Improved resolution in two-dimensional 1H NMR spectra of peptides by band-selective, homonuclear decoupling during both the evolution and acquisition periods: application to characterization of the binding of peptides by heparin

✍ Scribed by Jing Wang; Dan Borchardt; Dallas L. Rabenstein

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 436 KB
• Volume: 44
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1842

✦ Synopsis

Abstract

Two‐dimensional ^1^H NMR experiments that achieve band‐selective, homonuclear decoupling in both the indirectly detected F1 and directly detected F2 dimensions were used to assign the highly overlapped ^1^H NMR spectrum of the peptide Ac‐SRGKARVRAKVKDQTK‐NH~2~, both free in solution and bound to heparin. Band‐selective, homonuclear decoupling during the evolution period was achieved using a double pulsed field gradient spin‐echo (DPFGSE) with semi‐selective shaped pulses; band‐selective, homonuclear decoupling during the acquisition period was achieved by time‐shared semi‐selective shaped pulse decoupling. Regular TOCSY, ROESY and NOESY spectra and TOCSY, ROESY and NOESY spectra measured with band‐selective, homonuclear decoupling in the evolution (F1) dimension (BASHD‐TOCSY, ROESY and NOESY spectra) and with band‐selective, homonuclear decoupling in both the F1 and F2 dimensions (D‐(or Double)‐BASHD‐TOCSY, ROESY and NOESY spectra) are reported and compared for the peptide and its heparin complex. Complete assignment of the ^1^H‐NMR spectra of the free and heparin‐complexed peptide was achieved with the high resolution of the D‐BASHD‐TOCSY, ROESY and NOESY spectra. Characterization of the heparin‐complexed peptide is of interest because of the ability of the peptide to neutralize the anticoagulant activity of heparin. Copyright © 2006 John Wiley & Sons, Ltd.