15N nmr spectroscopy. I. Polysarcosine and related sequence polypeptides
✍ Scribed by Hans R. Kricheldorf; William E. Hull; Viktor Formacek
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1977
- Tongue
- English
- Weight
- 391 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
The natural abundance 15N nmr spectra of linear polysarcosine (DP = 35) has been recorded in Me2SO and H20 solution. Because of cisltrans isomerization at the peptide bond, a broad signal with several splittings was observed. These splittings appear to reflect the influence of three peptide bonds on a single N atom. The 15N signals from the sequence polypeptides (P-Ala-Sar,Gly),, and (B-Ala-Sar-D,L-Ala), also show a cisltrans splitting, as well as chemical shifts which are dependent on the peptide sequence. The tertiary nitrogen of the sarcosyl residue has a T I relaxation time which is longer than the 2'1 for secondary nitrogens of the other amino acids. The nuclear Overhauser effect is also discussed.