Roman A. Zubarev

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For proteins of < 20 kDa, this new radical site dissociation method cleaves different and many more backbone bonds than the conventional MS/MS methods (e.g., collisionally activated dissociation, CAD) that add energy directly to the even-electron ions. A minimum kinetic energy difference between the electron and ion maximizes capture; a 1 eV difference(More)
Here a fully automated computer algorithm is applied to complex mass spectra of peptides and proteins. This method uses a subtractive peak finding routine to locate possible isotopic clusters in the spectrum, subjecting these to a combination of the previous Fourier transform/Patterson method for primary charge determination and the method for least-squares(More)
Reactions of electrons in the energy range below 70 eV with polypeptide cations and anions are reviewed, as well as their applications for the structural analysis of polypeptides. At very low energies (</= 0.1 eV), the major outcome is electron-capture dissociation (ECD) of S-S and backbone N-C(alpha) bonds, leading to c' and z. fragments. ECD is useful in(More)
The recent proliferation of novel mass spectrometers such as Fourier transform, QTOF, and OrbiTrap marks a transition into the era of precision mass spectrometry, providing a 2 orders of magnitude boost to the mass resolution, as compared to low-precision ion-trap detectors. We investigate peptide de novo sequencing by precision mass spectrometry and(More)
The completed fruit fly genome was found to contain up to 15 putative UDP-N-acetyl-alpha-d-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-transferase) genes. Phylogenetic analysis of the putative catalytic domains of the large GalNAc-transferase enzyme families of Drosophila melanogaster (13 available), Caenorhabditis elegans (9 genes),(More)
A combination of external accumulation (XA) with electron capture dissociation (ECD) improves the electron capture efficiency, shortens the analysis time, and allows for rapid integration of multiple scans in Fourier transform mass spectrometry. This improves the signal-to-noise ratio and increases the number of detected products, including structurally(More)
Singly protonated, doubly protonated, and sodiated pentaglucosamide (GlcNAc)(5), oligoglucosamines (GlcN)(m)(), and (GlcN)(3)GlcN(3OH14:0) were analyzed in an FTICR mass spectrometer by electron-ion dissociation reactions and compared to collision activation. The general fragmentation mode was found as the asymmetrical sequence fragments (B(n)() and minor(More)
Electron capture dissociation (ECD) is a new fragmentation technique used in Fourier transform ion cyclotron resonance mass spectrometry and is complementary to traditional tandem mass spectrometry techniques. Disulfide bonds, normally stable to vibrational excitation, are preferentially cleaved in ECD. Fragmentation is fast and specific and labile(More)
Tandem mass spectrometry (MS/MS) of 28 residue peptides harboring gamma-carboxylated glutamic acid residues, a posttranslational modification of several proenzymes of the blood coagulation cascade, using either collisions or infrared photons results in complete ejection of the gamma-CO2 moieties (-44 Da) before cleavage of peptide-backbone bonds. However,(More)
Analysis of phosphotyrosine and phosphoserine containing peptides by nano-electrospray Fourier transform ion cyclotron resonance (FTICR) mass spectrometry established electron capture dissociation (ECD) as a viable method for phosphopeptide sequencing. In general, ECD spectra of synthetic and native phosphopeptides appeared less complex than conventional(More)