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 Targeting of the epidermal growth factor receptor with mesoporphyrin IX-peptide conjugates

2016 ◽  
Vol 20 (01n04) ◽  
pp. 352-366 ◽  
Author(s):  
Krystal R. Fontenot ◽  
Benson G. Ongarora ◽  
Logan E. LeBlanc ◽  
Zehua Zhou ◽  
Seetharama D. Jois ◽  
...  
Keyword(s):  
Energy Minimization ◽  
Growth Factor Receptor ◽  
Triethylene Glycol ◽  
Docking Studies ◽  
Peptide Conjugates ◽  
Cellular Targeting ◽  
Epidermal Growth ◽  
Targeting Ability ◽  
Molecular Modeling And Docking

The synthesis and in vitro evaluation of four mesoporphyrin IX-peptide conjugates designed to target EGFR, over-expressed in colorectal and other cancers, are reported. Two peptides with known affinity for EGFR, LARLLT (1) and GYHWYGYTPQNVI (2), were conjugated to mesoporphyrin IX (MPIX, 3) via one or both the propionic side chains, directly (4, 5) or with a triethylene glycol spacer (7, 8). The conjugates were characterized using NMR, MS, CD, SPR, UV-vis and fluorescence spectroscopies. Energy minimization and molecular dynamics suggest different conformations for the conjugates. SPR studies show that conjugate 4, bearing two LARLLT with no PEG spacers, has the greatest affinity for binding to EGFR, followed by conjugate 7with two PEG and two LARLLT sequences. Molecular modeling and docking studies suggest that both conjugates 4 and 7 can bind to monomer and dimer EGFR in open and closed conformations. The cytotoxicity and cellular targeting ability of the conjugates were investigated in human HEp2 cells over-expressing EGFR. All conjugates showed low dark- and photo-toxicities. The cellular uptake was highest for conjugates 4 and 8 and lowest for 7 bearing two LARLLT linked via PEG groups, likely due to decreased hydrophobicity. Among the conjugates investigated, 4 is the most efficient EGFR-targeting agent, and therefore the most promising for the detection of cancers that over-express EGFR.

Propargyloxyproline Regio- and Stereoisomers for Click-Conjugation of Peptides: Synthesis and Application in Linear and Cyclic Peptides

2015 ◽  
Vol 68 (9) ◽  
pp. 1365 ◽  
Author(s):  
Susan E. Northfield ◽  
Simon J. Mountford ◽  
Jerome Wielens ◽  
Mengjie Liu ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Peptide Synthesis ◽  
Cyclic Peptides ◽  
Click Reaction ◽  
Fluorescent Labels ◽  
Peptide Conjugates ◽  
Conformational Properties ◽  
Peptides Synthesis

The use of the click reaction for the introduction of conjugate groups, such as affinity or fluorescent labels, to a peptide for the study of peptide biochemistry and pharmacology is widespread. However, the nature and location of substituted 1,2,3-triazoles in peptide sequences may markedly affect conformation or binding as compared with native sequences. We have examined the preparation and application of propargyloxyproline (Pop) residues as a precursor to such peptide conjugates. Pop residues are available in a range of regio- and stereoisomers from hydroxyproline precursors and are readily prepared in Fmoc-protected form. They can be incorporated routinely in peptide synthesis and broadly retain the conformational properties of the parent proline containing peptides. This is exemplified by the preparation of biotin- and fluorophore-labelled peptides derived from linear and cyclic peptides.

scholarly journals Functional and Nonclinical Similarity of ABP 980, a Biosimilar of Trastuzumab

2019 ◽  
Vol 36 (12) ◽  
Author(s):  
Shea Jassem ◽  
Wei Wang ◽  
Heather Sweet ◽  
Raffi Manoukian ◽  
Vincent Chow ◽  
...  
Keyword(s):  
Growth Factor Receptor ◽  
Mechanisms Of Action ◽  
Functional Similarity ◽  
Functional Evaluation ◽  
Binding Studies ◽  
Monocyte Cell ◽  
Her2 Signaling ◽  
Primary Assessment

Abstract Purpose The in vitro and in vivo pharmacologic assessment of ABP 980 similarity to its reference product is intended to compare the activity of ABP 980 and trastuzumab and support the overall conclusion of similarity based on a comprehensive analytical and functional evaluation. Methods This work complements the primary assessment of functional similarity with additional in vitro assays, binding studies, and non-clinical studies including human epidermal growth factor receptor-2 (HER2) kinetic binding, HER2 signaling, HER2 internalization, synergy with docetaxel chemotherapy, FcγR kinetic binding, primary natural killer and monocyte cell binding, antibody-dependent cellular phagocytosis activity, in vivo xenograft studies, and toxicokinetic parameters. Results The results contribute to the totality of evidence with respect to functional similarity and support that ABP 980 is similar to trastuzumab in all primary and secondary mechanisms of action. Conclusions These results also support the scientific justification of extrapolation to all approved indications of trastuzumab given the established functional similarity of the two products and the same mechanisms of action across all conditions of use.

