scholarly journals Antifreeze glycopeptide diastereomers

2012 ◽  
Vol 8 ◽  
pp. 1657-1667 ◽  
Author(s):  
Lilly Nagel ◽  
Carsten Budke ◽  
Axel Dreyer ◽  
Thomas Koop ◽  
Norbert Sewald
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Antarctic Fish ◽  
Building Blocks ◽  
The Body ◽  
Ice Recrystallization ◽  
Harsh Conditions ◽  
Antifreeze Activity

Antifreeze glycopeptides (AFGPs) are a special class of biological antifreeze agents, which possess the property to inhibit ice growth in the body fluids of arctic and antarctic fish and, thus, enable life under these harsh conditions. AFGPs are composed of 4–55 tripeptide units -Ala-Ala-Thr- glycosylated at the threonine side chains. Despite the structural homology among all the fish species, divergence regarding the composition of the amino acids occurs in peptides from natural sources. Although AFGPs were discovered in the early 1960s, the adsorption mechanism of these macromolecules to the surface of the ice crystals has not yet been fully elucidated. Two AFGP diastereomers containing different amino acid configurations were synthesized to study the influence of amino acid stereochemistry on conformation and antifreeze activity. For this purpose, peptides containing monosaccharide-substituted allo-L- and D-threonine building blocks were assembled by solid-phase peptide synthesis (SPPS). The retro-inverso AFGP analogue contained all amino acids in D-configuration, while the allo-L-diastereomer was composed of L-amino acids, like native AFGPs, with replacement of L-threonine by its allo-L-diastereomer. Both glycopeptides were analyzed regarding their conformational properties, by circular dichroism (CD), and their ability to inhibit ice recrystallization in microphysical experiments.

Comparative acidic cleavage experiments with methyl-substituted benzyl esters of amino acids

1967 ◽  
Vol 20 (10) ◽  
pp. 2243 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Amino Acid ◽  
Solid Phase ◽  
Hydrogen Bromide ◽  
Solid Phase Peptide Synthesis ◽  
Amino Acid Derivatives ◽  
Methyl Substitution ◽  
Benzyl Esters ◽  
Layer Chromatography

The action of trifluoroacetic acid and hydrogen bromide in acetic acid, respectively, on the benzyl, p-methylbenzyl, 2,4,6-trimethylbenzyl, and penta-methylbenzyl esters of some amino acid derivatives has been investigated by thin-layer chromatography. Methyl substitution greatly enhances the lability of the ester groups. The possible bearing of the results on solid-phase peptide synthesis is discussed.

Caged Phospho-Amino Acid Building Blocks for Solid-Phase Peptide Synthesis

2003 ◽  
Vol 68 (17) ◽  
pp. 6795-6798 ◽  
Author(s):  
Deborah M. Rothman ◽  
M. Eugenio Vazquez ◽  
Elizabeth M. Vogel ◽  
Barbara Imperiali
Keyword(s):  
Amino Acid ◽  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Building Blocks

Synthesis of Trifluoromethyl Ketone Containing Amino Acid Building Blocks for the Preparation of Peptide-Based Histone Deacetylase (HDAC) Inhibitors

Synthesis ◽  
2018 ◽  
Vol 50 (20) ◽  
pp. 4037-4046 ◽  
Author(s):  
Christian Olsen ◽  
Carlos Moreno-Yruela
Keyword(s):  
Amino Acid ◽  
Histone Deacetylase ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Aqueous Media ◽  
Hdac Inhibitors ◽  
Building Blocks ◽  
Enantiomerically Pure ◽  
Trifluoromethyl Ketones ◽  
Class Iia Hdacs

Trifluoromethyl ketones (TFMKs) are electrophilic moieties which hydrate readily in aqueous media to give geminal diols. This ability has been exploited for the development of histone deacetylase (HDAC) inhibitors, because HDAC enzymes contain a Zn2+ ion which may be chelated by this functionality. Interestingly, TFMKs are exceptional Zn2+-binding groups for targeting the intriguing class IIa HDAC isozymes, involved in transcription factor recruitment and gene regulation. Here, we have developed a scalable and inexpensive synthetic procedure for preparation of the enantiomerically pure TFMK-containing amino acid building block (S)-2-amino-9,9,9-trifluoro-8-oxononanoic acid (Atona). In addition, we propose a protecting group strategy applicable to automated solid-phase peptide synthesis and demonstrate the ability of Atona-containing peptides to inhibit the enzymatic activity of class IIa HDACs with nanomolar potency. We envision that this synthesis will motivate the further development of peptide-based probes for the study of class IIa HDACs.

