QUANTITATIVE EFFECTS OF NUTRITIONAL ESSENTIAL AMINO ACID DEFICIENCY UPON IMMUNE RESPONSES TO TUMORS IN MICE

Mice were fed diets deficient in a single essential amino acid, and the primary immune responses to inoculation of allogenic tumor cells was measured by in vitro assay of cellular immunity. Moderate reduction of the amino acids phenylalanine-tyrosine, valine, threonine, methionine-cystine, isoleucine, and tryptophane in the diet produced profound depression of hemagglutinating and blocking antibody responses, although cytotoxic cell-mediated immunity remained intact. These diets had previously been shown to result in a selective depression of tumor growth in mice. Limitation of the amino acids arginine, histidine, and lysine in the diets gave rise to only slight depression of the immune responses. These diets had previously been shown to produce a proportional decrease in both tumor growth and host body weight. Moderate leucine restriction resulted in a paradoxical depression of cytotoxic cell-mediated immunity with little effect on serum blocking activity. Slight increases had previously been noted in the weight of tumors in mice fed leucine-restricted diets. Deficiency or imbalance of essential amino acids in the diet may produce profound depression of immune responses and apparent, marked changes in the immune resistance of the host animal to tumors.

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ywfE in Bacillus subtilis Codes for a Novel Enzyme, l-Amino Acid Ligase

Journal of Bacteriology ◽

10.1128/jb.187.15.5195-5202.2005 ◽

2005 ◽

Vol 187 (15) ◽

pp. 5195-5202 ◽

Cited By ~ 73

Author(s):

Kazuhiko Tabata ◽

Hajime Ikeda ◽

Shin-ichi Hashimoto

Keyword(s):

Amino Acids ◽

Bacillus Subtilis ◽

Amino Acid ◽

High Performance ◽

Consensus Sequence ◽

Reaction Products ◽

In Silico Screening ◽

Vitro Assay ◽

Hydrolysis Of

ABSTRACT The ATP-dependent carboxylate-amine/thiol ligase superfamily is known to contain enzymes catalyzing the formation of various types of peptide, such as d-alanyl-d-alanine, polyglutamate, and γ-peptide, but, curiously, no enzyme synthesizing α-dipeptides of l-amino acids is known. We attempted to find such an enzyme. By in silico screening based on the consensus sequence of the superfamily followed by an in vitro assay with purified enzyme to avoid the degradation of the peptide(s) synthesized, ywfE of Bacillus subtilis was found to code for the activity forming l-alanyl-l-glutamine from l-alanine and l-glutamine with hydrolysis of ATP to ADP. No AMP was formed, supporting the idea that the enzyme belongs to the superfamily. Surprisingly, the enzyme accepted a wide variety of l-amino acids. Among 231 combinations of l-amino acids tested, reaction products were obtained for 111 combinations and 44 kinds of α-dipeptides were confirmed by high-performance liquid chromatography analyses, while no tripeptide or longer peptide was detected and the d-amino acids were inert. From these results, we propose that ywfE encodes a new member of the superfamily, l-amino acid ligase.

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Amino acid digestibility of meat and bone meals for broiler chickens

Australian Journal of Agricultural Research ◽

10.1071/ar02055 ◽

2002 ◽

Vol 53 (11) ◽

pp. 1257 ◽

Cited By ~ 29

Author(s):