scholarly journals Systemic Antibacterial Activity of Novel Synthetic Cyclic Peptides

2005 ◽  
Vol 49 (8) ◽  
pp. 3302-3310 ◽  
Author(s):  
Véronique Dartois ◽  
Jorge Sanchez-Quesada ◽  
Edelmira Cabezas ◽  
Ellen Chi ◽  
Chad Dubbelde ◽  
...  
Keyword(s):  
Cyclic Peptides ◽  
Prolonged Exposure ◽  
Cyclic Peptide ◽  
Present Report ◽  
Bacterial Load ◽  
Pharmacokinetic Profile ◽  
Therapeutic Window ◽  
Infection Model

ABSTRACT Cyclic peptides with an even number of alternating d,l-α-amino acid residues are known to self-assemble into organic nanotubes. Such peptides previously have been shown to be stable upon protease treatment, membrane active, and bactericidal and to exert antimicrobial activity against Staphylococcus aureus and other gram-positive bacteria. The present report describes the in vitro and in vivo pharmacology of selected members of this cyclic peptide family. The intravenous (i.v.) efficacy of six compounds with MICs of less than 12 μg/ml was tested in peritonitis and neutropenic-mouse thigh infection models. Four of the six peptides were efficacious in vivo, with 50% effective doses in the peritonitis model ranging between 4.0 and 6.7 mg/kg against methicillin-sensitive S. aureus (MSSA). In the thigh infection model, the four peptides reduced the bacterial load 2.1 to 3.0 log units following administration of an 8-mg/kg i.v. dose. Activity against methicillin-resistant S. aureus was similar to MSSA. The murine pharmacokinetic profile of each compound was determined following i.v. bolus injection. Interestingly, those compounds with poor efficacy in vivo displayed a significantly lower maximum concentration of the drug in serum and a higher volume of distribution at steady state than compounds with good therapeutic properties. S. aureus was unable to easily develop spontaneous resistance upon prolonged exposure to the peptides at sublethal concentrations, in agreement with the proposed interaction with multiple components of the bacterial membrane canopy. Although additional structure-activity relationship studies are required to improve the therapeutic window of this class of antimicrobial peptides, our results suggest that these amphipathic cyclic d,l-α-peptides have potential for systemic administration and treatment of otherwise antibiotic-resistant infections.

Therapeutic targeting of extracellular FGFR2 activating deletions in intrahepatic cholangiocarcinoma.

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 567-567 ◽  
Author(s):  
James M. Cleary ◽  
Srivatsan Raghavan ◽  
Yvonne Y. Li ◽  
Liam Spurr ◽  
Qibiao Wu ◽  
...  
Keyword(s):  
Intrahepatic Cholangiocarcinoma ◽  
Acquired Resistance ◽  
Growth Factor Receptor ◽  
Extracellular Domain ◽  
Kinase Domain ◽  
Genomic Alteration ◽  
Resistance Mutations ◽  
Clinical Sensitivity

567 Background: Fibroblast growth factor receptor (FGFR) pathway alterations have been identified in approximately 20% of patients (pts) with intrahepatic cholangiocarcinoma (IHCC), most commonly by FGFR2 fusions. Early phase clinical trials have demonstrated encouraging efficacy of FGFR inhibitors in pts with FGFR2-translocated cholangiocarcinoma, but efficacy in pts with other FGFR2 activating alterations is less clear. Methods: Pts with cholangiocarcinoma underwent CLIA-certified next generation DNA sequencing (NGS) to identify actionable alterations. FGFR2 fusions and other FGFR2 genomic events were assessed, with genomic characterization performed before and after treatment with FGFR inhibitors in appropriate pts. Novel extracellular domain in-frame deletions (INDELs) of FGFR2 and apparent resistance mutations were investigated for oncogenic activity and inhibitor resistance in vitro and in vivo. Results: Cholangiocarcinomas from 284 pts (136 male, 148 female; median age, 64 [20-89], including 139 IHCCs, were sequenced. Among the IHCCs, 16 (11.5%) had FGFR2 fusions, with 9 different gene partners. Surprisingly, 5 (3.6%) IHCCs harbored extracellular domain FGFR2 INDELs. Two of these IHCCs harbored an exon 5 deletion FGFR2 p.H167_N173del. Expression of FGFR2 p.H167_N173del in 3T3 cells resulted in oncogenic transformation. In the clinic, two pts with FGFR2 p.H167_N173del were treated with Debio1347, an oral FGFR-1/2/3 inhibitor. Both patients achieved a durable partial response (PR) of 11 months, with one of the pts still on active treatment with Debio-1347. The patient who developed acquired resistance underwent repeat biopsy, and NGS identified a secondary mutation ( FGFR2 p. L617F) in the kinase domain. In vitro studies demonstrated that this mutation confers resistance to Debio1347. This patient was subsequently treated with another FGFR inhibitor and again experienced a PR lasting 17 months. A third biopsy after disease progression demonstrated a previously undetected L597Q BRAF mutation. Conclusions: Extracellular domain FGFR2 in-frame deletions are a novel genomic alteration in IHCC that are transforming and predict clinical sensitivity to FGFR inhibitors.

