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Results 901 - 950 of 1636
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Patti M E - - 1998
Amino acids have been shown to stimulate protein synthesis, inhibit proteolysis, and decrease whole-body and forearm glucose disposal. Using cultured hepatoma and myotube cells, we demonstrate that amino acids act as novel signaling elements in insulin target tissues. Exposure of cells to high physiologic concentrations of amino acids activates intermediates ...
Ota M - - 1998
The sweetness-suppressing polypeptide gurmarin isolated from Gymnema sylvestre consists of 35 amino acid residues and contains three intramolecular disulfide bonds. Nuclear magnetic resonance analysis showed that the hydrophobic side chains of Tyr-13, Tyr-14, Trp-28, and Trp-29 in gurmarin are oriented outwardly. Together with the hydrophobic side chains of Leu-9, Ile-11, ...
Ngouela S - - 1998
A new trachylobane derivative identified as 7alpha-hydroxytrachyloban-19beta-oic acid (1) has been isolated from the bark of Xylopia aethiopica and its structure elucidated by various NMR techniques and molecular modeling.
Weiss M - - 1998
Fast and reproducible separation and determination of amino acids serves the economical and reliable characterization and quantification of peptides and proteins as well as the identification of proteins by amino acid composition analysis on a large-scale. A prerequisite of a successful compositional analysis is a complete hydrolysis of the peptides ...
Tsutsui N - - 1998
Sake lees obtained by brewing from liquefied rice were deprived of water and alcohol by lyophilization, and then examined for nutritional availability with the aid of proximate food analysis, amino acid analysis and animal experiment. Freeze-dried sake lees powder was comprised of 44.6% protein, 37.4% carbohydrate, 2.5% fat, 6.7% fiber, ...
Douma C E - - 1998
OBJECTIVE: Intraperitoneal administration of amino acid based dialysis solutions affects the surface area available for diffusion, with almost no effect on the intrinsic permeability to macromolecules. Intraperitoneally administered nitroprusside affects the vascular surface area and the intrinsic permeability without effect on the peritoneal blood flow. In the present study, these ...
Nowak M W - - 1998
A general method for the incorporation of unnatural amino acids into ion channels and membrane receptors using a Xenopus oocyte expression system has been described. A large number of unnatural amino acids have been incorporated into the nAChR, GIRK, and Shaker K+ channels. Continuing efforts focus on incorporating unnatural amino ...
Fisher G H - - 1998
In 1939 Kögl and Erxleben [1-4] reported that tumor proteins contain appreciable amounts of D-amino acids, specifically glutamic acid, valine, leucine and lysine, implying that both the initiation and autonomous character of tumors depends on the formation and maintenance of these D-amino acids in the cell proteins. This postulate remained ...
Moughan P J - - 1998
Endogenous nitrogen and amino acid losses are associated with the digestion process. Different methods can be used to distinguish between gut endogenous and exogenous amino acid flows. These methods include feeding N-free diets, the regression approach, the use of enzyme hydrolysed proteins coupled with ultrafiltration and the use of markers ...
Schreurs V V - - 1997
Actual amounts of free amino acids in the blood are sufficient to support whole body protein synthesis for some minutes only. This indicates that the levels of free amino acids in the circulation are kept small and constant relative to the amounts of amino acids supplied by daily intake and ...
Tsai Y J - - 1997
A procedure for synthesizing NB1-palmitoyl insulin for incorporation into liposomes for targeting to hepatocytes was developed. The amino group of the first amino acid phenylalanine on the B chain (B1) of insulin was selected for conjugation with palmitic acid in anticipation that its binding to the insulin receptor would be ...
Muhandiram D R - - 1997
A triple-resonance pulse scheme is described which records(15)N, NH correlations of residues that immediately follow amethyl-containing amino acid. The experiment makes use of a(15)N, (13)C and fractionally deuterated proteinsample and selects for CH(2)D methyl types. The experiment isthus useful in the early stages of the sequential assignment process as wellas ...
