title: Low molecular weight proteins in urines from healthy subjects as well as diabetic, nephropathic and diabetic-nephropathic patients: a MALDI study.
abstract: Urine samples from healthy subjects as well as diabetic, nephropathic and diabetic-nephropathic patients were analyzed by matrix assisted laser desorption/ionization (MALDI) mass spectrometry in order to establish evidence of some possible differences in the peptide profile related to the pathological states. Multivariate analysis suggested the possibility of a distinction among the considered groups of patients. Some differences have been found, in particular, in the relative abundances of three ions at m/z 1912, 1219 and 2049. For these reasons, further investigation was carried out by MALDI/TOF/TOF to determine the sequence of these peptides and, consequently, to individuate their possible origin. By this approach, the peptide at m/z 1912 was found to originate from uromodulin, and its lower expression in the case of nephropathy can be well related to the pathological condition. Ions at m/z 2049 and 1219 originate from the collagen alpha-1(I) chain precursor and from the collagen alpha-5 (IV) chain precursor, respectively, and, also in this case, their different expressions can be related to the pathologies under investigation. The obtained data seem to indicate that urine is an interesting biological fluid to investigate on the peptide profile and to obtain, consequently, information on the dismetabolism activated by specific pathologies.
authors.affiliation: Department of Clinical and Surgical Sciences, Padova University, Via Giustiniani 2, I35100 Padova, Italy.
authors.forename: Annunziata
authors.initials: A
authors.lastname: Lapolla
authors.forename: Roberta
authors.initials: R
authors.lastname: Seraglia
authors.forename: Laura
authors.initials: L
authors.lastname: Molin
authors.forename: Katherine
authors.initials: K
authors.lastname: Williams
authors.forename: Chiara
authors.initials: C
authors.lastname: Cosma
authors.forename: Rachele
authors.initials: R
authors.lastname: Reitano
authors.forename: Annalisa
authors.initials: A
authors.lastname: Sechi
authors.forename: Eugenio
authors.initials: E
authors.lastname: Ragazzi
authors.forename: Pietro
authors.initials: P
authors.lastname: Traldi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003924:Diabetes Mellitus, Type 2 / Q000652:urine*; D003928:Diabetic Nephropathies / Q000652:urine*; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D007674:Kidney Diseases / Q000652:urine*; D008875:Middle Aged; D008970:Molecular Weight; D015999:Multivariate Analysis; D025341:Principal Component Analysis; D011507:Proteinuria / Q000652:urine*; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization