PROCESSING OF HETERONUCLEAR NMR RELAXATION DATA WITH THE NEW SOFTWAREDASHA

The new program DASHA is an efficient implementation of common data pr ocessing steps for the protein internal dynamic analysis. The ''model- free'' parameters and their uncertainties (Lipari G., Szabo A.: J. Am. Chem. Sec. 104, 4546-559 (1982) can be calculated from an arbitrary c ombination of experimental data sets (i.e. heteronuclear H-1-N-15 or H -1-C-13 relaxation times and NOE values at different spectrometer freq uencies). Anisotropy of the molecular rotational diffusion could be al so taken into account without introduction of the new adjustable param eters into the spectral density function J(omega), provided the struct ure of the molecule is known. Parameters of chemical (conformational) exchange can be estimated from the CPMG spin-lock frequency dependence s (Bloom et al.: J. Chem. Phys. 42, 1615-1624 (1965); Orekhov et al.: fur. J. Biochem. 219, 887-896 (1994). The program can be used both in the interactive and batch modes. It has sophisticated PostScript plott ing facilities.