Trueblood C E - - 1997
Protein prenyltransferases catalyze the covalent attachment of isoprenoid lipids (farnesyl or geranylgeranyl) to a cysteine near the C terminus of their substrates. This study explored the specificity determinants for interactions between the farnesyltransferase of Saccharomyces cerevisiae and its protein substrates. A series of substitutions at amino acid 149 of the ...
Manary M J - - 1997
This study tested the hypothesis that during treatment of kwashiorkor (including marasmic kwashiorkor) with infection there is a lower rate of amino acid oxidation when the dietary intake of amino acids resembles the amino acid composition of acute phase proteins (APPs). Twenty-two children in Blantyre, Malawi, with kwashiorkor and acute ...
MacLeod M G - - 1997
1. An experiment was performed with growing broiler chickens (14 to 21 d old) to examine 3 diet characteristics which have been implicated in regulatory elevation of metabolic rate: an imbalanced amino acid mixture, high dietary energy concentration and low protein concentration. 2. Differences in energy expenditure could be explained ...
Adán C - - 1997
The arterio-venous differences and balance of amino acids across the hind leg of rats were measured during an intense bout of exercise in a treadmill, as well as in the subsequent recovery period. The size and composition of muscle amino acid pool were also determined using another series of animals. ...
Runnerstam M - - 1997
The extracellular fluid of two cortical regions was investigated in eight patients who underwent surgery for subarachnoid hemorrhage within 7-96 h after the rupture of an arterial aneurysm. Microdialysis samples, collected from the cortex of the ipsilateral gyrus rectus and temporal lobe for 52-127 h, were analyzed with respect to ...
Casseron F - - 1997
The aim of this work was to determine by ion-exchange liquid chromatography and isotope ratio mass spectrometry the specific 15N enrichment of amino acids in casein and plasma proteins in cows receiving three successive daily oral doses (300, 150 and 150 g) of (15NH4)2SO4 (10 atom per cent isotopic enrichment) ...
Herrero M C MC Department de Bioquímica i Biotecnologia, Universitat Rovira i Virgili, Tarragona, - - 1997
To determine how the ability of skeletal muscle to manage amino acids is conditioned by obesity. The test was performed in two different models of obese rats: diet-obese rats and genetically obese rats. Lean and genetically obese (fa/fa) male Zucker rats were used. For up to 60 d of life ...
Dufton M J - - 1997
The synonym quotas within the genetic code for the 20 common amino acids are examined in relation to the ways in which these amino acids can be marshalled into different sets on the basis of shared physico-chemical properties. This reveals which shared properties are encouraged or discouraged during the course ...
Cilliers S C - - 1997
1. A study was conducted to compare apparent and true digestibility of amino acids in a high protein experimental diet between young ostriches (7 months of age) and cockerels. 2. A mean value for true digestibility of amino acids (TAAD) of 0.837 +/- 0.0073 (range 0.780 to 0.862) was derived ...
Heal R D - - 1997
The induction of the stress protein Grp75 in response to amino acid deprivation of Chinese Hamster Ovary cells was characterised using a specific monoclonal antibody. A 2-fold increase in the Grp75 protein content occurred over a period of 5-10 h after incubation of the cells in amino acid-free medium. A ...
Gerrits W J - - 1997
In a companion paper, a mechanistic model is described, integrating protein and energy metabolism in preruminant calves of 80-240 kg live weight. The model simulates the partitioning of nutrients from ingestion through intermediary metabolism to growth, consisting of accretions of protein, fat, ash and water. The model also includes a ...
Gerrits W J - - 1997
This paper describes the development of a mechanistic model integrating protein and energy metabolism in preruminant calves of 80-240 kg live weight. The objectives of the model are to gain insight into the partitioning of nutrients in the body of growing calves and to provide a tool for the development ...
Hill J L - - 1997
This study examined the effects of incorporating an ovine oviducal oestrus-associated glycoprotein (oEGP) and amino acids, at the concentrations present in the ovine oviduct around the time of oestrus, on in vitro production and subsequent viability of bovine embryos. The first experiment compared the influence of ovine oviducal concentrations of ...
