Motions of biomolecules monitored by spectral density mapping

V. Zapletal, P. Kadeřávek, R. Fiala, V. Sklenář, L. Žídek

NCBR, Faculty of Science and CEITEC, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic

vojtis@mail.muni.cz

Nucleic acids, proteins, saccharides and other biologically important molecules exhibit a broad variety of motions ranging from femtosecond vibrations to very slow processes. Description of the internal dynamics is necessary for correct understanding of the physiological functions of the studied molecules. A detailed picture of molecular motions is obtained by measuring and analyzing the NMR relaxation rates of suitable nuclei in the studied molecules. A suite of methods extending applicability of a straightforward analysis relaxation data, known as spectral density mapping, is presented. The methodology was tested on samples presenting a considerable challenge for the standard approaches, including a partially disordered protein, a uniformly ¹³C,¹⁵N-labeled RNA hairpin, and a disaccharide with a selectively ¹³C-labeled bridging methylene group.