Protein fibrils are involved in a number of biological processes. Because their structure is very complex and not completely understood, different spectroscopic methods are used to monitor different aspects of fibril structure. We have explored circularly polarized luminescence (CPL) induced in lanthanide compounds to indicate fibril growth and discriminate among fibril types. For hen egg-white lysozyme and polyglutamic acid-specific CPL, spectral patterns were obtained and could be correlated with vibrational circular dichroism (VCD) spectra and thioflavin T fluorescence. The CPL spectra were measured on a Raman optical activity spectrometer, and its various polarization modes are discussed. The experiments indicate that the induced CPL is sensitive to more local aspects of the fibril structure than VCD. For CPL, smaller amounts of the sample are required for the analysis, and thus this method appears to be a good candidate for future spectroscopic characterization of these peptide and protein aggregates.

• Publikační typ
• časopisecké články MeSH

We report as a proof-of-concept the first application of circularly polarized luminescence (CPL) measured with a Raman optical activity (ROA) spectrometer to differentiate several DNA structures without need of sensitizing complexes. The ROA/CPL approach provides sufficiently high CPL intensity to use hydrated Eu3+ ions, thus avoiding DNA structural changes associated with binding of sensitizers and overcoming the sensitizer quenching issue. We showed that deoxyguanosine monophosphate (dGMP), single- and double-stranded DNA provide different CPL spectra, which could be used for their discrimination. Our results demonstrate that ROA/CPL method is a promising approach to measure CPL spectra of complex biomolecules when the use of sensitizers is not possible. The method can be extended to other biomolecules, such as proteins, lipids, sugars, etc.

• MeSH
• deoxyguaninnukleotidy chemie   MeSH
• DNA chemie   MeSH
• europium chemie   MeSH
• luminiscence MeSH
• Ramanova spektroskopie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• deoxyguaninnukleotidy MeSH
• DNA MeSH
• europium MeSH