A convenient method to extract matrix-assisted laser desorption/ionization mass spectrometry spectra from phosphate-containing peptide mixtures.
Here we report that the addition of HCl or HNO(3) to the matrix at a limited concentration dramatically increases the signal-to-noise ratio of the matrix-assisted laser desorption/ionization mass spectrometry spectrum of phosphate-containing peptide mixtures such as those obtained from an immobilised metal affinity capture eluent or a phosphate-containing tryptic digest. These improved spectra permitted both peptide identification and the determination of protein phosphorylation sites. In comparison to existing methods for removing salts, this method requires less sample manipulation and thus less sample loss is expected.
Huang
Sheng-Yu
SY
Department of Chemistry, National Cheng Kung University, Tainan, Taiwan.
Hsu
Jue-Liang
JL
Morrice
Nicholas A
NA
Wu
Chin-Jen
CJ
Chen
Shu-Hui
SH
D000818:Animals; D002417:Cattle; D013058:Mass Spectrometry / Q000379:methods*; D010455:Peptides / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D010748:Phosphopeptides / Q000737:chemistry; D010766:Phosphorylation; D012492:Salts / Q000494:pharmacology; D012709:Serum Albumin / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013464:Sulfuric Acids / Q000737:chemistry; D014357:Trypsin / Q000737:chemistry / Q000494:pharmacology
D010455:Peptides; D010710:Phosphates; D010748:Phosphopeptides; D012492:Salts; D012709:Serum Albumin; D013464:Sulfuric Acids; D014357:Trypsin; C033158:sulfuric acid; C018279:sodium phosphate