Cleavage of a model peptide at its glycine residue by alkaline mercuric oxycyanide.
Treatment of peptides with excess HgO in the presence of alkaline cyanide leads to cleavage of the peptides at glycine residues. The reaction appears to involve both C- and N-mercuration with subsequent release of 2 mol mercury per mol of glycine. An intermediate glyoxylic acid residue in Schiff base linkage is postulated. Treatment of the heptapeptide Phe-Ala-Lys-Gly-Leu-Asp-Val with alkaline HgO and KCN for 6 h at 25 degrees resulted in greater than 90% cleavage, and the resultant reaction products were separated by reverse phase chromatography and identified by amino acid analysis. N-terminal products were approximately equimolar Phe-Ala-Lys, Phe-Ala-Lys-Gly, and Phe-Ala-Lys-amide. C-terminal products were predominantly Leu-Asp-Val (63%), plus Gly-Leu-Asp-Val (9%), and oxalyl-Leu-Asp-Val (8%). This method may be useful for cleavage of peptides or proteins containing glycine residues.
Krystek
S R
SR
Department of Biochemistry, Albany Medical College, New York.
Andersen
T T
TT
Weber
P B
PB
D000595:Amino Acid Sequence; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D003486:Cyanides; D005998:Glycine; D006863:Hydrogen-Ion Concentration; D008628:Mercury; D017669:Mercury Compounds; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009842:Oligopeptides; D010087:Oxides; D010446:Peptide Fragments / Q000302:isolation & purification; D011190:Potassium Cyanide
D003486:Cyanides; D017669:Mercury Compounds; D009842:Oligopeptides; D010087:Oxides; D010446:Peptide Fragments; D008628:Mercury; C019468:mercuric oxide; D011190:Potassium Cyanide; D005998:Glycine