Simultaneous membrane interaction of amphipathic peptide monomers, self-aggregates and cargo complexes detected by fluorescence correlation spectroscopy

Vasconcelos, Luis; Lehto, Tõnis; Madani, Fatemeh; Radoi, Vlad; Hällbrink, Mattias; Vukojević, Vladana; Langel, Ülo

doi:10.1016/j.bbamem.2017.09.024

Cited by 15 publications

(9 citation statements)

References 67 publications

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“…Moreover, we demonstrated that the presence of TAMRA-Tat, TAMRA-Tat-NR2B9c, and TAMRA-Tat- N -dimer boosted the cell uptake of 3–5 kDa FITC-dextran. Complexation between the peptides and FITC-dextran could, in principle, facilitate cell uptake of the latter, as exploited for intracellular delivery of oligonucleotides [ 40 , 41 ]. However, TAMRA-Tat-NR2B9c and TAMRA-Tat- N -dimer did not co-localize with FITC-dextran upon cell uptake, excluding that FITC-dextran uptake occurs only when complexed with the peptides.…”

Section: Discussionmentioning

confidence: 99%

Conjugation of Therapeutic PSD-95 Inhibitors to the Cell-Penetrating Peptide Tat Affects Blood–Brain Barrier Adherence, Uptake, and Permeation

et al. 2020

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Novel stroke therapies are needed. Inhibition of the interaction between the postsynaptic density-95 (PSD-95)/disc large/ZO-1 (PDZ) domains of PSD-95 and the N-methyl-D-aspartate (NMDA) receptor has been suggested as a strategy for relieving neuronal damage. The peptides NR2B9c and N-dimer have been designed to hinder this interaction; they are conjugated to the cell-penetrating peptide Tat to facilitate blood–brain barrier (BBB) permeation and neuronal uptake. Tat-N-dimer exhibits 1000-fold better target affinity than Tat-NR2B9c, but the same magnitude of improvement is not observed in terms of therapeutic effect. Differences in BBB permeation by Tat-NR2B9c and Tat-N-dimer may explain this difference, but studies providing a direct comparison of Tat-NR2B9c and Tat-N-dimer are lacking. The aim of the present study was therefore to compare the BBB uptake and permeation of Tat-NR2B9c and Tat-N-dimer. The peptides were conjugated to the fluorophore TAMRA and their chemical stability assessed. Endothelial membrane association and cell uptake, and transendothelial permeation were estimated using co-cultures of primary bovine brain capillary endothelial cells and rat astrocytes. In vivo BBB permeation was demonstrated in mice using two-photon microscopy imaging. Tissue distribution was evaluated in mice demonstrating brain accumulation of TAMRA-Tat (0.4% ID/g), TAMRA-Tat-NR2B9c (0.3% ID/g), and TAMRA-Tat-N-dimer (0.25% ID/g). In conclusion, we demonstrate that attachment of NR2B9c or N-dimer to Tat affects both the chemical stability and the ability of the resulting construct to interact with and permeate the BBB.

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Section: Discussionmentioning

confidence: 99%

Conjugation of Therapeutic PSD-95 Inhibitors to the Cell-Penetrating Peptide Tat Affects Blood–Brain Barrier Adherence, Uptake, and Permeation

et al. 2020

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“…Among the currently researched molecules, a group of particular interest to photochemists and physicists includes particles with photophysical properties related to the phenomenon of dual fluorescence. The mechanisms responsible for the spectroscopic properties of such molecules tend to contradict certain well established theories, e.g., Kasha’s principle [ 1 , 2 , 3 ]. The phenomenon’s significance is evident particularly in the physicochemical and spectroscopic perspective, and considerable efforts are now being made to provide a consistent theoretical description of the same.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic Studies of Dual Fluorescence in 2-(4-Fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thiadiazole: Effect of Molecular Aggregation in a Micellar System

et al. 2018

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The article presents the results of spectroscopic studies focused on a selected compound from the 1,3,4-thiadiazole group—2-(4-fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thia-diazole (FABT)—in a micellar system formed by Triton X-100, a non-ionic detergent. Fluorescence measurements revealed the phenomenon of dual fluorescence whose emergence is related to the particular molecular organisation of the compound, which depends both on the concentration of the detergent and, most of all, the concentration of the compound itself. Dual fluorescence of FABT in a micellar system was observed for the compound dissolved in a methanol aqueous system, i.e., an environment wherein the dual fluorescence of the compound had never been reported before. Based on the interpretation of UV-Vis electronic absorption, resonance light scattering (RLS), emission and excitation fluorescence spectra, as well as measurements of dynamic light scattering (DLS) and Principal Component Analysis (PCA), we were able to relate the occurrence of this effect to the process of molecular aggregation taking place between FABT molecules in the micellar system in question. Results of fluorescence spectra measurements and time-correlated single photon counting (TCSPC) indicate that dual fluorescence occurs at detergent concentrations necessary to form micellar systems, which in turn facilitate the process of aggregation of FABT molecules. The correlation between the observed fluorescence effects and the previous measurements performed for analogues from this group suggests the possibility of charge transfer (CT) within the range of detergent concentrations wherein the aforementioned fluorescence effects are observed. It ought to be emphasised that this type of fluorescence effects are relatively easy to induce, which predisposes this groups of fluorophores as ideal fluorescence probes in the context of biological samples.

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“…The coexistence of distinct molecular species (monomers, self-aggregates, peptide/oligonucleotide) in complexes of Fl-PF14/cyanine5-siRNA was studied by fluorescence correlation spectroscopy (FCS) and fluorescence cross-correlation spectroscopy (FCCS) in solution and at the plasma membrane of live cells. The ratio of the complex components varied with the pH, the peptide concentration and the proximity to the plasma membrane, suggesting “that the diverse cellular uptake mechanisms, often reported for amphipathic CPPs, might result from the synergistic effect of peptide monomers, self-aggregates and cargo complexes at the plasma membrane” [ 148 ].…”

Section: Mechanismsmentioning

confidence: 99%

Cell-Penetrating Peptides and Transportan

Langel

2021

Pharmaceutics

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In the most recent 25–30 years, multiple novel mechanisms and applications of cell-penetrating peptides (CPP) have been demonstrated, leading to novel drug delivery systems. In this review, I present a brief introduction to the CPP area with selected recent achievements. This is followed by a nostalgic journey into the research in my own laboratories, which lead to multiple CPPs, starting from transportan and paving a way to CPP-based therapeutic developments in the delivery of bio-functional materials, such as peptides, proteins, vaccines, oligonucleotides and small molecules, etc.

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Simultaneous membrane interaction of amphipathic peptide monomers, self-aggregates and cargo complexes detected by fluorescence correlation spectroscopy

Cited by 15 publications

References 67 publications

Conjugation of Therapeutic PSD-95 Inhibitors to the Cell-Penetrating Peptide Tat Affects Blood–Brain Barrier Adherence, Uptake, and Permeation

Conjugation of Therapeutic PSD-95 Inhibitors to the Cell-Penetrating Peptide Tat Affects Blood–Brain Barrier Adherence, Uptake, and Permeation

Spectroscopic Studies of Dual Fluorescence in 2-(4-Fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thiadiazole: Effect of Molecular Aggregation in a Micellar System

Cell-Penetrating Peptides and Transportan

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