Observing in-phase single-quantum 15N multiplets for NH2/NH3+ groups with two-dimensional heteronuclear correlation spectroscopy

J Magn Reson. 2008 Oct;194(2):313-6. doi: 10.1016/j.jmr.2008.07.018. Epub 2008 Jul 23.

Abstract

Two-dimensional (2D) F1-(1)H-coupled HSQC experiments provide 3:1:1:3 and 1:0:1 multiplets for AX(3) and AX(2) spin systems, respectively. These multiplets occur because, in addition to the 2S(y)H(z)(a)-->2S(y)H(z)(a) process, the coherence transfers such as 2S(y)H(z)(a)-->2S(y)H(z)(b) occurring in t(1) period provide detectable magnetization during the t(2) period. Here, we present a 2D F1-(1)H-coupled (1)H-(15)N heteronuclear correlation experiment that provides a 1:3:3:1 quartet for AX(3) spin system and a 1:2:1 triplet for AX(2). The experiment is a derivative of 2D HISQC experiment [J. Iwahara, Y.S. Jung, G.M. Clore, Heteronuclear NMR spectroscopy for lysine NH(3) groups in proteins: unique effect of water exchange on (15)N transverse relaxation. J. Am. Chem. Soc. 129 (2007) 2971-2980] and contains a scheme that kills anti-phase single-quantum terms generated in the t(1) period. The purge scheme is essential to observe in-phase single-quantum multiplets. Applications to the NH(2) and NH(3)(+) groups in proteins are demonstrated.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonia / chemistry*
  • Nitrogen Isotopes / chemistry*
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Quantum Theory
  • Spin Labels
  • Statistics as Topic

Substances

  • Nitrogen Isotopes
  • Spin Labels
  • Ammonia