Translational diffusion of macromolecular assemblies measured using transverse relaxation-optimized PFG-NMR.
 

Translational diffusion of macromolecular assemblies measured using transverse relaxation-optimized PFG-NMR.

Translational diffusion of macromolecular assemblies measured using transverse relaxation-optimized PFG-NMR.

J Am Chem Soc. 2011 Sep 16;

Authors: Horst R, Horwich AL, Wüthrich K

Abstract
ABSTRACT In structural biology, pulsed field gradient (PFG) NMR for characterization of size and hydrodynamic parameters of macromolecular solutes has the advantage over other techniques that the measurements can be recorded with identical solution conditions as used for NMR structure determination or for crystal-lization trials. This paper describes two transverse relaxation-optimized (TRO) 15N-filtered PFG stimulated-echo (STE) expe-riments for studies of macromolecular translational diffusion in solution, 1H-TRO-STE and 15N-TRO-STE, which include CRINEPT and TROSY elements. Measurements with mixed mi-celles of the Escherichia coli outer membrane protein X (OmpX) and the detergent Fos-10 were used for a systematic comparison of 1H-TRO-STE and 15N-TRO-STE with conventional 15N-filtered STE experimental schemes. The results provide an extended platform for evaluating the NMR experiments available for diffusion measurements in structural biology projects with molecular particles of different size ranges. An initial application of the 15N-TRO-STE experiment with very long diffusion delays showed that the tedradecamer structure of the 800 kDa Thermus thermophilus chaperonin GroEL is preserved in aqueous solution over the tem-perature range 25 - 60 degrees C.


PMID: 21919531 [PubMed - as supplied by publisher]



Source: PubMed