scholarly journals CPPs to the Test: Effects on Binding, Uptake and Biodistribution of a Tumor Targeting Nanobody

2021 ◽  
Vol 14 (7) ◽  
pp. 602
Author(s):  
Estel Collado Camps ◽  
Sanne A. M. van Lith ◽  
Cathelijne Frielink ◽  
Jordi Lankhof ◽  
Ingrid Dijkgraaf ◽  
...  
Keyword(s):  
Growth Factor Receptor ◽  
Cell Penetrating Peptides ◽  
Circulation Time ◽  
Tissue Cell ◽  
Target Tissue ◽  
Peptide Conjugates ◽  
Tracer Accumulation ◽  
And Performance

Nanobodies are well-established targeting ligands for molecular imaging and therapy. Their short circulation time enables early imaging and reduces systemic radiation exposure. However, shorter circulation time leads to lower tracer accumulation in the target tissue. Cell-penetrating peptides (CPPs) improve cellular uptake of various cargoes, including nanobodies. CPPs could enhance tissue retention without compromising rapid clearance. However, systematic investigations on how the functionalities of nanobody and CPP combine with each other at the level of 2D and 3D cell cultures and in vivo are lacking. Here, we demonstrate that conjugates of the epidermal growth factor receptor (EGFR)-binding nanobody 7D12 with different CPPs (nonaarginine, penetratin, Tat and hLF) differ with respect to cell binding and induction of endocytosis. For nonaarginine and penetratin we compared the competition of EGF binding and performance of L- and D-peptide stereoisomers, and tested the D-peptide conjugates in tumor cell spheroids and in vivo. The D-peptide conjugates showed better penetration into spheroids than the unconjugated 7D12. Both in vivo and in vitro, the behavior of the agent reflects the combination of both functionalities. Although CPPs cause promising increases in in vitro uptake and 3D penetration, the dominant effect of the CPP in the control of biodistribution warrants further investigation.

Synthesis and cellular studies of PPIX-homing peptide conjugates

2012 ◽  
Vol 16 (05n06) ◽  
pp. 603-615 ◽  
Author(s):  
Martha Sibrian-Vazquez ◽  
Xiaoke Hu ◽  
Timothy J. Jensen ◽  
M. Graça H. Vicente
Keyword(s):  
Cell Lines ◽  
Protoporphyrin Ix ◽  
Peptide Sequence ◽  
Side Chains ◽  
Human Leukemia ◽  
Cellular Internalization ◽  
Peptide Conjugates ◽  
Human Carcinoma ◽  
Homing Peptide

Five amphiphilic protoporphyrin IX-peptide conjugates bearing the sequences ATWLPPR, AAhexPQRRSARLSA and cERGDPhe conjugated via the propionic side chains, were synthesized and evaluated in vitro using two cell lines: human carcinoma HEp2 and human leukemia HL-60. All conjugates were found to have low dark- and photo-toxicities in both cell lines, and 3 to 10-fold higher accumulation was observed within HL-60 vs. HEp2 cells, depending on the nature of the peptide sequence. The preferential subcellular sites of localization for all conjugates were found to be the lysosomes in HEp2 cells, and the mitochondria in HL-60 cells, suggesting different mechanisms of cellular internalization.

scholarly journals A Cyclic Peptide Epitope of an Under-Explored VEGF-B Loop 1 Demonstrated In Vivo Anti-Angiogenic and Anti-Tumor Activities

2021 ◽  
Vol 12 ◽  
Author(s):  
Lei Wang ◽  
Meng Xu ◽  
Haofeng Hu ◽  
Lun Zhang ◽  
Fei Ye ◽  
...  
Keyword(s):  
Cyclic Peptides ◽  
Cyclic Peptide ◽  
Umbilical Vein ◽  
Chorioallantoic Membrane ◽  
Docking Study ◽  
Human Gastric Cancer ◽  
Nude Mouse Model ◽  
Peptide Epitope

