title: [Spectral division of conformational states of spin-labeled tRNA Phe from Escherichia coli].
abstract: A spectral division method of two conformational states of spin-labeled macromolecules is presented. The method is suitable in conditions of highly anisotropic motion of spin label and is based on titration of experimental spectra of spin-labeled macromolecule by theoretical ones. Theoretical spectra simulation uses the Freed theory and spin-Hamiltonian parameters, derived from independent experiments. Nomogrammes and formula for calculation of order parameter Sz and correlation time tau c in temperature-viscosity experiment are available. The method was applied to spectral division of two conformational states of spin-labeled tRNAPhe from E. coli and spectral parameters Sz and tau c were obtained for both states. ESR spectra of these conformational states at t degree = 20 degrees differ strongly from one another by order parameter Sz. The first conformer, that is characterised by a greater order parameter has no globular conformational transition (in terms of changes of the hydrodynamic macromolecule radius) between 2 degrees and 20 degrees, but local conformational changes take place in this temperature region.
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli / Q000235:genetics*; D007700:Kinetics; D008433:Mathematics; D009690:Nucleic Acid Conformation; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics*; D013113:Spin Labels
chemical_list: D012346:RNA, Transfer, Amino Acyl; D013113:Spin Labels
vernacular_title: Spektral'noe razdelenie konformatsionnykh sostoianiĭ na spin-mechenoĭ tRNK Phe iz Escherichia coli.