Selective extraction of peptides in acidic human plasma by porous silica nanoparticles for peptidome analysis with 2-D LC-MS/MS (original) (raw)

Selective enrichment of endogenous peptides by chemically modified porous nanoparticles for peptidome analysis

Journal of Chromatography A, 2009

We report the development of a combined strategy for high capacity, comprehensive enrichment of endogenous peptide from complex biological samples at natural pH condition. MCM-41 nanoparticles with highly ordered nanoscale pores (i.e. 4.8 nm) and high-surface area (i.e. 751 m 2 /g) were synthesized and modified with strong cation-exchange (SCX-MCM-41) and strong anion-exchange (SAX-MCM-41) groups. The modified nanoparticles demonstrated good size-exclusion effect for the adsorption of standard protein lysozyme with molecular weight (MW) of ca. 15 kDa; and the peptides with MW lower than this value can be well adsorbed.

Analysis of the human urine endogenous peptides by nanoparticle extraction and mass spectrometry identification

Analytica chimica acta, 2014

Peptides in urine are excreted by kidney from the blood and tissues, which are composed of a large amount of hormones, cytokines, regulatory factors and the metabolized fragments of proteins. The peptide distribution in urine will reflect the physiological and pathophysiological processes in body. In past, limited information was reported about the composition of the peptides in urine. One possible reason is that the peptides in urine are fairly low abundant and there are high concentrations of salts and organic metabolites in the urine. In this report, we extracted the peptides from human urine by highly ordered mesoporous silica particles with the pore size of 2 nm, which will exclude the high molecular weight proteins over 12 kDa. The extracted peptides were then separated into fractions according to their molecular weight by size exclusion chromatography. Each of the fractions was further analyzed by MALDI-TOF MS and μRPLC-MS/MS. Totally, 193 peptides were identified by two-dime...

Use of fullerene-, octadecyl-, and triaconthyl silica for solid phase extraction of tryptic peptides obtained from unmodified and in vitro glycated human serum albumin and fibrinogen

Journal of Separation Science, 2009

Use of fullerene-, octadecyl-, and triaconthyl silica for solid phase extraction of tryptic peptides obtained from unmodified and in vitro glycated human serum albumin and fibrinogen SPE plays a crucial role in bioanalytical research. In the present work a novel fullerene(C60)-derivatised silica material is compared with octadecyl(C18) -and triaconthyl(C30)-silicas regarding recoveries of peptides and sequence coverage of HSA and fibrinogen digests. C30-and C60(30 nm)-SPE materials were found to be the two most prominent SPE materials. At low peptide concentrations C60-material prepared from a silica gel with a pore size of 30 nm has proven to be the best material with regards to recoveries. By increasing the amount of loaded peptides recoveries decrease due to its relative low binding capacity in contrast to C30-silica particles, showing no changes. The best sequence coverages of Aa-and Bb-chains of 20 pmol fibrinogen digest can also be achieved using these two SPE materials, C60 (30 nm) demonstrates an outstanding value of sequence coverage (62.15%) achieved for the c-chain. After nonenzymatic glycation the digests of fibrinogen and HSA were also separated. This makes the detection of a considerably higher number of glycated peptides possible compared to the unfractionated digests and the use of boronate affinity chromatography in the case of fibrinogen. For HSA, ten new sites of glycation at lysine and arginine residues have been explored. Using the detailed SPE/offline MALDI method the glycation sites on fibrinogen are first described in this paper.

Nanoporous Surfaces as Harvesting Agents for Mass Spectrometric Analysis of Peptides in Human Plasma

Journal of Proteome Research

Silica-based nanoporous surfaces have been developed in order to capture low molecular weight peptides from human plasma. Harvested peptides were subjected to mass spectrometric analysis by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a means of detecting and assessing the bound molecules. Peptide profiles consisting of about 70 peaks in the range 800-10 000 m/z were generated. The method could allow detection of small peptides at ng/mL concentration levels, either in standard solutions or in plasma. The same molecular cutoff effect was observed for mixtures of standard proteins and peptides incubated with silicon-based nanoporous surfaces.

Selective on-line serum peptide extraction and multidimensional separation by coupling a restricted-access material-based capillary trap column with nanoliquid chromatography–tandem mass spectrometry

Journal of Chromatography A, 2009

As the serum peptidome gets increasing attention for biomarker discovery, one of the important issues is how to efficiently extract the peptides from highly complex human serum for peptidome analysis. Here we developed a fully automated platform for direct injection, on-line extraction, multidimensional separation and MS detection of peptides present in human serum. A capillary SPE column packed with a novel mix mode restricted access material (RAM) exhibiting strong cation exchange and size exclusion chromatography (SCX/SEC) properties were coupled with a nanoliquid chromatography-mass spectrometry (nanoLC-MS) system. The capillary SPE column excludes the high abundant serum proteins such as HSA by size exclusion chromatography and simultaneously extracts the low molecular weight peptides by binding to sulfonic acid residues. Subsequently, the trapped peptides are eluted to a capillary LC column packed with a RP-C18 stationary phase. After injection of only 2 L human serum to the one-dimensional nanoLC-MS system around 400 peptides could be identified. When conducting a multidimensional separation, the described SCX/SEC/RP-MS platform allows the separation and identification of 1286 peptides present in human serum by the injection and on-line processing of 20 L human serum sample.