V. Ravindran ◽

W. H. Hendriks ◽

B. J. Camden ◽

D. V. Thomas ◽

P. C. H. Morel ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Crude Protein ◽

Ash Content ◽

Meat And Bone Meal ◽

Bone Meal ◽

Vitro Assay ◽

Ileal Digestibility ◽

Gross Energy

Variation in the apparent ileal digestibility of amino acids in 19 meat and bone meal samples, obtained from commercial rendering plants in New Zealand, was determined using 5-week-old broilers. Assay diets contained meat and bone meal as the only source of protein, and chromic oxide as an indigestible marker for the calculation of amino acid digestibility values. Correlations of chemical composition (crude protein, ash, crude fat, and gross energy) and in vitro assays (protein solubility in 0.2% potassium hydroxide and nitrogen digestibility by 0.2% pepsin hydrolysis) with ileal amino acid digestibility were also examined. Considerable variation was observed in the contents of crude protein (38.5–67.2 g/100 g), ash (13.0– 56.5 g/100 g), crude fat (4.3–15.3 g/ 100�g), and gross energy (9.4–22.3 MJ/kg) of meat and bone meal samples. The amino acid concentrations and ileal digestibility of amino acids also varied substantially. Cystine, the first limiting amino acid in meat and bone meal, had the lowest digestibility estimates. Correlation analyses showed that the ash content was the only chemical parameter that was consistently correlated with amino acid digestibility. Digestibility of amino acids, with the exception of aspartic acid, threonine, serine, tyrosine, histidine, and cystine, was negatively correlated with ash content, with samples with high ash levels having lower digestibility. Both in vitro assay measurements were found to be insensitive indicators of variations in amino acid digestibility.

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Modulating oxidative stress and epigenetic homeostasis in preimplantation IVF embryos

Zygote ◽

10.1017/s0967199421000356 ◽

2021 ◽

pp. 1-10

Author(s):

Yves Menezo ◽

Patrice Clement ◽

Brian Dale ◽

Kay Elder

Keyword(s):

Oxidative Stress ◽

Amino Acids ◽

Amino Acid ◽

Essential Amino Acid ◽

Transition Period ◽

Essential Amino Acids ◽

Medical Intervention ◽

Dna Demethylation ◽

Preimplantation Embryos

Summary Assisted reproductive technology is today considered a safe and reliable medical intervention, with healthy live births a reality for many IVF and ICSI treatment cycles. However, there are increasing numbers of published reports describing epigenetic/imprinting anomalies in children born as a result of these procedures. These anomalies have been attributed to methylation errors in embryo chromatin remodelling during in vitro culture. Here we re-visit three concepts: (1) the so-called ‘in vitro toxicity’ of ‘essential amino acids’ before the maternal to zygotic transition period; (2) the effect of hyperstimulation (controlled ovarian hyperstimulation) on homocysteine in the oocyte environment and the effect on methylation in the absence of essential amino acids; and (3) the fact/postulate that during the early stages of development the embryo undergoes a ‘global’ demethylation. Methylation processes require efficient protection against oxidative stress, which jeopardizes the correct acquisition of methylation marks as well as subsequent methylation maintenance. The universal precursor of methylation [by S-adenosyl methionine (SAM)], methionine, ‘an essential amino acid’, should be present in the culture. Polyamines, regulators of methylation, require SAM and arginine for their syntheses. Cystine, another ‘semi-essential amino acid’, is the precursor of the universal protective antioxidant molecule: glutathione. It protects methylation marks against some undue DNA demethylation processes through ten-eleven translocation (TET), after formation of hydroxymethyl cytosine. Early embryos are unable to convert homocysteine to cysteine as the cystathionine β-synthase pathway is not active. In this way, cysteine is a ‘real essential amino acid’. Most IVF culture medium do not maintain methylation/epigenetic processes, even in mouse assays. Essential amino acids should be present in human IVF medium to maintain adequate epigenetic marking in preimplantation embryos. Furthermore, morphological and morphometric data need to be re-evaluated, taking into account the basic biochemical processes involved in early life.

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Dietary intake of tryptophan tied emotion-related impulsivity in humans

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000608 ◽

2019 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Florian Javelle ◽

Descartes Li ◽

Philipp Zimmer ◽

Sheri L. Johnson

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Food Intake ◽

Essential Amino Acid ◽

Food Habits ◽

Psychological Disorder ◽

Serotonin Synthesis ◽

Amino Acid Tryptophan ◽

Pass Through ◽

Three Factor

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r = –.502, p < . 010, and (lack-of) Follow-Through scores, r = –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.

