Nanoporous Surfaces as Harvesting Agents for Mass Spectrometric Analysis of Peptides in Human Plasma (original) (raw)
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Journal of the American Society for Mass Spectrometry, 2010
We have investigated six nanomaterials for their applicability as surfaces for the analyses of peptides and proteins using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). Gold nanoparticles (NPs) were useful nanomaterials for small analytes (e.g., glutathione); Pt nanosponges and Fe 3 O 4 NPs were efficient nanomaterials for proteins, with an upper detectable mass limit of ca. 25 kDa. Nanomaterials have several advantages over organic matrices, including lower limits of detection for small analytes and lower batch-to-batch variations (fewer problems associated with "sweet spots"), when used in laser desorption/ionization mass spectrometry. (J Am Soc Mass Spectrom 2010, 21, 1204 -1207
Affinity surface-assisted laser desorption/ionization mass spectrometry for peptide enrichment
The Analyst, 2012
In this paper, we report on the functionalization of silicon nanostructured (NanoSi) surface with an organic layer of nitrilotriacetic acid (NTA) and its subsequent use as an affinity surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) interface for histidine-tagged peptide enrichment and mass spectrometry analysis. The NTA terminal groups are immobilized onto the NanoSi surface via very stable Si-C covalent bonds. The NTA-modified NanoSi (NTA-NanoSi) interface was characterized by contact angle measurements, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The NTA-NanoSi interface has shown a good selectivity toward His-tagged peptide and permits its enrichment from an artificial mixture of both tagged and untagged peptides and its subsequent mass spectrometry detection with good signal/noise ratio.
Proteomics, 2006
The present manuscript describes a biomarker capturing strategy based on nanoporous silica particles. The method is shown to enrich the yield of species in the low-molecular weight proteome (LMWP), allowing detection of small peptides in the low-nanomolar range. Plasma samples were exposed to the silica particles, and the captured molecular species were profiled using MALDI-TOF. Mass spectra of the silica-treated human plasma samples showed a significant enrichment in MALDI-TOF protein profiles in the LMWP. Preliminary results indicated good level of reproducibility in plasma profiles with CVs on peak heights ranging from 6.3 to 14.7%. The MALDI-TOF signature changed significantly when the characteristics of the nanoporous silica were altered. The facile sample pretreatment before MS analysis, coupled to the potential for tailoring the surface properties of silica supports, hold promise for improving the recovery of low-abundance serum biomarkers.
Current Pharmaceutical Design, 2005
Thanks to the development of matrix assisted laser desorption/ionisation (MALDI), laser desorption based mass spectrometry became an essential method for the analysis of biomolecules. This review will discuss the various surface modifications used in combination with laser desorption mass spectrometry and their application for the analysis of peptides and proteins. In the first hand, some modified surfaces are designed to enhance the laser desorption/ionisation process; this includes the use of carbon, porous silicon surfaces and also immobilised matrix. In an other hand chemical and biochemical modified surfaces developed to isolate species with more or less specific interactions can be used for onslide sample clean-up before MALDI-MS analysis. In addition, different experimental devices as mass spectrometers and microfluidic devices used for such a purpose will be presented.
Journal of Separation Science, 2007
Selective extraction of peptides in acidic human plasma by porous silica nanoparticles for peptidome analysis with 2-D LC-MS/MS In this study, an improved method for human plasma peptidome analysis including selective porous silica nanoparticles (MCM-41) extraction and subsequent online 2-D nano-LC-MS/MS analysis was established. Enhanced enrichment efficiency for the MCM-41 extraction was obtained by adjusting the pH of the plasma sample to 2.5. A total of 1680 unique peptides were identified in the plasma sample obtained from one healthy donor, which is nearly twice the amount identified from the native state of the plasma sample. The hydrophobic property, molecular weight (MW), and pI distribution of the identified peptides at pH 2.5 and native state of the plasma sample were systematically investigated and compared. Furthermore, many unusual cleaved peptides from plasma proteins (e. g., HSA) were observed at pH 2.5, which clearly show a ladder pattern. The cleavage patterns for all of the identified peptides at pH 2.5 were summarized, and chymosin and cathepsin D were confirmed as the possible peptidases responsible for the change of cleavage pattern in peptide profiling.
