ssNMR Experiment Types

From version 2.2 onwards, a large number of solid-state NMR Experiment Prototypes have been added to CcpNmr Analysis. These are listed in the table below. Although it is not strictly necessary to specify the Experiment Type when reading in a spectrum, it provides numerous advantages, such as the automatic filtering of assignment options with the Correlated Dims option in the Assignment: Assignment Panel popup. In an NCACX experiment, for example, the N and Cα must always belong to the same residue, so if the NCACX Experiment Type has been the selected the assignment possibilities will be reduced to those where the N and Cα belong the same residue (unless there are no such pairs within the tolerances used).

The Experiment Types are based not on pulse sequences, but on the information contained in the spectrum. For instance there are three different 13C-13C correlation Experiments Types: CC (onebond), CC (relayed) and CC (through-space). Such spectra could be generated using a single pulse sequence (e.g. DARR) using different mixing times. Similarly, a CC (through-space) spectrum could also be generated with various other pulse sequences, e.g. PDSD, RFDF, PAR etc.

Details about Experiment Types in general are available in the Core Concepts section here. See also Fogh et al. (2006) for details about systematic experiment names. But note that the transfer types have been changed since then and for CcpNmr Analysis 2.2 and upwards are defined as:

• • ‘onebond’ – transfer between directly bonded atoms, regardless of transfer mechanism

  • ‘relayed’ – multiple stepwise transfer along chemical bonds (replaces ‘TOCSY’)

  • ‘relayed-alternate’ – like ‘relayed’, but peaks from alternating atoms along the bond network have alternating sign (mainly relevant for DREAM transfers).

  • ‘through-space’ – transfer through space, not limited to chemical bonds (replaces ‘NOESY’)

  • ‘Jcoupling’ – J coupling transfer, not limited to a particular number of bonds

  • ‘Jmultibond’ – J coupling transfer, excluding one-bond couplings

A fuller description of the nomenclature for solid-state experiments can be found in the article by Stevens et al. (2011).

New Experiment Types can be created using the Experiment: Experiment Prototypes popup or by contacting the CCPN team.

Solid-state Experiment Types

a In several cases synonyms have been created to reflect the experimental conditions under which an experiment is recorded (e.g. ‘NCACX (relayed)’ would be appropriate for an NCACX recorded with a  short mixing time and ‘NCACX (through-space) for one recorded with a long mixing time). In other cases synonyms have been created which cover all experiments that are appropriate for that experiment prototype.

b Examples for some of the spectra covered by the experiment prototype