Capillary-channeled polymer (C-CP) fibers as a stationary phase for sample clean-up of protein solutions for matrix-assisted laser/desorption ionization mass spectrometry.
Capillary-channeled polymer (C-CP) fibers are employed in a micropipette tip format to affect a stationary phase for the solid phase extraction (SPE) of proteins from buffer solutions prior to MALDI-MS analysis. Proteins readily adsorb to the polypropylene (PP) C-CP fibers while buffer species are easily washed off the tips using DI-H(2)O. Elution of the solutes is achieved with an aliquot of 50:50 ACN:H(2)O, which is compatible with the subsequent spotting on the MALDI target with the matrix solution. Lysozyme and cytochrome c are used as test species, with a primary buffer composition of 100 mM Tris-HCl. In this case, direct MALDI-MS produces no discernible protein signals. SPE on the C-CP fibers yields high fidelity mass spectra for 1 μL sample volumes. Limits of detection for cytochrome c in 100 mM Tris-HCl are on the order of 40 nM. Extraction of cytochrome c from buffer concentrations of up to 1 M Tris-HCl, provides signal recoveries that are suppressed by only ~50% versus neat protein solutions. Finally, extraction of 3.1 μM cytochrome c from a synthetic urine matrix exhibits excellent recovery.
Department of Chemistry, Biosystems Research Complex, Clemson University, Clemson, SC 29633, USA.
Benjamin T
BT
Manard
R Kenneth
RK
Marcus
D000818:Animals; D002417:Cattle; D011126:Polypropylenes / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods*
D011126:Polypropylenes; D011506:Proteins