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Specificity of the HIV-1 Protease on Substrates Representing the Cleavage Site in the Proximal Zinc-Finger of HIV-1 Nucleocapsid Protein

Viruses ◽

10.3390/v13061092 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1092

Author(s):

János András Mótyán ◽

Márió Miczi ◽

Stephen Oroszlan ◽

József Tőzsér

Keyword(s):

Amino Acid ◽

Zinc Finger ◽

Cleavage Site ◽

Potential Role ◽

Binding Mode ◽

Interaction Energies ◽

Vitro Assay ◽

Hiv 1

To explore the sequence context-dependent nature of the human immunodeficiency virus type 1 (HIV-1) protease’s specificity and to provide a rationale for viral mutagenesis to study the potential role of the nucleocapsid (NC) processing in HIV-1 replication, synthetic oligopeptide substrates representing the wild-type and modified versions of the proximal cleavage site of HIV-1 NC were assayed as substrates of the HIV-1 protease (PR). The S1′ substrate binding site of HIV-1 PR was studied by an in vitro assay using KIVKCF↓NCGK decapeptides having amino acid substitutions of N17 residue of the cleavage site of the first zinc-finger domain, and in silico calculations were also performed to investigate amino acid preferences of S1′ site. Second site substitutions have also been designed to produce “revertant” substrates and convert a non-hydrolysable sequence (having glycine in place of N17) to a substrate. The specificity constants obtained for peptides containing non-charged P1′ substitutions correlated well with the residue volume, while the correlation with the calculated interaction energies showed the importance of hydrophobicity: interaction energies with polar residues were related to substantially lower specificity constants. Cleavable “revertants” showed one residue shift of cleavage position due to an alternative productive binding mode, and surprisingly, a double cleavage of a substrate was also observed. The results revealed the importance of alternative binding possibilities of substrates into the HIV-1 PR. The introduction of the “revertant” mutations into infectious virus clones may provide further insights into the potential role of NC processing in the early phase of the viral life-cycle.

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FRUCTOSE-AMINO ACIDS IN LIVER: STIMULI OF AMINO ACID INCORPORATION IN VITRO

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)66021-1 ◽

1955 ◽

Vol 215 (1) ◽

pp. 111-124 ◽

Cited By ~ 3

Author(s):

Henry Borsook ◽

Adolph Abrams ◽

Peter H. Lowy

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Amino Acid Incorporation ◽

Acid Incorporation

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Transdermal Delivery Systems for Ibuprofen and Ibuprofen Modified with Amino Acids Alkyl Esters Based on Bacterial Cellulose

International Journal of Molecular Sciences ◽

10.3390/ijms22126252 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6252

Author(s):

Paula Ossowicz-Rupniewska ◽

Rafał Rakoczy ◽

Anna Nowak ◽

Maciej Konopacki ◽

Joanna Klebeko ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Bacterial Cellulose ◽

Acid Ester ◽

Active Pharmaceutical Ingredient ◽

Amino Acid Ester ◽

Isopropyl Ester ◽

Isopropyl Esters ◽

Transdermal Application

The potential of bacterial cellulose as a carrier for the transport of ibuprofen (a typical example of non-steroidal anti-inflammatory drugs) through the skin was investigated. Ibuprofen and its amino acid ester salts-loaded BC membranes were prepared through a simple methodology and characterized in terms of structure and morphology. Two salts of amino acid isopropyl esters were used in the research, namely L-valine isopropyl ester ibuprofenate ([ValOiPr][IBU]) and L-leucine isopropyl ester ibuprofenate ([LeuOiPr][IBU]). [LeuOiPr][IBU] is a new compound; therefore, it has been fully characterized and its identity confirmed. For all membranes obtained the surface morphology, tensile mechanical properties, active compound dissolution assays, and permeation and skin accumulation studies of API (active pharmaceutical ingredient) were determined. The obtained membranes were very homogeneous. In vitro diffusion studies with Franz cells were conducted using pig epidermal membranes, and showed that the incorporation of ibuprofen in BC membranes provided lower permeation rates to those obtained with amino acids ester salts of ibuprofen. This release profile together with the ease of application and the simple preparation and assembly of the drug-loaded membranes indicates the enormous potentialities of using BC membranes for transdermal application of ibuprofen in the form of amino acid ester salts.

