Synthesis of N-Carboxy-α-amino Acid Anhydrides from N-Carbalkoxy-α-amino Acids by the Use of Phosphorus Tribromide

1952 ◽  
Vol 74 (14) ◽  
pp. 3688-3689 ◽  
Author(s):  
Dov Ben-Ishai ◽  
Ephraim Katchalski
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Phosphorus Tribromide ◽  
Acid Anhydrides

scholarly journals Small Hairpin RNAs and the Origin of Protein Synthesis

2019 ◽  
Author(s):  
Chris Broka
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Raw Materials ◽  
Rna World ◽  
Hydrolytic Stability ◽  
Selective Advantage ◽  
Sequence Information ◽  
Early Environment ◽  
Rna Molecules ◽  
Acid Anhydrides

A model of the early RNA world is proposed. Nearly self-complementary sequences that could adopt double-stranded, smallhairpin-like (shRNA), structures would be selected for due to their greater hydrolytic stability. These would be phosphorylated attheir 5' ends. We suppose that dehydrating conditions arise (perhaps intermittently) in the early environment allowing amino acidsto condense with these RNA molecules. The resulting phosphate-amino acid anhydrides would play the role of early, charged,tRNAs. A crude genetic code could emerge owing to the greater resistance of some amino acid-shRNA pairings to hydrolysisrelative to others. Early on there is no division of labor between mRNAs and tRNAs; the same molecules perform both functions.But the first systems would have encoded little in the way of protein sequence information. Rather they would have served as catalysts for the random polymerization of amino acids. It is speculated that the selective advantage inhering in such systems lay intheir ability to supply raw materials for the formation of coacervates within which the various molecules essential to proto-lifecould be concentrated. This would greatly facilitate the necessary chemistries. The evolution of homochiral protein and RNA populations is discussed. An appealing feature of this model is its ability to explain the transition from phosphorylated amino acids to the 3' ester-linked aminoacyl-tRNAs employed by modern life.

Metallkomplexe mit biologisch wichtigen Liganden, XXXIII. Reaktionen von α-Aminosäuren und α-Aminosäurederivaten mit Gold(III)-chlorid/ Metal Complexes with Biological Important Ligands, XXXIII. Reactions of α-Amino Acids and Derivatives there of with Gold(III) Chloride

1984 ◽  
Vol 39 (8) ◽  
pp. 1129-1134 ◽  
Author(s):  
Eberhard Ambach ◽  
Mano Mohan Singh ◽  
Ulrich Nagel ◽  
Wolfgang Beck
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Metal Complexes ◽  
Thionyl Chloride ◽  
Ammonium Salts ◽  
Acid Chlorides ◽  
X Ray ◽  
Amino Acids And Derivatives ◽  
Acid Anhydrides

AbstractThe hydrochlorides of a-aminoacid esters react with Au2Cl6 in thionyl chloride to give the ammonium salts [H3NCHRCO2R′]+AuCl4- (R = H , Me, R′ = H , Me, Et). The X-ray structure of [H3NCH(Me)CO2Me]+AuCl4- has been determined. The reactions of a-aminoacids with Au2Cl6 in SOCl2 afford mixtures of ammonium tetrachloroaurate(III) salts with a-amino acids, a-amino acid chlorides or a-amino acid anhydrides as amine components. Cysteine esters reduce gold(III) to give the gold(I) compounds [AuSCH2CH(N H2)CO2R]n (R = Me, Et).

Nucleic Acid Related Compounds. 14. 3′-O-Aminoacyl-2′-O-methyladenosines and 2′-O-Aminoacyl-3′-O-methyladenosines Related to Charged tRNA Termini

1974 ◽  
Vol 52 (22) ◽  
pp. 3803-3813 ◽  
Author(s):  
Morris J. Robins ◽  
Malcolm MacCoss ◽  
G. Ramani
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nucleic Acid ◽  
Protein Biosynthesis ◽  
Glycosidic Bonds ◽  
Acid Anhydrides ◽  
High Yields ◽  
First Time ◽  
Hydrolysis Of ◽  
Related Compounds

Aminoacyl nucleosides derived from 2′-O-methyladenosine and 3′-O-methyladenosine have been isolated as pure solids and completely characterized for the first time. Coupling of 5′-O-(mono-p-methoxytrityl)-2′-O-methyl- (and 3′-O-methyl-) adenosines (1 and 6, respectively) with N-tert-butyloxycarbonyl(N-tBOC)-amino acid anhydrides (2a–c) (generated insitu from the corresponding N-tBOC-amino acids and N,N′-dicyclohexylcarbodiimide) in the presence of 4-N,N-dimethylaminopyridine gave the 3′-O-(N-tBOC-aminoacyl)-5′-O-(mono-p-methoxytrityl-2′-O-methyladenosines (3a–c) and 2′-O-(N-tBOC-aminoacyl)-5′-O-(mono-p-methoxytrityl-3′-O-methyladenosines (7a–c), respectively, in good yields. The L-leucine (a), L-phenylalanine (b), and L-methionine (c) compounds were prepared in each series. Complete deblocking was effected using 98% formic acid since usual procedures had disadvantages with these molecules. The 3′-O-(L-aminoacyl)-2′-O-methyladenosines (4a–c) and 2′-O-(L-aminoacyl)-3′-O-methyladenosines (8a–c) were obtained in high yields with no detectable hydrolysis of the aminoacyl or glycosidic bonds under these conditions.N-Formylmethionyl and N-acetylphenylalanyl derivatives were prepared in each series by acylation of the deblocked products with acetic formic anhydride and p-nitrophenyl acetate, respectively. Biochemical rationale for the use of these compounds in the study of protein biosynthesis and initiation processes are discussed. The puromycin-like activity of 3′-O-phenylalanyl-2′-O-methyl-adenosine (4b) was confirmed.

Dietary intake of tryptophan tied emotion-related impulsivity in humans

2019 ◽  
pp. 1-8 ◽  
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.

Purification of Antihemophilic Factor (Factor VIII) by Amino Acid Precipitation*

1964 ◽  
Vol 11 (01) ◽  
pp. 064-074 ◽  
Author(s):  
Robert H Wagner ◽  
William D McLester ◽  
Marion Smith ◽  
K. M Brinkhous
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Factor Viii ◽  
Plasma Protein ◽  
Acid Precipitation ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Specific Procedure ◽  
Beta Alanine ◽  
Antihemophilic Factor

Summary1. The use of several amino acids, glycine, alpha-aminobutyric acid, alanine, beta-alanine, and gamma-aminobutyric acid, as plasma protein precipitants is described.2. A specific procedure is detailed for the preparation of canine antihemophilic factor (AHF, Factor VIII) in which glycine, beta-alanine, and gammaaminobutyric acid serve as the protein precipitants.3. Preliminary results are reported for the precipitation of bovine and human AHF with amino acids.

Complete Covalent Structure of Human Platelet Factor 4

1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Human Platelet ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Disulphide Bonds ◽  
Covalent Structure

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.

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