Congo Red bound to α-1-proteinase inhibitor as a model of supramolecular ligand and protein complex

Self-Assembled Molecules – New Kind of Protein Ligands

et al. 2017

The antimicrobial activity of metal ions, especially silver ions, has been known since ancient times. Consequently, finding an accessible, cheap and efficient carrier of metal ions remains an important challenge in molecular biology. The supramolecular system presented in this chapter consists of a mixture of Congo red and Titan yellow molecules forming a supramolecular ligand which is a potent complexing agent of silver ions. Delivery of ions in complex with supramolecular dye is advantageous due to the reduced toxicity. In addition, the use of Congo red provides selective action and -thanks to increased solubility -facilitates efficient dispersion of the carrier dye and excretion from the organism.

Section: Silver Complexes With Ty In the Supramolecular Cr Systemmentioning

confidence: 99%

Supramolecular Structures as Carrier Systems Enabling the Use of Metal Ions in Antibacterial Therapy

Natkaniec

Self-Assembled Molecules – New Kind of Protein Ligands

et al. 2017

“…The fluorescence of CR induced in a rosette system indicates that the supramolecular ligand is destabilized and partly dissociated by structural strain in its attached protein which does not provide a close match for the ligand's own preferred conformation [40]. Similar results are obtained when heating complexes of CR with IgG light chains, which usually form two distinct fractions -the slow-moving and the fast-moving fraction.…”

Section: Fluorescence Property Of Congo Redmentioning

confidence: 83%

Protein Conditioning for Binding Congo Red and Other Supramolecular Ligands

Zemanek

Self-Assembled Molecules – New Kind of Protein Ligands

et al. 2017

Self-assembled organic compounds which form ribbon-like micellar clusters may attach themselves to proteins, penetrating in areas of low stability. Such complexation involves regions other than the protein's natural binding site. The supramolecular ligand adheres to beta folds or random coils which become susceptible to complexation as a result of function-related structural changes -e.g. antibodies engaged in immune complexes or acute phase proteins. However, even seemingly unsusceptible helical proteins may bind Congo red if they include chameleon sequences (short peptide fragments capable of adopting different secondary conformations depending on environmental conditions). Examples of such proteins include hemoglobin and albumin. Complexation of supramolecular Congo red is often associated with increased fluorescence, indicating breakdown of ligand micelles in the complex. This phenomenon may be used in diagnostic tests. Keywords

“…In contrast, our study revealed that CR may form complexes with a wide variety of proteins and that it does so as a supramolecular ligand -i.e. a distinct structure consisting of many associated dye molecules acting as a single unit [17][18][19][20][21][22][23][24][25]. An important breakthrough occurred when CR was found to interact with immune complexes, but not with free antibodies.…”

Section: Evidences Of Intramolecular Signaling Supplied By Using Congmentioning

confidence: 99%

Supramolecular Congo Red as Specific Ligand of Antibodies Engaged in Immune Complex

Self-Assembled Molecules – New Kind of Protein Ligands

Piekarska

et al. 2017

Supramolecular Congo red has been used to validate long-lasting theories regarding intramolecular signaling in antibodies and its relation to activation of the complement system. Strong enhancement of antigen-antibody complexation resulting from the binding of supramolecular ligands enables also polyclonal antibodies having intermediate affinity to trigger complement cascade apart of high affinity antibody fraction. This would not have been possible in the absence of Congo red. The property of antibodies provides specifically their ability to trigger the complement system allowed when sufficient structural strain is produced by antigen complexation provides an evidence of intramolecular signaling.The selective complexation of supramolecular ligands with antibodies engaged in immune complexes enables their using as carriers of drugs in immunotargeting system. Self-associating organic molecules which form ribbonlike micellar structures may, owing to their structural characteristics, penetrate inside proteins and form stable complexes. Such penetration is possible in areas of the protein which have been destabilized, either temporarily or permanently -such as antibody/antigen complexes. Since Congo red (CR) has been used in research as the most typical Keywords