A novel cause of mass extinction of fauna close to the (K/T) Boundary is suggested. A large amount of non-protein amino acids (AIB and ISOVAL) has been observed close to this event. It is speculated that these amino acids may be toxic and are responsible for the extinction. The toxicity ...

The non-protein amino acid, beta-N-methyl-amino-L-alanine (L-BMAA) from Cycas circinalis seeds, has been implicated as a causative agent of amyotrophic lateral sclerosis-Parkinsonism dementia complex (ALS-PDC), a disease known from Guam and other areas in the western Pacific. We analyzed C. circinalis seeds for additional free non-protein amino acids by a recently ...

Ceruloplasmin, a blue copper oxidase found in plasma, is synthesized in hepatocytes as a single polypeptide chain consisting of a 19 amino acid leader peptide plus 1046 amino acids of mature protein (132 kDa). Holoceruloplasmin is secreted into the plasma with 6-7 atoms of copper bound per molecule. In this ...

The quantitative needs for the dietary indispensable amino acids in adult human protein nutrition are still poorly established. Tracer studies with 13C-labeled amino acids have been undertaken previously in our laboratories to reevaluate and further determine the minimum physiological needs for selected indispensable amino acids in healthy adult volunteers. For ...

Sodium azide is widely used as bacteriostatic agent during downstream processing of proteins. Amino acid composition analysis of protein samples, subjected to hydrolysis with hydrochloric acid in a buffer containing sodium azide, revealed the presence of cysteic acid, methionine sulfoxide, and methionine sulfone in addition to the expected reaction products. ...

The acid extractable amino acid pool (AEP) demonstrates time and concentration dependent saturation kinetics in cold-incubated (0-2 degrees C) Escherichia coli cells. Attention is drawn in particular to the contribution of the AEP to the total non-covalently bound amino acid intracellular levels (total pool) at low exogenous amino acid concentrations. ...

: Patients with active inflammatory bowel disease (IBD) have increased levels of n3 and decreased levels of n6 plasma long-chain polyunsaturated fatty acids (LC-PUFA). Using multivariate statistical techniques, this study assessed the influence of the potentially important factors of diagnosis (ulcerative colitis versus Crohn's disease), disease activity, malnutrition, location of ...

Deep-sea hydrothermal systems have been proposed to be likely environments for chemical evolution and the origin of life on Earth. Recently, experiments have, therefore, been carried out in order to test the hypothesis that amino acids can be synthesized under conditions representing hydrothermally altered oceanic crust. The variety of amino ...

The role of arylphorin as a storage protein was studied using 14C-arylphorin. 14C-arylphorin was produced optimally by incubating one-half fat body from Manduca sexta fifth instar larvae at 22 degrees C for 24 h, in 1 ml of medium containing amino acids at 25% of their physiological concentration with [U-14C]-phenylalanine ...

Coherent neutron scattering measurements of an amorphous, in vivo deuterated C-phycocyanin are compared with a calculation of the individual protein molecule's coherent static structure factor. Both show the significant features associated with known structure factors of several amorphous materials, most notably, an unusually sharp first diffraction peak occurring near 1.4 ...

The experiment was carried out to clarify the roles of insulin and amino acids on protein synthesis in fed lactating goats (30 days postpartum). Protein synthesis in the liver and various skeletal muscles was assessed after an intravenous injection of a large dose of unlabeled valine containing a tracer dose ...

A neural network trained to classify the 61 nucleotide triplets of the genetic code into 20 amino acid categories develops in its internal representation a pattern matching the relative cost of transferring amino acids with satisfied backbone hydrogen bonds from water to an environment of dielectric constant of roughly 2.0. ...

Ninety-five female pigs from 20 to 45 kg body weight were used to elucidate the effects of energy and protein intake on the amino acid composition of the protein in the carcass, organs and empty body of growing pigs. In a 2 x 15 factorial arrangement, protein intake ranged from ...

The anabolism of isotopically labeled amino acids was compared between the cerebrum and the cerebellum in conscious rat at three feeding conditions. After L-[2-18F]fluorophenylalanine and L-[2,6-3H]phenylalanine injections, the incorporation rate of both radioactivity into protein fraction showed no difference between the cerebrum and the cerebellum at normal condition, but the ...

N-[2-14C]Acetyldopamine (NADA) was incubated in vitro with a series of homopolyamino acids or proteins in the presence of cell-free cuticle from locusts. The oxidized NADA was bound to the materials in varying degrees. The results indicate that lysine and histidine sidechains in the cuticular proteins might be the most likely ...

This paper describes a method for the evaluation of the unfolding heat capacity change of proteins by their amino-acid composition. The method hinges on a set of hydration heat capacity changes of amino acids extracted from the Protein Data Bank of crystallographic structures (Oobatake, M. and Ooi, T. (1988) J. ...

Today because of tools capable of probing the details of metabolism, we are able to study the utilization of amino acids in specific, physiologically important processes. Such information may lead to recommended dietary allowances for each amino acid specific for subpopulations and perhaps individuals. These new findings identify the metabolic ...

Using o-pthaldialdehyde (OPT) fluorescence, the amino acids associated with DNA were studied following exposure of intact Chinese hamster ovary cells to chromate. Rigorous extraction with EDTA, acid, or base was required to release the amino acids cross-linked to the DNA isolated from control or chromate-treated cells by standard procedures (i.e., ...

We have analyzed DNA from three exons of the human protein-L-isoaspartate(D-aspartate) O-methyltransferase gene in 30 individuals. We present evidence for two polymorphisms in these regions that result in amino acid changes. At a site corresponding to amino acid position 119, we find the ATA codon for Ile at a frequency ...

The mechanisms are discussed by which the body maintains nitrogen balance and constancy of the amount and pattern of body proteins. A distinction is made between effectors, such as hormones, and regulators. Free amino acid concentrations, which are maintained remarkably constant, may play an important role. The key step in ...

A group of low molecular weight protein substrates was found to co-purify with casein kinase II from broccoli (Brassica oleracea var italica). These substrates showed very high affinity toward casein kinase II and were efficiently phosphorylated even in the presence of an excess of exogenous substrates. The broccoli substrates were ...

Fructose-1,6-bisphosphatase (FruP2ase) from Saccharomyces cerevisiae is rapidly inactivated upon addition of glucose to a culture growing on non-sugar carbon sources. Under the same conditions the FruP2ases from Schizosaccharomyces pombe or Escherichia coli expressed in S. cerevisiae were not affected. A chimaeric protein containing the first 178 amino acids from the ...

A unique derivatization procedure is described for the simultaneous determination of protein and non-protein amino acids present in aqueous samples. This procedure involves N(O,S)-isobutyloxycarbonylation combined with solid-phase extraction with subsequent tert.-butyldimethylsilylation for gas chromatographic analysis. Using this combined procedure, linear responses were obtained in the range of 10-100 ppm, with ...

Nonnatural amino acids with photofunctional groups were incorporated site-specifically into a polypeptide by using in vitro protein synthesizing system. The nonnatural amino acids were attached to tRNA(CCU) through chemical misacylation method, and added to the in vitro system with a mRNA containing a single AGG codon. L-p-Phenylazophenylalanine, L-2-anthrylalanine, L-1-naphthylalanine, L-2-naphthylalanine ...

Guanidinated proteins when fed to non-ruminants provide values for both endogenous amino acid losses and amino acid digestibilities, provided that the homoarginine residues in the treated protein are randomly distributed. Earlier studies have established that guanidination has only minor effects on the structure of the protein and, in particular, on ...

This paper reviews the evidence for and against the adoption of methods for the measurement of human tissue protein synthesis based upon the incorporation of stable isotopically labeled amino acids administered either as a continuous infusion or as a flooding dose. The practical advantages of the flooding dose method are ...

A simple, quantitative assay has been established to determine the glycation-dependent crosslinking ability of any sugar by measuring the incorporation of [14C]-lysine into protein. The assay was shown to be both sugar-dependent and protein-dependent and was completely inhibited by sodium cyanoborohydride, 2-aminoguanidine, and semicarbazide. A typical 1.0-ml reaction mixture contained ...

The changes in hind leg tissue (muscle and skin) amino acid pool size and arteriovenous balance were measured in rats subjected to 0-90 min of cold exposure (4 degrees C). Tissue free amino acid pools presented a different composition pattern from protein amino acids. Muscle rapidly reacted to cold exposure ...

Hepatocytes from a 70-d-old male broiler were dissociated using a modified technique of double perfusion with an isotonic solution through the jejunum mesenteric and pancreatic veins followed by collagenase perfusion. A basal medium was made up with the same amino-acid composition of the whole chicken egg, diluted 25 times. Dilutions ...

The age-related formation of succinimides in proteins, through spontaneous deamidation of asparagine, and through cyclization of aspartic acid, is thought to be followed by the hydrolysis of the succinimide ring, yielding a mixture of "normal" aspartic acid sites and beta-isomerized aspartic acid sites (isoaspartic acid). The chemical reduction of an ...

Amino acid starvation of mammalian cells results in a pronounced fall in the overall rate of protein synthesis. This is associated with increased phosphorylation of the alpha-subunit of the initiation factor eIF-2, which in turn impairs the activity of the guanine nucleotide exchange factor, eIF-2B. Similar mechanisms have now been ...

Given the central role of protein synthesis in cellular function, it is likely that intricate mechanisms exist to detect and respond to amino acid deprivation. However, the current understanding of amino acid-dependent control of gene expression in mammalian cells is limited. A few examples of enzyme, transporters, and unidentified mRNA ...

Outer membrane protein PhoE of E. coli appears to be a suitable carrier for the expression of foreign antigenic determinants at the bacterial cell-surface. Insertion of stretches of amino acids in the cell-surface exposed regions of PhoE does not interfere with the biogenesis of the protein. Dependent on the cell-surface ...

