[Hydrolysis of primary amide groups in Asn/Gln-containing peptides].
Peptides Boc-Ala-Asn/Gln-OH and Boc-Asn/Gln-Ala-OH were saponified with barium hydroxide to corresponding Asp/Glu-containing peptides. Under the conditions of saponification, Boc-Asn-Ala-OH additionally afforded Boc-Asp-OH, isopeptide Boc-Asp(Ala)-OH, and Boc-NHSuc > Ala-OH, with the third being the key intermediate in these transformations. Boc-Asp(OMe)-Ala-OMe underwent similar transformations under treatment with diazomethane or triethylamine. Saponification with barium hydroxide was accompanied by a high epimerization of N-terminal amino acid residues, whereas the products of the diazomethane treatment of Boc-Asp(OMe)-Ala-OMe had a low degree of epimerization.
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia. onovv@ibch.siobc.ras.ru
V V
VV
Onoprienko
E A
EA
Elin
A I
AI
Miroshnikov
D000577:Amides / Q000737:chemistry*; D001216:Asparagine / Q000737:chemistry*; D017609:Barium Compounds / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D005998:Glycine / Q000737:chemistry*; D006868:Hydrolysis; D013058:Mass Spectrometry; D010455:Peptides / Q000737:chemistry*
D000577:Amides; D017609:Barium Compounds; D010455:Peptides; C012766:barium hydroxide; D001216:Asparagine; D005998:Glycine