Arylboronate Ester Protected Amino Acids as Orthogonal Building Blocks for Fmoc Solid-Phase Peptide Synthesis

2017 ◽  
Vol 2017 (39) ◽  
pp. 5916-5920 ◽  
Author(s):  
Chao Liu ◽  
Yan Zou ◽  
Hui Song ◽  
Yuan-Ye Jiang ◽  
Hong-Gang Hu
Keyword(s):  
Amino Acids ◽  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Building Blocks

Nα-Amino acid containing privileged structures: design, synthesis and use in solid-phase peptide synthesis

2018 ◽  
Vol 16 (29) ◽  
pp. 5359-5362 ◽  
Author(s):  
Eva Schütznerová ◽  
Adam Přibylka ◽  
Viktor Krchňák
Keyword(s):  
Amino Acid ◽  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Building Blocks ◽  
Design Synthesis ◽  
Mild Conditions ◽  
Privileged Structures

Fmoc-protected Nα-amino acid containing heterocyclic privileged structures, O-(1-methyl-5-oxo-2,5-dihydro-1H-pyrrol-3-yl)-l-serine and O-((S)-5-oxo-2,3,5,7a-tetrahydro-1H-pyrrolizin-7-yl)-l-serine, were synthesized on the solid phase from simple commercially available building blocks under mild conditions.

scholarly journals Targeted Degradation of Proteins — The Ubiquitin System

2021 ◽  
Vol 9 ◽  
Author(s):  
Aaron Ciechanover
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chemical Composition ◽  
Nobel Prize ◽  
Building Blocks ◽  
Spoken Language ◽  
The Body ◽  
Cancer Center ◽  
Ubiquitin System ◽  
Specific Order

Proteins are the engines of all forms of life, for humans and for all the plant and animal kingdoms. Proteins are used both to build organs (such as bones, muscles, and skin) and to perform bodily functions. These functions range from digestion (processing food and converting it into energy), to enabling movement and sensation (sight and hearing), to protecting the body from foreign invaders with our antibodies, which are also proteins. What are proteins? They can be compared to words in a language that contains letters. In the Hebrew alphabet, there are 26 letters out of which countless words can be composed. But when we write, we use just a fraction of these infinite options, with the average number of letters in a word ranging between 3 and 8. The biological “protein alphabet” is comprised of 20 “letters” called amino acids, which are the building blocks of the proteins that make up the body. Proteins are chains of amino acid, linked together in a specific order governed by the DNA. Unlike the words of a spoken language, the average protein consists of hundreds of amino acids. The extensive length of proteins and the chemical composition of the amino acids make proteins sensitive to many factors, such as high temperatures, radiation, and chemicals. All these factors damage proteins and alter their fragile structures, negatively affecting how they function. When proteins are damaged or when they finish performing their functions and are no longer needed, the body breaks them down. With my doctoral adviser, Prof. Avram Hershko, and our research collaborator, Prof. Irwin Rose from the Fox Chase Cancer Center in Philadelphia, we discovered the mechanism responsible for targeted degradation of proteins in cells. This degradation can recognize damaged proteins or proteins that are not needed anymore, while leaving intact the “healthy,” functional ones. This mechanism is called the ubiquitin system after its principal protein, ubiquitin, which was the first protein we discovered in the system. Ubiquitin’s role is to tag undesirable proteins so that the cell’s “grinder” can recognize them and break them down, enabling the cell to function normally. In this article, we will explain the story of proteins and the ubiquitin system that we discovered in a study that earned us, among other prizes, the Nobel Prize in Chemistry in 2004.

scholarly journals Caged O-phosphorothioyl amino acids as building blocks for Fmoc-based solid phase peptide synthesis

Tetrahedron ◽  
2007 ◽  
Vol 63 (27) ◽  
pp. 6185-6190 ◽  
Author(s):  
Andreas Aemissegger ◽  
Christina N. Carrigan ◽  
Barbara Imperiali
Keyword(s):  
Amino Acids ◽  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Building Blocks

scholarly journals 45 Opportunity with functional role of supplemental amino acids

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 24-24
Author(s):  
Yanbin Shen ◽  
Sung Woo Kim
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Social Stress ◽  
Functional Role ◽  
Building Blocks ◽  
Animal Production ◽  
The Body ◽  
Technological Advancement ◽  
Crystalline Amino Acids

Abstract The technological advancement in production of crystalline amino acids has driven the cost of crystalline amino acids down significantly and facilitated the wide use of crystalline amino acids in food animal production. The primary reason of use of crystalline amino acids in am animal’s diet is to provide dietary essential nutrients for protein synthesis and to balance the diet and reduce dietary cost. Extensive researches with amino acids have greatly enabled such use. As a result, most swine diets today are formulated with 3 or 4 supplemental amino acids. However, the economical return on including beyond 4 supplemental amino acids becomes low and thus discourages the use of more than 4 supplemental amino acids for dietary saving purpose. The use of the functional role of amino acids might bear the new opportunity for amino acids. Tryptophan has unique physiological functions involving synthesize serotonin in the body. Increasing tryptophan intake is shown to elevate serotonin synthesis in the brain of pigs and reduce stress and improve performance of pigs under social stress. Research shows that methionine is used as a precursor of glutathione to protect intestinal mucosa from oxidative damages during weaning stress. Arginine, glutamine, and glutamate are shown to have functions in cell proliferation, potentially improving intestinal and immune function of nursery pigs and preventing loss of lean body mass in the sow. Leucine is a ketogenic amino acid. The carbon skeleton of leucine is converted to acetylCoA, which could be used for fatty acid synthesis in muscle tissue. Research showed that intramuscular fat was increased by feeding high dietary leucine levels. Overall, the different functions of individual AA beyond their roles as the building blocks for proteins give additional opportunities of amino acid application in animal production.

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