Decoration of Coiled-Coil Peptides with N-Cysteine Peptide Thioesters As Cyclic Peptide Precursors Using Copper-Catalyzed Azide–Alkyne Cycloaddition (CuAAC) Click Reaction

2018 ◽  
Vol 20 (23) ◽  
pp. 7493-7497 ◽  
Author(s):  
W. Mathis Rink ◽  
Franziska Thomas
Keyword(s):  
Cyclic Peptide ◽  
Click Reaction ◽  
Coiled Coil ◽  
Peptide Precursors ◽  
Peptide Thioesters

scholarly journals Click Conjugation of Boron Dipyrromethene (BODIPY) Fluorophores to EGFR-Targeting Linear and Cyclic Peptides

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 593 ◽  
Author(s):  
Tyrslai M. Williams ◽  
Nichole E. M. Kaufman ◽  
Zehua Zhou ◽  
Sitanshu S. Singh ◽  
Seetharama D. Jois ◽  
...  
Keyword(s):  
Cyclic Peptides ◽  
Cyclic Peptide ◽  
Click Reaction ◽  
Cycloaddition Reaction ◽  
Growth Factor Receptor ◽  
Extracellular Domain ◽  
Binding Studies ◽  
Peptide Conjugates ◽  
Human Carcinoma

Through a simple 1,3-cycloaddition reaction, three BODIPY-peptide conjugates that target the extracellular domain of the epidermal growth factor receptor (EGFR) were prepared and their ability for binding to EGFR was investigated. The peptide ligands K(N3)LARLLT and its cyclic analog cyclo(K(N3)larllt, previously shown to have high affinity for binding to the extracellular domain of EGFR, were conjugated to alkynyl-functionalized BODIPY dyes 1 and 2 via a copper-catalyzed click reaction. This reaction produced conjugates 3, 4, and 5 in high yields (70–82%). In vitro studies using human carcinoma HEp2 cells that overexpress EGFR demonstrated high cellular uptake, particularly for the cyclic peptide conjugate 5, and low cytotoxicity in light (~1 J·cm−2) and darkness. Surface plasmon resonance (SPR) results show binding affinity of the three BODIPY-peptide conjugates for EGFR, particularly for 5 bearing the cyclic peptide. Competitive binding studies using three cell lines with different expressions of EGFR show that 5 binds specifically to EGFR-overexpressing colon cancer cells. Among the three conjugates, 5 bearing the cyclic peptide exhibited the highest affinity for binding to the EGFR protein.

scholarly journals Papain-like cysteine proteases prepare plant cyclic peptide precursors for cyclization

2019 ◽  
Vol 116 (16) ◽  
pp. 7831-7836 ◽  
Author(s):  
Fabian B. H. Rehm ◽  
Mark A. Jackson ◽  
Ewout De Geyter ◽  
Kuok Yap ◽  
Edward K. Gilding ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Cyclic Peptide ◽  
Cysteine Proteases ◽  
Heterologous Production ◽  
In Planta ◽  
Peptide Cyclization ◽  
Peptide Precursors ◽  
Agricultural Applications ◽  
Head To Tail Cyclization

Cyclotides are plant defense peptides that have been extensively investigated for pharmaceutical and agricultural applications, but key details of their posttranslational biosynthesis have remained elusive. Asparaginyl endopeptidases are crucial in the final stage of the head-to-tail cyclization reaction, but the enzyme(s) involved in the prerequisite steps of N-terminal proteolytic release were unknown until now. Here we use activity-guided fractionation to identify specific members of papain-like cysteine proteases involved in the N-terminal cleavage of cyclotide precursors. Through both characterization of recombinantly produced enzymes andin plantapeptide cyclization assays, we define the molecular basis of the substrate requirements of these enzymes, including the prototypic member, here termed kalatase A. The findings reported here will pave the way for improving the efficiency of plant biofactory approaches for heterologous production of cyclotide analogs of therapeutic or agricultural value.

