title: Proteomic analysis of a matrix stone: a case report.
abstract: Matrix stones are radiolucent bodies that present as soft muco-proteinaceous material within the renal collecting system. Following wide-angle X-ray diffraction (XRD) and scanning electron microscopy (SEM), we homogenized a surgically removed matrix stone, extracted and purified protein, and analyzed samples using tandem mass spectrometry for proteomic composition. Resulting spectra were searched using ProteinPilot 2.0, and identified proteins were reported with >95% confidence. Primary XRD mineral analysis was a biological apatite, and SEM revealed fibrous, net-like laminations containing bacterial, cellular, and crystalline material. Of the 33 unique proteins identified, 90% have not been previously reported within matrix stones and over 70% may be considered inflammatory or defensive in nature. Characterization of other matrix stone proteomes, in particular from non-infectious populations, may yield insights into the pathogenesis of this rare stone as well as the mineralogical process that occurs within crystalline calculi.
authors.affiliation: Department of Urologic Surgery, University of Minnesota, Minneapolis, MN, USA. Benjamin.canales@urology.ufl.edu
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Canales
authors.forename: Lorraine
authors.initials: L
authors.lastname: Anderson
authors.forename: LeeAnn
authors.initials: L
authors.lastname: Higgins
authors.forename: Chris
authors.initials: C
authors.lastname: Frethem
authors.forename: Alice
authors.initials: A
authors.lastname: Ressler
authors.forename: Il Won
authors.initials: IW
authors.lastname: Kim
authors.forename: Manoj
authors.initials: M
authors.lastname: Monga
mesh_terms: D000328:Adult; D001031:Apatites / Q000378:metabolism; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000378:metabolism; D053040:Nephrolithiasis / Q000378:metabolism*; D040901:Proteomics; D011513:Proteus mirabilis / Q000302:isolation & purification; D014552:Urinary Tract Infections / Q000378:metabolism / Q000382:microbiology; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D008903:Minerals