D. Marion, P.C. Driscoll, L.E. Kay, P.T. Wingfield, A. Bax, A.M. Gronenborn and G.M. Clore (1989) Biochemistry 28 6150-6156. (Link to Article)

Minimum labelleing: 15N

Dimensions: 3D

To start with, an isotropic mixing step transfers magnetisation between 1H spins. Then the magnetisation is transferred to neighbouring 15N nuclei and back to 1H for detection.

15N-TOCSY-HSQC magnetisation transfer

This can help identify amino acid types. If assignment is being done using 15N protein, only, it is a must. It can also help with the assignment of side-chain hydrogen atoms, though normally an HCCH-TOCSY or HCCH-COSY spectrum is necessary for unambiguous side-chain hydrogen assignment.

15N-HSQC-TOCSY spectrum