title: An investigation on the nature of the peptide at m/z 904, overexpressed in plasma of patients with colorectal cancer and familial adenomatous polyposis.
abstract: In an investigation devoted to the search for plasma markers for colorectal cancer (CRC), carried out by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, a series of overexpressed peptides were identified in the plasma of patients. Among them the peptide with molecular weight 903 Da was the most abundant one, with a mean +/- (SD) relative abundance of 37 +/- 17% and a frequency over 60%. Interestingly, also in plasma samples of ten subjects affected by familial adenomatous polyposis (FAP), the peptide with molecular weight 903 was overexpressed. In this investigation, MALDI/MS/MS experiments were carried out on the ion at m/z 904 detected in the MALDI mass spectra of CRC and FAP patients. The data analysis by SwissProt.2007.01.09 indicates that this peptide is due to the sequence RPPGFSPF, found in the kininogen-1 precursor, which is an alpha-2-thiol proteinase inhibitor. In the case of subjects affected by a particular FAP syndrome, the MALDI/MS/MS spectra were quite different from those obtained from CRC and FAP patients. In fact, two sequences have been evidenced: RPPGFSPF belonging to kininogen-1 precursor, and PRKSSSSR belonging to Forkhead box protein 01A.
authors: CNR-ISTM, Corso Stati Uniti 4, I35127 Padova, Italy.
authors: Roberta
authors: R
authors: Seraglia
authors: Laura
authors: L
authors: Molin
authors: Loris
authors: L
authors: Tonidandel
authors: Salvatore
authors: S
authors: Pucciarelli
authors: Marco
authors: M
authors: Agostini
authors: Emanuele Damiano
authors: ED
authors: Urso
authors: Chiara
authors: C
authors: Bedin
authors: Michele
authors: M
authors: Quaia
authors: Donato
authors: D
authors: Nitti
authors: Pietro
authors: P
authors: Traldi
mesh_terms: D011125:Adenomatous Polyposis Coli / Q000737:chemistry*; D000595:Amino Acid Sequence; D014408:Biomarkers, Tumor / Q000097:blood*; D015179:Colorectal Neoplasms / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000097:blood*; D010455:Peptides / Q000097:blood*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D010455:Peptides