Detoxification of apricot kernels by soaking in distilled water and ammonium hydroxide for 30 h at 47 degrees C decreased the total protein, non-protein nitrogen, total ash, glucose, sucrose, minerals, non-essential amino acids, polar amino acids, acidic amino acids, aromatic amino acids, antinutritional factors, hydrocyanic acid, tannins and phytic acid. ...

A new versatile reagent, 3-bromopropylamine, for the quantitative analysis of cysteine residues in proteins and peptides is reported. When added to amino acid standards, the 3-bromopropylamine derivative of cysteine, S-3-aminopropylcysteine, elutes in a unique position on four different amino acid analysis systems without modification to their standard gradients. Optimized conditions ...

Rat tail tendons from 54-day-old and 900-day-old animals were incubated with different concentrations of the dibasic amino acids, lysine and arginine. We observed a significant incorporation of these amino acids into the tendons. Uniaxial tension tests and relaxation experiments were performed at strain levels within the linear portion of the ...

The object of this study was to examine the effects of extracellular amino acids on hepatic apoB100 metabolism using a transformed human liver cell line (HepG2) as a hepatocyte model. The data demonstrate that reduced extracellular amino acids resulted in marked increases in apoB100 concentrations in the medium (87 +/- ...

The interactions between UDP-glucuronic acid and two human liver UDP-glucuronosyltransferase 2B4 peptides (14-150 and 299-446) purified from E. coli as Staphylococcus aureus protein A fusion proteins have been investigated. Photoaffinity labeling with azidonucleotides ([beta-32P]5N3UDP-Glucuronic acid and [beta-32P]5N3UDP-Glucose) and competition experiments with UDP-glucuronic acid and structurally related compounds emphasized the presence ...

1. Impaired body growth, loss of lean body mass and negative nitrogen balance are common findings in chronic renal failure. Enhanced endogenous protein catabolism in skeletal muscle induced by co-existent metabolic acidosis seems to be an important aetiological factor. 2. In uraemic patients abnormalities in blood amino acid profiles are ...

Helminth parasitic infestations are of great concern to the health of man and other animals. Limited studies have been carried out on the process of protein synthesis which, apart from having academic importance, could possibly provide a target for drug attack. In the present study distribution pattern of newly synthesized ...

Basic concepts of amino acid nutrition are summarized and quantitative amino acid requirements of different age-groups based on current knowledge are presented. The newer concepts of "conditionally indispensable" amino acids and organ-specific requirements for amino acids are discussed. The concepts of nitrogen balance, limiting amino acid, protein utilization, protein efficiency ...

Increasing the relative amount of protein in the diet of athletes has been suggested to optimise anabolic processes and improve both physiological responses to training and performance. While energy balance studies generally support the concept that athletes may require additional protein in their diets in comparison with the Recommended Dietary ...

Amino acids labelled with 18(O) on both carboxy oxygen atoms have the potential for use as non-recyclable tracers to measure protein turnover. During protein synthesis one of the labelled oxygen atoms is removed, and thus release of the mono-labelled amino acid could be used to determine proteolysis. Primary cultures of ...

The separation of cysteine from proline using a variant of the classical cation exchange system for amino acid analysis is described. From reducing hydrolyzates (6 M HCl/0.1% phenol/5% thioglycollic acid, 18 h, 110 degrees C) the halfcystine content of proteins can be accurately determined as cysteine. The system is useful ...

In this report we describe several novel methods for the preparation of selectively deuterated aromatic amino acids. New syntheses for [2,3,5,6-2H4]phenylalanine and [2,4,6,7-2H4]tryptophan, as well as improved catalytic exchange methods for [2,3,5,6-2H4]tyrosine and [2,3,4,5,6-2H5]phenylalanine are presented. Isotopic substitution levels for all compounds are generally found to be greater than 95%. ...

Jasmonic acid or its methyl ester induce de novo synthesis of a number of proteins of mostly unknown function in barley (Hordeum vulgare L.). In a topical spray application, 30 [mu]g of jasmonic acid per plant effectively protected barley against subsequent infection by Erysiphe graminis f.sp. hordei. Examination of jasmonic ...

The effects of sorghum type on amino acid digestion were determined by feeding heifers (230 kg) equipped with ruminal, duodenal, and ileal cannulas bird-resistant (BR) or non-BR grains that had a normal or waxy endosperm (NORMAL-BR, WAXY-BR, NORMAL, WAXY). Dry-rolled grain diets were fed at 2% of BW in a ...

An empirical relation between the amino acid composition and three-dimensional folding pattern of several classes of proteins has been determined. Computer simulated neural networks have been used to assign proteins to one of the following classes based on their amino acid composition and size: (1) 4 alpha-helical bundles, (2) parallel ...

The fate of a small oral dose of protein given to overnight-starved rats was studied. After 3 h, 62% of the protein amino acids had been absorbed. Most of the absorbed N went into the bloodstream through the portal in the form of amino acids, but urea and ammonia were ...

The administration of metaproterenol induced an increase in gastrocnemius muscle weight without change in body growth rate or tissue protein concentrations, while epididymal fat was reduced. This effect was accompanied by an enhancement in the levels of intracellular amino acids in muscle. By contrast, liver amino acids were unaffected by ...