of in vivo transcription and inhibits purified casein kinase II activity and specific in vitro transcription at 6-10 times lower concentrations than DRB. Moreover, addition of an excess of the purified calf thymus casein kinase II enzyme to a HeLa in vitro transcription reaction inhibited by DRB partially overcomes this inhibition. Thus, we conclude that casein kinase II is involved directly or indirectly in the inhibition by DRB of specific RNA polymerase II-mediated transcription. This demonstrates the participation of a protein kinase in a eukaryotic RNA polymerase II-specific transcription system.

Animals↗

PubMed1986

Phosphorylation of muscle and non-muscle actins by casein kinase 1 in vitro.

Skeletal muscle and Physarum actins were markedly phosphorylated by casein kinase 1, but not by casein kinase 2. The amount of radioactive phosphate incorporated into muscle actin with 110 units of casein kinase 1 was approx. 0.2 mol per mol of actin, which was significantly greater than those catalyzed using the same number of enzyme units of protein kinase A or protein kinase C. The Km values of casein kinase 1 for muscle and Physarum actins were 0.270 and 0.667 mg/ml, respectively.

Actins↗

PubMed1985

Phosphorylation of high mobility group protein 14 by casein kinase II.

Phosphorylation of chromosomal high mobility group (HMG) protein 14 by casein kinase II has been characterized. Two mol of 32P are incorporated per mol of bovine HMG 14. Kinetic analysis provided evidence for two distinct sites with apparent Km values of 14.5 and 134 microM and respective Vmax values of 0.17 and 0.68 mumol/min/mg casein kinase II. Tryptic peptide mapping identified two phosphorylated products, each with phosphoserine. Amino acid composition and sequence analysis demonstrate that the major high affinity phosphorylation site for casein kinase II is serine 89. This sequence located at the carboxyl-terminal of HMG 14 contains the primary sequence determinants for casein kinase II. On the basis of reverse-phase high performance liquid chromatography and amino acid analysis, HMG 14, serine 99 represents the low affinity phosphorylation site.

Amino Acids↗

PubMed1979

The nutritional value of irradiated casein-fat mixtures-effect of anaerobic conditions, storage time, added vitamin E and degree of unsaturation of lipids.

The effect of oxygen elimination during irradiation (5 Mrad) and subsequent storage, storage time (12 weeks), degree of lipid-unsaturation and added antioxidant (vitamin E) in protein-lipid mixtures (casein : fat - 11.1 : 4) on the nutritive value of protein was studied during 8-day nitrogen balance trials in 12 groups of 6 weanling rats each. When casein-cocofat-cornoil mixtures were irradiated and stored under aerobic conditions a reduction of NPU appeared upon prolonged storage time, which was prevented by excluding oxygen during irradiation and storage. When the lipid component consisted entirely of cocofat no loss in NPU occurred under aerobic processing and storage conditions throughout the 12 week storage period. Replacement of cocofat through sunfloweroil resulted in a drastic reduction of NPU and in growth inhibition, which was not prevented by the addition of vitamin E (0.05 g/100 g lipid). Irradiation of casein-lipid mixtures resulted in a significant increase of carbonyl compounds. A further increase was effectively prevented by elimination of oxygen during irradiation and storage. A drastic increase of carbonyl compounds as well as a significant reduction of available lysine occurred in casein-sunfloweroil mixtures. Added vitamin E afforded only limited protection against these changes.

Animal Feed↗

PubMed1982

Effects of cholestyramine on low density lipoprotein binding sites on liver membranes from rabbits with endogenous hypercholesterolemia induced by a wheat starch-casein diet.

Rabbits fed a wheat starch-casein diet develop a marked hypercholesterolemia with a lipoprotein distribution similar to that of humans. Approximately 76% of the total cholesterol is carried in the low density lipoprotein (LDL) fraction (1.006 less than d less than 1.063 g/ml). Inclusion of 1% cholestyramine in the diet prevents the increase in plasma cholesterol. The cholestyramine effect is mediated through an increased fractional catabolic rate of 125I-LDL. In order to determine the potential role of hepatic LDL receptors in the removal of LDL from the plasma, binding of 125I-LDL and 125I-beta-VLDL (beta-migrating very low density lipoproteins) to hepatic membranes prepared from livers of rabbits fed the wheat starch-casein diet with or without cholestyramine supplementation was investigated. Membranes from livers of the cholestyramine-supplemented animals exhibit high levels of specific EDTA-sensitive binding of either of the 125I-labeled lipoproteins. Very little EDTA-sensitive binding occurs on liver membranes from wheat starch-casein-fed rabbits that have not been treated with cholestyramine. These results indicate that the hypercholesterolemia in rabbits associated with the wheat starch-casein diet is wholly or partially the result of a decreased number of specific hepatic LDL receptors and thus a decreased catabolism of plasma cholesterol. The response of the liver to the inclusion in the diet of the bile acid sequestrant, cholestyramine, is to maintain or increase the number of specific LDL binding sites, thus promoting catabolism of plasma cholesterol.

Animals↗

PubMed1983

Purification and characterization of a type II casein kinase from Drosophila melanogaster.

A cyclic nucleotide-independent protein kinase has been isolated from Drosophila melanogaster by chromatography on phosphocellulose and hydroxylapatite followed by gel filtration and glycerol gradient sedimentation. As determined by sodium dodecyl sulfate gel electrophoresis, the purified enzyme is greater than 95% homogeneous and is composed of two distinct subunits, alpha and beta, having Mr = 36,700 and 28,200, respectively. The native form of the enzyme is an alpha 2 beta 2 tetramer having a Stokes radius of 48 A, a sedimentation coefficient of 6.4 S, and Mr approximately 130,000. The purified kinase undergoes an autocatalytic reaction resulting in the specific phosphorylation of the beta subunit, exhibits a low apparent Km for both ATP and GTP as nucleoside triphosphate donor (17 and 66 microM, respectively), phosphorylates both casein and phosvitin but neither histones nor protamine, modifies both serine and threonine residues in casein, and is strongly inhibited by heparin (I50 = 21 ng/ml). These properties are remarkably similar to those of casein kinase II, an enzyme previously described in several mammalian and avian species. The strong similarities among the insect, avian, and mammalian enzymes suggest that casein kinase II has been highly conserved during evolution.

Animals↗