Kataoka H - - 1997
A selective and sensitive method for the determination of protein and non-protein amino acids by capillary gas chromatography (GC) has been developed. The amino acids were converted into their N(O,S)-isobutoxycarbonyl methyl ester derivatives and measured by GC with nitrogen-phosphorus selective detection using a DB-17ht capillary column. Using this method, the ...
King J. E. - - 1997
The mobilization and utilization of the major storage proteins in loblolly pine (Pinus taeda L.) seeds following imbibition were investigated. Most of the seed protein reserves were contained within the megagametophyte. Breakdown of these proteins occurred primarily following radicle emergence and correlated with a substantial increase in the free amino ...
Beckman D A - - 1997
The technique pioneered by D.A.T. New for the in vitro culture of early post-implantation rat embryos has been used to study nutritional mechanisms during early organogenesis. The results indicate that the principal route for amino acid supply to the 8.5- to 11.5-day embryo involves the endocytosis of proteins into cells ...
Liu Z - - 1997
Five experiments, utilizing 3741 embryos produced in vitro, were designed to test the effects of Eagle's nonessential amino acids, and combinations of Eagle's essential amino acids and the RNA polymerase inhibitor alpha-amanitin on the development of preimplantation bovine embryos in a modified protein-free KSOM medium. Embryos were cultured in 5% ...
Samuel D - - 1997
The effect of proline on the prevention of trichloroacetic acid (TCA)-induced protein precipitation is studied. It is found that proline at high concentrations (> 4.0 M) completely prevents TCA-induced precipitation of hen egg white lysozyme. Other osmolytes such as ethylene glycol, glycerol and sucrose fail to prevent the TCA-induced precipitation ...
Jakubowski H - - 1997
Editing of the non-protein amino acid homocysteine, a frequent type of error-correcting process in amino acid selection for protein synthesis by an aminoacyl-tRNA synthetase, results in formation of a cyclic thioester, homocysteine thiolactone. Here it is shown that human cells in which homocysteine metabolism is deregulated by a mutation in ...
Lien K A - - 1997
The 15N-enrichments (atom percentage excess) were determined in the plasma free amino acids of blood samples taken at the time of feeding and in samples taken hourly and pooled over 12 h, as well as in ileal digesta, crude mucin, and bacteria collected at the distal ileum of pigs fed ...
Tomandl D - - 1997
The insertion of random sequences into protein-encoding genes in combination with biological selection techniques has become a valuable tool in the design of molecules that have useful and possibly novel properties. By employing highly effective screening protocols, a functional and unique structure that had not been anticipated can be distinguished ...
Wheatley D N - - 1996
In previous work, no chiral differences were found between D and L enantiomers of Leu in their ability to displace one another from the acid-extractable pool in mammalian cells. Recent evidence suggested otherwise. Our aim is to examine whether, in physiological range, D-amino acids have an equivalent ability to displace ...
Beckman D A - - 1996
It was previously shown that uptake and digestion of protein by the visceral yolk sac supplies almost all of the amino acid needed by the 9.5-11.5-day rat conceptus cultured in vitro. Our aim was to test the hypothesis that protein uptake and digestion may not be as important as an ...
Schindler J F - - 1996
Improved and efficient techniques have led to an explosive growth in the application of site-directed mutagenesis to the study of enzymes. However, the limited availability of only those 20 amino acids that are translated by the genetic code has prevented the systematic variation of an amino acid's properties in order ...
Lloyd J B - - 1996
Rat conceptuses at 9.5 days post-conception were cultured for 27 h in whole rat serum. [3H]Methionine, or rat serum proteins containing [3H]methionine, was introduced at 24 or 6 h before the termination of the culture. The total clearance of radioactivity into the embryo and the visceral yolk sac from the ...
Wolfe R R - - 1996
The optimal nutritional support of critically ill patients should be based on the metabolic response. Therefore, we performed a series of experiments in patients using stable isotopic tracers designed to elucidate the responses of glucose, fatty acids, and protein metabolism in severely burned patients. Glucose production was elevated above normal ...
Stephanie Ann Hoogendoorn
The purpose of this project is to enable high-quality visualization of the primary data from protein X-ray crystallography, electron-density contours, alongside molecular models. No current software package does this well. Such visualization is critical to assessing how well a model describes the data. We are designing and implementing a package ...
