¹H NMR study of ¹⁵N‐labeled tRNA

TROSY-based NMR experiments for NMR studies of large biomolecules

“…R ZQ and R DQ are the relaxation rates of the zero-quantum and double-quantum coherences given by Eqs. (13) and (14).…”

“…The transverse relaxation rates of these individual components of spin, S, in a single-quantum (SQ) spectrum may differ widely [13] due to the effect of interference between the IS DD coupling and CSA of spin S [4,12,63,64]. They can be described by using the singletransition basis operators, S 12 and S 34 , which refer to the transitions 1 fi 2 and 3 fi 4 in a standard energy-level diagram (Fig.…”

“…The experimental scheme correlates the 15 N-1 H N (i) group with 13 C a (i) and 13 C a (i À 1). With the TROSY principle, during the critical 15 N evolution and 1 H N detection periods, the relaxation rates of 15 N and 1 H N are effectively reduced due to the cancellation of CSA and DD coupling.…”

“…Similarly, the multiple-quantum (MQ) coherence also presents a line-narrowing effect on the methyl-groups due to the cancellation of the dipole-dipole interaction of the coupled system of 13 C and 1 H in six of eight 13 C transitions and this effect is also independent of external magnetic field strength B 0 [61,62]. Parallel to the application of SQ-TROSY, ZQ-and MQ-TROSY have been used to study protein-protein interactions [31][32][33], protein dynamics and exchange phenomena [28][29][30].…”

“…TROSY [4] is based on the fact that the cross-correlated relaxation introduced by the interference of the dipoledipole (DD) interaction and chemical shift anisotropy (CSA) gives rise to much smaller transverse relaxation rates at high fields in a system of two coupled spins (1/2), I and S, such as the 15 N-1 H moiety in the protein backbone [4,12,13] and the 13 C-1 H moiety in the aromatic group of amino acids [5], allowing NMR studies of much larger proteins and nucleic acids. This effect, the single-quantum (SQ) TROSY effect, was initially demonstrated in one of the quadruplets in a undecoupled HSQC spectrum of a 15 Nlabeled protein-DNA complex (64 kDa) at 750 MHz.…”