scholarly journals Tunable, biodegradable grafting-from glycopolypeptide bottlebrush polymers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zachary S. Clauss ◽  
Casia L. Wardzala ◽  
Austin E. Schlirf ◽  
Nathaniel S. Wright ◽  
Simranpreet S. Saini ◽  
...  
Keyword(s):  
Amino Acids ◽  
Extracellular Matrix ◽  
Amino Acid ◽  
Polymer Synthesis ◽  
Human Cells ◽  
One Pot ◽  
Grafting Density ◽  
Monomer Feed ◽  
Dual Catalysis ◽  
Grafting From

AbstractThe cellular glycocalyx and extracellular matrix are rich in glycoproteins and proteoglycans that play essential physical and biochemical roles in all life. Synthetic mimics of these natural bottlebrush polymers have wide applications in biomedicine, yet preparation has been challenged by their high grafting and glycosylation densities. Using one-pot dual-catalysis polymerization of glycan-bearing α-amino acid N-carboxyanhydrides, we report grafting-from glycopolypeptide brushes. The materials are chemically and conformationally tunable where backbone and sidechain lengths were precisely altered, grafting density modulated up to 100%, and glycan density and identity tuned by monomer feed ratios. The glycobrushes are composed entirely of sugars and amino acids, are non-toxic to cells, and are degradable by natural proteases. Inspired by native lipid-anchored proteoglycans, cholesterol-modified glycobrushes were displayed on the surface of live human cells. Our materials overcome long-standing challenges in glycobrush polymer synthesis and offer new opportunities to examine glycan presentation and multivalency from chemically defined scaffolds.

A facile one pot route for the synthesis of imide tethered peptidomimetics

2016 ◽  
Vol 14 (2) ◽  
pp. 556-563 ◽  
Author(s):  
Veladi Panduranga ◽  
Girish Prabhu ◽  
Roopesh Kumar ◽  
Basavaprabhu Basavaprabhu ◽  
Vommina V. Sureshbabu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Efficient Method ◽  
One Pot ◽  
Protected Amino Acid

A simple and efficient method for the synthesis of N,N’-orthogonally protected imide tethered peptidomimetics is presented. The imide peptidomimetics were synthesized by coupling the in situ generated selenocarboxylate of Nα-protected amino acids with Nα-protected amino acid azides in good yields.

scholarly journals Insulin-Like Growth Factor Binding Protein-5 Binds to Plasminogen Activator Inhibitor-I*

Endocrinology ◽  
1997 ◽  
Vol 138 (7) ◽  
pp. 2972-2978 ◽  
Author(s):  
Taek Jeong Nam ◽  
Walker Busby ◽  
David R. Clemmons
Keyword(s):  
Amino Acids ◽  
Extracellular Matrix ◽  
Amino Acid ◽  
Growth Factor ◽  
Heparan Sulfate ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Insulin-like growth factor binding protein-5 (IGFBP-5) has been shown to bind to the extracellular matrix (ECM) of both fibroblasts and smooth muscle cells. The ECM-IGFBP-5 interaction is mediated in part by binding to heparan sulfate containing proteoglycans. Because proteoglycans may not be the only components of ECM that bind to IGFBP-5, we have determined its ability to bind to other ECM proteins. When a partially purified mixture of the proteins that were present in fibroblast conditioned medium was purified by IGFBP-5 affinity chromatography, a 55-kDa protein was eluted. Amino acid sequencing of the amino terminal 28 amino acids showed that it was human plasminogen activator inhibitor-1 (PAI-1). To determine if this interaction was specific, purified human PAI-1 was incubated with IGFBP-5 and the IGFBP-5/PAI-1 complex immunoprecipitated with anti-PAI-1 antiserum. When the precipitate was analyzed by immunoblotting using anti-IGFBP-5 antiserum, the intensity of the IGFBP-5 band was substantially increased compared with controls that did not contain human PAI-1. A synthetic IGFBP-5 peptide that contained the amino acid sequence between positions 201 and 218 inhibited IGFBP-5/PAI-1 interaction. Coincubation of IGFBP-5 mutants that contained substitutions for specific basic residues located between positions 201 and 218 with PAI-1 indicated that some of these amino acids were important for binding. Two mutants that contained neutral substitutions for specific basic amino acids within the glycosaminoglycan binding domain had reduced binding to PAI-1. In contrast, three other mutants that also had substitutions for charged residues in the same region had no reduction in binding. Heparin and heparan sulfate inhibited the IGFBP-5/PAI-1 interaction; however, several other glycosaminoglycans had no effect. PAI-1 was determined to be an important ECM component for binding because approximately 27% of total ECM binding could be inhibited with anti-PAI-1 antiserum. Competitive binding studies with unlabeled IGFBP-5 showed that the dissociation constant of PAI-1 for IGFBP-5 was 9.1 × 10−8m. In summary, IGFBP-5 binds specifically to plasminogen activator inhibitor-1. Because this is present in the extracellular matrix of several cell types, it may be one of the important binding components of ECM. PAI-1 binding partially protects IGFBP-5 from proteolysis, suggesting that it is one of the ECM components that is involved in mediating this effect.

scholarly journals Biocatalytic stereoinversion ofd-para-bromophenylalanine in a one-pot three-enzyme reaction

2017 ◽  
Vol 19 (2) ◽  
pp. 503-510 ◽  
Author(s):  
Fahimeh Khorsand ◽  
Cormac D. Murphy ◽  
Andrew J. Whitehead ◽  
Paul C. Engel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Enzyme Reaction ◽  
One Pot ◽  
Phenylalanine Dehydrogenase

d-Amino acid transaminase plus mutant phenylalanine dehydrogenase offer an effective one-pot system for 100% conversion ofdl-amino acids to thel-form.