Millward D J - - 1996
Current post-prandial studies of amino acid metabolism and utilization are consistent with a feeding mechanism mediated primarily by insulin and amino acids, with the balance between protein conservation and net deposition dependent on the amino acid supply [1-13C]leucine post-prandial kinetic tracer studies of leucine oxidation, non-oxidative disappearance and endogenous appearance ...
Ge S J - - 1996
The enzymatic complete hydrolysis of casein was investigated by using immobilized endopeptidase and exopeptidase packed in the jacketed column reactors. The mass transfer efficiency of proteins was improved by using sliced shrimp chitin hull as enzyme support, which formed a network structure inside the column reactor that prevented the formation ...
Svanberg E - - 1996
Synthesis and degradation of globular and myofibrillar proteins across arm and leg muscles were examined during stepwise increased intravenous infusion of amino acids (0.1, 0.2, 0.4, and 0.8 g N.kg-1.day-1) to healthy volunteers. Protein dynamics were measured by a primed constant infusion of L-[ring-2H5]phenylalanine and the release of 3-methylhistidine from ...
Dragutan H - - 1996
Stable free mono- and diradicals containing reactive primary or secondary amino groups in the side-chain have been synthesized by transesterification of amino-substituted esters with paramagnetic alcohols or from spin-labeled acid derivatives and amines. In the second approach the new radical 18 (1-oxyl-3-(2-bromoethoxycarbonyl)-2,2,5,5-tetramethylpyrroline) is proposed as an efficient alkylating species. The ...
Saks M E - - 1996
A new tRNA, THG73, has been designed and evaluated as a vehicle for incorporating unnatural amino acids site-specifically into proteins expressed in vivo using the stop codon suppression technique. The construct is a modification of tRNAGln(CUA) from Tetrahymena thermophila, which naturally recognizes the stop codon UAG. Using electrophysiological studies of ...
Volpi E - - 1996
The contribution of dietary amino acids and endogenous hyperinsulinemia to prandial protein anabolism still has not been established. To this end, leucine estimates ([1-14C]leucine infusion, plasma alpha-ketoisocaproic acid [KIC] specific activity [SA] as precursor pool SA) of whole-body protein kinetics and fractional secretory rates (FSRs) of albumin, fibrinogen, antithrombin III, ...
Iyer M S - - 1996
A novel cyclic dipeptide -cyclo[(S)-His-(S)-NorArg] - has been prepared which catalyzes an enantioselective version of the Strecker amino acid synthesis. The catalyst, when present in 2 mol % quantity in methanol solution, catalyzes the addition of hydrogen cyanide toN-alkylimines to affordα-amino nitriles in high yield and high enantiomeric excess. Furthermore, ...
Hubert F - - 1996
Plasma from the mussel Mytilus galloprovincialis previously immunized by injecting them with bacteria contains several bactericidal proteins. One protein, MGD-1, was purified by reverse-phase HPLC of supernatant from acidified cell-free hemolymph. Its biological activity is directed against both gram-positive and gram-negative bacteria but it is not cytotoxic towards human erythrocytes ...
Mansour E H - - 1996
The effects of germination, extraction (double extraction with 70% ethanol and water at isoelectric point) and alpha-amylase treatments of chick pea seed flours on crude protein, total carbohydrate, protein efficiency ratio (PER), biological value (BV), true digestibility (TD), net protein utilization (NPU), essential amino acid composition, in-vitro protein digestibility (IVPD) ...
Citores L - - 1996
The new type 2 RIPs ebulin l, nigrin b and nigrin f present in Sambucus display toxicity to HELA cells several orders of magnitude lower than that displayed by ricin. Despite N-terminal amino acid homology between the three RIPs in both the A and the B chains, these compounds display ...
Tanhuanpää P K - - 1996
Bulk segregant analysis was used to search for RAPD (random amplified polymorphic DNA) markers linked to gene(s) affecting oleic acid concentration in an F2 population from the Brassica rapa ssp. oleifera cross Jo4002 x a high oleic acid individual from line Jo4072. Eight primers (=8 markers) out of 104 discriminated ...
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