Running a ¹⁵N-HSQC

Pulse programs available

In the Bruker pulse program catalogue, there are several pulse programs available. These include:

the standard echo / anti-echo versions with sensitivity improvement:

• hsqcetfpf3gpsi
• hsqcetfpf3gpsi2

along with their TROSY versions:

• trosyetf3gpsi
• trosyetf3gpsi2
• trosyetfpf3gpsi

SO-FAST HMQC:

• sfhmqcf3gpph
• sfhmqcf3gpphiasi

BEST version with TROSY options:

• b_hsqcetf3gpsi
• b_trosyetf3gpsi
• b_trosyetf3gpsi.2
• b_trosyetf3gpsi.3

Pulse sequences already tested and standard parameters implements on our systems are in bold.

Standard parameters

Standard 15N-HSQC

For the standard 15N-HSQC (hsqcetfpf3gpsi): PROT_N-HSQC

For the TROSY version of the 15N-HSQC (trosyetfpf3gpsi): TROSYETF3GPSI (from the Bruker library)

For the SO-FAST 15N-HMQC (sfhmqcf3gpph): PROT_SFHMQC

BEST versions

if you want to investigate downfield shifted signals (such as tryptophan side chain resonances) or signals which are very close to the water frequency, the bandwidth and/or offset frequency may need to be fine tuned. The offset is simply changed by altering the parameter cnst19 (or cnst54), but changing the bandwidth requires all shape lengths and amplitudes to be recalculated. The python script “bestbw” provides an easy-to-use solution for changing both these parameters

The Python program bestbw lengths and amplitudes can be used to change the excitation bandwidth and recalculate the shape lengths and amplitudes of the pulses.

For the BEST version of the 15N-HSQC (b_hsqcetf3gpsi): B_HSQCETF3GPSI (from the Bruker library)

For the BEST version with TROSY of the 15N-HSQC (b_trosyetf3gpsi): B_TROSYETF3GPSI (from the Bruker library)