Fractionation of Serum Components Using Nanoporous Substrates
Bioconjugate Chemistry, 2006
Numerous previously uncharacterized molecules resident within the low molecular weight circulatory proteome may provide a picture of the ongoing pathophysiology of an organism. Recently, proteomic signatures composed of low molecular weight molecules have been identified using mass spectrometry combined with bioinformatic algorithms. Attempts to sequence and identify the molecules that underpin the fingerprints are currently underway. The finding that many of these low molecular weight molecules may exist bound to circulating carrier proteins affords a new opportunity for fractionation and separation techniques prior to mass spectrometry-based analysis. In this study we demonstrate a method whereby nanoporous substrates may be used for the facile and reproducible fractionation and selective binding of the serum-based biomarker material, including subcellular proteins found within the serum. Aminopropyl-coated nanoporous silicon, when exposed to serum, can deplete serum of proteins and yield a serum with a distinct, altered MS profile. Additionally, aminopropyl-coated, nanoporous controlledpore glass beads are able to bind a subset of serum proteins and release them with stringent elution. The eluted proteins have distinct MS profiles, gel electrophoresis profiles, and differential peptide sequence identities, which vary based on the size of the nanopores. These material surfaces could be employed in strategies for the harvesting and preservation of labile and carrier-protein-bound molecules in the blood.
We present in this work a simple and fast preparation method of a new affinity surface-assisted laser/ desorption ionization mass spectrometry (SALDI-MS) substrate based on silicon nanostructures decorated with copper particles. The silicon nanostructures were fabricated by the metal-assisted chemical etching (MACE) method. Then, superhydrophilic areas surrounded by superhydrophobic regions were formed through hydrosilylation reaction of 1-octadecene, followed by local degradation of the octadecyl layer. After that, copper particles were deposited in the hydrophilic areas by using the electroless method. We have demonstrated that these surfaces were able to perform high selective capture of model His-tag peptide even in a complex mixture such as serum solution. Then, the captured peptide was detected by mass spectrometry at a femtomolar level without the need of organic matrix.
SCIENCE CHINA …, 2010
This study investigated the optimization of mesoporous silica thin films by nanotexturing using oxygen plasma versus thermal oxidation. Calcination in oxygen plasma provides superior control over pore formation with regard to the pore surface and higher fidelity to the structure of the polymer template. The resulting porous film offers an ideal substrate for the selective partitioning of peptides from complex mixtures. The improved chemico-physical characteristics of porous thin films (pore size distribution, nanostructure, surface properties and pore connectivity) were systematically characterized with XRD, Ellipsometry, FTIR, TEM and N2 adsorption/desorption. The enrichment of low molecular weight proteins captured from human serum on mesoporous silica thin films fabricated by both methodologies were investigated by comparison of their MALDI-TOF MS profiles. This novel on-chip fractionation technology offers advantages in recovering the low molecular weight peptides from human serum, which has been recognized as an informative resource for early diagnosis of cancer and other diseases.
Microporous and Mesoporous Materials, 2008
Matrix-free laser desorption/ionization was studied on two-layered sample plates consisting of a substrate and a thin film coating. The effect of the substrate material was studied by depositing thin films of amorphous silicon on top of silicon, silica, polymeric photoresist SU-8, and an inorganic-organic hybrid. Des-arg 9 -bradykinin signal intensity was used to evaluate the sample plates. Silica and hybrid substrates were found to give superior signals compared with silicon and SU-8 because of thermal insulation and compatibility with amorphous silicon deposition process. The effect of surface topography was studied by growing amorphous silicon on hybrid micro-and nanostructures, as well as planar hybrid. Compared with planar sample plates, micro-and nanostructures gave weaker and stronger signals, respectively. Different coating materials were tested by growing different thin film coatings on the same substrate. Good signals were obtained from titania and amorphous silicon coated sample plates, but not from alumina coated, silicon nitride coated, or uncoated sample plates. Overall, the strongest signals were obtained from oxygen plasma treated and amorphous silicon coated inorganic-organic hybrid, which was tested for peptide-, protein-, and drug molecule analysis. Peptides and drugs were analyzed with little interference at low masses, subfemtomole detection levels were achieved for des-arg 9 -bradykinin, and the sample plates were also suitable for ionization of small proteins. (J Am Soc Mass