Asymmetric synthesis of highly functionalized polyazamacrocycles via reduction of cyclic peptide precursors

1994 ◽  
Vol 35 (22) ◽  
pp. 3687-3690 ◽  
Author(s):  
Karl W. Aston ◽  
Susan L. Henke ◽  
Anil S. Modak ◽  
Dennis P. Riley ◽  
Kirby R. Sample ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Cyclic Peptide ◽  
Peptide Precursors

scholarly journals Characterization of a New Operon, as-48EFGH, from the as-48 Gene Cluster Involved in Immunity to Enterocin AS-48

2003 ◽  
Vol 69 (2) ◽  
pp. 1229-1236 ◽  
Author(s):  
Marta Diaz ◽  
Eva Valdivia ◽  
Manuel Martínez-Bueno ◽  
Matilde Fernández ◽  
Andrés Santos Soler-González ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Cyclic Peptide ◽  
Coiled Coil ◽  
Amino Acid Sequences ◽  
Conjugative Plasmid ◽  
Wild Type ◽  
Genetic Determinants ◽  
Reading Frame ◽  
Self Protection

ABSTRACT Enterocin AS-48 is a cyclic peptide produced by Enterococcus faecalis S-48 whose genetic determinants have been identified in the conjugative plasmid pMB2. A region of 7.8 kb, carrying the minimum information required for production of and immunity against AS-48, had been previously cloned and sequenced in pAM401 (pAM401-52). In this region, the as-48A structural gene and as-48B, as-48C, as-48C1 , as-48D, and as-48D1 genes and open reading frame 6 (ORF6) and ORF7 had been identified. The sequence analysis carried out in this work in the BglII B fragment (6.6-kb) from pMB2 cloned downstream from the last ORF identified (ORF7) revealed the existence of two new ORFs, as-48G and as-48H, necessary for full AS-48 expression. Thus, JH2-2 transformants obtained with the pAM401-81 plasmid became producers and resistant at the wild-type level. Tn5 disruption experiments in the last genes, as-48EFGH, were not able to reproduce these expression levels, confirming that expression of these genes is necessary to get the phenotype conferred by the wild-type pMB2 plasmid. The as-48EFGH operon encodes a new ABC transporter that could be involved in producer self-protection. On the basis of the observed similarities, As-48G would be the ATP-binding domain, the deduced amino acid sequences of As-48E and As48-H could be assigned as transmembrane subunits, and As-48F, with an N-terminal transmembrane segment and a coiled-coil domain, strongly resembles the structure of some known ABC transporter accessory proteins whose localization in the cell is discussed. This cluster of genes is expressed by two polycistronic mRNAs, T2 and T3, in JH2-2(pAM401-81) in coordinate expression. Our results also suggest that expression of T3 could be regulated, because in JH2-2(pAM401EH) transformants, T3 was not detected, suggesting that these genes do not by themselves confer immunity, in accordance with the requirement for the as-48D1 gene for immunity against AS-48.

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

Biologically Active Cyclic Peptide from Collectotrichum sp.

Planta Medica ◽  
2008 ◽  
Vol 74 (03) ◽  
Author(s):  
HMTB Herath ◽  
SI Khan ◽  
B Tekwani ◽  
NPD Nanayakkara
Keyword(s):  
Cyclic Peptide ◽  
Biologically Active

A Target-Based Method for Designing Heterochiral Cyclic Peptide Binders: De Novo Inhibitors of the PD-1/PD-L1 Interaction

2020 ◽  
Author(s):  
Salvador Guardiola ◽  
Monica Varese ◽  
Xavier Roig ◽  
Jesús Garcia ◽  
Ernest Giralt
Keyword(s):  
Protein Interactions ◽  
Cyclic Peptides ◽  
General Framework ◽  
Large Scale ◽  
Cyclic Peptide ◽  
De Novo ◽  
Inhibitory Effect ◽  
Original Text ◽  
Retraction Notice ◽  
Pharmaceutical Properties

<p>NOTE: This preprint has been retracted by consensus from all authors. See the retraction notice in place above; the original text can be found under "Version 1", accessible from the version selector above.</p><p><br></p><p>------------------------------------------------------------------------</p><p><br></p><p>Peptides, together with antibodies, are among the most potent biochemical tools to modulate challenging protein-protein interactions. However, current structure-based methods are largely limited to natural peptides and are not suitable for designing target-specific binders with improved pharmaceutical properties, such as macrocyclic peptides. Here we report a general framework that leverages the computational power of Rosetta for large-scale backbone sampling and energy scoring, followed by side-chain composition, to design heterochiral cyclic peptides that bind to a protein surface of interest. To showcase the applicability of our approach, we identified two peptides (PD-<i>i</i>3 and PD-<i>i</i>6) that target PD-1, a key immune checkpoint, and work as protein ligand decoys. A comprehensive biophysical evaluation confirmed their binding mechanism to PD-1 and their inhibitory effect on the PD-1/PD-L1 interaction. Finally, elucidation of their solution structures by NMR served as validation of our <i>de novo </i>design approach. We anticipate that our results will provide a general framework for designing target-specific drug-like peptides.<i></i></p>

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