hplc electrospray ionization ion trap mass spectrometry

... multienzymes to short peptide fragments, fractionate the complex mixture and use high-resolution electrospray ionization Fourier-Transform mass spectrometry Changing patterns of covalent active-site ... machineries using electrospray ionization Fourier-Transform mass spectrometry Nat Prod Rep 23, 893–918 35 Bumpus SB & Kelleher NL (2008) Accessing natural product biosynthetic processes by mass spectrometry ... [34,35] In addition, specific ejection of the phosphopantetheinyl prosthetic group from the ACP can be induced in the mass spectrometer, allowing highly accurate determination of the mass of the attached...

Ngày tải lên: 16/03/2014, 03:20

... structural studies In our work, ion trap mass spectrometry was used Compared with the Fourier transform -ion cyclotron resonance (FT-ICR) mass spectrometer [16,17], the ion trap is less expensive and ... in combination with on-line liquid chromatography ion trap mass spectrometry studies on the multifunctional proteins, DEBS1-TE, DEBS3 and DKS as model systems, introduces an additional powerful ... in Fig 2C The masses corresponding to each of the fractions are shown in Table The precise location and identity of each digestion fragment were assigned by mass mapping in combination with N-terminal...

Ngày tải lên: 16/03/2014, 18:20

... Wong SF & Whitehouse CM (1989) Electrospray ionization for mass spectrometry of large biomolecules Science 246, 6471 52 Loo JA (2000) Electrospray ionization mass spectrometry: a technology for ... GlcNAc-6-O-sulfotransferase by electrospray ionization FT-ICR mass spectrometry J Am Soc Mass Spectrom 15, 1400 1407 58 Daneshfar R, Kitova EN & Klassen JS (2004) Determination of proteinligand association thermochemistry ... binding to folded and unfolded conformations of cardiac troponin C Electrospray ionization and Fourier transform ion cyclotron resonance mass spectrometry Eur J Mass Spectrom 8, 471481 2331 Thioxylo-oligosaccharide...

Ngày tải lên: 07/03/2014, 17:20

... reaction deviations In addition to real-time monitoring, tandem mass spectrometry (MSn) helps to identify unknown species, validate proposed intermediates and further understand the reaction mechanisms ... chemical reactions using EESI-MS 2997 Figure Collision-induced dissociation spectra of some [MþH]þ ions of products and intermediates from the 4-DMAP-catalyzed acetylation reaction, including ... followed by background subtraction over the m/z 50–800 range (MassLynx 4.0, Waters, Manchester, UK) Collisioninduced dissociation (CID) was performed at a collision energy of 10–25 arbitrary units,...

Ngày tải lên: 14/02/2014, 08:20

... detection such as mass spectrometry (MS) in contrast to the mostly applied ELISA analytical methods applied yet For a sensitive detection, including structural information, tandem mass spectrometry ... 10 ng/mL solution This solution was used as working solution for the preparation of the other standard concentrations for calibration and quality control material For the preparation of internal ... in occupational medicine Methods With recent progress in liquid chromatography separations and mass spectrometry detection systems, improvement in sensitivity and simultaneous detection of multiple...

Ngày tải lên: 20/06/2014, 00:20

... distinction of chain type and blood-group type (such as Lea/x and Leb/y) of underivatized oligosaccharides by negative -ion electrospray mass spectrometry (ES-MS) with collision-induced dissociation ... molecular ions in negative -ion electrospray mass spectrometry J Am Soc Mass Spectrom 13, 670–679 15 Domon, B & Costello, C.E (1988) A systematic nomenclature for carbohydrate fragmentations in ... biology to derive structure/function relationships, particularly in the postgenome era, in order to understand post-translational glycosylation and its function Expansion of our knowledge on the repertoire...

