From relax wiki
Jump to: navigation, search

The software DASHA is designed for the model-free analysis for NMR relaxation data. DASHA can be used as an optimisation engine to replace the minimisation algorithms implemented within relax.



The original DASHA website is http://www.nmr.ru/dasha.html (and archived on the Internet Archive).


From the DASHA homepage:

DASHA is an interactive program designed to investigate dynamics of biomolecules, for which data of 15N or 13C heteronuclear relaxation are available from NMR measurements. A number of sets of longitudinal and transverse relaxation rates of 15N or 13C nuclei and 1H-15N, 13C NOE's obtained at various NMR spectrometer frequencies might be used as the input. The measured longitudinal, transverse relaxation rates and NOE values are interpreted using the model-free approach of Lipari and Szabo (1982, J. Am. Chem. Soc., 104, 4546-4559). In addition to the overall rotational correlation time of the molecule, the internal dynamics of backbone N-H or C-H vectors of two types of internal motions - fast, on a time scale of <20 ps, and intermediate, close to 1 ns could be evaluated by constructing correspondent spectral density functions. Contribution of the conformational exchange to transverse relaxation rates of individual nitrogens or carbons could be elucidated using a set of different rates of the CPMG spin-lock pulse train in measuring T2 relaxation times (Orekhov et al., 1994, Eur. J. Biochem., 219, 887-896). Separate module DIFFC, included into the DASHA software, performs hydrodynamic calculations for proteins with known spatial structure. All input and output data could be easily presented in PostScript format.


  • Vladislav Yu. Orekhov
  • Dmitry M. Korzhnev
  • Dmitry E. Nolde
  • Alexander P. Golovanov
  • Alexander S. Arseniev.


The last release was 3.48c in May 2000.


  • Orekhov, V. Y., Nolde, D. E., Golovanov, A. P., Korzhnev, D. M. and Arseniev, A. S. (1995). Processing of heteronuclear NMR relaxation data with the new software DASHA Appl. Magn. Reson., 9(4), 581-588. (DOI: 10.1007/bf03162365)

Usage in relax

To use DASHA within relax, the following user function are provided:

These allow DASHA to be used as a model-free optimisation within relax, replacing the built-in algorithms.

See also