Pathological angiogenesis is mainly initiated by the binding of abnormal expressed vascular endothelial growth factors (VEGFs) to their receptors (VEGFRs). Blocking the VEGF/VEGFR interaction is a clinically proven treatment in cancer. Our previous work by epitope scan had identified cyclic peptides, mimicking the loop 1 of VEGF-A, VEGF-B and placental growth factor (PlGF), inhibited effectively the VEGF/VEGFR interaction in ELISA. We described here the docking study of these peptides on VEGFR1 to identify their binding sites. The cellular anti-angiogenic activities were examined by inhibition of VEGF-A induced cell proliferation, migration and tube formation in human umbilical vein endothelial cells (HUVECs). The ability of these peptides to inhibit MAPK/ERK1/2 signaling pathway was examined as well. On chick embryo chorioallantoic membrane (CAM) model, a cyclic peptide named B-cL1 with most potent in vitro activity showed important in vivo anti-angiogenic effect. Finally, B-cL1 inhibited VEGF induced human gastric cancer SGC-7901 cells proliferation. It showed anti-tumoral effect on SGC-7901 xenografted BALB/c nude mouse model. The cyclic peptides B-cL1 constitutes an anti-angiogenic peptide drug lead for the design of new and more potent VEGFR antagonists in the treatment of angiogenesis related diseases.

scholarly journals Discovery of Antiviral Cyclic Peptides Targeting the Main Protease of SARS-CoV-2 via mRNA Display

2021 ◽  
Author(s):  
Jason Johansen-Leete ◽  
Sven Ullrich ◽  
Sarah Fry ◽  
Rebecca Frkic ◽  
Max Bedding ◽  
...  
Keyword(s):  
Cyclic Peptides ◽  
Cyclic Peptide ◽  
Peptide Inhibitors ◽  
Mrna Display ◽  
High Affinity ◽  
Main Protease ◽  
Binding Epitope ◽  
Affinity Peptide ◽  
Micromolar Range

Antivirals that specifically target SARS-CoV-2 are needed to control the COVID-19 pandemic. The main protease (Mpro) is essential for SARS-CoV-2 replication and is an attractive target for antiviral development. Here we report the use of the Random nonstandard Peptide Integrated Discovery (RaPID) mRNA display on a chemically cross-linked SARS-CoV-2 Mpro dimer, which yielded several high-affinity thioether-linked cyclic peptide inhibitors of the protease. Structural analysis of Mpro complexed with a selenoether analogue of the highest-affinity peptide revealed key binding interactions, including glutamine and leucine residues in sites S1 and S2, respectively, and a binding epitope straddling both protein chains in the physiological dimer. Several of these Mpro peptide inhibitors possessed antiviral activity against SARS-CoV-2 in vitro with EC50 values in the low micromolar range. These cyclic peptides serve as a foundation for the development of much needed antivirals that specifically target SARS-CoV-2.

scholarly journals Contemplating 1,2,4-Thiadiazole-Inspired Cyclic Peptide Mimics: A Computational Investigation

2019 ◽  
Vol 72 (11) ◽  
pp. 894 ◽  
Author(s):  
Sida Xie ◽  
Paul V. Bernhardt ◽  
Lawrence R. Gahan ◽  
Craig M. Williams
Keyword(s):  
Metal Binding ◽  
Metal Ion ◽  
Cyclic Peptides ◽  
Cyclic Peptide ◽  
Computational Study ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Binding Studies ◽  
Naturally Occurring ◽  
The Stability

Marine derived cyclic peptides have inspired chemists for decades as the cavitand architecture can be compared with macrocyclic ligands, and hence easily conceived as mediators of metal-ion transport. Lissoclinamide 5 and ascidiacyclamide are two such cyclic peptides that have received much attention both for their metal ion complexation properties and biological activity; the metal ion binding properties of mimics of these two systems have been reported. Reported herein is a computational study aimed at evaluating the stability, and potential for copper(ii) ion binding by lissoclinamide 5 mimics that substitute the naturally occurring 4-carboxy-1,3-thiazole units for novel valine- and phenylalanine-derived 1,2,4-thiadiazole units. Our results suggest that one lissoclinamide 5 mimic, 1,2,4-thiadiazole (TDA)-lissoclinamide 9, may be capable of forming a complex with one CuII ion, [Cu(9-H)(H2O)]+. A complex with two CuII ions, [Cu2(9-H)(μ-OH)]2+, was also considered. These results set the stage for synthetic and experimental metal binding studies.

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