Practical Protein Chemistry - A. Darbre 1989

Determination of C-terminal amino acid sequence
Determination of C-terminal sequence
Other chemical cleavage methods

It was proposed to use n-toluylcarbodiimide to prepare acylurea, subsequent Treatment of which with 0.01 M NaOH cleaves off the N-toluylcarbonyltoluidide of the C-terminal amino acid [47]. However, because acylurea undergoes Hydrolysis with a high yield, regenerating the starting peptide, this reaction cannot serve as the basis for a sequential amino acid Cleavage method.

An attempt was made to apply the method of Selective reduction of terminal Amino Acids (Sec. 18.3.3) for the analysis of N-acyl-2-oxazolidone, from which 2-oxazolidone is cleaved under mild conditions (0.3 M acid, 1–2 h); this yields a shortened peptide with a new C-terminal amino acid (Fig. 18.12).

Other Methods for sequential C-terminal analysis have also been proposed [54, 61, 67]. Alcoholysis of oxazole (Sec. 18.3.5) was employed for C-terminal sequential cleavage [68]. In this case, challenges related to a decrease in the yield of residual amino acids due to incomplete cleavage and The conversion of the new carboxyl derivative (obtained upon Cleavage of the C-terminal residue) into an ester suitable for sequential degradation still need to be overcome. A solid-phase version of this method is currently under development.