Ngày tải lên: 19/02/2014, 12:20

... either desorption or desolvation methods if they are to be analyzed by mass spectrometry Although ionization and desorption/desolvation are usually separate processes, the term "ionization method" ... ionization' methods such as field desorption and electrospray ionization tend to produce mass spectra with little or no fragment -ion content Gas-Phase Ionization These methods rely upon ionizing ... ionization and desorption (or desolvation) methods The choice of ionization method depends on the nature of the sample and the type of information required from the analysis So-called 'soft ionization' ...

Ngày tải lên: 22/03/2014, 14:20

... MS Electrospray mass and tandem mass spectra were recorded on an AutoSpec-OATOFFPD high-resolution magnetic sector-orthogonal acceleration time-of-flight (OATOF) tandem mass spectrometer (Micromass) ... generated by ADH3 catalysed reduction of GSNO, nano -electrospray mass spectra of the reaction mixture with and without the addition of enzyme were recorded (Fig 1) In addition, the same experiment was ... glutathione sulfinic acid (generated through acidification of the reaction mixture after incubation as described [16]), glutathione sulfonic acid and HMGSH (Fig 3) From the spectra of these glutathione...

Ngày tải lên: 31/03/2014, 07:20

... 1100 series HPLC- DAD system (Agilent, USA) coupled with an ion trap mass spectrometry detector was used The system was equipped with an electrospray ionization (ESI) source and an ion trap analyzer ... cultured Cordyceps by pressurized liquid extraction and high performance liquid chromatography -electrospray ionization tandem mass spectrometry (HPLC- ESI-MS/MS) Anal Chim Acta 2006, 567(2):218-228 ... coextraction and elution along with other compounds in the fingerprint Our repeated trials for an optimal extraction showed that 100% methanol is the only choice capable of coextraction and elution...

Ngày tải lên: 13/08/2014, 15:21

... secondary ion mass spectrometry- On the sample surface, an energy-rich primary ion beam generates secondary ions, which are separated and detected with a mass spectrometer Secondary ion mass spectrometry ... ion induced mass transport (ion mixing) One critical application of SIMS is the accurate determination of dopant concentration profiles across a p-n junction Chapter N- P+ Measured p-n junction ... post -ionization with laser light have been established, resonant and non-resonant ionization 2.1.4 Mixing and Implantation Movements of atoms can be divided into two phases: (1) ballistic collision...

Ngày tải lên: 16/09/2015, 15:23

... controlled at 65, 60, 25 and psi, respectively Ion electrospray voltage was 5500 V for positive ionization mode and 4500 V for negative ionization mode The ion source temperature was 500 ◦ C The optimum ... water/methanol (9:1, v/v) The solution was filtered through a 0.22 ␮m nylon membrane prior to LC-MS/MS analysis 2.3 Instrumentation LC coupled with electrospray ionization tandem mass spectrometry (ESI-MS/MS) ... determined in the negative ionization mode, and the rest were appropriate for determination in the positive ionization mode Three columns were tested to obtain the best resolution for these dyes, including...

Ngày tải lên: 25/08/2016, 22:30

... mL/min Mass spectrometry was carried out using a 5973 Mass Selective Detector (Hewlett Packard, Wilmington, DE, USA) in electron -ionization mode with an ionization voltage of 70 eV and ion source ... region 400 Kansai region Shikoku region 300

Ngày tải lên: 05/09/2013, 10:15

... activity Fig Classification of the identified proteins (A) Subcellular localization (B) Molecular function classification of identified proteins from CRC patients Classification and annotation were performed ... location and molecular function (Fig 3) To better understand the probable roles of the membrane proteomes in terms of their biological functions, the subcellular localization and molecular functions ... used strategy is multidimensional chromatography, where a first dimension, usually the strong cation-exchange chromatography, is combined with the second dimension RP -HPLC However, the limited amount...

Ngày tải lên: 16/02/2014, 15:20

... in different samples The conclusions from these experiments were not dependent on identical ionization of the two peptides but only on identical relative ionization of the two species in different ... protein abundance depends on equal crystallization of the protein in the matrix and equal ionization of the proteins in the mass spectrometer This assumption appears quite good for nearly identical ... enzymes [3–5] increases the question of a role for truncation in protein–protein interactions If truncation serves a biological function, it may enhance the functional differences between the S45...