Microwave-assisted one pot-synthesis of amino acid ionic liquids in water: simple catalysts for styrene carbonate synthesis under atmospheric pressure of CO2

2014 ◽  
Vol 4 (4) ◽  
pp. 963-970 ◽  
Author(s):  
Kuruppathparambil Roshith Roshan ◽  
Tharun Jose ◽  
Dongwoo Kim ◽  
Kathalikkattil Amal Cherian ◽  
Dae Won Park
Keyword(s):  
Amino Acids ◽  
Ionic Liquids ◽  
Amino Acid ◽  
Atmospheric Pressure ◽  
Microwave Energy ◽  
One Pot ◽  
Microwave Assisted ◽  
One Pot Synthesis ◽  
Styrene Carbonate

A novel variety of ionic liquids based on amino acids is synthesized in water using microwave energy.

scholarly journals One-Pot Ring-Opening Peptide Synthesis Using α,α-Difluoro-β-Lactams

Synthesis ◽  
2020 ◽  
Vol 52 (23) ◽  
pp. 3657-3666 ◽  
Author(s):  
Masaaki Omote ◽  
Atsushi Tarui ◽  
Masakazu Ueo ◽  
Marino Morikawa ◽  
Masahiko Tsuta ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Peptide Synthesis ◽  
Ring Opening ◽  
Reactive Intermediates ◽  
One Pot ◽  
Open Chain ◽  
Lactam Ring

α,α-Difluoro-β-lactams successfully underwent ring-opening aminolysis with various amino acids in 2,2,2-trifluoroethanol to afford fluorine-containing peptides. In this aminolysis, it was found that 2,2,2-trifluoroethanol first attacked the α,α-difluoro-β-lactams with cleavage of lactam ring to form the corresponding open-chain 2,2,2-trifluoroethyl esters as reactive intermediates. The trifluoroethyl esters were more electrophilic compared with the corresponding methyl ester and thereby accelerated the aminolysis with various amino acids to form β-amino acid peptides with α,α-difluoromethylene unit.

Requirements for Growth of Single Human Cells

PEDIATRICS ◽  
1959 ◽  
Vol 23 (4) ◽  
pp. 709-709
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basal Medium ◽  
Optimal Growth ◽  
Essential Amino Acids ◽  
Human Cells ◽  
Human Nutrition ◽  
Traditional Concept ◽  
Original Medium ◽  
Number Of Cells

The experiments reported in this paper may foreshadow a change in the traditional concept of so-called essential amino acids in human nutrition. It has been shown that a number of strains of single types of human cells may be propagated serially in a medium containing 13 "essential" amino acids along with other ingredients when a relatively large inoculum of cells is employed. In the present experiments it was learned that this medium did not permit successful propagation if relatively small inocula of cells were used, unless additional amino acids not included in the original medium, were added. The efficiency of the medium in promoting growth in the case of lighter inocula was restored when seven amino acids, not required for optimal growth with heavy inocula, were added to the basal medium. Serine was the most important of the seven non-essential amino acids that were not required in the medium to support optimal growth with heavy inocula. Thus the essentiality or non-essentiality of an amino acid may depend upon the capacity of the number of cells involved to meet the requirements for amino acids by biosynthesis within the cells, as may be determined by the population of cells and their rate of growth.

One-pot synthesis of β-amino acid derivatives from α-amino acids

2006 ◽  
Vol 47 (49) ◽  
pp. 8757-8760 ◽  
Author(s):  
Carlos J. Saavedra ◽  
Rosendo Hernández ◽  
Alicia Boto ◽  
Eleuterio Álvarez
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Derivatives ◽  
One Pot ◽  
One Pot Synthesis

Straightforward Synthesis of Succinimide-Fused Pyrrolizidines by A Three-Component Reaction of α-Diketone, Amino Acid, and Maleimide

Synthesis ◽  
2020 ◽  
Author(s):  
Hua Zhao ◽  
Hongbin Zhai ◽  
Peng Shen ◽  
Yeting Guo ◽  
Jian Wei ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Functional Group ◽  
High Efficiency ◽  
Cycloaddition Reaction ◽  
Azomethine Ylide ◽  
High Yield ◽  
One Pot ◽  
Keto Ester ◽  
Three Component Reaction

AbstractAn efficient, one-pot, three-component [3+2] cycloaddition reaction of azomethine ylide obtained from α-dicarbonyl compounds (cyclic and acyclic diketone or keto ester) and amino acids with maleimides under catalyst-free conditions has been developed. This cascade protocol shows high efficiency and remarkable functional group tolerance, and the ubiquitous succinimide-fused pyrrolizidines with a highly compact and strained scaffold were obtained with high yield and excellent diastereoselectivity. Furthermore, this novel and atom-economical strategy could be performed on a gram scale with comparable reaction efficiency.

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