Interaction of Fluorescently Labeled Triethyleneglycol and Peptide Derivatives with β‐Cyclodextrin

Abstract

A triethyleneglycol (TEG) chain, a linear peptide, and a cyclic peptide labeled with 7-methoxycoumarin-3-carboxylic acid (MC) and 7-diethylaminocoumarin-3-carboxylic acid (DAC) were used to thoroughly study Förster resonance energy transfer (FRET) in inclusion complexes. (1) H NMR evidence was given for the formation of a 1:1 inclusion complex between β-cyclodextrin (β-CD) and the fluorophore moieties of model compounds. The binding constant was 20 times higher for DAC than for MC derivatives. Molecular modeling provided additional information. The UV/Vis absorption and fluorescence properties were studied and the energy transfer process was quantified. Fluorescence quenching was particularly strong for the peptide derivatives. The presence of β-CDs reduced the FRET efficiency slightly. Dye-labeled peptide derivatives can thus be used to form inclusion complexes with β-CDs and retain most of their FRET properties. This paves the way for their subsequent use in analytical devices that are designed to measure the activity of matrix metalloproteinases.

Supramolecular Peptide/Surface Assembly for Monitoring Proteinase Activity and Cancer Diagnosis

“…All of these results highlight that our doubly-labeled peptides formed a 1:1 supramolecular assembly through only their DAC moiety with the β-CD support, as expected from the previous studies in solution. 20 Due to similar peptide structure and our previous published data in solution 20 of these peptides (SMMP-1, 2 and 9), we expect that Ka values for SMMP-2 and SMMP-9 are in the same range than for SMMP-1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 To validate the sensor regeneration, a supramolecular assembly between β-CD modified SAW SAM ® 5 chip and SMMP-1 (500 µM) was performed.…”

“…Recently, we have reported that our biscoumarinic MMP substrates interact with β-CD in solution and form only a stable supramolecular complex between diethylaminocoumarin (DAC) and β-CD. 20 These results highlight intrinsic property of our peptides to potentially form supramolecular assembly with a β-CD surface. To tackle the challenges related to both MMP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 5 activity screening and biosensor development, we present an innovative supramolecular peptide sensor for screening in vitro and ex vivo MMPs activities ( Figure 1).…”

“…37,38 We have previously demonstrated that our biscoumarinic MMP substrates interact with β-CD in solution and form only a stable supramolecular complex between diethylaminocoumarin (DAC)/ β-CD with a K a constant of 3236 M -1 . 20 To validate the ability of our biscoumarinic MMP substrates to form a stable supramolecular assembly with our β-CD surfaces, Surface Acoustic Wave (SAW) studies were performed to investigate their interactions. A SAW SAM ® 5 chip (5 channels: one for reference and the other for binding studies) was modified with the GraftFast™ process with two different monomers: 2-hydroxyethyl methacrylate (HEMA) for the reference channel and GMA-β-CD for the measuring channels.…”

“…To overcome some of these drawbacks, we developed a solid sensor based on covalent grafting of fluorogenic substrates on a solid support as a proof-of-concept that MMPs activities can be also monitored with solid assay. 10 However, some points such as the behavior and stability of this sensor with tumor biopsy or tumor cells, the ease of synthesis and the regeneration of the device biosensing area remained to be addressed in order to obtain an innovative and relevant device for MMP activity screening. Some of these points are also relevant for other scientific communities involved in biosensor or lab-on-chips development.…”

Supramolecular FRET modulation by pseudorotaxane formation of a ditopic stilbazolium dye and carboxylato-pillar[5]arene

“…photoresponsive supramolecular systems are widely studied [12,13], especially in the case of interlocked structures [14][15][16]. A few studies have been published on the effect of cyclodextrins on the fluorescence behavior of FRET dyads in aqueous solutions [17,18], however the modulation of FRET in covalently linked donor-acceptor pairs by supramolecular interactions is virtually unexplored. In the present work we studied this effect on the example of a complex formed by a stilbazolium dyad (G) and a pillararene macrocycle.…”