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Abstract

Spin-state selective experiments, HSQC-alpha/beta and CT-HMQC-alpha/beta, are proposed for the simple and rapid measurement of scalar one-bond coupling constants in two-dimensional, 1H-detected 15N-1H or 13C-1H correlation experiments based on HSQC and HMQC schemes. Pairs of subspectra are obtained, containing either the high-field or the low-field component of the doublet representing the one-bond coupling constant. The subspectral editing procedure retains the full sensitivity of HSQC and HMQC spectra recorded without heteronuclear decoupling during data acquisition, with a spectral resolution similar to that of decoupled spectra.

Pulse Sequences for Measurement of One-Bond 15N–1H Coupling Constants in the Protein Backbone

“…Techniques within the S 3 E category (4,5,9) have the lowest tolerance of variation in the coupling constants as cross talk occurs to first order in ⌬J ϭ ͉J Ϫ J 0 ͉ where J 0 is the value used in setting the pertinent delays of the pulse sequences. This is a disadvantage except for applications involving, e.g., 1 J NH in isotropic solution (11), and it is not outweighed by the S 3 E-type elements having a duration of only (4J) Ϫ1 .…”

A Small-Molecule Probe Induces a Conformation in HIV TAR RNA Capable of Binding Drug-Like Fragments

“…To measure residual dipolar couplings (RDC), in-phase-anti-phase (IPAP) HSQC data were collected for unaligned samples of the MV2003/RNA complex as reference 53 . The sample was then partially aligned using Pf1 phage (Asla Ltd.) in a 99.9% D 2 O buffer (10 mM potassium phosphate, pH 6.6) to a final concentration of 15 mg/mL of phage.…”

TROSY-based NMR experiments for NMR studies of large biomolecules

“…There are several methods, such as S3E [95,103,104], IPAP [105], TROSY [4,6], double S3CT [106] and a/b-HSQC-a/b [71], used for this purpose. In the S3E-type techniques, the tolerance for variation in the J-coupling is low, although the S3E element for the selection of the spin state has a short duration of (4J IS ) À1 .…”