Related Experiment Video
Updated: Aug 8, 2026

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Main-chain-directed strategy for the assignment of 1H NMR spectra of proteins
1Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia 19104.
Abstract:
A strategy for assigning the resonances in two-dimensional (2D) NMR spectra of proteins is described. The method emphasizes the analysis of through-space relationships between protons by use of the two-dimensional nuclear Overhauser effect (NOE) experiment. NOE patterns used in the algorithm were derived from a statistical analysis of the combinations of short proton-proton distances observed in the high-resolution crystal structures of 21 proteins. One starts with a search for authentic main-chain NH-C alpha H-C beta H J-coupled units, which can be found with high reliability. The many main-chain units of a protein are then placed in their proper juxtaposition by recognition of predefined NOE connectivity patterns. To discover these connectivities, the 2D NOE spectrum is examined, in a prescribed order, for the distinct NOE patterns characteristic of helices, sheets, turns, and extended chain. Finally, the recognition of a few amino acid side-chain types places the discovered secondary structure elements within the polypeptide sequence. Unlike the sequential assignment approach, the main-chain-directed strategy does not rely on the difficult task of recognizing many side-chain spin systems in J-correlated spectra, the assignment process is not in general sequential with the polypeptide chain, and the prescribed connectivity patterns are cyclic rather than linear. The latter characteristic avoids ambiguous branch points in the analysis and imposes an internally confirmatory property on each forward step.
Related Concept Videos
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
Two-Dimensional (2D) NMR: Overview
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
NMR Spectroscopy Of Amines
2D NMR: Overview of Heteronuclear Correlation Techniques

