Nmr studies of aqueous solutions of tetra and branched peptides. I. Sequence determination of amino-acid residues and the assignment of peptide hydrogen signals

✍ Scribed by M. Sheinblatt; Y. Rahamim

• Publisher: Wiley (John Wiley & Sons)
• Year: 1976
• Tongue: English
• Weight: 530 KB
• Volume: 15
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1976.360150902

✦ Synopsis

Abstract

Sequential determination of glycyl residues (and in several cases different amino‐acid residues) in tetra and branched peptides using the nmr technique is reported. The method is based on changes in the nmr spectra of (1) the peptide hydrogens of the different residues and (2) the methylene groups of the glycyl residues, as a result of increasing the rate of the base‐catalyzed exchange reaction of the peptide hydrogens. Hence, the spectral changes are pH dependent. However, the exact pH dependence is a function of the location of the residue in the peptide molecule. Thus, it is possible to determine the sequence of the amino‐acid residues by studying the changes in the spectra with pH.

For peptide molecules of known sequences, the above method can be used for unequivocal assignment of the peptide hydrogen signals.