The reaction of N-[1-13C] acetylimidazole with cytochrome c and guanidinated cytochrome c was evaluated as a means of introducing NMR-detectable groups as conformation-dependent probes. Resonances from both N-[1-13C]acetyl lysyl and O-[1-13C]acetyl tyrosyl groups were observed when ferricytochrome c was acetylated. However, only O-[1-13C]acetyl tyrosyl resonances were seen with acetylated guanidinated ferricytochrome c. Chemical shifts of the four O-[1-13C]acetyl tyrosyl groups were conformation dependent and ranged from 172 to 176 ppm. A convenient method for the preparation of N-[1-13C]acetylimidazole is described.
ASJC Scopus subject areas
- Molecular Biology