Enrichment of peptides from plasma for peptidome analysis using multiwalled carbon nanotubes

Journal of Separation Science, 2007

Enrichment of peptides from plasma for peptidome analysis using multiwalled carbon nanotubes Human plasma contains a complex matrix of proteolytically derived peptides (plasma peptidome) that may provide a correlate of biological events occurring in the entire organism. Analyzing these peptides from a small amount of serum/ plasma is difficult due to the complexity of the sample and the low levels of these peptides. Here, we describe a novel peptidome analysis approach using multiwalled carbon nanotubes (MWCNTs) as an alternative adsorbent to capture endogenous peptides from human plasma. Harvested peptides were analyzed by using liquid chromatography-mass spectrometry as a means of detecting and assessing the adsorbed molecules. The improved sensitivity and resolution obtained by using liquid chromatography-mass spectrometry allowed detection of 2521 peptide features (m/z 300 -1800 range) in about 50 lL of plasma. 374 unique peptides were identified with high confidence by two-dimensional liquid chromatography system coupled to a nano-spray ionization linear ion trap-mass spectrometer. High recovery of BSA digest peptides enriched with MWCNTs, in both standard buffer and high abundance protein solution, was observed. Comparative studies showed that MWCNTs were superior to C18 and C8 for the capture of the smaller peptides. This approach could hold promise of routine plasma peptidome analysis.

Automated multi-dimensional liquid chromatography: sample preparation and identification of peptides from human blood filtrate

Journal of Chromatography B, 2004

A comprehensive on-line sample clean-up with an integrated two-dimensional HPLC system was developed for the analysis of natural peptides. Samples comprised of endogenous peptides with molecular weights up to 20 kDa were generated from human hemofiltrate (HF) obtained from patients with chronic renal failure. The (poly-)peptides were separated using novel silica-based restricted access materials with strong cation-exchange functionalities (SCX-RAM). The size-selective sample fractionation step is followed by cation-exchange chromatography as the first dimension. The subsequent second dimension of separation is based on hydrophobic interaction using four parallel short reversed-phase (RP) columns implemented via a fully automated column switching technique. More than 1000 peaks were resolved within the total analysis time of 96 min. Substances of selected peaks were sampled to analyse their molecular weights by off-line MALDI-TOF mass spectrometry and to determine their amino acid sequence by Edman degradation. The potential for comprehensive peptide mapping and identification is demonstrated.

Cation-exchange chromatography of peptides on poly(2-sulfoethyl aspartamide)-silica

Journal of Chromatography A, 1988

A strong cation-exchange material, poly(Zsulfoethy1 aspartamide)-silica (PolySULFOETHYL Aspartamide) was developed for purification and analysis of peptides by high-performance liquid chromatography. All peptides examined were retained at pH 3, even when the amino terminus was the only basic group. Peptides were eluted in order of increasing number of basic residues with a salt gradient. Capacity was high, as was selectivity and column efficiency. This new column material displays modest mixed-mode effects, allowing the resolution of peptides having identical charges at a given pH. The selectivity can be manipulated by the addition of organic solvent to the mobile phases; this increases the retention of some peptides and decreases the retention of others. The retention in any given case may reflect a combination of steric factors and non-electrostatic interactions. Selectivity was complementary to that of reversed-phase chromatography (RPC) materials. Excellent purifications were obtained by sequential use of Poly-SULFOETHYL Aspartamide and RPC columns for purification of peptides from crude tissue extracts. The new cation exchanger is quite promising as a supplement to RPC for general peptide chromatography.

Purification of a peptide tagged protein via an affinity chromatographic process with underivatized silica

Engineering in Life Sciences

Silica is widely used for chromatography resins due to its high mechanical strength, column efficiency, easy manufacturing (i.e. controlled size and porosity), and low-cost. Despite these positive attributes to silica, it is currently used as a backbone for chromatographic resins in biotechnological downstream processing. The aim of this study is to show how the octapeptide (RH)4 can be used as peptide tag for high-purity protein purification on bare silica. The tag possesses a high affinity to deprotonated silanol groups because the tag's arginine groups interact with the surface via an ion pairing mechanism. A chromatographic workflow to purify GFP fused with (RH)4 could be implemented. Purities were determined by SDS-PAGE and RP-HPLC. The equilibrium binding capacity of the fusion protein GFP-(RH)4 on silica is 450 mg/g and the dynamic binding capacity around 3 mg/mL. One-step purification from clarified lysate achieved a purity of 93% and a recovery of 94%. Overloading the column enhances the purity to >95%. Static experiments with different buffers showed variability of the method making the system independent from buffer choice. Our designed peptide tag allows bare silica to be utilized in preparative chromatography for downstream bioprocessing; thus, providing a cost saving factor regarding expensive surface functionalization. Underivatized silica in combination with our (RH)4 peptide tag allows the purification of proteins, in all scales, without relying on complex resins.