Transition dipole coupling modeling of optical activity enhancements in macromolecular protein systems

0489322 - ÚOCHB 2019 RIV US eng J - Journal Article
Průša, Jiří - Bouř, Petr
Transition dipole coupling modeling of optical activity enhancements in macromolecular protein systems.
Chirality. Roč. 30, č. 1 (2018), s. 55-64. ISSN 0899-0042. E-ISSN 1520-636X
R&D Projects: GA ČR GA15-09072S; GA MŠMT(CZ) LTC17012
Institutional support: RVO:61388963
Keywords : optical activity * vibrational circular dichroism * protein fibrils
OECD category: Biophysics
Impact factor: 1.927, year: 2018

Optical activity of regular molecular assemblies, such as protein fibrils or nucleic acid condensates, is often significantly stronger than for isolated molecules. Previous modeling suggested that this may be caused by the ordered quasi-periodic structure and a long-order synchronization of chromophore excitations. In the present study, we briefly review this phenomenon and investigate some aspects on simple models related to protein vibrational optical activity. The transition dipole coupling (TDC) model is used to generate vibrational circular dichroism (VCD) and Raman optical activity (ROA) spectra. While a linear arrangement of chromophores produced relatively simple couplet intensity patterns, a richer band structure was predicted for planar geometries. A stacking of beta-sheet planes has been identified as another powerful source of the enhancement. The results do not completely reproduce experimental observations but are consistent with them and confirm that chiroptical methods may be extremely useful to study aggregation of chiral molecules.
Permanent Link: http://hdl.handle.net/11104/0283764