Proteomic analysis of multiple sclerosis cerebrospinal fluid.

Two-dimensional gel electrophoresis and peptide mass fingerprinting were used to identify proteins in cerebrospinal fluid (CSF) pooled from three patients with multiple sclerosis (MS) and in CSF pooled from three patients with non-MS inflammatory central nervous system (CNS) disorders. Resolution of CSF proteins on three pH gradients (3-10, 4-7 and 6-11) enabled identification of a total of 430 spots in the MS CSF proteome that represented 61 distinct proteins. The gels containing MS CSF revealed 103 protein spots that were not seen on control gels. All but four of these 103 spots were proteins known to be present in normal human CSF. The four exceptions were: CRTAC-IB (cartilage acidic protein), tetranectin (a plasminogen-binding protein), SPARC-like protein (a calcium binding cell signalling glycoprotein), and autotaxin t (a phosphodiesterase). It remains unknown whether these four proteins are related to the cause and pathogenesis of MS.

Characterization of inorganic coordination complexes by matrix-assisted laser desorption/ionization mass spectrometry.

We report the direct laser desorption/ionization (LDI) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOFMS) analysis of four inorganic coordination complexes: monometallic [Ir(dpp)(2)Cl(2)](PF(6)), homonuclear trimetallic ([(bpy)(2)Ru(dpp)](2)RuCl(2))- (PF(6))(4), and heteronuclear [(tpy)Ru(tpp)Ru(tpp)RhCl(3)](PF(6))(4) and ([(bpy)(2)Ru(dpp)](2)IrCl(2))(PF(6))(5) (dpp = 2,3-bis-(2'-pyridyl)pyrazine, bpy = 2,2'-bipyridine, tpy = 2,2',6',2"-terpyradine, tpp = 2,3,5,6,-tetrakis-(2'-pyridyl)pyrazine). Spectral intensities and fragmentation patterns are compared and evaluated for instrument parameters, matrix selection, and matrix-to-analyte ratio. Direct LDI and MALDI mass spectra of the monometallic complex showed the same ion peaks and differed only in the relative peak intensities. Direct LDI of the trimetallic complexes produced only low-mass fragments containing one metal at most. MALDI spectra of the trimetallic complexes exhibited little fragmentation in the high-mass region (>1500 Da) and less fragmentation in the low-mass region compared to direct LDI. Significant fragments of the molecules were detected and identified, including ligand fragments, intermediate-mass fragments such as [Ru(tpy)](+), and molecular ions with varying degrees of PF(6)(-) loss ([M - n(PF(6))](+), where n = 1-3). A correlation exists between the solution-phase electrochemistry and the observed [M - n(PF(6))](+) series of peaks for the trimetallic complexes. Proper matrix selection for MALDI analysis was vital, as was an appropriate matrix-to-analyte ratio. The results demonstrate the applicability of MALDI-TOFMS for the structural characterization of labile inorganic coordination complexes.