Interaction of the dye Congo red with fibrils of lysozyme, beta2-microglobulin, and transthyretin

Forensic dye analysis in cultural heritage: Unraveling the authenticity of the earliest Persian knotted-pile silk carpet

“…The Congo red in the carpet fragment may have been made using this earlier synthetic procedure, potentially resulting in synthetic byproducts not seen in modern manufacture of the dye. Indeed, other studies of Congo red have noted major impurities [ 56 , 57 ], and one of those studies separated the compounds using normal phase TLC with an elution order consistent with that found here using reverse phase LC [ 56 ]. The contaminants, however, were never identified.…”

Time Machine: Can a Dye from 1928 be Re-Purposed for Modern, Fluorescence-Based Detection of Amyloid-Like Fibrils?

“…The addition of protein fibrils to AF dye solutions (at pH 8.0) revealed shifts in absorption maxima: from 500 nm to 514 nm for lysozyme fibrils; from 500 nm to 525 nm for insulin fibrils; and from 500 nm to 524 nm for beta-2 microglobulin fibrils. Increases in absorption intensity were also seen (Figure 4).The shift of the absorption maximum to the right resembles the Congo red shift[5], and may be due to similar mechanisms seen in AF and CR binding. AF dye in solution shows red fluorescence.…”

The amyloidogenicity of the influenza virus PB1-derived peptide sheds light on its antiviral activity

“…Peptides used as a model for the influenza A virus polymerase complex PB1 subunit N-terminal region: MDVNPTLLFLKVPAQNAISTTFPYT (PB1 ) and TLLFLKVPAQNAISTTFPYT (PB1 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)). The peptides tested were: TLLFLKVP (PB1 (6)(7)(8)(9)(10)(11)(12)(13)); TLLFLKVPA (PB1(6-13)-Ala); and FITClabeled TLLFLKVPA (FITC-PB1(6-13)-Ala).…”

“…At the first stage, the interaction between the PB1(6-13) peptide fibrils and the PB1 subunit N-terminal region was studied by the SANS method ( Figure 5). (6)(7)(8)(9)(10)(11)(12)(13) in fibrillar form (black dots); and the normalized mathematical sum of the individual scattering curves for PB1 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) and PB1(6-13) (red curve)…”

“…Analogous calculations were made in the study of the PB1(6-13) and PB1 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) peptides' SAXS spectra in the q interval from 0.01 to 0.2 nm -1 . The changes in the singular decomposition zero and first components are shown in Figure 7(A) and 7(B), respectively.…”