Chemical Synthesis of Amino Acid Containing Lipids I: Lipids Derived from Monobasic Amino Acids

Fluorescent d-amino acids (FDAAs) are molecular probes that are widely used for labelling the peptidoglycan layer of bacteria. When added to growing cells they are incorporated into the stem peptide by a transpeptidase reaction, allowing the timing and localization of peptidoglycan synthesis to be determined by fluorescence microscopy. Herein we describe the chemical synthesis of an OregonGreen488-labelled FDAA (OGDA). We also demonstrate that OGDA can be efficiently incorporated into the PG of Gram-positive and some Gram-negative bacteria, and imaged by super-resolution stimulated emission depletion (STED) nanoscopy at a resolution well below 100 nm.

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Prebiotic Synthesis of Cysteine Peptides That Catalyze Peptide Ligation in Neutral Water

10.26434/chemrxiv.12578699 ◽

2020 ◽

Author(s):

Callum Foden ◽

Saidul Islam ◽

Christian Arturo Fernandez Garcia ◽

Leonardo Maugeri ◽

Tom Sheppard ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Chemical Synthesis ◽

Prebiotic Synthesis ◽

Biomimetic Synthesis ◽

Strecker Reaction ◽

Simple Chemical ◽

Peptide Biosynthesis ◽

Neutral Water ◽

Life On Earth

<div>Peptides and the proteinogenic α-amino acids are essential to all life on Earth. Peptide biosynthesis is orchestrated by a complex suite of enzymes in extant biology, but this must have been predated by a simple chemical synthesis at the origins of life. α-Aminonitriles, the nitrile precursors of α-amino acids, are generally readily produced by Strecker reactions, but the origin of cysteine—the thiol-bearing amino acid—is not understood. The aminothiol moiety of cysteine is chemically incompatible with nitriles at physiological pH, therefore cysteine nitrile is not stable, and it is widely believed that cysteine was a biological invention and a late addition to the genetic code<sub>.</sub> Here, we report the first high-yielding, prebiotic synthesis of cysteine peptides. Our biomimetic synthesis converts serine to cysteine, by-passing the Strecker reaction of β-mercaptoacetaldehyde, but exploits nitrile–activated dehydroalanine synthesis at near-neutral pH. We additionally demonstrate the catalytic prowess of <i>N</i>-acylcysteines (and related peptides and thiols) in the organocatalytic synthesis of peptides and peptidyl amidines in neutral water. Thiol catalysis directly couples kinetically stable—but energy-rich—α-amidonitriles to proteinogenic amines, in a reaction that tolerates all twenty proteinogenic side chains. This is a rare, prebiotically plausible example of selective and efficient organocatalysis in water. Our results implicate cysteine derivatives and thiol-catalysis at the onset of evolution.</div>

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Prebiotic Synthesis of Cysteine Peptides That Catalyze Peptide Ligation in Neutral Water

10.26434/chemrxiv.12578699.v1 ◽

2020 ◽

Author(s):

Callum Foden ◽

Saidul Islam ◽

Christian Arturo Fernandez Garcia ◽

Leonardo Maugeri ◽

Tom Sheppard ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Chemical Synthesis ◽

Prebiotic Synthesis ◽

Biomimetic Synthesis ◽

Strecker Reaction ◽

Simple Chemical ◽

Peptide Biosynthesis ◽

Neutral Water ◽

Life On Earth

<div>Peptides and the proteinogenic α-amino acids are essential to all life on Earth. Peptide biosynthesis is orchestrated by a complex suite of enzymes in extant biology, but this must have been predated by a simple chemical synthesis at the origins of life. α-Aminonitriles, the nitrile precursors of α-amino acids, are generally readily produced by Strecker reactions, but the origin of cysteine—the thiol-bearing amino acid—is not understood. The aminothiol moiety of cysteine is chemically incompatible with nitriles at physiological pH, therefore cysteine nitrile is not stable, and it is widely believed that cysteine was a biological invention and a late addition to the genetic code<sub>.</sub> Here, we report the first high-yielding, prebiotic synthesis of cysteine peptides. Our biomimetic synthesis converts serine to cysteine, by-passing the Strecker reaction of β-mercaptoacetaldehyde, but exploits nitrile–activated dehydroalanine synthesis at near-neutral pH. We additionally demonstrate the catalytic prowess of <i>N</i>-acylcysteines (and related peptides and thiols) in the organocatalytic synthesis of peptides and peptidyl amidines in neutral water. Thiol catalysis directly couples kinetically stable—but energy-rich—α-amidonitriles to proteinogenic amines, in a reaction that tolerates all twenty proteinogenic side chains. This is a rare, prebiotically plausible example of selective and efficient organocatalysis in water. Our results implicate cysteine derivatives and thiol-catalysis at the onset of evolution.</div>

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

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654806 ◽

1964 ◽

Vol 11 (01) ◽

pp. 064-074 ◽

Cited By ~ 24

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.

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Complete Covalent Structure of Human Platelet Factor 4

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657071 ◽

1979 ◽

Vol 42 (05) ◽

pp. 1652-1660 ◽

Cited By ~ 4

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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