ja103582n_si_001.pdf (311.4 kB)
Download file

Microsecond Time Scale Mobility in a Solid Protein As Studied by the 15N R Site-Specific NMR Relaxation Rates

Download (311.4 kB)
journal contribution
posted on 01.09.2010, 00:00 by Alexey Krushelnitsky, Tatiana Zinkevich, Detlef Reichert, Veniamin Chevelkov, Bernd Reif
For the first time, we have demonstrated the site-resolved measurement of reliable (i.e., free of interfering effects) 15N R relaxation rates from a solid protein to extract dynamic information on the microsecond time scale. 15N R NMR relaxation rates were measured as a function of the residue number in a 15N,2H-enriched (with 10−20% back-exchanged protons at labile sites) microcrystalline SH3 domain of chicken α-spectrin. The experiments were performed at different temperatures and at different spin-lock frequencies, which were realized by on- and off-resonance spin-lock irradiation. The results obtained indicate that the interfering spin−spin contribution to the R rate in a perdeuterated protein is negligible even at low spin-lock fields, in contrast to the case for normal protonated samples. Through correlation plots, the R rates were compared with previous data for the same protein characterizing different kinds of internal mobility.