LTQ

Enzymes like Rapidase LTQ" " contain enough pectolytic activities to depectinize the juice during the liquefaction time, giving an average yield of 93-95% according to this type of process. The juice has a good quality and its composition fits with RSK values. 

Breast cancer cells Ammonium acetate Biphasic LCQ DECA/LTQ SEQUEST (Sandhu et al., 2005)... 

The LCQ, LCQ DECA, and LTQ are products of Thermo Electron corporation (San Jose, CA), and the QSTAR is a product of Applied Biosystems (Foster City, CA). 

FIGURE 5.2 Ion path for LTQ-Orbitrap. (Courtesy of Thermo Fisher Scientific, Waltham, Massachusetts.)... 

MS11 capabilities. However, ions may then subsequently be detected at unit resolution using an electron multiplier or, alternatively, focused in a C-Trap (Figure 5.2) and then transferred and detected at high resolution using the Orbitrap. In our experience with the LTQ-Orbitrap, ions may be measured with a resolution of approximately 60,000 with online LC/MS in the full scan mode. 

Due to the limited peak capacity of the 15 cm analytical column utilized in 2-D nano LC-MS, several elution steps are required to achieve the required separation. The 15 cm analytical column can be replaced with a 100 cm nano LC column to increase the resolution of sample in each step. As shown by Yang,20 a 100 cm column allows the one-step separation of more than 2000 polypeptides from trypsin digest of mouse brain lysate, P2 fraction using XtremeSimple ultrahigh pressure nano LC (Micro-Tech Scientific, Vista, California) and LTQ MS (Thermo Electron, San Jose, California) in 6 hr (Figure 14.16). In addition to the improvement of resolving power with a 100 cm column, it... 

FIGURE 14.17 Ultrahigh resolution nano LC-MS separation of base peak chromatogram of 2351 peptides identified in trypsin digest of mouse brain lysate P2 fraction using Micro-Tech XtremeSimple nano-LC and Thermo Electron LTQ. Column 100 cm x 75 fim C18 column, 3 /mi, 8000 psi column head pressure. Solvent composition time 350 min gradient, 5 to 35% B. Solvent A 2% acetonitrile, 0.1% formic acid. Solvent B 95% acetonitrile, 0.1% formic acid. Data analysis Sequest, PeptideProphet, and Protein Prophet. 

A. Makarov, E. Denisov, O. Lange, and S. Homing. Dynamic Range of Mass Accuracy in LTQ Orbitrap Hybrid Mass Spectrometer. J. Am. Soc. Mass Spectrom., 17(2006) 977-982. 

LITs capable of scanning, axial or radial excitation of ions, and precursor ion selection for MS/MS experiments [118,134-136] have lately been incorporated in commercial mass spectrometers (Fig. 4.39). The replacement of Q3 in a QqQ instrument with a scanning LIT, for example, enhances its sensitivity and offers new modes of operation (Applied Biosystems Q-Trap). Introduction of a scanning LIT [118,135] as MSI in front of an FT-ICR instrument (Thermo Electron LTQ-FT) shields the ultrahigh vacuum of the FT-ICR from collision gas and decomposition products in order to operate under optimum conditions. In addition, the LIT accumulates and eventually mass-selects ions for the next cycle while the ICR cell is still busy with the previous ion package. 

The next higher level of performance can be achieved by replacing the oaTOF MS2 with an FT-ICR analyzer while employing a linear ion trap (Thermo Electron LTQ-FT) or a quadmpole as MSI (Bruker Daltonik APEX-Q). 

Figure 12 (a) Lysyl oxidation reaction, (b) cofactor of lysyl oxidase, lysyl tyrosine quinone (LTQ), and (c) an example of the intermolecular cross-link, histidinyl glucosylgalactosyl hydroxylysinorleucine. 

A broad range of high silica and pure silica molecular sieves have been synthesized by employing hydrothermal synthesis in fluoride media at low H2O concentration, near neutral pH and alkali-free [81]. The significant new pure silica zeolite, lTQ-29, a structural analog of zeolite A (LTA) was reported by Corma at al [82]. Unlike the highly hydrophilic zeolite A, the ITQ-29 is hydrophobic. 

Corma, A., Diaz-Cabanas, M.J., Rey, E., Nicolopoulus, S., and Boulahya, K. (2004) lTQ-15 the first ultralarge pore zeolite with a bi-directional pore system formed by intersecting 14- and 12-ring channels, and its catalytic implications. Chem. Commun., 2004,1356. 

Onida, B., Geobaldo, F., Borello, L., and Garrone, E. (2001) Addity of lTQ-2 zeolite as studied by FT-IT spectroscopy of adsorbed molecules in comparison with that of MCM-22. Stud. Surf Sd. Catal., vol. 135, Elsevier, Amsterdam, pp. 1984-1990. 

Castaneda, R., Corma, A., Eornes, V., Martinez-Triguero, J., and Valencia, S. (2006) Direct synthesis of a 9 x 10 member ring zeolite (Al-lTQ-13) a highly shape-selective catalyst for catalytic cracking. J. Catal., 238, 79-87. 

Fig. 1.30 Schematic of the linear ion trap (LIT)-orbitrap (LTQ orbitrap, Thermo). One of the specificities of the system is that the LIT has two detectors. Therefore the LIT can perform various experiments at the same time. Adapted with permission from reference [76].

Figure 4.1 Separation of H3 9-17 trimethylated subsequentlydigested with trypsin. The resulting at l<9 from H3 9-17 monoacetylated. Histone peptides were analyzed by LC-MS/MSemploying H3 isolated from Drosophila melanogaster was LTQ-Orbitrap (Thermo Scientific) as detector, acylated with deuterated acetic anhydride and (a) Chromatogram of the analysis. The y axis...

HPLC-LTQ/FTMS N-Unked glycosylation structures in human plasma HPLC-Ion Trap MS Proteins expressing differences among isolates of Meloidogyne spp. HPLC-MALDI Monosaccharide anhydride levoglucosan, galactosan, and mannosan in the... 

Lysine tyrosylquinone (LTQ). Another copper amine oxidase, lysyl oxidase, which oxidizes side chains of lysine in collagen and elastin (Eq. 8-8) contains a cofactor that has been identified as having a lysyl group of a different segment of the protein in place of the - OH in the 2 position of topaquinone.465 Lysyl oxidase plays an essential role in the crosslinking of collagen and elastin. 

Mechanisms. Studies of model reactions473-476 and of electronic, Raman,456 477 478 ESR,479/480 and NMR spectra and kinetics481 have contributed to an understanding of these enzymes.459 461 464 482 483 For these copper amine oxidases the experimental evidence suggests an aminotransferase mechanism.450 453 474 4743 d Tire structure of the E.coli oxidase shows that a single copper ion is bound by three histidine imidazoles and is located adjacent to the TPQ (Eq. 15-53). Asp 383 is a conserved residue that may be the catalytic base in Eq. 15-53.474b A similar mechanism can be invoked for LTQ and TTQ. 

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