Spektroskopia magnetycznego rezonansu jądrowego w wyznaczaniu budowy białek

Abstrakt

Summary Nuclear magnetic resonance spectroscopy (NMR) is a method well suited to play an important part in proteomics programs. It provides structural information at the atomic resolution. Isotopes of biologically important elements, 1H, 13C, 15N, and 31P, display narrow resonance lines while the most abundant nitrogen (14N) and carbon (12C) isotopes are uselessness in the NMR studies of macromolecules. Internuclear interactions, modulated by even small structural and conformational changes, influence line shape and intensity of signals in NMR spectra. Last but not least, NMR provides high resolution structures in solution allowing to study those proteins that fail to crystallize or to compare differences between their crystal and solution structures. The pros and cons of NMR spectroscopy as a tool for the protein structure determination are discussed. Recently, the advance in the NMR equipment, spectral techniques and isotope labelling resulted in an enormous growth of the number of NMR-determined protein structures. Modern NMR-based procedure of structure determination comprises three stages: assignment of as many signals as possible in the spectra of NMR-active isotopes, identification of structural constraints, and calculation of a family of three-dimensional structures fulfilling experimental constraints. Approaches used at the first two stages depend on the size of the protein studied whereas the approach applied at the third stage depends on the type and number of identified constraints.