title: Imaging phosphorylated peptide distribution in human lens by MALDI MS.
abstract: Phosphorylation plays vital roles in complex biological processes such as cellular growth, division and signaling transduction. However, due to the low ionization efficiency of phosphorylated peptides, it is still a huge challenge to obtain region-specific phosphorylated peptide distribution by imaging mass spectrometry. To achieve the on-tissue analysis of phosphorylated peptides, we took advantage of a graphene oxide-immobilized enzyme reactor to conduct the in situ digestion, followed by dephosphorylation treatment that removed the phosphate groups and thereby helped to improve the signal intensity of phosphorylated peptides. A visual representation of the phosphoproteome of a human lens was successfully mapped. Results showed that phosphorylated peptides localized mainly in the nucleus region of a healthy lens while the outer cortex is the dominant region for phosphorylated peptides of a cataractous lens.
authors.affiliation: Shanghai Cancer Center and Key Laboratory of Glycoconjugates Research Ministry of Public Health, Fudan University, Shanghai 200032, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Jiao
authors.forename: Aizhu
authors.initials: A
authors.lastname: Miao
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qi
authors.initials: Q
authors.lastname: Fan
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.forename: Haojie
authors.initials: H
authors.lastname: Lu
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D006108:Graphite / Q000737:chemistry; D006801:Humans; D007908:Lens, Crystalline / Q000378:metabolism*; D057054:Molecular Imaging / Q000379:methods* / Q000592:standards; D010087:Oxides / Q000737:chemistry; D010748:Phosphopeptides / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D021381:Protein Transport; D012015:Reference Standards; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods* / Q000592:standards
chemical_list: D004800:Enzymes, Immobilized; D010087:Oxides; D010748:Phosphopeptides; D006108:Graphite; D000469:Alkaline Phosphatase