A modified CRISIS-HSQC for band-selective IMPRESS

Area of Science:

• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Biophysical Chemistry
• Structural Biology

Background:

• CRISIS (Compensation of Refocusing Inefficiency with Synchronized Inversion Sweep) is a sensitive NMR technique.
• CRISIS waveforms have limitations for band selection and integration with other methods like IMPRESS (IMProved REsolution using Symmetrically Shifted pulses).

Purpose of the Study:

• To develop a modified CRISIS-gHSQC pulse sequence for enhanced NMR spectral acquisition.
• To enable simultaneous multiplicity editing and band selection in HSQC spectra.
• To improve spectral assignment in crowded regions of complex molecules.

Main Methods:

• Implementation of a modified CRISIS-gHSQC pulse sequence incorporating time-reversed 13C pi/2 EBURP-2 pulses.
• Development of the IMPRESS-CRISIS-bs-gHSQC sequence.
• Acquisition of multiplicity-edited, band-selective spectra individually and in tandem with IMPRESS.

Main Results:

• The novel IC-bs-gHSQC sequence successfully acquires multiplicity-edited, band-selective spectra.
• Tandem acquisition with IMPRESS significantly reduces experiment time for analyzing crowded spectral regions.
• IC-bs-gHSQC demonstrates superior sensitivity compared to the original IMPRESS sequence for band-selective spectra.

Conclusions:

• The IMPRESS-CRISIS-bs-gHSQC sequence offers a versatile and sensitive approach for NMR spectral editing and band selection.
• This method is particularly advantageous for unambiguous assignment in complex and crowded NMR spectra.
• The modified sequence overcomes limitations of the original CRISIS technique, enhancing its applicability in various NMR experiments.