In living organisms, carotenoids are incorporated in biomembranes, remarkably modulating their mechanical characteristics, fluidity, and permeability. Significant resonance enhancement of Raman optical activity (ROA) signals carotenoid chiral aggregates makes ROA (RROA), a highly selective tool to study exclusively assemblies model membranes. Hence, RROA is combined with electronic circular dichroism (ECD), dynamic light scattering (DLS), molecular dynamics, quantum-chemical calculations...

Computational methods based on the Schrödinger equation have been traditionally confined to rather small molecules. Using an automatic computational methodology, however, we obtained a stunning agreement between experimental and theoretical vibrational spectra of large globular proteins containing thousands atoms as well. Principle atomic properties are from molecular fragments combined with minimal accuracy loss. This "first-principles" interpretation data reveals wealth information, such...

Fragment-based density-functional simulations allow us to better interpret protein vibrational circular dichroism spectra and relate them fine structural variations.

Detection and resolution of simple monosaccharides are difficult tasks because their structure is quite similar. The present study shows that circularly polarized luminescence (CPL) induced in europium complexes provides very specific spectral patterns for fructose, mannose, glucose, galactose. Differences were also observed between bare Eu3+ ion its complexes, when interacting with these sugars. CPL spectra measured on a Raman optical activity (ROA) spectrometer, which ensured high...

Previously, we and other laboratories have reported an unusual strong Raman optical activity (ROA) induced in solvents by chiral dyes. Various theories of the phenomenon appeared, but they were not capable explaining fully observed ROA band signs intensities. In this work, analysis based both on light scattering theory dedicated experiments provides a more complete understanding. For example, double-cell magnetic circular dichroism with copper-porphyrin complex show that chirality is without...

Chiroptical spectroscopy of lanthanides sensitively reflects their environment and finds various applications including probing protein structures. However, the measurement is often hampered by instrumental detection limits. In present study circularly polarized luminescence (CPL) a europium complex induced amino acids monitored Raman optical activity (ROA) spectroscopy, which enables us to detect weak CPL bands invisible conventional spectrometers. detail, spectroscopic response protonation...

Nucleotide conformational flexibility affects their biological functions. Although the spectroscopy of Raman optical activity (ROA) is well suited to structural analyses in aqueous solutions, link between spectral shape and nucleotide geometry not fully understood. We recorded ROA spectra model nucleotides (rAMP, rGMP, rCMP, dTMP) interpreted them on basis molecular dynamics (MD) combined with density functional theory (DFT). The relation sugar puckering, base conformation intensities...

We report the molecular dynamics and electronic circular dichroism computations of astaxanthin aggregates, to find a link between aggregate structure spectral shapes, environment.

Abstract We report extremely strong chirality transfer from a chiral nickel complex to solvent molecules detected as Raman optical activity (ROA). Electronic energies of the were in resonance with excitation‐laser light. The phenomenon was observed for wide range achiral and solvents. For 2‐butanol, induced ROA even stronger than natural one. observations related so‐called quantum (molecular) plasmons that enable Rayleigh scattering resonating complex. According model presented here, maximal...

Depending on crystallization conditions, many organic compounds can form crystals of different structure. Their proper characterization is important, for example, in the pharmaceutical industry. While X-ray diffractometry established as a standard method, alternative techniques are desirable broader application flexibility and economic reasons. In present study, Raman spectroscopy combined with density functional calculations suggested complementary method to other higher resolution...

Highly ordered assemblies of β-sheet-forming peptide and protein fibrils have been the focus much attention because their multiple partially unknown biological functions, in particular as related to degenerative neuronal disorders. Recently, vibrational circular dichroism (VCD) spectra shown provide a unique means detection for such extended structures utilizing modes main chain backbone. In case poly-glutamic acid, surprising VCD responses were also found side modes. this study, an attempt...

Determination of the saccharide structure in solution is a laborious process that can be significantly enhanced by optical spectroscopies. Raman activity (ROA) spectra are particularly sensitive to chirality and conformation. However, interpretation them largely dependent on computational tools providing limited precision only. To understand limitations link between spectral shapes structure, present study we measured interpreted using combination molecular dynamics (MD) density functional...

Abstract Identification of saccharides is difficult due to their similar chemical structure. However, they interact very selectively with lanthanide probes. To explore the potential for saccharide recognition, we compare circularly polarized luminescence induced by a variety oligo‐ and polysaccharides in three europium compounds. Measurement on standard Raman optical activity spectrometer made it possible use high excitation powers provided distinct spectral patterns, which were sensitive...

Vibrational frequencies of modes involving intermolecular motions in liquids are relatively small, the Raman scattering close to excitation frequency, and bands may merge into a diverging uninterpretable signal. optical activity (ROA) spectral shapes this region, however, structured more better reflect nature studied systems. To understand origin signal its relation molecules, ROA spectra six chiral neat recorded analyzed on basis molecular dynamics density functional theory computations....

Chiral gold nanostructured films were found to exhibit extremely strong surface-enhanced Raman scattering chiral anisotropy, but the physical origin of this phenomenon remained a mystery. In present study, robust model is presented, revealing properties wires important for interaction with analytes and discrimination molecular enantiomers. Molecular dynamics quantum chemical computations are utilized; enhanced electromagnetic field clusters treated without multipole approximation. The...

Molecular dynamics and density functional simulations are used to explain changes in Raman optical activity accompanying the formation of insulin fibrils.

Amyloidal protein fibrils occur in many biological events, but their formation and structural variability are understood rather poorly. We systematically explore fibril polymorphism for polyglutamic acid (PGA), insulin hen egg white lysozyme. The were grown the presence of "seeds", that is same or different protein. seeds concentrations higher than about 5 % total amount fully determined structure final fibrils. Fibril was monitored by vibrational circular dichroism (VCD) spectroscopy other...

For α-synuclein novel structural markers were identified in vibrational optical activity spectra and supported by theoretical modeling.

Abstract Clusters of a solute and few solvent molecules obtained from molecular dynamics (MD) are powerful tool to study solvation effects by advanced quantum chemical (QC) methods. For spectroscopic properties strongly dependent on the solvation, however, large number clusters needed for good convergence. In this work, parallel variable selection (PVS) method is proposed that in some cases efficiently reduces averaging. The mass, charge, or atomic density MD distributions used as secondary...

Abstract Previously, we and other laboratories have reported an unusual strong Raman optical activity (ROA) induced in solvents by chiral dyes. Various theories of the phenomenon appeared, but they were not capable explaining fully observed ROA band signs intensities. In this work, analysis based both on light scattering theory dedicated experiments provides a more complete understanding. For example, double‐cell magnetic circular dichroism with copper‐porphyrin complex show that chirality...

Molecular pincers or tweezers are designed to hold and release the target molecule. Potential applications involve drug distribution in medicine, environment technologies, microindustrial techniques. Typically, binding is dominated by van der Waals forces. Modeling of such complexes can significantly enhance their design; yet obtaining accurate complexation energies theory difficult. In this study, density functional (DFT) computations combined with dielectric continuum solvent model...

Resonance Raman optical activity (RROA) spectra with high sensitivity reveal details on molecular structure, chirality, and excited electronic properties. Despite the difficulty of measurements, recorded data for Co(III) complex S,S-N,N-ethylenediaminedisuccinic acid are exceptional quality and, coupled theory, spectacularly document behavior in resonance. This includes a huge enhancement chiral scattering, contribution antisymmetric polarizabilities to signal, Herzberg-Teller effect...