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Phylogenetic analysis and predicted functional effect of protein mutations of E6 and E7 HPV16 strains isolated in Indonesia

Medical Journal of Indonesia ◽

10.13181/mji.v24i4.1197 ◽

2015 ◽

Vol 24 (4) ◽

pp. 197-205

Author(s):

Dwi Wulandari ◽

Lisnawati Rachmadi ◽

Tjahjani M. Sudiro

Keyword(s):

Amino Acids ◽

Phylogenetic Analysis ◽

Amino Acid ◽

Asian American ◽

Protein Function ◽

Single Amino Acid ◽

Hpv16 E6 ◽

E6 And E7 ◽

Neutral Mutations

Background: E6 and E7 are oncoproteins of HPV16. Natural amino acid variation in HPV16 E6 can alter its carcinogenic potential. The aim of this study was to analyze phylogenetically E6 and E7 genes and proteins of HPV16 from Indonesia and predict the effects of single amino acid substitution on protein function. This analysis could be used to reduce time, effort, and research cost as initial screening in selection of protein or isolates to be tested in vitro or in vivo.Methods: In this study, E6 and E7 gene sequences were obtained from 12 samples of Indonesian isolates, which were compared with HPV16R (prototype) and 6 standard isolates in the category of European (E), Asian (As), Asian-American (AA), African-1 (Af-1), African-2 (Af-2), and North American (NA) branch from Genbank. Bioedit v.7.0.0 was used to analyze the composition and substitution of single amino acids. Phylogenetic analysis of E6 and E7 genes and proteins was performed using Clustal X (1.81) and NJPLOT softwares. Effects of single amino acid substitutions on protein function of E6 and E7 were analysed by SNAP.Results: Java variants and isolate ui66* belonged to European branch, while the others belonged to Asian and African branches. Twelve changes of amino acids were found in E6 and one in E7 proteins. SNAP analysis showed two non neutral mutations, i.e. R10I and C63G in E6 proteins. R10I mutations were found in Af-2 genotype (AF472509) and Indonesian isolates (Af2*), while C63G mutation was found only in Af2*.Conclusion: E6 proteins of HPV16 variants were more variable than E7. SNAP analysis showed that only E6 protein of African-2 branch had functional differences compared to HPV16R.

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Identification in skeletal muscle of a distinct extracellular pool of amino acids, and its role in protein synthesis

Biochemical Journal ◽

10.1042/bj1210817 ◽

1971 ◽

Vol 121 (5) ◽

pp. 817-827 ◽

Cited By ~ 74

Author(s):

R. C. Hider ◽

E. B. Fern ◽

D. R. London

Keyword(s):

Skeletal Muscle ◽

Amino Acids ◽

Protein Synthesis ◽

Amino Acid ◽

Incubation Medium ◽

Extensor Digitorum Longus ◽

Extensor Digitorum ◽

Longus Muscle ◽

Kinetics Of

1. The kinetics of radioactive labelling of extra- and intra-cellular amino acid pools and protein of the extensor digitorum longus muscle were studied after incubations with radioactive amino acids in vitro. 2. The results indicated that an extracellular pool could be defined, the contents of which were different from those of the incubation medium. 3. It was concluded that amino acids from the extracellular pool, as defined in this study, were incorporated directly into protein.

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Effect of Cycloheximide on In Vitro and In Vivo Protein Synthesis by Certain Tissues of Rats and Pigeons with Special Reference to Muscle

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y73-141 ◽

1973 ◽

Vol 51 (12) ◽

pp. 933-941 ◽

Cited By ~ 2

Author(s):

Njanoor Narayanan ◽

Jacob Eapen

Keyword(s):

Amino Acids ◽

Body Weight ◽

Protein Synthesis ◽

Amino Acid ◽

Amino Acid Incorporation ◽

Contrast Administration ◽

Acid Incorporation ◽

Tissue Homogenates

The effect of cycloheximide in vitro and in vivo on the incorporation of labelled amino acids into protein by muscles, liver, kidneys, and brain of rats and pigeons was studied. In vitro incorporation of amino acids into protein by muscle microsomes, myofibrils, and myofibrillar ribosomes was not affected by cycloheximide. In contrast, administration of the antibiotic into intact animals at a concentration of 1 mg/kg body weight resulted in considerable inhibition of amino acid incorporation into protein by muscles, liver, kidneys, and brain. This inhibition was observed in all the subcellular fractions of these tissues during a period of 10–40 min after the administration of the precursor. Tissue homogenates derived from in vivo cycloheximide-treated animals did not show significant alteration in in vitro amino acid incorporation with the exception of brain, which showed a small but significant enhancement.

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