Enhancing the intensities of lysine-terminated tryptic peptide ions in matrix-assisted laser desorption/ionization mass spectrometry.
Tryptic digests of three proteins are reacted with O-methylisourea in order to convert lysine residues to homoarginines. The resulting homoarginine-terminated peptides exhibit more intense MALDI mass spectral peaks than their lysine-terminated predecessors. This simple chemical reaction should therefore facilitate protein sequencing and mass mapping.
Beardsley
R L
RL
Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
Karty
J A
JA
Reilly
J P
JP
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D016208:Databases, Factual; D006147:Guanine / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000737:chemistry*; D008782:Methylurea Compounds / Q000737:chemistry; D008969:Molecular Sequence Data; D010449:Peptide Mapping / Q000379:methods*; D010455:Peptides / Q000032:analysis / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014357:Trypsin / Q000737:chemistry / Q000378:metabolism*
D006454:Hemoglobins; D008782:Methylurea Compounds; D010455:Peptides; C002249:O-methylisourea; D012710:Serum Albumin, Bovine; D006147:Guanine; D014357:Trypsin; D008239:Lysine