Comparison of the cyclosporine variants A and D by NMR spectroscopy

Abstract

A natural variant of cyclosporine A, cyclosporine D, has been studied using high-resolution NMR spectroscopy in a non-polar solution (chloroform). A complete assignment of the 1H and 13C NMR signals has been made. A comparative analysis of the obtained spectra with the data on cyclosporine A has revealed certain differences between these two peptides, which are most noticeable in the chemical shifts of the atoms of the main chain of residues 5, 8 and the appearance of the hydrogen bond in residue 1. Cyclosporine D is slightly different from CsA in its spectral parameters, but it shows practically no immunological activity. The presented results fill in the gap in the NMR data for cyclosporine variants other than CsA and provide more details about the differences between the peptide variants that may be responsible for their different biological activity.

Keywords

• nmr
• cyclosporine
• csa
• csd
• backbone chemical shifts
• hydrogen bond