title: Removal of N-terminal formyl groups and deblocking of pyrrolidone carboxylic acid of proteins with anhydrous hydrazine vapor.
abstract: Many proteins have a blocked alpha-amino group which renders them inaccessible to sequence analysis by the classical Edman degradation procedure. Blockage typically occurs when the alpha-amino groups are acylated with acetyl or formyl groups or when the N-terminal residue is pyrrolidone carboxylic acid formed by cyclization of glutamine. We have found that N-formyl groups of proteins and peptides can be removed by exposure to hydrazine vapor at -5 degrees C for 8 h. Under these conditions, peptide-bond cleavage or modification of the constituent amino-acid residues does not occur. Deblocking of N-terminal pyrrolidone carboxylate residues by conversion to gamma-hydrazidyl glutamic acid can be achieved by exposure to hydrazine vapor at 20 degrees C for 4 h. These conditions cause partial modification of asparagine and glutamine residues to their corresponding hydrazides, and conversion of arginine residues to ornithine.
authors: Research Institute for Biosciences, Science University of Tokyo, Japan.
authors: N
authors: N
authors: Miyatake
authors: M
authors: M
authors: Kamo
authors: K
authors: K
authors: Satake
authors: Y
authors: Y
authors: Uchiyama
authors: A
authors: A
authors: Tsugita
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004151:Dipeptides / Q000737:chemistry*; D005561:Formates; D005973:Glutamine; D006834:Hydrazines; D007202:Indicators and Reagents; D008969:Molecular Sequence Data; D009496:Neurotensin / Q000737:chemistry; D009842:Oligopeptides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D010669:Phenylthiohydantoin; D011761:Pyrrolidonecarboxylic Acid; D016339:Spectrometry, Mass, Fast Atom Bombardment
chemical_list: D000596:Amino Acids; D004151:Dipeptides; D005561:Formates; D006834:Hydrazines; D007202:Indicators and Reagents; D009842:Oligopeptides; D010455:Peptides; D005973:Glutamine; D010669:Phenylthiohydantoin; C029424:hydrazine; D009496:Neurotensin; D011761:Pyrrolidonecarboxylic Acid