title: Novel post-digest isotope coded protein labeling method for phospho- and glycoproteome analysis.
abstract: In the field of proteomics there is an apparent lack of reliable methodology for quantification of posttranslational modifications. Present study offers a novel post-digest ICPL quantification strategy directed towards characterization of phosphorylated and glycosylated proteins. The value of the method is demonstrated based on the comparison of two prostate related metastatic cell lines originating from two distinct metastasis sites (PC3 and LNCaP). The method consists of protein digestion, ICPL labeling, mixing of the samples, PTM enrichment and MS-analysis. Phosphorylated peptides were isolated using TiO(2), whereas the enrichment of glycosylated peptides was performed using hydrazide based chemistry. Isolated PTM peptides were analyzed along with non enriched sample using 2D-(SCX-RP)-Nano-HPLC-MS/MS instrumentation. Taken together the novel ICPL labeling method offered a significant improvement of the number of identified (∼600 individual proteins) and quantified proteins (>95%) in comparison to the classical ICPL method. The results were validated using alternative protein quantification strategies as well as label-free MS quantification method. On the biological level, the comparison of PC3 and LNCaP cells has shown specific modulation of proteins implicated in the fundamental process related to metastasis dissemination. Finally, a preliminary study involving clinically relevant autopsy cases reiterated the potential biological value of the discovered proteins.
authors.affiliation: Histology-Cytology Laboratory, Department of Biomedical and Preclinical Sciences, University of Liege, B-4000 Liege, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Fleron
authors.forename: Y
authors.initials: Y
authors.lastname: Greffe
authors.forename: D
authors.initials: D
authors.lastname: Musmeci
authors.forename: A C
authors.initials: AC
authors.lastname: Massart
authors.forename: V
authors.initials: V
authors.lastname: Hennequiere
authors.forename: G
authors.initials: G
authors.lastname: Mazzucchelli
authors.forename: D
authors.initials: D
authors.lastname: Waltregny
authors.forename: M C
authors.initials: MC
authors.lastname: De Pauw-Gillet
authors.forename: V
authors.initials: V
authors.lastname: Castronovo
authors.forename: E
authors.initials: E
authors.lastname: De Pauw
authors.forename: A
authors.initials: A
authors.lastname: Turtoi
mesh_terms: D045744:Cell Line, Tumor; D006023:Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D007150:Immunohistochemistry; D007553:Isotope Labeling / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D010750:Phosphoproteins / Q000737:chemistry* / Q000302:isolation & purification; D011471:Prostatic Neoplasms / Q000737:chemistry; D011499:Protein Processing, Post-Translational; D040901:Proteomics / Q000379:methods*; D014746:Vimentin / Q000096:biosynthesis
chemical_list: D006023:Glycoproteins; D010750:Phosphoproteins; D014746:Vimentin