Ngày tải lên: 19/02/2014, 05:20

... Characterization of the intramolecular cyclization reaction Pyroglutamyl formation From the set of data described in the preceding section, it was also possible to monitor the cyclization reaction as ... residue at position and leucine replacing methionine at position 23) formation as a function of guanidinium chloride concentration and pH The rate of (Pyr1)-ONC (M23L) formation was calculated ... Influence of ions on cyclization of the amino terminal glutamine residues of tryptic peptides of streptococcal PepM49 protein Resolution of cyclized peptides by HPLC and characterization by mass spectrometry...

Ngày tải lên: 19/02/2014, 12:20

... black) all three mass spectra are almost identical to the stick spectrum (insets, white) calculated for [5-1H]F420 from its elemental composition considering the isotope composition of the elements: ... for the auto-oxidation reaction As a control, F420 was reduced with NaB2H4 (NaBD4) yielding a mixture of (5S)-[5-2H1]F420H2 and (5R)-[5-2H1]F420H2 The FprA-catalysed oxidation of the mixture ... intensities of the 772 and 773 Da mass peaks (Fig 2Cc) The results are consistent with FprA catalyzing the oxidation of (5S)[5-2H1]F420H2 to [5-1H]F420 and the oxidation of (5R)[5-2H1]F420H2 to [5-2H]F420...

Ngày tải lên: 20/02/2014, 03:20

... region of the plasma where the ionization is carefully controlled Thus, ionization of the elements of interest can be maintained, but the potential interfering polyatomic ions can be attenuated, due ... or consequential damages in connection with the furnishing, performance or use of this material Information, descriptions and specifications in this publication are subject to change without notice ... and a mass flow controller capable of adding oxygen to the plasma In routine operation, automatic switching between one set of cool plasma conditions and one set of normal plasma conditions is...

Ngày tải lên: 05/03/2014, 21:20

... metabolite overproduction Science 252, 1675–1681 44 Klapa, M.I., Aon, J.C & Stephanopoulos, G (2003) Using iontrap mass spectrometry in combination with gas chromatography for high resolution metabolic ... its mass isotopomer distribution is measured (e.g phenylalanine), then balances (ii) contain the equations that relate the measured mass isotopomer distribution of the amino acid with the positional ... analysis (1) In mass isotopomer distribution analysis, the relationship between the measurements (mass isotopomer fractions) and the unknown fluxes is nonlinear due to the format of the positional isotopomer...

Ngày tải lên: 08/03/2014, 08:20

... Biosystems NanoLC-linear ion trap (LTQ)-Orbitrap mass spectrometry Tryptic and chymotryptic peptide digests were analyzed by NanoLC MS ⁄ MS using a HPLC system (Ultimate U3000; Dionex, Sunnyvale, CA, ... lack of modification upon complex formation can only be attributed to a conformational rearrangement within Ssa1p that occurs upon Ure2p–Ssa1p complex formation Discussion The propagation of the [URE3] ... datadependent acquisition mode The mass of the precursors was measured with a high resolution (60 000 FWHM) in the Orbitrap The four most intense ions, above an intensity corresponding to 400 ions, were...

Ngày tải lên: 15/03/2014, 00:20

... field of MS using relatively soft ionization of the sample by electrospray ionization from solutions at physiological pH, which enables the maintenance, detection and analysis of macromolecular ... International, Crawley, UK) Native MS experiments were performed as described previously [9] using a nanoflow electrospray ionization orthogonal time-of-flight mass spectrometer (Micromass LC-T; ... mass spectrometry Anal Chem 78, 7473–7483 33 van den Heuvel RH, Gato S, Versluis C, Gerbaux P, Kleanthous C & Heck AJ (2005) Real-time monitoring of enzymatic DNA hydrolysis by electrospray ionization...

Ngày tải lên: 16/03/2014, 03:20